JP7619011B2 - Manufacturing method of semiconductor device and adhesive used therein - Google Patents

Description

This disclosure relates to a method for manufacturing a semiconductor device and an adhesive used therein.

In recent years, in order to meet the demand for high functionality, high integration, high speed, etc. for semiconductor devices, the flip chip connection method (FC connection method) has been widely adopted, in which conductive protrusions called bumps are provided as connection parts on a semiconductor chip or wiring circuit board, and the semiconductor chip is directly connected to the wiring circuit board or other semiconductor chips by connecting the connection parts together. The FC connection method is used, for example, in a COB (chip on board) type connection method for connecting a semiconductor chip to a wiring circuit board, a CoC (chip on chip) type connection method for providing bumps or wiring on a semiconductor chip as a connection part and connecting between semiconductor chips, COW (chip on wafer) in which a semiconductor chip is connected on a wafer and then diced to produce a semiconductor package, WOW (wafer on wafer) in which wafers are pressure-bonded together and then diced to produce a semiconductor package, or POP (package on package) in which semiconductor packages are pressure-bonded together. The FC connection method is also used in the manufacture of chip stack packages in which the package is made smaller by arranging semiconductor chips three-dimensionally instead of flatly, and semiconductor devices with a TSV (through-silicon via) structure.

A known method for manufacturing a semiconductor device using such an FC connection method is disclosed in, for example, the following Patent Document 1. This document discloses a method for manufacturing a semiconductor device through a process of temporarily bonding semiconductor chips having connection parts together via a thermosetting adhesive at a temperature lower than the melting point of the connection parts, a process of sandwiching the resulting temporarily bonded body between a pair of opposing pressing members and heating it while applying pressure at a temperature equal to or higher than the melting point of at least one of the connection parts of the two semiconductor chips to produce a bonded body, and a process of heating the bonded body in a pressurized atmosphere.

International Publication No. 2019/123518

However, the method for manufacturing a semiconductor device described in the above-mentioned Patent Document 1 has the following problems.
That is, although the method for manufacturing a semiconductor device described in the above-mentioned Patent Document 1 ensures connection reliability, there is room for improvement in terms of suppressing the generation of voids that occur in the temporary pressure bonding step.

The present disclosure therefore aims to provide a method for manufacturing a semiconductor device that can produce a semiconductor device in which the occurrence of voids is suppressed while ensuring good connection reliability, and an adhesive to be used therein.

In order to solve the above problem, one aspect of the present disclosure is a manufacturing method for a semiconductor device in which a first member having a first connection portion and a second member having a second connection portion are connected via an adhesive layer, and the first connection portion and the second connection portion are electrically connected, the manufacturing method including a temporary compression step of temporarily bonding the first member and the second member with the first connection portion and the second connection portion disposed opposite each other via a thermosetting adhesive for forming the adhesive layer to obtain a temporary compression body, a temporary compression body pressurizing step of pressurizing the temporary compression body under a pressurized atmosphere to obtain a pressurized temporary compression body, and a pressurizing step of pressing the pressurized temporary compression body while heating it to obtain the first The method includes a final pressure bonding process in which the first and second connection parts are connected to obtain a pressure bonded body by crimping the first and second members, in which the first and second members are pre-pressed at a temperature lower than the melting point of the first and second connection parts, in which the pre-pressing process pressurizes the pre-pressed body at a temperature lower than the melting point of the first and second connection parts, and in which the pre-pressing process heats the pressurized body at a temperature equal to or higher than the melting point of at least one of the first and second connection parts.

According to the manufacturing method of the semiconductor device disclosed herein, in the main bonding process performed after the temporary pressure bonding process and the temporary pressure body pressurizing process, the pressurized temporary pressure body is heated to a temperature equal to or higher than the melting point of at least one of the first and second connecting parts, so that the first and second connecting parts are connected. At this time, in the temporary pressure body pressurizing process performed before the main bonding process, the temporary pressure body is pressurized at a temperature lower than the melting point of the first and second connecting parts, so that at the start of the main bonding process, the adhesive has not yet hardened sufficiently and the viscosity of the adhesive is low. Therefore, when the first member and the second member are pressed in the main bonding process, the repulsive force from the adhesive against the first member or the second member is reduced, making it easier to pressurize the first member and the second member, and therefore the first and second connecting parts can be easily connected. As a result, it is possible to ensure good connection reliability.

On the other hand, in the temporary pressure-bonded body obtained in the temporary pressure-bonding process, voids are likely to be formed at least between the adhesive and the first member and between the adhesive and the second member, and if these voids remain as they are, they will remain as voids in the semiconductor device. The voids can be eliminated by compressing them with pressure. If this pressurization is performed after the main pressure-bonding process, the adhesive is heated to a temperature equal to or higher than the melting point of at least one of the first and second connection parts in the main pressure-bonding process, and hardening proceeds, and the viscosity of the adhesive is already high. In addition, after the main pressure-bonding process, the connection between the first and second connection parts is completed, and the position of the second member relative to the first member is fixed. For this reason, it is difficult to apply sufficient pressure to the adhesive even if the adhesive is pressurized. Therefore, after the main pressure-bonding process, the voids cannot be sufficiently compressed, and they tend to remain as voids in the adhesive layer of the semiconductor device. In contrast, when the voids are compressed at a temperature lower than the melting point of the first connection part and the melting point of the second connection part in the temporary compression body compression step before the main compression step, as in the manufacturing method disclosed herein, the adhesive does not harden as much as when the compression is performed at a temperature equal to or higher than the melting point of at least one of the first connection part and the second connection part, and the viscosity of the adhesive is low, making it easier to compress the voids and less likely to leave voids as voids in the adhesive layer of the semiconductor device. As a result, the manufacturing method disclosed herein can manufacture a semiconductor device in which the generation of voids is suppressed. From the above, the manufacturing method disclosed herein can manufacture a semiconductor device in which the generation of voids is suppressed while ensuring good connection reliability.

In the above manufacturing method, it is preferable that the temporary pressure-bonding step is performed at a temperature lower than the reaction start temperature of the adhesive.

In this case, the adhesive reaction is less likely to start, and the adhesive will not have hardened sufficiently at the start of the temporary pressure bonding process, making it easier to eliminate voids that occur during the temporary pressure bonding process.

In the above manufacturing method, it is preferable that the temporary compression body is compressed at a pressure of 0.05 to 0.8 MPa in the temporary compression body compression step.

In this case, it is possible to suppress the occurrence of voids in the adhesive layer of the semiconductor device and to further improve the connection reliability of the semiconductor device.

In the above manufacturing method, it is preferable that in the temporary pressure-bonded body pressurizing step, the temporary pressure-bonded body is pressurized at a temperature equal to or higher than the reaction start temperature of the adhesive.

In this case, the gaps can be compressed more effectively while allowing the adhesive to flow.

Another aspect of the present disclosure is a thermosetting adhesive used to bond the first member and the second member in the above-mentioned semiconductor device manufacturing method.

The adhesive preferably contains an epoxy resin, a curing agent, and a fluxing agent, has a minimum melt viscosity of 1500 Pa·s or less, and has a gel time of 35 seconds or more and 80 seconds or less at 150°C.

In this case, compared to when the minimum melt viscosity of the adhesive exceeds 1500 Pa·s, the adhesive is less likely to get caught between the first connection part and the second connection part, and connection failure between the first connection part and the second connection part is less likely to occur, thereby improving the connection reliability of the semiconductor device. Also, compared to when the gel time is longer than 80 seconds, the adhesive is more likely to harden in the temporary pressure bonding process and the main pressure bonding process, and voids are less likely to remain in the adhesive layer of the semiconductor device, making it possible to manufacture a semiconductor device in which the occurrence of voids is more suppressed. Also, compared to when the gel time is shorter than 35 seconds, the reaction of the adhesive is less likely to proceed during the temporary pressure bonding process, and the adhesive is less likely to harden before the voids are removed in the temporary pressure bonding process, making it easier to remove the voids, making it possible to manufacture a semiconductor device in which the occurrence of voids is more suppressed.

In the above adhesive, it is preferable that the weight average molecular weight of the epoxy resin contained in the adhesive is less than 10,000.

It is preferable that the adhesive further contains a polymer component, and that the weight average molecular weight of the polymer component is 10,000 or more.

In this case, the adhesive has better heat resistance and film-forming properties than when the weight-average molecular weight of the polymer component is less than 10,000. Therefore, by using the adhesive, a semiconductor device with better heat resistance can be manufactured. In addition, the shape of the adhesive is more easily maintained during the temporary pressure bonding process, temporary pressure-bonded body pressurization process, and main pressure bonding process, allowing semiconductor devices to be manufactured efficiently.

In the above adhesive, it is preferable that the weight average molecular weight of the polymer component is 30,000 or more, and the glass transition temperature of the polymer component is 200°C or less.

In this case, the adhesive can have good film-forming properties by itself, and the shape of the adhesive is more easily maintained during the temporary pressure bonding process, the temporary pressure-bonded body pressurizing process, and the final pressure bonding process, which further improves the manufacturing efficiency of the semiconductor device. In addition, the adhesive is more likely to fill in irregularities on the surface of the first member facing the second member, or the surface of the second member facing the first member, which tends to relatively increase the effect of suppressing voids.

The adhesive is preferably a film-like adhesive.

In this case, since the adhesive is in film form, the manufacturing efficiency of the semiconductor device is further improved.

In this disclosure, the "melting point of the first connection part" refers to the melting point of the material that forms the surface of the first connection part. The "melting point of the second connection part" refers to the melting point of the material that forms the surface of the second connection part.

The present disclosure provides a semiconductor device manufacturing method and adhesive used therein that can manufacture a semiconductor device in which the occurrence of voids is suppressed while ensuring good connection reliability.

1 is a partial cross-sectional view showing a semiconductor device manufactured by an embodiment of a manufacturing method of a semiconductor device according to the present disclosure. 4A to 4C are process diagrams illustrating a temporary compression bonding step in one embodiment of a manufacturing method for a semiconductor device according to the present disclosure. 10A to 10C are process diagrams illustrating a temporary pressure-bonding body pressurizing step in one embodiment of the manufacturing method for a semiconductor device of the present disclosure. 4A to 4C are process diagrams showing a main compression bonding step in one embodiment of the manufacturing method of the semiconductor device of the present disclosure. 11 is a partial cross-sectional view showing a semiconductor device manufactured by another embodiment of the semiconductor device manufacturing method of the present disclosure. 11 is a partial cross-sectional view showing a semiconductor device manufactured by another embodiment of the semiconductor device manufacturing method of the present disclosure. 11 is a partial cross-sectional view showing a semiconductor device manufactured by another embodiment of the semiconductor device manufacturing method of the present disclosure. 11 is a partial cross-sectional view showing a semiconductor device manufactured by another embodiment of the semiconductor device manufacturing method of the present disclosure.

Embodiments of the present disclosure are described in detail below.

<Semiconductor Device>
First, prior to describing the method for manufacturing a semiconductor device according to the present disclosure, a semiconductor device manufactured by the method for manufacturing a semiconductor device according to the present disclosure will be described with reference to Fig. 1. Fig. 1 is a partial cross-sectional view showing a semiconductor device manufactured by one embodiment of the method for manufacturing a semiconductor device according to the present disclosure.

As shown in FIG. 1, the semiconductor device 100 is electrically connected to a semiconductor chip (first member) 1 having a bump 30 as a first connection portion and a wiring circuit board (second member) 2 having wiring 16 as a second connection portion via an adhesive layer 40A.

The semiconductor chip 1 comprises a semiconductor chip body 10, wiring 15 provided on one surface of the semiconductor chip body 10, and bumps 30 provided on the wiring 15. On the other hand, the wired circuit board 2 comprises a substrate body 20 and wiring 16 provided on one surface of the substrate body 20. In the semiconductor device 100, the bumps 30 on the semiconductor chip 1 and the wiring 16 on the wired circuit board 2 are electrically connected.

<Method of Manufacturing Semiconductor Device>
Next, a method for manufacturing the above-mentioned semiconductor device 100 will be described with reference to Figures 2 to 4. Figure 2 is a process diagram showing a temporary compression bonding step in one embodiment of the method for manufacturing a semiconductor device of the present disclosure, Figure 3 is a process diagram showing a temporary compression body pressurizing step in one embodiment of the method for manufacturing a semiconductor device of the present disclosure, and Figure 4 is a process diagram showing a main compression bonding step in one embodiment of the method for manufacturing a semiconductor device of the present disclosure.

As shown in Figures 2 to 4, a first embodiment of the method for manufacturing a semiconductor device disclosed herein includes a temporary compression bonding process (see Figure 2) in which a semiconductor chip 1 having bumps 30 and a wiring circuit board 2 having wiring 16 are temporarily compressed with the bumps 30 and the wiring 16 arranged opposite each other via a thermosetting adhesive 40 to form an adhesive layer 40A to obtain a temporary compression body 4, a temporary compression body pressurizing process (see Figure 3) in which the temporary compression body 4 is pressurized in a pressurized atmosphere to obtain a pressurized temporary compression body 5, and a main compression bonding process (see Figure 4) in which the pressurized temporary compression body 5 is pressurized while being heated to compress the semiconductor chip 1 and the wiring circuit board 2, thereby connecting the bumps 30 and the wiring 16 to obtain a compression body 6. In the temporary bonding process, the semiconductor chip 1 and the wiring circuit board 2 are temporarily bonded at a temperature lower than the melting point of the bumps 30 and the melting point of the wiring 16, and in the temporary bonded body pressurizing process, the temporary bonded body 4 is pressed at a temperature lower than the melting point of the bumps 30 and the melting point of the wiring 16. In the main bonding process, the pressurized temporary bonded body 5 is heated at a temperature equal to or higher than the melting point of at least one of the bumps 30 and the wiring 16.

According to the above-mentioned manufacturing method of the semiconductor device 100, in the main pressure bonding process performed after the temporary pressure bonding process and the temporary pressure bonding body pressurizing process, the pressurized temporary pressure bonding body 5 is heated to a temperature equal to or higher than the melting point of at least one of the bumps 30 and the wiring 16, so that the bumps 30 and the wiring 16 are connected. At this time, in the temporary pressure bonding body pressurizing process performed before the main pressure bonding process, the temporary pressure bonding body 4 is pressurized at a temperature lower than the melting point of the bumps 30 and the melting point of the wiring 16, so that at the start of the main pressure bonding process, the adhesive 40 has not yet hardened sufficiently and the viscosity of the adhesive 40 is low. Therefore, when the semiconductor chip 1 and the wiring circuit board 2 are pressed together in the main pressure bonding process, the repulsive force from the adhesive 40 against the semiconductor chip 1 or the wiring circuit board 2 is reduced, and it becomes easier to pressurize the semiconductor chip 1 and the wiring circuit board 2, so that the bumps 30 and the wiring 16 can be easily connected. As a result, it is possible to ensure good connection reliability.

On the other hand, in the temporary pressure-bonded body 4 obtained in the temporary pressure-bonding process, voids are likely to be formed between the adhesive 40 and the semiconductor chip 1 and between the adhesive 40 and the wiring circuit board 2, and if these voids remain as they are, they will remain as voids in the semiconductor device 100. The above-mentioned voids can be eliminated by compressing them with pressure. Here, if this pressurization is performed after the main pressure-bonding process, the adhesive 40 is heated to a temperature equal to or higher than the melting point of at least one of the bumps 30 and the wiring 16 in the main pressure-bonding process, and hardening proceeds, and the viscosity of the adhesive 40 is already high. In addition, after the main pressure-bonding process, the connection between the bumps 30 and the wiring 16 is completed, and the position of the semiconductor chip 1 relative to the wiring circuit board 2 is fixed. For this reason, even if the adhesive 40 is pressurized, it is difficult to apply sufficient pressure to the adhesive 40. Therefore, after the main pressure-bonding process, the voids cannot be sufficiently compressed, and they are likely to remain as voids in the adhesive layer 40A of the semiconductor device 100. In contrast, when the voids are compressed by heating at a temperature lower than the melting point of the bumps 30 and the melting point of the wiring 16 in the temporary compression body compression process before the main compression process, as in the manufacturing method of this embodiment, the adhesive 40 does not harden as much as when the compression is performed at a temperature equal to or higher than the melting point of at least one of the bumps 30 and the wiring 16, and the viscosity of the adhesive 40 is low, so that the voids can be compressed easily and the voids are less likely to remain as voids in the adhesive layer 40A of the semiconductor device 100. As a result, the manufacturing method of this embodiment can manufacture a semiconductor device 100 in which the generation of voids is suppressed. From the above, the manufacturing method of the semiconductor device of this embodiment can manufacture a semiconductor device 100 in which the generation of voids is suppressed while ensuring good connection reliability.

Next, the temporary bonding process, the temporary bonded body pressurization process, and the final bonding process will be described in detail.

(Temporary pressure bonding process)
In the temporary pressure bonding process, first, as shown in FIG. 2A, a semiconductor chip 1 having a semiconductor chip body 10 and bumps 30 as a first connection part is superimposed on a wiring circuit board 2 having a substrate body 20 and wiring 16 as a second connection part while disposing an adhesive 40 between them to form a laminate 3. The semiconductor chip 1 is formed, for example, by dicing a semiconductor wafer, and then picked up and transported to the wiring circuit board 2, and aligned so that the bumps 30 as the first connection part and the wiring 16 are disposed opposite each other. The laminate 3 is formed on a stage 42 of a pressing device 43 having a pressure bonding head 41 and a stage 42 as a pair of temporary pressure bonding pressing members disposed opposite each other. In the laminate 3, the bumps 30 are provided on the wiring 15 provided on the semiconductor chip body 10. The wiring 16 of the wiring circuit board 2 is provided at a predetermined position on the substrate body 20. The bumps 30 and the wiring 16 each have a surface portion formed of a metal material.

The adhesive 40 may be applied to the surface of the semiconductor chip 1 facing the wiring circuit board 2, or to the surface of the wiring circuit board 2 facing the semiconductor chip 1, or a film-like adhesive prepared in advance may be attached to the wiring circuit board 2. The film-like adhesive 40 may be attached by hot pressing, roll lamination, vacuum lamination, or the like. The area and thickness of the adhesive 40 are appropriately set according to the size of the semiconductor chip 1 or the wiring circuit board 2, the height of the bumps 30 and the wiring 16, and the like. The film-like adhesive 40 may be attached to the semiconductor chip 1. In this case, for example, the film-like adhesive is attached to a semiconductor wafer, and then the semiconductor wafer is diced to separate the semiconductor wafer, thereby obtaining the semiconductor chip 1 to which the film-like adhesive 40 is attached.

2(b), the laminate 3 is pressed by being sandwiched between a stage 42 and a bonding head 41 as a temporary pressure bonding press member, thereby temporarily bonding the semiconductor chip 1 and the wiring circuit board 2 to obtain a temporary pressure bonded body 4. In FIG. 2, the bonding head 41 is disposed on the semiconductor chip 1 side, and the stage 42 is disposed on the wiring circuit board 2 side. A flip chip bonder or the like can be used as a temporary pressure bonding press device 43 having the stage 42 and the bonding head 41.

The laminate 3 is pressurized for temporary bonding when at least one of the stage 42 and the bonding head 41 is at a temperature lower than the melting point of the bumps 30 serving as the first connection parts of the semiconductor chip 1 and the melting point of the wiring 16 serving as the second connection parts of the wiring circuit board 2.

In the pre-pressure bonding process, from the viewpoint of suppressing the transfer of heat to the semiconductor chip 1 due to contact of the pre-pressure bonding press member with the semiconductor chip 1 when picking up the semiconductor chip 1 as the first member, it is preferable that the pre-pressure bonding press member is set to a low temperature.
On the other hand, while the laminate 3 is pressurized for temporary bonding, the temporary pressure member may be heated to a certain high temperature in order to increase the fluidity of the adhesive 40 to such an extent that the entrapped voids can be eliminated. At this time, from the viewpoint of shortening the cooling time of the temporary pressure member, it is preferable that the difference between the temperature of the temporary pressure member when picking up the semiconductor chip 1 and the temperature of the temporary pressure member when heating and pressing the laminate 3 to obtain the temporary pressure member 4 is small. Specifically, this temperature difference is preferably 100°C or less, more preferably 60°C or less, and even more preferably substantially 0°C. This temperature difference may be constant. If the temperature difference is 100°C or less, the time required for cooling the temporary pressure member can be shortened.

The temperature of the press member for temporary pressure bonding when pressing the laminate 3 to obtain the temporary pressure bonded body 4 may be a temperature equal to or higher than the reaction start temperature of the adhesive 40, or may be a temperature lower than the reaction start temperature of the adhesive 40, but is preferably lower than the reaction start temperature of the adhesive 40. In this case, the reaction of the adhesive 40 is less likely to start, and the adhesive 40 is not cured at the start of the temporary pressure bonded body pressing process, so that voids generated in the temporary pressure bonding process can be easily eliminated. The reaction start temperature refers to the on-set temperature in the DSC thermogram obtained when measuring under the conditions of a sample amount of 10 mg of adhesive 40, a heating rate of 10°C/min, and a measurement atmosphere: nitrogen, using a DSC (manufactured by PerkinElmer, product name "DSC-Pyrs1"). From the viewpoint of more easily eliminating voids generated in the temporary pressure bonding process in the pressurized temporary pressure bonding process, the temperature of the press member for temporary pressure bonding is preferably 70°C or higher.

The pressure load for pressing the laminate 3 to obtain the temporary pressure-bonded body 4 is appropriately set in consideration of the number of bumps 30, the absorption of the height variation of the bumps 30, and the deformation amount of the bumps 30. At this time, it is preferable that the pressure load is set so that the laminate 3 is pressed and the bumps 30 of the semiconductor chip 1 and the wiring 16 of the wiring circuit board 2 come into contact with each other in the temporary pressure-bonded body 4. In this case, in the actual pressure-bonding process performed later, metal bonds between the bumps 30 and the wiring 16 are easily formed, and there is a tendency for the adhesive 40 to be less likely to be caught between the bumps 30 and the wiring 16. From the viewpoint of sufficient contact between the bumps 30 and the wiring 16, the pressure load for pressing the laminate 3 to obtain the temporary pressure-bonded body 4 may be set to, for example, 0.009 to 0.5 N per bump 30 of the semiconductor chip 1.

The time for which the laminate 3 is pressurized to obtain the temporary pressure-bonded body 4 is not particularly limited, but from the viewpoint of improving productivity, it is preferably 5 seconds or less, more preferably 3 seconds or less, and particularly preferably 2 seconds or less. However, the time for which the laminate 3 is pressurized to obtain the temporary pressure-bonded body 4 may be 0.1 seconds or more. Furthermore, when the bumps 30 and the wiring 16 are brought into contact with each other, it is desirable that the time for which the laminate 3 is pressurized to obtain the temporary pressure-bonded body 4 is the time until the bumps 30 and the wiring 16 come into contact with each other.

There are no particular limitations on the semiconductor chip body 10, and various types of semiconductors can be used, such as elemental semiconductors composed of the same type of element, such as silicon and germanium, and compound semiconductors, such as gallium arsenide and indium phosphide.

The wired circuit board 2 is not particularly limited, and examples thereof include a circuit board having an insulating substrate as the substrate body 20 whose main component is glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimide triazine, etc., and in which unnecessary portions of a metal layer formed on the surface of the substrate are etched away to form wiring (wiring pattern), a circuit board in which wiring (wiring pattern) is formed on the surface of the insulating substrate by metal plating, etc., and a circuit board in which wiring (wiring pattern) is formed by printing a conductive material on the surface of the insulating substrate.

The material of the bump 30 and the wiring 16 contains, as a main component, a metal such as gold, silver, copper, solder (the main component being, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper), tin, or nickel. The bump 30 and the wiring 16 may be composed of only a single component, or may be composed of multiple components. The bump 30 and the wiring 16 may have a structure in which these metals are layered.

Among the above metals, from the viewpoint of manufacturing a semiconductor device (package) 100 having excellent electrical conductivity and thermal conductivity of the bumps 30 and wiring 16, gold, silver, or copper is preferred, and silver or copper is more preferred. From the viewpoint of manufacturing a semiconductor device (package) 100 at reduced cost, inexpensive silver, copper, or solder is preferred, copper or solder is more preferred, and solder is particularly preferred. From the viewpoint of suppressing the formation of an oxide film on the surface of the metal at room temperature and suppressing a decrease in productivity and an increase in cost, gold, silver, copper, or solder is preferred, gold, silver, or solder is more preferred, and gold or silver is even more preferred. From the viewpoint of improving the connection reliability of the semiconductor device 100 and suppressing warping, solder is preferred.

The bump 30 and the wiring 16 may have a metal layer on the surface thereof, the main component of which may be gold, silver, copper, solder (main components may be, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. Such a metal layer may be formed, for example, by plating. This metal layer may be composed of only a single component, or may be composed of multiple components. The metal layer may have a structure consisting of a single layer, or a structure in which multiple metal layers are laminated.

(Temporary pressure-bonded body pressurization process)
In the temporary pressure-bonding process, after obtaining the temporary pressure-bonded body 4, as shown in FIG. 3, the temporary pressure-bonded body 4 is heated while being pressurized in a pressurized atmosphere in a heating furnace 60. At this time, it is preferable to pressurize a plurality of temporary pressure-bonded bodies 4 collectively in one heating furnace 60. This is for the following reason. That is, when a plurality of temporary pressure-bonded bodies 4 are pressed collectively using a pressing member, it is difficult to pressurize the plurality of temporary pressure-bonded bodies 4 uniformly. In contrast, when a plurality of temporary pressure-bonded bodies 4 are pressed collectively using a heating furnace 60, a large number of temporary pressure-bonded bodies 4 can be easily pressed uniformly, thereby improving the productivity of the semiconductor device 100. As the heating furnace 60, a reflow furnace, a pressure oven, etc. can be used.

When the temporary pressure-bonded body 4 is pressurized under a pressurized atmosphere, fillets tend to be suppressed compared to when the temporary pressure-bonded body 4 is pressurized using a pressing member. Fillet suppression is particularly important in the manufacture of a miniaturized and highly dense semiconductor device 100. Here, fillet suppression means suppressing the fillet width to a small value, and the fillet width is the length of the adhesive that protrudes from the outer periphery of the semiconductor device 100. The fillet width can be measured, for example, by taking an external image of the semiconductor device 100 with a digital microscope (manufactured by KEYENCE, product name "VHX-5000") and measuring it on the image obtained. At this time, the length (fillet width) of the adhesive 40 that protrudes from the four peripheral sides of the semiconductor chip 1 is measured, and the average value is obtained as the fillet value. From the viewpoint of mounting many semiconductor chips 1 on the wiring circuit board 2, it is preferable that the fillet value is 150 μm or less.

The atmosphere inside the heating furnace 60 is not particularly limited and may be, for example, air, nitrogen, or formic acid.

The pressure (air pressure) of the pressurized atmosphere in the heating furnace 60 is set appropriately depending on the size and number of the semiconductor chips 1 or wiring circuit boards 2 to be connected. The pressure for pressurization is not particularly limited, but may be, for example, 1 MPa or less above atmospheric pressure. At this time, from the viewpoint of suppressing voids and improving connection reliability, a high pressure is preferable. On the other hand, from the viewpoint of suppressing fillets, a low pressure is preferable. Therefore, when considering suppressing voids and improving connection reliability, the pressure for pressurization is preferably 0.05 to 0.8 MPa.

In the temporary pressure-bonding body pressurizing process, when the temporary pressure-bonding body 4 is pressurized, the set temperature of the heating furnace 60 is set to a temperature lower than the melting point of the bump 30 as the first connection part of the semiconductor chip 1 and the melting point of the wiring 16 as the second connection part of the wiring circuit board 2. In this case, compared to the case where the set temperature of the heating furnace 60 is set to a temperature equal to or higher than the melting point of at least one of the bump 30 as the first connection part of the semiconductor chip 1 and the wiring 16 as the second connection part of the wiring circuit board 2, the gap between the semiconductor chip 1 and the adhesive 40 or between the wiring circuit board 2 and the adhesive 40 can be easily compressed, and the occurrence of voids in the adhesive layer 40A of the semiconductor device 100 can be sufficiently suppressed. In addition, since the hardening of the adhesive 40 does not proceed excessively, in the main pressure-bonding process, it is possible to easily connect the bump 30 and the wiring 16 in the pressurized temporary pressure-bonding body 5, and the connection reliability of the semiconductor device 100 can be further improved.

In the temporary pressure-bonded body pressurizing process, the set temperature of the heating furnace 60 when pressurizing the temporary pressure-bonded body 4 may be equal to or higher than the reaction start temperature of the adhesive 40, or may be lower than the reaction start temperature, but it is preferable that the temperature be equal to or higher than the reaction start temperature of the adhesive 40. In this case, the voids can be compressed more effectively while causing the adhesive 40 to flow. In this case, from the viewpoint of more easily eliminating voids in the temporary pressure-bonded body pressurizing process, the difference (ΔT2) between the set temperature of the heating furnace 60 and the reaction start temperature of the adhesive 40 is preferably 5°C or more, and more preferably 10°C or more. However, it is preferable that ΔT2 is 100°C or less.

The set temperature of the heating furnace 60 when pressurizing the temporary pressure-bonded body 4 may be a temperature lower than the temperature of the temporary pressure-bonding press member when pressurizing the laminate 3 to obtain the temporary pressure-bonded body 4 in the temporary pressure-bonding process (when temporary pressure-bonding the semiconductor chip 1 and the wiring circuit board 2 is performed), or may be a temperature higher than the temperature of the temporary pressure-bonding press member when pressurizing the laminate 3 to obtain the temporary pressure-bonded body 4, but it is preferable that the temperature be higher than the temperature of the temporary pressure-bonding press member when pressurizing the laminate 3 to obtain the temporary pressure-bonded body 4.

The set temperature of the heating furnace 60 when pressurizing the temporary pressure-bonded body 4 is preferably 140°C or higher, more preferably 145°C or higher, and particularly preferably 150°C or higher, from the viewpoint of effectively compressing the voids while allowing the body to flow. However, the set temperature of the heating furnace 60 when pressurizing the temporary pressure-bonded body 4 is preferably 260°C or lower.

(Main pressure bonding process)
In the main pressure bonding process, after obtaining the pressurized temporary pressure-bonded body 5, as shown in (a) and (b) of FIG. 4, a pressing device 46 having a stage 45 and a pressure-bonding head 44 arranged opposite to each other as a pair of main pressure-bonding members is used to pressurize the pressurized temporary pressure-bonded body 5 by a heat press in which the pressurized temporary pressure-bonded body 5 is sandwiched between the stage 45 and the pressure-bonding head 44 while heating it, thereby forming a pressure-bonded body 6. At this time, the pressing device 46 may be the same as the pressing device 43, or may be prepared separately. In addition, when at least one of the stage 45 and the pressure-bonding head 44 pressurizes the pressurized temporary pressure-bonded body 5, it is heated to a temperature equal to or higher than at least one of the melting points of the bumps 30 and the wiring 16. In addition, in the pressure-bonded body 6, the semiconductor chip 1 and the wiring circuit board 2 are usually electrically connected by metal bonding of the bumps 30 and the wiring 16. The pressure-bonded body 6 may be used as a semiconductor device as it is, or after this pressure-bonding process, the pressure-bonded body 6 may be further heated under a pressurized atmosphere to further harden the adhesive 40 and form an adhesive layer 40A, and then the semiconductor device 100 may be formed.

In FIG. 4, the bonding head 44 is disposed on the semiconductor chip 1 side of the pressurized temporary bonded body, and the stage 45 is disposed on the wiring circuit board 2 side of the pressurized temporary bonded body. In the pressure bonded body 6, the wiring 16 and the bumps 30 are sealed by the adhesive 40 so as to be isolated from the external environment.

When the pressurized temporary pressure-bonded body 5 is heated and pressurized to obtain the pressure-bonded body 6, the oxide film on the surface of at least one of the bumps 30 and the wiring 16 may be removed. For this purpose, the temperature of at least one of the stage 45 and the pressure-bonding head 44 may be set to a temperature at which the oxide film on the surface of at least one of the bumps 30 and the wiring 16 is efficiently removed or higher. From this viewpoint, it is preferable that the temperature of at least one of the stage 45 and the pressure-bonding head 44 is 220°C or higher and 330°C or lower. In this case, if the metal material of the bumps 30 or the wiring 16 contains solder, the solder of the bumps 30 or the wiring 16 melts and a sufficient metal bond is formed more easily than when the temperature of at least one of the stage 45 and the pressure-bonding head 44 is lower than 220°C. When the temperature is 330°C or lower, voids are less likely to occur and solder is less likely to splash than when the temperature exceeds 330°C. The temperature of at least one of the stage 45 and the bonding head 44 may be 220°C or higher even if the metal material of at least one of the bumps 30 and the wiring 16 contains Sn/Ag, which has a melting point of approximately 220°C.

When the pre-pressurized pre-pressurized body 5 is pressurized while being heated using the pressing device 46, the pressing load is appropriately set in consideration of the removal of the oxide film on the surface of at least one of the bumps 30 and the wiring 16, the number of bumps 30, the absorption of the height variation of the bumps 30, and the control of the deformation amount of the bumps 30. If the pressing load is large, the oxide film tends to be easily removed. The pressing load may be, for example, 0.009 to 0.2 N per bump 30 of the semiconductor chip 1. If this pressing load is 0.009 N or more, the oxide film formed on at least one of the bumps 30 and the wiring 16 is easily removed, and the adhesive 40 is difficult to be trapped in at least one of the bumps 30 and the wiring 16. If the pressing load is 0.2 N or less, defects such as crushing or scattering of the bumps containing solder or the like are unlikely to occur.

From the viewpoint of improving productivity, the time for which the pressurized temporary pressure-bonded body 5 is pressurized while being heated in order to obtain the pressure-bonded body 6 is preferably 5 seconds or less, more preferably 3 seconds or less, and particularly preferably 2 seconds or less. However, the time for which the pressurized temporary pressure-bonded body 5 is pressurized while being heated in order to obtain the pressure-bonded body 6 may be 0.1 seconds or more.

The method of heating and pressurizing the pressurized pre-bonded body 5 is not limited to the heat press as shown in FIG. 4, but may be, for example, a heating furnace in which the pressurized pre-bonded body 5 is heated in a pressurized atmosphere in the heating furnace. The heating furnace may be a reflow furnace, a pressurized oven, or the like. The atmosphere in the heating furnace is not particularly limited, but may be air, nitrogen, formic acid, or the like.

<Adhesive>
Next, an adhesive used in the embodiment of the method for manufacturing a semiconductor device described above will be described.
The adhesive of the present embodiment is not particularly limited as long as it is a thermosetting adhesive, and contains, for example, an epoxy resin, a curing agent, and a fluxing agent.

(Epoxy resin)
The epoxy resin is not particularly limited as long as it has two or more epoxy groups in the molecule. As the epoxy resin, various polyfunctional epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, dicyclopentadiene type epoxy resin, etc. can be used. These can be used alone or in combination of two or more.

The weight average molecular weight of the epoxy resin is not particularly limited, but is preferably less than 10,000.

From the viewpoint of preventing the epoxy resin from decomposing and generating volatile components during connection at high temperatures, it is preferable to use an epoxy resin whose thermal weight loss rate at the connection temperature (heating temperature in the main pressure bonding process) is 5% or less. For example, if the connection temperature is 250°C, it is preferable to use an epoxy resin whose thermal weight loss rate at 250°C is 5% or less, and if the connection temperature is 300°C, it is preferable to use an epoxy resin whose thermal weight loss rate at 300°C is 5% or less.

The epoxy resin content is, for example, 5 to 75 mass %, preferably 10 to 50 mass %, and more preferably 15 to 35 mass %, based on the total amount of adhesive 40.

(Hardening agent)
Examples of the curing agent include a phenolic resin-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, an imidazole-based curing agent, and a phosphine-based curing agent. From the viewpoint of exhibiting flux activity that suppresses the generation of an oxide film on the bump 30 or the wiring 16 and improving connection reliability and insulation reliability, the curing agent preferably contains at least one selected from a phenolic resin-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, and an imidazole-based curing agent, and more preferably contains an imidazole-based curing agent. Each curing agent will be described below.

There are no particular limitations on the phenolic resin-based hardener, so long as it has two or more phenolic hydroxyl groups in the molecule. Examples include phenol novolac resin, cresol novolac resin, phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane-type polyfunctional phenol, and various polyfunctional phenol resins. These can be used alone or as a mixture of two or more.

From the viewpoint of good curing properties, adhesion and storage stability, the equivalent ratio of the phenolic resin-based hardener to the epoxy resin (phenolic hydroxyl group/epoxy group, molar ratio) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0. When the equivalent ratio is 0.3 or more, the curing properties and adhesion tend to improve, and when it is 1.5 or less, there is no excess of unreacted phenolic hydroxyl groups remaining, the water absorption rate is kept low, and the insulation reliability of the semiconductor device 100 tends to improve. When the equivalent ratio is 0.3 to 1.5, it is easy to adjust the gel time to an appropriate range.

Examples of acid anhydride curing agents include methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, and ethylene glycol bisanhydrotrimellitate. These can be used alone or as a mixture of two or more.

From the viewpoint of good curing properties, adhesion, and storage stability, the equivalent ratio of the acid anhydride-based curing agent to the epoxy resin (acid anhydride group/epoxy group, molar ratio) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0. When the equivalent ratio is 0.3 or more, the curing properties and adhesion tend to improve, and when it is 1.5 or less, there is no excess unreacted acid anhydride remaining, the water absorption rate is kept low, and the insulation reliability of the semiconductor device 100 tends to improve. When the equivalent ratio is 0.3 to 1.5, it is easy to adjust the gel time to an appropriate range.

An example of an amine-based curing agent that can be used is dicyandiamide.

The equivalent ratio of the amine-based curing agent to the epoxy resin (amino group/epoxy group, molar ratio) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0, from the viewpoint of good curability, adhesion, and storage stability. When the equivalent ratio is 0.3 or more, the curability and adhesion tend to improve, and when it is 1.5 or less, there is no excess unreacted amine remaining, and the insulation reliability of the semiconductor device 100 tends to improve. When the equivalent ratio is 0.3 to 1.5, it is easy to adjust the gel time to an appropriate range.

Examples of imidazole-based curing agents include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6 -[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins and imidazoles. From the viewpoint of excellent curing property, storage stability and connection reliability, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl ... The imidazole-based hardener may be selected from 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. These may be used alone or in combination of two or more. Microcapsules containing these may also be used as latent hardeners.

The content of the imidazole-based curing agent is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 3.2 to 5.5 parts by mass, relative to 100 parts by mass of the epoxy resin. If the content of the imidazole-based curing agent is 0.1 parts by mass or more, the curing property of the adhesive 40 tends to improve, and if it is 20 parts by mass or less, the adhesive 40 does not cure before a metal bond is formed between the bump 30 and the wiring 16, and poor connection between the bump 30 and the wiring 16 tends to be less likely to occur. If the content of the imidazole-based curing agent is 0.1 to 20 parts by mass, it is easy to adjust the gel time to an appropriate range.

Examples of phosphine-based curing agents include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra(4-methylphenyl)borate, and tetraphenylphosphonium(4-fluorophenyl)borate.

The content of the phosphine-based curing agent is preferably 0.1 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the epoxy resin. If the content of the phosphine-based curing agent is 0.1 parts by mass or more, the curing property of the adhesive 40 tends to improve, and if it is 10 parts by mass or less, the adhesive 40 does not cure before a metal bond is formed between the bump 30 and the wiring 16, and poor connection between the bump 30 and the wiring 16 tends to be less likely to occur.

The phenolic resin-based hardener, acid anhydride-based hardener, and amine-based hardener can each be used alone or in a mixture of two or more. The imidazole-based hardener and phosphine-based hardener can each be used alone, but can also be used together with the phenolic resin-based hardener, acid anhydride-based hardener, or amine-based hardener.

(Flux agent)
The fluxing agent is, for example, a compound having a group represented by formula (1). As the fluxing agent, a compound containing only one type of group represented by the following formula (1) or two or more types of group can be used.

式（１）中、Ｒ^１は、水素原子又は電子供与性基を示す。電子供与性基としては、例えば、アルキル基、水酸基、アミノ基、アルコキシ基、アルキルアミノ基が挙げられる。電子供与性基は、他の成分（エポキシ樹脂等）と反応しにくいものが好ましく、アルキル基、水酸基又はアルコキシル基であることが好ましく、アルキル基であることがより好ましい。

In formula (1), R ¹ represents a hydrogen atom or an electron-donating group. Examples of the electron-donating group include an alkyl group, a hydroxyl group, an amino group, an alkoxy group, and an alkylamino group. The electron-donating group is preferably one that is less reactive with other components (such as epoxy resins), and is preferably an alkyl group, a hydroxyl group, or an alkoxyl group, and more preferably an alkyl group.

As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, and an alkyl group having 1 to 5 carbon atoms is more preferable. Basically, the more electron-donating groups there are, the stronger the electron-donating property is, but the greater the steric hindrance is. Therefore, the alkyl group may be either linear or branched, but linear is preferable. When the alkyl group is linear, from the viewpoint of reducing steric hindrance, the number of carbon atoms in the alkyl group is preferably equal to or less than the number of carbon atoms in the main chain including the carboxy group.

As the alkoxy group, an alkoxy group having 1 to 10 carbon atoms is preferred, and an alkoxy group having 1 to 5 carbon atoms is more preferred. The more electron-donating groups there are, the stronger the electron-donating property, but the greater the steric hindrance. Therefore, the alkyl group portion of the alkoxy group may be linear or branched, and is preferably linear. When the alkyl group portion of the alkoxy group is linear, from the viewpoint of reducing steric hindrance, it is preferred that the number of carbon atoms is equal to or less than the number of carbon atoms of the main chain containing the carboxylic acid.

Examples of the alkylamino group include a monoalkylamino group and a dialkylamino group. As the monoalkylamino group, a monoalkylamino group having 1 to 10 carbon atoms is preferable, and a monoalkylamino group having 1 to 5 carbon atoms is more preferable. The alkyl group portion of the monoalkylamino group may be linear or branched, and is preferably linear.

As the dialkylamino group, a dialkylamino group having 1 to 20 carbon atoms is preferable, and a dialkylamino group having 1 to 10 carbon atoms is more preferable. The alkyl group portion of the dialkylamino group may be linear or branched, and is preferably linear.

The fluxing agent is preferably a compound having two carboxy groups (dicarboxylic acid). A compound having two carboxy groups is less likely to volatilize even at high temperatures during connection compared to a compound having one carboxy group (monocarboxylic acid), and the occurrence of voids can be further suppressed. Furthermore, when a compound having two carboxy groups is used, the increase in viscosity of the adhesive 40 during storage and connection work can be further suppressed compared to when a compound having three or more carboxy groups is used. As a result, the connection reliability of the semiconductor device 100 can be further improved.

式（２）中、Ｒ^１及びＲ^２はそれぞれ独立に、水素原子又は電子供与性基を示し、ｎは０～１０の整数を示す。 As the fluxing agent, a compound represented by the following formula (2) can be suitably used. The fluxing agent made of the compound represented by the following formula (2) can further improve the reflow resistance and connection reliability of the semiconductor device 100.

In formula (2), R ¹ and R ² each independently represent a hydrogen atom or an electron-donating group, and n represents an integer of 0 to 10.

In formula (2), n is preferably an integer between 2 and 10, and more preferably an integer between 2 and 8. When n is 10 or less, the flux activity is exerted in a shorter time, and even better connection reliability can be obtained, especially when the connection time is short. Furthermore, when n is 2 or more, the flux is less likely to volatilize even at high temperatures during connection, and the occurrence of voids can be further suppressed.

R ¹ and R ² may be hydrogen atoms or electron donating groups. When R ¹ and R ² are hydrogen atoms, the melting point of the adhesive 40 tends to be lower, and the connection reliability (solder wettability) may be improved. For example, a flux agent in which R ¹ and R ² are both the same methyl group has a higher melting point than one in which one (R ¹ or R ² ) has a methyl group, and the solder wettability tends to decrease depending on the melting point (for example, when it is 150° C. or higher).

As a fluxing agent, for example, a compound in which an electron donating group is substituted at the 2-position of a dicarboxylic acid selected from succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid can be used.

The melting point of the fluxing agent is preferably 150°C or less, more preferably 140°C or less, and even more preferably 130°C or less. Such a fluxing agent exhibits sufficient fluxing activity before the curing reaction between the epoxy resin and the curing agent occurs. Therefore, an adhesive 40 containing such a fluxing agent can realize a semiconductor device 100 with even better connection reliability. In addition, the fluxing agent is preferably solid at room temperature, and the melting point of the fluxing agent is preferably 25°C or more, and more preferably 50°C or more. The melting point of the fluxing agent can be measured, for example, by a device in which a capillary tube filled with a sample is attached to a double-tube thermometer and heated in a warm bath.

The melting point of the flux agent contained in the adhesive 40 of this embodiment is preferably higher than the temperature of the stage 42 of the pressing device 43 for forming the temporary pressure-bonded body 4. If the melting point of the flux agent is higher than the stage temperature of the pressing device 43, the bumps 30 and the wiring 16 can be easily brought into contact with each other in the main pressure-bonding process, so that it is possible to manufacture a semiconductor device 100 with excellent connection reliability even if the thermal history at the beginning and end of the main pressure-bonding process is different.

The fluxing agent content is preferably 0.5 to 10 mass % based on the total amount of adhesive 40, and more preferably 0.5 to 5 mass %.

(Polymer component)
The adhesive 40 may further contain a polymer component.

The polymer component is composed of a polymer different from the epoxy resin. Examples of such polymer components include phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, acrylic resin, polyester resin, polyethylene resin, polyethersulfone resin, polyetherimide resin, polyvinyl acetal resin, urethane resin, and acrylic rubber. Among these, from the viewpoint of excellent heat resistance and film formability, phenoxy resin, polyimide resin, acrylic rubber, cyanate ester resin, and polycarbodiimide resin are preferred, and phenoxy resin, polyimide resin, and acrylic rubber are more preferred. These polymer components can be used alone or as a mixture or copolymer of two or more kinds.

The weight average molecular weight of the polymer component is not particularly limited, but is preferably 10,000 or more. In this case, the adhesive 40 containing the polymer component is more excellent in terms of heat resistance and film formability. Therefore, by using the adhesive 40, a semiconductor device 100 with better heat resistance can be manufactured. In addition, the shape of the adhesive 40 is more easily maintained in the temporary pressure bonding process, the temporary pressure bonded body pressurization process, and the main pressure bonding process, and the semiconductor device 100 can be manufactured efficiently.

The weight average molecular weight of the polymer component is preferably 30,000 or more, more preferably 40,000 or more, and even more preferably 50,000 or more, from the viewpoint of imparting good film-forming properties to the adhesive 40 alone and making it easier to maintain the shape of the adhesive 40 in the temporary pressure bonding process, the temporary pressure-bonded body pressurizing process, and the main pressure bonding process, thereby efficiently manufacturing the semiconductor device 100.

When the adhesive 40 contains a polymer component having a weight average molecular weight of 10,000 or more, the ratio C _a /C _d (mass ratio) of the epoxy resin content C _a to the polymer component content C _d having a weight average molecular weight of 10,000 or more is preferably 0.01 to 5, more preferably 0.05 to 3, and even more preferably 0.1 to 2. By making the ratio C _a /C _d 0.01 or more, better curing properties and adhesive strength can be obtained. Furthermore, by making the ratio C _a /C _d 5 or less, better film formability can be obtained in the adhesive 40, so that the shape of the adhesive 40 is easily maintained in the temporary pressure bonding process, the temporary pressure bonded body pressurizing process, and the main pressure bonding process, and the semiconductor device 100 can be efficiently manufactured.

The glass transition temperature (Tg) of the polymer component is not particularly limited, but is preferably 200°C or less, more preferably 180°C or less, and even more preferably 150°C or less. In this case, the adhesive 40 tends to be embedded in the bumps 30 of the semiconductor chip 1, the electrodes formed on the wiring circuit board 2, the wiring pattern, and other irregularities, and the effect of suppressing voids tends to be relatively large. Here, Tg is measured using a DSC (manufactured by PerkinElmer Co., Ltd., product name "DSC-7 type") under conditions of a sample amount of 10 mg, a heating rate of 10°C/min, and an air atmosphere.

The glass transition temperature (Tg) of the polymer component is preferably 50°C or higher. If the Tg of the polymer component is 50°C or higher, the tack (viscosity) of the adhesive 40 tends to be moderately weak.

The glass transition temperature (Tg) of the polymer component may be 50°C or higher and 200°C or lower, preferably 50°C or higher and 180°C or lower, and more preferably 50°C or higher and 150°C or lower, from the viewpoint of excellent adhesion of the adhesive 40 to the wiring circuit board 2 or the semiconductor chip 1.

(Fila)
In order to control the viscosity and the physical properties of the cured product, and to suppress the generation of voids and the moisture absorption rate when the semiconductor chip 1 and the wiring circuit board 2 are connected, the adhesive 40 may contain a filler. The filler may be an inorganic filler, examples of which include insulating inorganic fillers such as glass, silica, alumina, titanium oxide, mica, and boron nitride, and conductive inorganic fillers such as carbon black. Among these, from the viewpoint of the properties of the adhesive 40, it is preferable to use an insulating inorganic filler selected from silica, alumina, titanium oxide, and boron nitride, or an insulating inorganic filler selected from silica, alumina, and boron nitride. The filler may be a whisker, examples of which include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, and boron nitride. The filler may be a resin filler (organic filler), examples of which include polyurethane resin, polyimide resin, methyl methacrylate resin, and methyl methacrylate-butadiene-styrene copolymer resin (MBS). These fillers may be used alone or in combination of two or more. There are no particular limitations on the shape, average particle size, and content of the filler.

The filler may have its physical properties appropriately adjusted by surface treatment.

From the viewpoint of adjusting the minimum melt viscosity to an appropriate range, the filler content is preferably 10 to 80 mass % based on the total amount of adhesive 40, and more preferably 15 to 60 mass %.

(Other ingredients)
The adhesive 40 may further contain other components such as an ion trapper, an antioxidant, a silane coupling agent, a titanium coupling agent, and a leveling agent. These may be used alone or in combination of two or more. The amounts of these additives may be appropriately adjusted so that the effects of each additive are exerted.

The adhesive 40 may be in the form of a film from the viewpoint of improving the manufacturing efficiency of the semiconductor device 100. The film-like adhesive can be manufactured by applying a resin varnish containing an epoxy resin, a hardener, a fluxing agent, and, if necessary, an organic solvent and other components, onto a base film to form a coating film, and then drying the coating film.

The resin varnish is prepared by mixing an epoxy resin, a hardener, a fluxing agent, and optionally added polymer components and fillers with an organic solvent, and dissolving or dispersing the mixture by stirring or kneading. The resin varnish is applied to a substrate film that has been subjected to a release treatment, for example, using a knife coater, roll coater, applicator, die coater, or comma coater. The organic solvent is then reduced from the coating of the resin varnish by heating, i.e., the coating is dried, to form a film of adhesive on the substrate film. A film of the resin varnish may also be formed on a semiconductor wafer or the like by a method such as spin coating, and then the coating is dried to form a film of adhesive on the semiconductor wafer.

The organic solvent used in preparing the resin varnish is preferably one that has the property of dissolving or dispersing each component uniformly, and examples thereof include dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. These organic solvents can be used alone or in combination of two or more. Stirring and kneading during the preparation of the resin varnish can be performed using, for example, a stirrer, a grinding machine, a three-roll mill, a ball mill, a bead mill, or a homodisper.

The substrate film is not particularly limited as long as it has heat resistance sufficient to withstand the heating conditions when volatilizing the organic solvent, and examples thereof include polyolefin films such as polypropylene film and polymethylpentene film, polyester films such as polyethylene terephthalate film and polyethylene naphthalate film, polyimide film, and polyetherimide film. The substrate film is not limited to a single layer of these films, and may be a multilayer film made of two or more materials.

The heating performed to volatilize the organic solvent from the applied resin varnish may be specifically heating at 50 to 200°C for 0.1 to 90 minutes. The organic solvent may be removed until the remaining amount is 1.5 mass% or less, within a range that does not substantially affect the suppression of void generation and viscosity adjustment in the adhesive layer 40A of the semiconductor device 100.

The minimum melt viscosity of the adhesive 40 is preferably 1500 Pa·s or less. If the minimum melt viscosity of the adhesive 40 is in this range, voids are less likely to remain in the adhesive layer 40A of the semiconductor device 100, and good connection reliability can be easily ensured between the semiconductor chip 1 and the wiring circuit board 2. In addition, compared to when the minimum melt viscosity of the adhesive 40 is greater than 1500 Pa·s, the adhesive 40 is less likely to be caught between the bump 30 and the wiring 16, and connection defects between the bump 30 and the wiring 16 are less likely to occur, thereby further improving the connection reliability of the semiconductor device 100. The minimum melt viscosity of the adhesive 40 can be adjusted to a range of 1500 Pa·s or less by adjusting the composition of the components in the adhesive 40.

The minimum melt viscosity of the adhesive 40 is the minimum value of viscosity in the relationship between viscosity (complex viscosity) and temperature obtained when the viscoelasticity of the adhesive 40 is measured while applying a 1% strain to a test piece and raising the temperature in the range of 35 to 150°C under conditions of a heating rate of 10°C/min and a frequency of 10 Hz. As a test piece for viscoelasticity measurement, for example, a laminate obtained by laminating multiple film-like adhesives 40 to a thickness of 400 μm may be used. As a viscosity measurement device, a dynamic viscoelasticity measurement device (product name "ARES") manufactured by TA Instruments is used.

From the viewpoint of further improving the connection reliability of the semiconductor device 100, it is preferable that the minimum melt viscosity of the adhesive 40 is 1500 Pa·s or less.

The minimum melt viscosity of the adhesive 40 is preferably 100 Pa·s or more. In this case, the adhesive 40 is easier to handle as a film than when the minimum melt viscosity is less than 100 Pa·s, and the manufacturing efficiency of the semiconductor device 100 is further improved.

The adhesive 40 preferably has a gel time of 35 seconds or more and 80 seconds or less at 150 ° C. By having a gel time in this range, voids are less likely to remain in the adhesive layer 40A of the semiconductor device 100, and good connection reliability can be ensured between the semiconductor chip 1 and the wiring circuit board 2. The gel time of the adhesive 40 can be adjusted to a range of 35 seconds or more and 80 seconds or less depending on the type and content of the curing agent. By setting the gel time of the adhesive 40 to 35 seconds or more and 80 seconds or less at 150 ° C, voids are less likely to remain in the adhesive layer 40A of the semiconductor device 100 compared to when the gel time is longer than 80 seconds, and a semiconductor device 100 in which the generation of voids is more suppressed can be manufactured. In addition, compared to when the gel time is shorter than 35 seconds, the curing reaction does not proceed easily during the temporary pressure bonding process (because it is difficult to cure at a low temperature such as 80 ° C), making it easier to remove voids, and voids are less likely to remain in the adhesive layer 40A of the semiconductor device 100, so a semiconductor device 100 in which the generation of voids is more suppressed can be manufactured.

The gel time here is the time from when the adhesive 40 is placed on a hot plate at 150°C until the adhesive 40 gels. More specifically, the gel time is the time until the film hardens.

The gel time of the adhesive 40 is preferably 38 seconds or more and 78 seconds or less in order to further suppress the occurrence of voids in the adhesive layer 40A of the semiconductor device 100.

The present disclosure is not limited to the above embodiment. For example, in the above embodiment, an example was shown in which the method for manufacturing a semiconductor device of the present disclosure is applied to the semiconductor device 100, but the method for manufacturing a semiconductor device of the present disclosure can also be applied to the manufacturing of the semiconductor devices 200, 300, 400, and 500 shown in Figures 5, 6, and 7. Figures 5, 6, and 7 are each a partial cross-sectional view showing a semiconductor device manufactured by another embodiment of the method for manufacturing a semiconductor device of the present disclosure.

The semiconductor device 200 shown in FIG. 5 includes a semiconductor chip 1 (first member) having a semiconductor chip body 10, a wiring circuit board 2 (second member) having a substrate body 20, and an adhesive layer 40A interposed between them. In the case of the semiconductor device 200, the semiconductor chip 1 has a bump 32 arranged on the surface of the semiconductor chip 1 facing the wiring circuit board 2 as a first connection part. The wiring circuit board 2 has a bump 33 arranged on the surface of the substrate body 20 facing the semiconductor chip 1 as a second connection part. The bump 32 of the semiconductor chip 1 and the bump 33 of the wiring circuit board 2 are electrically connected by metal bonding. That is, the semiconductor chip 1 and the wiring circuit board 2 are flip-chip connected by the bumps 32 and 33. The bumps 32 and 33 are sealed by the adhesive layer 40A and are isolated from the external environment.

Figures 6 and 7 show CoC type semiconductor devices 300 and 400, which are connections in which semiconductor chips 1 are connected to each other. The configuration of the semiconductor device 300 shown in Figure 6 is similar to that of the semiconductor device 100, except that two semiconductor chips 1 are flip-chip connected via wiring 15 and bumps 30 as a first member and a second member. The configuration of the semiconductor device 400 shown in Figure 7 is similar to that of the semiconductor device 200, except that two semiconductor chips 1 having bumps 32 are flip-chip connected via bumps 32.

In addition, in the semiconductor devices 100, 200, 300, and 400 shown in FIG. 1 and FIG. 5 to FIG. 7, the first connection portion or the second connection portion of the wiring 15, the bump 32, etc. may be a metal film (e.g., gold plating) called a pad, or a post electrode (e.g., copper pillar). For example, one semiconductor chip 1 may have a copper pillar and a connection bump (solder: tin-silver) as the first connection portion, and the other semiconductor chip 1 or the wiring circuit board 2 may have gold plating as the second connection portion.

The method for manufacturing a semiconductor device according to the present disclosure can also be applied to the manufacture of a semiconductor device 500 shown in FIG. 8. FIG. 8 is a partial cross-sectional view showing a semiconductor device manufactured by another embodiment of the method for manufacturing a semiconductor device according to the present disclosure.

8 is a cross-sectional view showing another embodiment of a semiconductor device. The semiconductor device 500 shown in FIG. 8 has a TSV structure in which a plurality of semiconductor chips 1 are stacked. In the semiconductor device 500 shown in FIG. 8, the wiring 15 formed on the interposer body 50 of the interposer 501 as the second member is connected to the bump 30 of the semiconductor chip 1, so that the semiconductor chip 1 and the interposer 501 are flip-chip connected. An adhesive layer 40A is interposed between the semiconductor chip 1 and the interposer 501. On the surface of the semiconductor chip 1 opposite to the interposer 501, the semiconductor chips 1 are repeatedly stacked via the wiring 15, the bump 30, and the adhesive layer 40A. The wiring 15 on the pattern surfaces on the front and back of the semiconductor chip 1 are connected to each other by the through electrodes 34 filled in the holes that penetrate the inside of the semiconductor chip body 10. The through electrodes 34 can be made of copper, aluminum, or the like.

The semiconductor device 500 in FIG. 8 can be manufactured by stacking multiple semiconductor chips 1 one by one and sequentially temporarily bonding them together, heating the multiple semiconductor chips 1 together in a heating furnace 60 while applying pressure under a pressurized atmosphere, and then bonding them in a final bonding process.

In addition, in the semiconductor device 500 of FIG. 8, a motherboard may be used instead of the interposer 501. In this case, the semiconductor chip 1 is directly mounted on the motherboard without the interposer 501.

Furthermore, other examples of semiconductor devices having multiple semiconductor chips include chip-stacked packages and POP (Package On Package), and the manufacturing method of the semiconductor device disclosed herein can also be applied to the manufacture of such semiconductor devices. These semiconductor devices can be manufactured by the same method as the semiconductor device 500 having a TSV structure.

The present disclosure will be explained in more detail below with reference to examples, but the present disclosure is not limited to these examples.

The present disclosure will be explained in more detail below using examples, but the present disclosure is not limited to these examples.

The materials used in each of the examples and comparative examples are as follows.
(i) Epoxy resin EP1032H60: polyfunctional solid epoxy resin containing a triphenolmethane skeleton (manufactured by Japan Epoxy Resins Co., Ltd., product name "EP1032H60", weight average molecular weight: 800 to 2000)
YL983U: Bisphenol F type liquid epoxy resin (manufactured by Japan Epoxy Resins Co., Ltd., product name "YL983U", weight average molecular weight: about 336)
- YL7175: Flexible epoxy resin (manufactured by Japan Epoxy Resins Co., Ltd., product name "YL7175", weight average molecular weight: 1000 to 5000)
(ii) Curing agent: 2MAOK-PW: 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct (manufactured by Shikoku Chemical Industry Co., Ltd., product name "2MAOK-PW")
(iii) Fluxing agent: glutaric acid (manufactured by Tokyo Chemical Industry Co., Ltd., melting point: about 98° C.)
(iv) Polymer component ZX1356-2: phenoxy resin (manufactured by Tohto Kasei Co., Ltd., product name "ZX1356-2", Tg: about 71°C, weight average molecular weight: about 63,000)
(v) Filler (inorganic filler)
SE2050: Silica filler (manufactured by Admatechs Co., Ltd., product name "SE2050", average particle size 0.5 μm)
SE2050-SEJ: Epoxy silane-treated silica filler (manufactured by Admatechs Co., Ltd., product name "SE2050-SEJ", average particle size 0.5 μm)
SM nanosilica: Acrylic surface-treated nanosilica filler (manufactured by Admatechs Co., Ltd., product name "YA050C-SM", average particle size approximately 50 nm)
SM Nano Silica 2: Acrylic surface-treated nano silica filler (manufactured by Admatechs Co., Ltd., product name "YA180C-SM", average particle size approximately 180 nm)
(Organic filler)
EXL2655: Core-shell type organic fine particles (manufactured by Rohm and Haas Japan Co., Ltd., product name "EXL2655")

Example 1
(1) Preparation of film-like adhesive 3.1 g of epoxy resin ("EP1032": 2.4 g, "YL983": 0.5 g, "YL7175": 0.2 g), 0.1 g of curing agent "2MAOK", 0.1 g (0.7 mmol) of glutaric acid, 1.9 g of filler (inorganic filler) (0.4 g of "SE2050", 0.4 g of "SE2050-SEJ", 1.1 g of "SM nanosilica"), 0.3 g of organic filler (EXL-2655), and methyl ethyl ketone (amount to give a solid content of 63% by mass) were charged into the container of a bead mill (Fritsch Japan Co., Ltd., planetary fine grinder P-7), and beads with a diameter of 0.8 mm and beads with a diameter of 2.0 mm were added in the same weight as the total weight of the solid content and stirred for 30 minutes to obtain a mixture. Next, 1.7 g of phenoxy resin (ZX1356-2) was added to the container, and the mixture was stirred again for 30 minutes with the beads mill. After that, the beads used for stirring were removed by filtration to obtain a resin varnish.

The obtained resin varnish was applied to a substrate film (manufactured by Teijin Film Solutions Limited, product name "Purex A53") using a small precision coating device (manufactured by Yasui Seiki Co., Ltd.) to form a coating film. This coating film was then dried at 70°C for 10 minutes using a clean oven (manufactured by ESPEC), and a film-like adhesive (thickness 0.040 mm) was obtained. The reaction initiation temperature of this film-like adhesive was 135°C.

(2) Measurement of minimum melt viscosity A laminate was obtained by laminating a plurality of film-like adhesives to a thickness of 400 μm. This laminate was then used as a test piece, and the viscoelasticity of the adhesive was measured while heating the test piece in a temperature range of 35 to 150° C. under conditions of a heating rate of 10° C./min and a frequency of 10 Hz, with a 1% strain applied to the test piece. The minimum viscosity value in the relationship between the viscosity (complex viscosity) and temperature obtained at this time was taken as the minimum melt viscosity of the adhesive. The results are shown in Table 1.

(3) Measurement of gel time Three sheets of the film-like adhesive were laminated under an atmosphere of 80 ° C. to a total thickness of 120 μm. A test piece of 11 mm square was cut out from the formed laminate film. The obtained test piece was placed on a hot plate at 150 ° C. to melt, and the test piece was stirred in a small circle with a stirring rod. When the test piece began to thicken, the whole was stirred and continued to be stirred until the test piece gelled and lost its fluidity. The time from the time the test piece was placed on the hot plate to the time the test piece gelled and lost its fluidity was measured in units of 1 second as the "gel time". The same measurement was performed twice, and if the higher value of the two measured values from the two measurements was 1.05 times or less than the lower value, the average value of the two measured values was recorded as the gel time of the test piece. If the higher value of the two measured values was greater than 1.05 times the lower value, a third measurement was performed, and the average value of the three measured values from the three measurements was recorded as the gel time of the test piece. The results are shown in Table 1.

(4) Fabrication of a Semiconductor Device Next, a semiconductor device was fabricated as follows using the film-like adhesive prepared as described above.
(Production of temporary pressure-bonded body)
The film adhesive thus produced was cut out to prepare a film adhesive having a size of 8 mm x 8 mm x 0.045 mm thick. This was attached to a semiconductor chip (10 mm x 10 mm), thickness 0.1 mm, connection metal: Au, product name: WALTS-TEG IP80, manufactured by WALTS). A semiconductor chip with solder bumps (chip size: 7.3 mm x 7.3 mm x thickness 0.05 mm, solder bump melting point: about 220°C, bump height: total of copper pillar and solder: about 45 μm, number of bumps 1048 pins, pitch 80 μm, product name: WALTS-TEG CC80, manufactured by WALTS) was attached thereto to obtain a laminate. Next, this laminate was placed on a stage at 80° C. of a flip chip bonder (product name “FCB3”, manufactured by Panasonic Corporation) having a stage and a pressure bonding head, and heated to 80° C. for 3 seconds while pressing the laminate with a load of 25 N by a heat press sandwiched between the stage and the pressure bonding head. In this way, a temporary pressure bonded body was produced.

(Production of pressurized temporary pressure-bonded body)
The pre-bonded body prepared as described above was placed in the oven of a pressurized oven device (product name: PCOA-01T, manufactured by NTT-AT Creative Co., Ltd.). Then, the pressure in the oven was set to 0.7 MPa, and the temperature was raised from room temperature to 150 ° C. at a heating rate of 20 ° C. / min. Next, while maintaining the pressure and temperature, the pre-bonded body was heated under pressure for 30 minutes. In this way, a pressurized pre-bonded body was prepared.

(Preparation of pressure-bonded body)
The pressurized pre-bonded body prepared as described above was moved onto a stage at 80°C of another flip chip bonder (product name: FCB3, manufactured by Panasonic Corporation), and a heat press was performed in which the pressurized pre-bonded body was heated at 230°C for 1 second while being pressed with a load of 25N by the stage and the bonding head. In this way, a semiconductor device was prepared. This semiconductor device was used as a semiconductor device sample for evaluation.

(Examples 2 to 4)
Semiconductor devices of Examples 2 to 4 were fabricated in the same manner as in Example 1, except that the composition of the adhesive used was changed as shown in Table 1 below.

(Comparative Example 1)
The film adhesive prepared in the same manner as in Example 1 was cut out to prepare a film adhesive having a size of 8 mm x 8 mm x 0.045 mm thick. This was attached to a semiconductor chip (10 mm, thickness 0.1 mm, connection metal: Au, product name: WALTS-TEG IP80, manufactured by WALTS). A semiconductor chip with solder bumps (chip size: 7.3 mm x 7.3 mm x thickness 0.05 mm, solder bump melting point: about 220°C, bump height: total of copper pillar and solder: about 45 μm, number of bumps 1048 pins, pitch 80 um, product name: WALTS-TEG CC80, manufactured by WALTS) was attached thereto to obtain a laminate. The laminate was placed on the stage of a flip chip bonder (FCB3, manufactured by Panasonic Corporation) having a stage and a pressure bonding head, and heated to 80° C. for 1 second while pressing the laminate with a load of 25 N by a heat press sandwiched between the stage and the pressure bonding head. In this way, a temporary pressure bonded body was produced.

The pre-bonded body produced as described above was moved onto the stage of another flip chip bonder (FCB3, manufactured by Panasonic Corporation), and was clamped between the stage and the bonding head, where it was subjected to a heat press in which it was heated to 230°C for 3 seconds while being pressurized with a load of 25 N. In this way, a bonded body was produced.

The bonded body prepared as described above was placed in the oven of a pressurized oven device (product name: PCOA-01T, manufactured by NTT-AT Creative Co., Ltd.). The pressure inside the oven was first set to 0.7 MPa, and the temperature was raised from room temperature to 175°C at a rate of 20°C/min. Next, while maintaining the pressure and temperature, the bonded body was heated under pressure for 10 minutes. In this way, a semiconductor device was prepared. This semiconductor device was used as a semiconductor device sample for evaluation.

<Evaluation>
The evaluation semiconductor device samples obtained in Examples 1 to 4 and Comparative Example 1 as described above were evaluated for void suppression effect and connection reliability.

(Evaluation of void suppression effect)
For the evaluation semiconductor device samples obtained in Examples 1 to 4 and Comparative Example 1, external images were taken using an ultrasonic imaging diagnostic device (product name: Insight-300, manufactured by Insight). From the obtained images, the adhesive layer portion on the chip was captured using a scanner (product name: GT-9300UF, manufactured by Seiko Epson Corporation). Using image processing software Adobe Photoshop (registered trademark), void portions were identified by color correction and two-tone gradation, and the proportion of the void portion (void occurrence rate) was calculated using a histogram, assuming the area of the adhesive layer to be 100%. The occurrence state of voids was evaluated according to the following criteria. The results are shown in Table 1.

A: Void occurrence rate is 5% or less. B: Void occurrence rate is more than 5%.

(Evaluation of connection reliability)
The initial connection resistance of the evaluation semiconductor device samples obtained in Examples 1 to 4 and Comparative Example 1 was measured using a multimeter (manufactured by ADVANTEST, product name: R6871E). The connection reliability was then evaluated according to the following criteria. The results are shown in Table 1.

A: The connection resistance value is within the optimal connection resistance value range for the semiconductor chip in the evaluation semiconductor device sample (10.0 to 15.0 Ω in this embodiment and comparative example). B: The connection resistance value is outside the range A (10.0 to 15.0 Ω), or the connection resistance value cannot be measured due to a poor connection. Whether or not a poor connection occurred in the evaluation semiconductor device sample was determined by checking the cross section of the sample to confirm that the solder bumps were not wet, i.e., that the solder bumps of the semiconductor chip with solder bumps did not reach the connection portion of the opposing semiconductor chip.

It was confirmed that the semiconductor devices of Examples 1 to 4 all had a low void occurrence rate, suppressed void occurrence, and also showed appropriate connection resistance values and good connection reliability. In contrast, it was confirmed that the semiconductor device of Comparative Example 1 had a high void occurrence rate, and did not suppress void occurrence.

1...semiconductor chip (first member), 2...wired circuit board (second member), 15...wiring (second connection portion), 16...wiring (second connection portion), 30...bump (first connection portion), 32...bump (first connection portion or second connection portion), 33...bump (second connection portion), 40...adhesive, 40A...adhesive layer, 501...interposer (second member), 100, 200, 300, 400, 500...semiconductor device.

Claims (13)

A method for manufacturing a semiconductor device, comprising: connecting a first member having a first connection portion and a second member having a second connection portion via an adhesive layer; and electrically connecting the first connection portion and the second connection portion, the method comprising the steps of:
A temporary pressure-bonding process in which the first member and the second member are temporarily pressure-bonded to each other in a state in which the first connection portion and the second connection portion are arranged opposite each other via a thermosetting adhesive for forming the adhesive layer to obtain a temporary pressure-bonded body;
A temporary pressure-bonded body pressurizing step of pressurizing the temporary pressure-bonded body under a pressurized atmosphere to obtain a pressurized temporary pressure-bonded body;
and a final pressure bonding step of heating and pressurizing the pressurized temporary pressure-bonded body by a heat press sandwiched between a pair of final pressure-bonding members to pressure-bond the first member and the second member, thereby connecting the first connection portion and the second connection portion to obtain a pressure-bonded body,
In the temporary pressure bonding step, the first member and the second member are temporarily pressure bonded at a temperature lower than a melting point of the first connection portion and a melting point of the second connection portion,
In the temporary pressure-bonded body pressurizing step, the temporary pressure-bonded body is pressurized at a temperature lower than the melting point of the first connection portion and the melting point of the second connection portion,
A method for manufacturing a semiconductor device, wherein in the main pressure bonding step, the pressurized pre-pressure bonded body is heated to a temperature equal to or higher than a melting point of at least one of the first connection portion and the second connection portion. The method for manufacturing a semiconductor device according to claim 1, wherein in the temporary pressure bonding step, the temporary pressure bond is applied at a temperature lower than the reaction start temperature of the adhesive. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein in the temporary compression body pressurizing step, the temporary compression body is pressurized at a pressure of 0.05 to 0.8 MPa. The method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein in the temporary pressure-bonding body pressurizing step, the temporary pressure-bonding body is pressurized at a temperature equal to or higher than the reaction start temperature of the adhesive. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein the adhesive contains an epoxy resin, a hardener, and a fluxing agent, exhibits a minimum melt viscosity of 1500 Pa·s or less, and exhibits a gel time of 35 seconds or more and 80 seconds or less at 150°C. The method for manufacturing a semiconductor device according to claim 5, wherein the weight average molecular weight of the epoxy resin contained in the adhesive is less than 10,000. The adhesive further comprises a polymer component;
7. The method for manufacturing a semiconductor device according to claim 5, wherein the polymer component has a weight average molecular weight of 10,000 or more. The method for manufacturing a semiconductor device according to claim 7, wherein the weight average molecular weight of the polymer component is 30,000 or more, and the glass transition temperature of the polymer component is 200°C or less. The method for manufacturing a semiconductor device according to any one of claims 1 to 8, wherein the adhesive is a film-like adhesive. A thermosetting adhesive used to bond the first member and the second member in the method for manufacturing a semiconductor device according to any one of claims 1 to 4,
Contains epoxy resin, hardener and flux agent,
An adhesive having a minimum melt viscosity of 1500 Pa·s or less and a gel time of 35 seconds or more and 80 seconds or less at 150°C . The adhesive of claim 10 , wherein the epoxy resin has a weight average molecular weight of less than 10,000. The adhesive further comprises a polymer component;
The adhesive according to claim 10 or 11 , wherein the polymer component has a weight average molecular weight of 10,000 or more. The adhesive according to claim 12 , wherein the polymer component has a weight average molecular weight of 30,000 or more and a glass transition temperature of 200° C. or less.

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