JP7176532B2 - Semiconductor device, method for manufacturing semiconductor device, and adhesive - Google Patents

Description

The present invention relates to a semiconductor device, a method for manufacturing a semiconductor device, and an adhesive.

Conventionally, when connecting a semiconductor chip and a substrate, a wire bonding method using thin metal wires such as gold wires has been widely applied.

In recent years, in order to meet the demands for high functionality, high integration, high speed, etc. for semiconductor devices, conductive protrusions called bumps are provided as connection parts on a semiconductor chip or a wiring circuit board, and the semiconductor chip and wiring are connected by connecting the connection parts. A flip chip connection method (FC connection method) for directly connecting a circuit board or another semiconductor chip is widely adopted. For example, a COB (Chip On Board) type connection method for connection between a semiconductor chip and a printed circuit board is an FC connection method. The FC connection method is also widely used in a CoC (Chip On Chip) type connection method in which bumps or wires are provided as connection portions on semiconductor chips to connect between semiconductor chips.

In the FC connection method, in general, from the viewpoint of reliability of the connecting portion, the connecting portion is often metal-bonded with solder, tin, gold, silver, copper, or the like.

JP 2008-294382 A

In the assembly of FC connection type semiconductor devices, generally first, semiconductor chips are picked up from a diced semiconductor wafer by a collet and supplied to a pressing device. Next, the semiconductor chip is pressure-bonded to a wiring circuit board or another semiconductor chip by a pressing device. During crimping, the temperature of the pressing device is raised so that the metal of one or both of these connections reaches above its melting point so that a metallurgical bond is formed. Then, after cooling the high-temperature pressing device, the semiconductor chip is supplied to the pressing device again. A semiconductor adhesive may be supplied in advance on the semiconductor chip picked up by the collet. It is necessary to cool the semiconductor chip supplied with the adhesive to a low temperature that can be supplied.

Therefore, a semiconductor chip is temporarily pressure-bonded to a wiring circuit board or another semiconductor chip at a relatively low temperature using one pressing device, and the obtained temporarily pressure-bonded body is heated at a high temperature using a pressing device separate from the temporary pressure-bonding. By adopting a method of obtaining a connecting body in which the semiconductor chip is adhered to the wiring circuit board or other semiconductor chip and electrically connected to the wiring circuit board or another semiconductor chip by applying pressure while applying pressure, there is no need to repeat heating and cooling of the pressing device. It is expected that production efficiency will improve.

However, even such a method is not necessarily sufficient in terms of production efficiency. Continuous production of a large number of semiconductor devices requires a large number of pressing devices, thus limiting the improvement in production efficiency.

According to studies by the present inventors, a step of temporarily press-bonding a semiconductor chip and a substrate or another semiconductor chip at a relatively low temperature using a first pressing device, and a second pressing device separate from the first pressing device. using a pressing device to obtain a crimped body by applying pressure while heating at a temperature equal to or higher than the melting point of the metal of the connection portion of the semiconductor chip or substrate; and further heating the crimped body in a heating furnace. The method can further improve production efficiency. However, in the case of manufacturing a high-density, thin, and miniaturized semiconductor device by this method, there is a possibility that poor connection may occur or voids may remain in the adhesive. It was clarified by further examination by the authors. Since voids can cause a decrease in reliability, it is desirable to suppress voids.

Accordingly, an object of one aspect of the present invention includes bonding a semiconductor chip or a semiconductor wafer having a connection portion to another member having a connection portion via an adhesive and electrically connecting the connection portions. Another object of the present invention is to make it possible to efficiently manufacture a large number of semiconductor devices while suppressing the generation of voids in the adhesive and ensuring appropriate electrical connections in relation to a method of manufacturing semiconductor devices.

According to one aspect of the present invention, a first member having a connecting portion and a second member having a connecting portion are bonded to each other by a thermosetting adhesive between the melting point of the connecting portion of the first member and the second member. A step of obtaining a temporarily crimped body in which the connecting portion of the first member and the connecting portion of the second member are arranged to face each other by crimping at a temperature lower than the melting point of the connecting portion of the two members; By sandwiching the temporary pressure-bonded body between a pair of pressing members arranged to face each other, while heating to a temperature equal to or higher than the melting point of at least one of the connecting portion of the first member and the connecting portion of the second member Provided is a method for manufacturing a semiconductor device, comprising the steps of: obtaining a compressed body by applying pressure; and heating the compressed body in a pressurized atmosphere. The first member may be a semiconductor chip or a semiconductor wafer, and the second member may be a wiring circuit board, a semiconductor chip or a semiconductor wafer.

Here, in the present specification, the step of obtaining a temporary pressure-bonded body by pressure-bonding the first member and the second member via a thermosetting adhesive may be referred to as the "first pressure-bonding step". . A step of obtaining a crimped body by heating and pressurizing the temporary crimped body to a temperature equal to or higher than the melting point of at least one of the connecting portion of the first member and the connecting portion of the second member is referred to as a "second crimping step". Sometimes. The step of further heating the crimped body in a pressurized atmosphere may be referred to as a "third crimping step". By combining these three pressure bonding processes, it is possible to efficiently manufacture a large number of semiconductor devices while suppressing the generation of voids in the adhesive and ensuring proper electrical connections.

In the second pressure-bonding step of obtaining a pressure-bonded body by applying pressure while heating the temporary pressure-bonded body, the thermosetting adhesive is partially cured and the pressure-bonded body is heated in a pressurized atmosphere in the third pressure-bonding step. In, the thermosetting adhesive may be further cured. In this case, the thermosetting adhesive may be cured until the curing reaction rate is 30% or less in the second compression bonding step. Also, in the third pressure-bonding step, the thermosetting adhesive may be further cured until the curing reaction rate reaches 85% or higher.

In the third pressure-bonding step of heating the pressure-bonded bodies in a pressurized atmosphere, a plurality of pressure-bonded bodies may be heated collectively. The heating temperature in the third pressure-bonding step may be 130° C. or higher and 300° C. or lower.

The thermosetting adhesive may contain a thermosetting resin with a weight average molecular weight of less than 10,000, a curing agent for the thermosetting resin, and a polymer component with a weight average molecular weight of 10,000 or more.

Another aspect of the invention relates to thermosetting adhesives for use in the methods described above. The minimum melt viscosity of this adhesive may be 3000 Pa·s or less. Also, the thermosetting adhesive may be in the form of a film.

Still another aspect of the present invention comprises a first member having a connection portion, a second member having a connection portion, and an adhesive layer interposed therebetween, wherein the connection portion of the first member and a connection portion of a second member are electrically connected by metal bonding. The adhesive layer may be made of a cured thermosetting adhesive, and the lowest melt viscosity of the thermosetting adhesive may be 3000 Pa·s or less. A semiconductor device in which a first member is a semiconductor chip or a semiconductor wafer, and a second member is a wiring circuit board, a semiconductor chip or a semiconductor wafer.

One aspect of the present invention is a semiconductor device including bonding a semiconductor chip or a semiconductor wafer having a connection portion to another member having a connection portion via an adhesive and electrically connecting the connection portions to each other. It is possible to efficiently manufacture a large number of semiconductor devices while suppressing the generation of voids in the adhesive and ensuring appropriate electrical connections.

It is process drawing which shows one Embodiment of the process of pressure-bonding a 1st member and a 2nd member and obtaining a temporary pressure-bonded body. It is a process drawing which shows one Embodiment of the process of heating and pressurizing a temporary press-bonded body and obtaining a press-bonded body. It is a process drawing which shows one Embodiment of the process of heating a compression-bonding body in a pressurized atmosphere. It is a schematic cross section showing another embodiment of a semiconductor device. It is a schematic cross section showing another embodiment of a semiconductor device. It is a schematic cross section showing another embodiment of a semiconductor device. It is a schematic cross section showing another embodiment of a semiconductor device.

Several embodiments of the invention are described in detail below. However, the present invention is not limited to the following embodiments.

(Method for manufacturing semiconductor device)
1, 2 and 3 are process diagrams showing an embodiment of a method for manufacturing a semiconductor device. In the method according to the present embodiment, a first member having a connection portion and a second member having a connection portion are bonded to each other by a thermosetting adhesive between the melting point of the connection portion of the first member and the second member. a first crimping step of obtaining a temporarily crimped body in which the connecting portion of the first member and the connecting portion of the second member are arranged to face each other by crimping at a temperature lower than the melting point of the connecting portion of the member; , by sandwiching the temporary pressure-bonded body between a pair of pressing members arranged to face each other, the connecting portion of the first member or the connecting portion of the second member is heated to a temperature equal to or higher than the melting point of at least one; It includes a second compression step of obtaining a crimped body by pressing, and a third compression step of heating the crimped body in a pressurized atmosphere.

FIG. 1 shows a first pressure-bonding step of pressure-bonding a semiconductor chip 1 (first member) and a wiring circuit board 2 (second member) to obtain a temporary pressure-bonded body 4 . First, as shown in FIG. 1(a), a semiconductor chip 1 having a semiconductor chip body 10 and bumps 30 as connection portions is mounted on a printed circuit board 2 having a substrate body 20 and wiring 16 as connection portions. Then, the laminate 3 is formed by laminating them while disposing a thermosetting adhesive layer 40 therebetween. After being formed by dicing a semiconductor wafer, the semiconductor chip 1 is picked up and transported onto the wiring circuit board 2, and aligned so that the bumps 30 as connecting portions and the wiring 16 are arranged opposite to each other. The layered product 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 pressing members for temporary pressing that are arranged to face each other. The bumps 30 are provided on the wirings 15 provided on the semiconductor chip body 10 . The wiring 16 of the printed circuit board 2 is provided at a predetermined position on the board body 20 . The bumps 30 and the wirings 16 each have a surface made of a metal material.

The thermosetting adhesive layer 40 may be a layer formed by applying a film-like adhesive prepared in advance to the printed circuit board 2 . A film-like adhesive can be applied by hot pressing, roll lamination, vacuum lamination, or the like. The supply area and thickness of the adhesive layer are appropriately set according to the size of the semiconductor chip 1 or the wiring circuit board 2, the height of the connecting portion, and the like. A film adhesive may be attached to the semiconductor chip 1 . The semiconductor chips 1 to which the film-like adhesive is applied may be manufactured by applying the film-like adhesive to the semiconductor wafer and then dividing the semiconductor wafer into individual pieces by dicing the semiconductor wafer.

Subsequently, as shown in FIG. 1B, the laminate 3 is sandwiched between a stage 42 as a pressure member for temporary pressure and a pressure bonding head 41 to heat and press the semiconductor chip 1. The wiring circuit board 2 is temporarily pressure-bonded to obtain a temporary pressure-bonded body 4 . In the case of the embodiment of FIG. 1, the pressure bonding head 41 is arranged on the semiconductor chip 1 side, and the stage 42 is arranged on the wiring circuit board 2 side. A flip chip bonder or the like can be used as a pressing device for temporary pressing having a stage and a pressing head.

When at least one of the stage 42 and the pressure bonding head 41 heats and presses the laminate 3 for temporary pressure bonding, the melting point of the bumps 30 as the connection portions of the semiconductor chip 1 and the connection portion of the wiring circuit board 2 are It is heated to a temperature below the melting point of the wiring 16 . In this specification, the "melting point of the connecting part" means the melting point of the metal material forming the surface of the connecting part.

In the step of obtaining the temporary pressure-bonded body, the pressing member for temporary pressure is set to a low temperature so that heat is not transferred to the semiconductor chip or the like when picking up the semiconductor chip or the like as the first member. During the heating and pressing of the laminate for temporary pressure bonding, the pressing member for temporary pressure bonding may be heated to a certain high temperature in order to increase the fluidity of the adhesive layer to the extent that the voids that are involved can be eliminated. In order to shorten the cooling time, the difference between the temperature of the pressing member when picking up the semiconductor chip or the like and the temperature of the pressing member when heating and pressing the laminated body to obtain the temporary pressed body may be small. This temperature difference may be 100°C or less, or 60°C or less. This temperature difference may be constant. When the temperature difference is 100° C. or less or 60° C. or less, the time required for cooling the pressing member for temporary press can be shortened.

The temperature of the pressure member for temporary pressure bonding when heating and pressing the laminate to obtain the temporary pressure bonding body may be a temperature lower than the reaction initiation temperature of the adhesive layer. The reaction initiation temperature is measured using a DSC (PerkinElmer, DSC-Pyirs1) under the conditions of an adhesive sample amount of 10 mg, a heating rate of 10° C./min, and a measurement atmosphere of air or nitrogen. Refers to the On-set temperature in the DSC thermogram obtained.

From the above point of view, the temperature of the stage 42 and/or the pressure bonding head 41 when heating and pressurizing the laminated body to obtain the temporary pressure bonded body should be such that the adhesive adheres to the wiring circuit board or the semiconductor wafer and can be set to a temperature at which the curing reaction does not proceed. From this point of view, the temperature of the stage 42 and/or the pressure bonding head 41 when heating and pressing the laminate to obtain the temporary pressure bonded body may be 140° C. or less, 110° C. or less, or 80° C. or less, It may be 25°C or higher. Even if the first compression bonding step is performed at a low temperature in this way, it is possible to obtain a semiconductor device with sufficient void suppression and connection through the subsequent second compression bonding step and third compression bonding step. can.

The pressure load for pressing the laminated body 3 to obtain the temporary pressure-bonded body 4 is appropriately set in consideration of the number of bumps, absorption of height variations of the bumps, and control of the amount of bump deformation. In the temporary pressure-bonded body 4, the connection portion (bump 30) of the semiconductor chip 1 and the connection portion (wiring 16) of the wiring circuit board 2 may be in contact with each other. As a result, metal bonding is likely to be formed in subsequent steps, and there is a tendency for the adhesive to be less likely to get caught. From the viewpoint of sufficiently contacting the connecting portions, the pressing load for pressing the laminate 3 to obtain the temporary pressure-bonded body 4 is, for example, 0.009 to 0.009 to 0.009 for each bump 30 of the semiconductor chip 1 . It may be 2N.

From the viewpoint of improving productivity, the time for which the laminate 3 is pressed to obtain the temporary pressure-bonded body 4 may be 5 seconds or less, 3 seconds or less, or 1 second or less, or 0.5 seconds or more. good too.

FIG. 2 shows a second pressure-bonding step of obtaining a pressure-bonded body 6 by applying pressure while heating the temporary pressure-bonded body 4 . As shown in FIGS. 2(a) and 2(b), a pressing device 46 having a pressing head 44 and a stage 45 as a pressing member for main pressing, which is prepared separately from the pressing device 43, is used. to heat and pressurize the temporary pressure-bonded body 4 . The temporary pressure bonding body 4 is heated and pressurized by being sandwiched between the stage 45 and the pressure bonding head 44 . In the case of the embodiment of FIG. 2, the pressure bonding head 44 is arranged on the semiconductor chip 1 side of the temporary pressure bonding body 4 , and the stage 45 is arranged on the wiring circuit board 2 side of the temporary pressure bonding body 4 .

When at least one of the stage 45 and the pressure-bonding head 44 heats and presses the temporary pressure-bonding body 4, the melting point of the bumps 30 serving as the connection portions of the semiconductor chip 1 or the temperature of the wiring 16 serving as the connection portions of the wiring circuit board 2 is reduced. It is heated to a temperature equal to or higher than at least one of the melting points.

The second crimping step may generally remove the oxide film on the connection surface. Therefore, the temperature of the stage 45 and/or the pressure bonding head 44 (that is, the heating temperature in the second pressure bonding step) can be set to a temperature higher than the temperature at which the oxide film on the surface of the connecting portion is efficiently removed. From this point of view, the heating temperature in the second pressure-bonding step may be 220° C. or higher and 330° C. or lower. When the metal material of the connecting portion contains solder, if the heating temperature in the second crimping step is 220° C. or higher, the solder of the connecting portion will melt and a sufficient metallic bond will easily be formed. When the temperature is 330° C. or less, voids are less likely to occur and solder is less likely to scatter. The heating temperature in the second crimping step may be 220°C or higher even when the metal material of the connecting portion contains Sn/Ag with a melting point of about 220°C.

The pressure load in the second pressure bonding step is appropriately set in consideration of the removal of the oxide film on the surface of the connecting portion, the number of bumps, the absorption of variations in height of the bumps, the control of the amount of bump deformation, and the like. When 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 connection portion (bump) of the semiconductor chip. When the pressing load is 0.009 N or more, the oxide film formed on the connecting portion is easily removed, and the adhesive is less likely to be trapped in the connecting portion. Further, when the pressing load is 0.2 N or less, problems such as crushing or scattering of bumps containing solder or the like are less likely to occur.

The adhesive may be partially cured by the second pressing step to the extent that it has some degree of fluidity in the third pressing step of heating the pressed body under a pressurized atmosphere. Voids remaining in the adhesive layer can be further suppressed by causing the adhesive to flow in contact with the adhesive to some extent in the third press-bonding step. Further, by setting the heat history applied to the adhesive in the second press-bonding process to such an extent that the curing reaction rate remains small, it is possible to suppress the formation of fillets around the connecting portion. From these points of view, the curing reaction rate of the adhesive after the second pressure bonding step may be 50% or less, 30% or less, 27% or less, or 25% or less.

The curing reaction rate of the adhesive after the second pressing step is determined based on the change in exotherm due to the curing reaction as measured by differential scanning calorimetry. Let ΔH0 be the amount of heat generated by the curing reaction of the adhesive before the first pressure-bonding process, and ΔH2 be the amount of heat generated by the curing reaction after the second pressure-bonding process. , the curing reaction rate after the second compression step can be calculated by the following formula. Here, the curing reaction rate of the adhesive that is subjected to the first pressure-bonding step is considered to be 0%.
Curing reaction rate (%) after the second compression step = (ΔH0-ΔH2)/ΔH0×100
Differential scanning calorimetry for measuring the amount of heat generated by the curing reaction can be performed at a temperature increase rate of 20°C/min and a temperature range of 30 to 300°C. Instead of the actual crimping process, a hot plate, an oven, etc. are used to measure the curing reaction rate using the adhesive after applying heat history under the same conditions as the first crimping process and the first crimping process. By doing so, it is possible to estimate the curing reaction rate after the second pressure-bonding step.

The curing reaction rate after the second crimping step can be adjusted primarily based on the time of heating and pressing. For example, if the heating and pressurizing time in the second pressure bonding step is 3 seconds or less, or 1 second or less, the curing reaction rate becomes, for example, 50% or less, 30% or less, 27% or less, or 25% or less. Allow the adhesive to cure up to

The pressing member for temporary crimping and the pressing member for crimping may each be installed in two or more separate devices, or both may be installed in one device.

Subsequently, as shown in FIG. 3, the semiconductor device 100 is obtained through a third pressure-bonding step of heating the pressure-bonded body 6 in a pressurized atmosphere in a heating furnace 60 . A plurality of crimping bodies 6 can be collectively heated in one heating furnace 60 . If a pressing member is used to pressurize a plurality of pressure-bonded bodies at once, it is difficult to uniformly heat the plurality of pressure-bonded bodies. In contrast, a heating furnace can easily and uniformly heat a large number of pressure-bonded bodies, thereby improving productivity. As the heating furnace, a reflow furnace, a pressure oven, or the like can be used.

When the crimped body is heated in a pressurized atmosphere, fillets tend to be suppressed compared to the case where the crimped body is heated and pressurized using a pressing member. Fillet suppression is particularly important in the manufacture of miniaturized and densely packed semiconductor devices. Here, suppressing the fillet means suppressing the fillet width, and the fillet width is the length of the adhesive protruding to the outer peripheral portion of the semiconductor device. For example, the fillet width can be measured on the obtained image by photographing an external image of the semiconductor device with a digital microscope (manufactured by KEYENCE, VHX-5000). The length (fillet width) of the adhesive layer protruding from the four sides of the semiconductor chip is measured, and the average value is obtained as the fillet value. The fillet value may be 150 μm or less from the viewpoint of mounting many semiconductor chips or the like on a semiconductor wafer, wiring circuit board or the like.

The pressurized body is heated while the inside of the heating furnace 60 is in a pressurized atmosphere. As used herein, "pressurized atmosphere" means a gaseous atmosphere having an atmospheric pressure or higher. The pressure inside the heating furnace 60 may be 0.1 MPa or more and 0.8 MPa or less, or 0.2 MPa or more and 0.5 MPa or less. When the air pressure is 0.1 MPa or more, the voids disappear particularly effectively. If the atmospheric pressure is 0.8 MPa or less, problems such as increased warping of the semiconductor device are less likely to occur.

The heating temperature (atmospheric temperature in the heating furnace 60) in the third pressure-bonding step may be a temperature at which the adhesive melts or a temperature equal to or higher than the glass transition temperature (Tg) of the adhesive. may be the temperature at which The ambient temperature in the heating furnace 60 may be, for example, 130° C. or higher and 300° C. or lower, or 140° C. or higher and 270° C. or lower. When this temperature is 130° C. or higher, the adhesive tends to be appropriately cured while having some fluidity, and voids tend to be particularly effectively suppressed by pressurization. When the temperature is 300° C. or lower, voids are particularly suppressed, and warping of the semiconductor device is less likely to occur. When raising the temperature of the atmosphere in the heating furnace 60 as described later, the maximum temperature may be within the above range.

The time for heating and pressing in the third press-bonding step is set to such an extent that the curing of the adhesive progresses sufficiently. For example, the time during which the ambient temperature in the heating furnace 60 is 130° C. or higher and 300° C. or lower may be 1 minute or longer and 120 minutes or shorter, or 5 minutes or longer and 60 minutes or shorter.

The atmosphere in the heating furnace 60 may be heated during the third crimping step. The rate of temperature increase in that case is not particularly limited, but may be 5° C./minute or more and 300° C./minute or less, or 10° C./minute or more and 250° C./minute or less. When the heating rate is 5° C./min or more, productivity tends to improve and voids tend to disappear particularly effectively. When the heating rate is 300° C./min or less, problems such as void generation due to rapid temperature rise are less likely to occur.

The adhesive is further cured by the third press-bonding step, and the semiconductor chip 1 (first member) and the wiring circuit board 2 (second member) are firmly bonded together by the cured adhesive layer 40. (Semiconductor device 100) can be formed. The curing reaction rate of the adhesive after the third crimping step may be 80% or more, 85% or more, or 90% or more. When the curing reaction rate of the adhesive after the third pressure-bonding step is 80% or more, the generation of voids due to springback or the like can be more effectively suppressed.

The curing reaction rate of the adhesive after the third crimping step is also determined based on the change in exotherm due to the curing reaction as measured by differential scanning calorimetry. Let ΔH0 be the amount of heat generated by the curing reaction of the adhesive before the first pressure-bonding step, and ΔH3 be the amount of heat generated by the curing reaction after the third pressure-bonding step. , the curing reaction rate after the second compression step can be calculated by the following formula.
Curing reaction rate (%) after the third compression step = (ΔH0-ΔH3)/ΔH0×100
The conditions for differential scanning calorimetry are the same as for determining the curing reaction rate after the second pressing step.

The atmosphere in the heating furnace 60 is not particularly limited, but may be air, nitrogen, formic acid, or the like.

From the viewpoint of improving productivity, a semiconductor wafer may be used as at least one of the first member and the second member. Examples thereof include CoW (Chip On Wafer) in which a semiconductor wafer is singulated after connecting a semiconductor chip thereto, and WoW (Wafer On Wafer) in which semiconductor wafers are press-bonded to each other and then singulated.

(semiconductor device)
4, 5, 6 and 7 are cross-sectional views respectively showing another embodiment of a semiconductor device that can be manufactured by the method according to the above embodiments.

A semiconductor device 200 shown in FIG. 4 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 interposed therebetween. and an agent layer 40 . In the case of the semiconductor device 200, the semiconductor chip has bumps 32 arranged on the surface of the semiconductor chip on the wiring circuit board 2 side as a connecting portion. The printed circuit board 2 has bumps 33 arranged on the surface of the substrate body 20 on the semiconductor chip side as connection portions. The bumps 32 of the semiconductor chip 1 and the bumps 33 of the printed circuit board 2 are electrically connected by metal bonding. That is, the semiconductor chip 1 and the printed circuit board 2 are flip-chip connected by the bumps 32 and 33 . The bumps 32 and 33 are sealed with an adhesive layer 40 to be isolated from the external environment.

5 and 6 show a CoC type semiconductor device, which is a connecting body in which semiconductor chips are connected to each other. The configuration of the semiconductor device 300 shown in FIG. 5 is the same as that of the semiconductor device 100 except that two semiconductor chips are flip-chip connected as a first member and a second member via wiring 15 and bumps 30. is. The configuration of a semiconductor device 400 shown in FIG. 6 is the same as that of the semiconductor device 200 except that two semiconductor chips 1 are flip-chip connected via bumps 32 .

In the semiconductor devices 100, 200, 300, and 400 shown in FIGS. 3 to 6, the connection portions such as the wiring 15 and the bumps 32 may be metal films (for example, gold plating) called pads, and post electrodes. (eg, copper pillars). For example, in (b) of FIG. 2, even if one semiconductor chip has copper pillars and connection bumps (solder: tin-silver) as connection portions, and the other semiconductor chip has gold plating as connection portions, good. In this case, it is sufficient that the connecting portion reaches a temperature equal to or higher than the melting point of solder, which has the lowest melting point among the metal materials forming the surface of the connecting portion.

The semiconductor chip body 10 is not particularly limited, and various semiconductors such as elemental semiconductors composed of the same type of elements such as silicon and germanium, and compound semiconductors such as gallium arsenide and indium phosphide can be used.

The wiring circuit board 2 is not particularly limited, and has an insulating board whose main component is glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimide triazine, or the like as a board body, and a metal layer formed on the surface thereof. A circuit board on which wiring (wiring pattern) is formed by removing unnecessary parts by etching, a circuit board on which wiring (wiring pattern) is formed by metal plating or the like on the surface of the insulating substrate, and a conductive surface on the surface of the insulating substrate A circuit board or the like on which a wiring (wiring pattern) is formed by printing a material can be used.

The materials of the connection portions such as the wirings 15 and 16, the bumps 30, and the bumps 32 and 33 include gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, etc.). , tin-copper, tin-silver-copper), tin, nickel and the like are used. The connecting portion may consist of only a single component, or may consist of a plurality of components. The connection part may have a structure in which these metals are laminated. Among metal materials, copper and solder are relatively inexpensive. From the viewpoint of improving connection reliability and suppressing warpage, the connecting portion may contain solder.

Materials of the pad include gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper), tin and nickel. etc. are used. The pad may consist of only a single component, or it may consist of multiple components. The pad may have a structure in which these metals are laminated. From the viewpoint of connection reliability, the pads may contain gold or solder.

Gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. are mainly used on the surfaces of the wirings 15 and 16 (wiring patterns). A component metal layer may be formed. This metal layer may consist of only a single component, or it may consist of a plurality of components. The metal layer may have a structure in which a plurality of metal layers are laminated. Metal layers may include relatively inexpensive copper or solder. From the viewpoint of improving connection reliability and suppressing warpage, the metal layer may contain solder.

Semiconductor devices (packages) such as the semiconductor devices 100, 200, 300, and 400 are stacked, gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin- Copper, tin-silver-copper), tin, nickel, or the like may be used for electrical connection. The metal for connection may be relatively inexpensive copper or solder. For example, adhesive layers may be interposed between the semiconductor chips, flip-chip bonded or laminated, such as in TSV technology, to form holes through the semiconductor chips and connect to electrodes on the pattern surface.

FIG. 7 is a cross-sectional view showing another embodiment of the semiconductor device. A semiconductor device 500 shown in FIG. 7 has a TSV structure in which a plurality of semiconductor chips are stacked. In the semiconductor device 500 shown in FIG. 7, the wires 15 formed on the interposer main body 50 as a wiring circuit board are connected to the bumps 30 of the semiconductor chip 1, so that the semiconductor chip 1 and the interposer 5 are flip-chipped. It is connected. An adhesive layer 40 is interposed between the semiconductor chip 1 and the interposer 5 . The semiconductor chip 1 is repeatedly laminated on the surface of the semiconductor chip 1 opposite to the interposer 5 via the wiring 15 , the bump 30 and the adhesive layer 40 . The wirings 15 on the pattern surfaces on the front and back of the semiconductor chip 1 are connected to each other by through-electrodes 34 filled in holes penetrating through the interior of the semiconductor chip body 10 . Copper, aluminum, or the like can be used as the material of the through electrode 34 .

According to a semiconductor device having a TSV (Through-Silicon Via) structure as illustrated in FIG. 7, signals can be acquired even from the back surface of the semiconductor chip, which is not normally used. Furthermore, since the through electrodes 34 are vertically passed through the semiconductor chip 1, the distance between the opposing semiconductor chips 1 and the distance between the semiconductor chip 1 and the interposer 5 can be shortened to enable flexible connection.

In the case of the semiconductor device 500 of FIG. 7, a plurality of semiconductor chips 1 are stacked one by one and temporarily crimped sequentially, then a crimped body is obtained by a second crimping step, and finally the plurality of semiconductor chips are collectively pressed. You may heat under atmosphere.

Another example of a semiconductor device having multilayer semiconductor chips is a chip stack type package, POP (Package On Package), which can also be manufactured by the same method as TSV.

These are also effective in reducing the mounting area, improving functionality, reducing noise, and saving power by further miniaturizing and thinning the semiconductor device.

(glue)
Adhesives (thermosetting adhesives) that can be used in the above-described method for manufacturing a semiconductor device will be described below.

An adhesive according to one embodiment contains a thermosetting resin and its curing agent. The adhesive may further contain a polymer component with a weight average molecular weight of 10,000 or more.

<Thermosetting resin>
The weight average molecular weight of the thermosetting resin may be less than 10,000. The thermosetting resin having a weight-average molecular weight of less than 10,000 reacts with the curing agent, thereby improving the curability of the adhesive. It is also advantageous in terms of void suppression and heat resistance.

Thermosetting resins include, for example, epoxy resins and acrylic resins.

Epoxy resins are not particularly limited as long as they have two or more epoxy groups in the molecule. As the epoxy resin, bisphenol A type, bisphenol F type, naphthalene type, phenol novolak type, cresol novolak type, phenol aralkyl type, biphenyl type, triphenylmethane type, dicyclopentadiene type, various polyfunctional epoxy resins, etc. can be used. can be done. These can be used singly or as a mixture of two or more.

The acrylic resin is not particularly limited as long as it has one or more (meth)acrylic groups in its molecule. Examples of acrylic resins include bisphenol A type, bisphenol F type, naphthalene type, phenol novolak type, cresol novolak type, phenol aralkyl type, biphenyl type, triphenylmethane type, dicyclopentadiene type, fluorene type, adamantane type, and various other types. A functional acrylic resin or the like can be used. These can be used singly or as a mixture of two or more. As used herein, the term "(meth)acryl group" means either an acryl group or a methacryl group.

The acrylic resin may be solid at room temperature (25° C.). Solid adhesives are less prone to voids than liquid adhesives, and tend to be easier to handle because the B-stage adhesive has less viscosity (tack) before curing.

The number of (meth)acrylic groups possessed by the acrylic resin may be 3 or less per molecule. When the number of (meth)acrylic groups is 3 or less, curing tends to proceed sufficiently in a short time until the number of remaining unreacted groups is reduced.

The content of the thermosetting resin in the adhesive is, for example, 10 to 50 parts by mass with respect to 100 parts by mass of the total mass of the adhesive (the mass of components other than the solvent). When the content of the thermosetting resin is 10 parts by mass or more, there is a tendency that the flow of the adhesive after curing can be easily controlled. When the content of the thermosetting resin is 50 parts by mass or less, warping of the semiconductor device tends to be suppressed.

<Curing agent>
The curing agent can be a compound that reacts with the thermoset, a compound that functions as a catalyst for the curing reaction of the thermoset, or a combination thereof. Examples of curing agents include phenol resin curing agents, acid anhydride curing agents, amine curing agents, imidazole curing agents, phosphine curing agents, azo compounds, and organic peroxides. Among these, imidazole curing agents may be used.

The phenolic resin-based curing agent is not particularly limited as long as it has two or more phenolic hydroxyl groups in the molecule. Examples include triphenylmethane type polyfunctional phenol and various polyfunctional phenol resins. These can be used alone or as a mixture of two or more.

The equivalent ratio of the phenolic resin-based curing agent to the thermosetting resin (phenolic hydroxyl group/epoxy group, molar ratio) is 0.3 to 1.5, 0 from the viewpoint of good curability, adhesion and storage stability. .4 to 1.0, or 0.5 to 1.0. When the equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be improved. It tends to be kept low and insulation reliability improves.

Acid anhydride-based curing agents include, for example, 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.

The equivalent ratio of the acid anhydride curing agent to the thermosetting resin (acid anhydride group/epoxy group, molar ratio) is 0.3 to 1.5 from the viewpoint of good curability, adhesion and storage stability. , 0.4 to 1.0, or 0.5 to 1.0. When the equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be improved. It tends to be kept low and insulation reliability improves.

Dicyandiamide, for example, can be used as the amine curing agent.

The equivalent ratio (amine/epoxy group, molar ratio) of the amine curing agent to the thermosetting resin is 0.3 to 1.5, 0.4 to 1 from the viewpoint of good curability, adhesion and storage stability. .0, or 0.5 to 1.0. When the equivalent ratio is 0.3 or more, the curability tends to improve and the adhesive strength tends to improve, and when it is 1.5 or less, unreacted amine does not remain excessively, and insulation reliability improves. tend to

Examples of imidazole 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 isocyanurate Acid adducts, 2-phenylimidazole isocyanuric acid adducts, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins and imidazoles mentioned. From the viewpoint of excellent curability, 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-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct , 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole. These can be used alone or in combination of two or more. Microcapsules containing these can also be used as latent curing agents.

The content of the imidazole-based curing agent may be 0.1 to 20 parts by mass, or 0.1 to 10 parts by mass with respect to 100 parts by mass of the thermosetting resin. When the content of the imidazole-based curing agent is 0.1 parts by mass or more, the curability tends to be improved, and when the content is 20 parts by mass or less, the adhesive does not harden before metal bonding is formed. Poor connection tends to be less likely to occur.

Phosphine-based curing agents include, for example, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra(4-methylphenyl)borate and tetraphenylphosphonium(4-fluorophenyl)borate.

The content of the phosphine-based curing agent may be 0.1 to 10 parts by mass, or 0.1 to 5 parts by mass with respect to 100 parts by mass of the thermosetting resin. When the content of the phosphine-based curing agent is 0.1 parts by mass or more, the curability tends to be improved. Poor connection tends to be less likely to occur.

The phenolic resin-based curing agent, acid anhydride-based curing agent, and amine-based curing agent can be used singly or as a mixture of two or more thereof. The imidazole-based curing agent and the phosphine-based curing agent may be used alone, or may be used together with a phenol resin-based curing agent, an acid anhydride-based curing agent, or an amine-based curing agent.

Examples of organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and peroxyesters. From the viewpoint of storage stability, hydroperoxide, dialkyl peroxide, or peroxyester may be selected. Furthermore, from the viewpoint of heat resistance, hydroperoxide or dialkyl peroxide may be selected. These can be used singly or as a mixture of two or more.

The content of the organic peroxide may be 0.5 to 10% by mass, or 1 to 5% by mass relative to the acrylic resin. When the content of the organic peroxide is 0.5% by mass or more, curing tends to proceed sufficiently. When the content of the organic peroxide is 10% by mass or less, there is a tendency to suppress deterioration in reliability due to shortening of the molecular chain after curing and remaining unreacted groups.

There are no particular restrictions on the curing agent that can be used in combination with the epoxy resin or acrylic resin as long as the curing progresses. Curing agents that can be combined with epoxy resins include, from the viewpoint of handling, storage stability, and curability, a combination of a phenolic resin curing agent and an imidazole curing agent, a combination of an acid anhydride curing agent and an imidazole curing agent, and an amine curing agent. A combination of a hardener and an imidazole hardener, or an imidazole hardener alone may be used. Imidazole-based curing agents having excellent rapid curing properties may be used alone, since connecting in a short time improves productivity. Curing in a short period of time can suppress volatile components such as low-molecular-weight components, so voids can also be suppressed. The curing agent to be combined with the acrylic resin may be an organic peroxide from the viewpoint of handleability and storage stability.

<Polymer Component with Weight Average Molecular Weight of 10,000 or More>
The polymeric component with a weight average molecular weight of 10,000 or greater can be a thermosetting resin, a thermoplastic resin, or a combination thereof. Examples of polymer components include epoxy resins, phenoxy resins, polyimide resins, polyamide resins, polycarbodiimide resins, cyanate ester resins, acrylic resins, polyester resins, polyethylene resins, polyethersulfone resins, polyetherimide resins, and polyvinyl acetal resins. , urethane resin, and acrylic rubber. Epoxy resins, phenoxy resins, polyimide resins, acrylic resins, acrylic rubbers, cyanate ester resins, or polycarbodiimide resins, which are excellent in heat resistance and film-forming properties, may be selected. Epoxy resins, phenoxy resins, polyimide resins, acrylic resins, or acrylic rubbers, which are excellent in heat resistance and film formability, may be selected. These polymer components can be used alone or as a mixture or copolymer of two or more. The polymer component having a weight average molecular weight of 10,000 or more may be a thermosetting resin that reacts with a curing agent.

The mass ratio between the polymer component and the epoxy resin as the thermosetting resin is not particularly limited. The mass ratio of epoxy resin to polymer component may be 0.01-5, 0.05-4, or 0.1-3 so that the adhesive retains its film-like form. When this mass ratio is 0.01 or more, there is a tendency that the curability is improved and the adhesive force is further improved. When this mass ratio is 5 or less, good film formability is likely to be obtained.

The mass ratio of the polymer component and the acrylic resin as the thermosetting resin is not particularly limited. The weight ratio of acrylic resin to polymeric component may be 0.01-10, 0.05-5, or 0.1-5. When this mass ratio is 0.01 or more, there is a tendency that the curability is improved and the adhesive force is further improved. When this mass ratio is 10 or less, good film formability is likely to be obtained.

The glass transition temperature (Tg) of the polymer component may be 50° C. or higher and 200° C. or lower from the viewpoint of excellent adhesion of the adhesive to a wiring circuit board or a semiconductor chip. If the polymer component has a Tg of 50° C. or higher, the tackiness (viscosity) of the adhesive tends to be moderately weak. When the polymer component has a Tg of 200° C. or less, the adhesive tends to easily fill bumps of a semiconductor chip, electrodes and wiring patterns formed on a wiring circuit board, and the effect of suppressing voids tends to be relatively large. There is Here, Tg is measured using a DSC (manufactured by PerkinElmer Co., Ltd., Model DSC-7) under the conditions of a sample amount of 10 mg, a heating rate of 10° C./min, and an air atmosphere.

The weight average molecular weight of the polymer component is 10,000 or more. The weight average molecular weight of the polymer component may be 30,000 or more, 40,000 or more, 50,000 or more, or 500,000 or less in order to exhibit good film formability by itself. As used herein, the weight average molecular weight means a value measured by gel permeation chromatography (GPC) and converted to standard polystyrene.

The adhesive can contain a flux activator, which is a compound that exhibits flux activity (activity to remove oxides and impurities). Flux activators include nitrogen-containing compounds having unshared electron pairs such as imidazoles and amines, carboxylic acids, phenols and alcohols. Compared to alcohols and the like, organic acids exhibit stronger flux activity and improve connectivity.

The organic acid that can be used as a flux activator may be a carboxylic acid, since the acid hardly remains in the adhesive by reacting with an epoxy resin or the like. The carboxylic acid may be solid from the viewpoint of heat resistance. The melting point of the carboxylic acid may be 70° C. or higher and 150° C. or lower from the viewpoint of stability and handleability.

In order to control the viscosity and physical properties of the cured product, and to suppress the occurrence of voids and moisture absorption when connecting semiconductor chips or a semiconductor chip and a wiring circuit board, the adhesive may contain a filler. good. The filler may be an insulating inorganic filler, examples of which include glass, silica, alumina, titanium oxide, carbon black, mica, boron nitride, and the like. Among these, a filler selected from silica, alumina, titanium oxide and boron nitride, or silica, alumina and boron nitride may be used. Fillers may be whiskers, examples of which include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, boron nitride. The filler may be a resin filler, examples of which include polyurethane, polyimide, methyl methacrylate resin, methyl methacrylate-butadiene-styrene copolymer resin (MBS). These fillers can be used alone or in combination of two or more. The shape, particle size and content of the filler are not particularly limited.

Compared to inorganic fillers, resin fillers can impart flexibility at high temperatures such as 260° C., and are therefore suitable for improving reflow resistance. The resin filler is also advantageous in terms of improving film formability.

From the viewpoint of insulation reliability, the filler may be insulating. The adhesive may not substantially contain conductive metal fillers such as silver fillers and solder fillers.

From the viewpoint of improving dispersibility and adhesive strength, the filler may be surface-treated. The filler is surface-treated with, for example, a glycidyl-based (epoxy-based), amine-based, phenyl-based, phenylamino-based, (meth)acrylic-based, or vinyl-based surface treating agent. From the viewpoint of dispersibility, fluidity, and adhesive strength, the filler may be surface-treated with a glycidyl-based, phenylamino-based, or (meth)acrylic-based surface treatment agent. From the viewpoint of storage stability, the surface treatment agent may be phenyl, acrylic, or (meth)acrylic. For ease of surface treatment, the surface treatment agent may be a silane compound such as an epoxysilane, aminosilane, or acrylsilane compound.

The average particle size of the filler may be 1.5 μm or less from the viewpoint of preventing entrapment during flip-chip bonding, and may be 1.0 μm or less from the viewpoint of visibility and transparency.

The filler content may be 30 to 90% by mass, or 40 to 80% by mass, based on the solid mass of the adhesive (the mass of components other than the solvent). When the filler content is 30% by mass or more, the heat dissipation tends to be high, and voids tend to occur and the moisture absorption tends to decrease. When the filler content is 90% by mass or less, the adhesive has appropriate fluidity, and there is a tendency to suppress deterioration in connection reliability due to filler biting (trapping) into the connection portion.

The adhesive may further include other ingredients such as ion trappers, antioxidants, silane coupling agents, titanium coupling agents, and leveling agents. These may be used individually by 1 type, and may be used in combination of 2 or more types. The blending amounts of these additives may be appropriately adjusted so that the effects of each additive are exhibited.

From the viewpoint of void suppression, the minimum melt viscosity of the adhesive may be 3000 Pa·s or less, 2700 Pa·s or less, or 300 Pa·s or more. The minimum melt viscosity of the adhesive is the viscosity (complex viscosity ) is the lowest viscosity value in the relationship between ) and temperature. As a test piece for viscoelasticity measurement, for example, a laminate obtained by laminating a plurality of film adhesives to a thickness of 300 to 450 μm may be used. As a viscosity measuring device, for example, ARES G2 manufactured by TA can be used.

The adhesive may be in the form of a film from the viewpoint of improving the production efficiency of semiconductor devices. A film-like adhesive can be produced by a method of applying a resin varnish containing a thermosetting resin, a curing agent, and optionally other components to a material film and drying the coating film.

The resin varnish is prepared by mixing a thermosetting resin curing agent and, if necessary, other components with an organic solvent and dissolving or dispersing them by stirring or kneading. The resin varnish is applied onto the release-treated substrate film using, for example, a knife coater, roll coater, applicator, die coater, or comma coater. After that, the organic solvent is reduced from the coating film of the resin varnish by heating, that is, the coating film is dried to form a film-like adhesive on the substrate film. A film of resin varnish may be formed on a semiconductor wafer or the like by a method such as spin coating, and then a film-like adhesive may be formed on the semiconductor wafer by drying the coating film.

The base film is not particularly limited as long as it has heat resistance that can withstand the heating conditions when volatilizing the organic solvent. An ether naphthalate film, a methylpentene film, etc. can be illustrated. The base film is not limited to a single layer made of these films, and may be a multi-layered film made of two or more materials.

Specifically, the conditions for volatilizing the organic solvent from the applied resin varnish may be heating at 50 to 200° C. for 0.1 to 90 minutes. The organic solvent may be removed until the residual amount is 1.5% by mass or less within a range that does not substantially affect voids after mounting and viscosity control.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Study 1
(1-1) Film Adhesive A film adhesive (thickness: 0.045 mm) having the composition shown in Table 1 was prepared using the materials shown below.
(i) a thermosetting resin (epoxy resin) having a weight average molecular weight of less than 10,000
・Triphenolmethane skeleton-containing polyfunctional solid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: EP1032H60, weight average molecular weight: 800 to 2000)
- Bisphenol F type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: YL983U, weight average molecular weight: about 336)
・ Flexible semi-solid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: YL7175-1000, weight average molecular weight: 1000 to 5000)
(ii) curing agent 2,4-diamino-6-[2′-methylimidazolyl-(1′)]-ethyl-s-triazine isocyanurate adduct (manufactured by Shikoku Kasei Kogyo Co., Ltd., product name: 2MAOK-PW )
(iii) Polymer component with a weight-average molecular weight of 10,000 or more Phenoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., product name: ZX1356-2, Tg: about 71°C, weight-average molecular weight: about 63000, hereinafter referred to as "ZX1356".)
(iv) fluxing agent (carboxylic acid)
・ 2-Methylglutaric acid (manufactured by Sigma-Aldrich, melting point about 77 ° C.)
(v) filler (inorganic filler)
・ Silica filler (manufactured by Admatechs Co., Ltd., product name: SE2050, average particle size 0.5 μm)
・ Finil surface-treated nano silica filler (manufactured by Admatechs Co., Ltd., product name: YA050C-SP (hereinafter referred to as “SP nano silica”), average particle size of about 50 nm)
(resin filler)
・ Organic filler (manufactured by Dow Chemical Japan Co., Ltd., product name: EXL-2655, core-shell type organic fine particles)

(1-2) Fabrication of semiconductor device (Example 1)
First Compression Bonding Step The produced film-like adhesive was cut out to prepare a film-like adhesive having a size of 8 mm×8 mm×0.045 mm in thickness. This was attached to a semiconductor chip (10 mm, thickness 0.1 mm, connection metal: Au, product name: WALTS-TEG IP80, manufactured by WALTS). There, a semiconductor chip with solder bumps (chip size: 7.3 mm × 7.3 mm × thickness 0.05 mm, solder bump melting point: about 220°C, bump height: about 45 μm in total for copper pillars and solder, number of bumps: 1048 Pins, pitch 80 um, product name: WALTS-TEG CC80, manufactured by WALTS) were attached to obtain a laminate. The laminate is placed on the stage of a flip chip bonder (FCB3, manufactured by Panasonic Corporation) having a stage and a crimping head, and the laminate is pressed with a load of 25 N for 1 second by a heat press sandwiched between the stage and the crimping head. While heating to 80° C., a temporary press-bonded body was obtained.

Second crimping step The obtained temporary crimped body is moved onto the stage of another flip chip bonder (FCB3, manufactured by Panasonic Corporation), and sandwiched between the stage and the crimping head to apply a load of 25 N to 230. A press-bonded body was obtained by hot pressing with heating at °C for 1 second.

Third crimping step The crimped body was placed in the oven of a pressure reflow device (manufactured by Shinapex, product name: VSU28). The pressure inside the oven was set to 0.4 MPa, and the temperature was raised from room temperature to 175° C. at a temperature elevation rate of 20° C./min. Next, while maintaining the pressure and temperature, the compressed body was heated under a pressurized atmosphere for 10 minutes to obtain a semiconductor device sample for evaluation.

(Example 2)
A semiconductor device sample for evaluation was obtained in the same manner as in Example 1, except that the heating temperature for heating the pressure-bonded body in the oven of the pressure reflow device was changed from 175°C to 260°C.

(Comparative example 1)
A temporarily pressed body was obtained in the same manner as in Example 1. The resulting temporary press-bonded body was heated at 175° C. for 10 minutes under atmospheric pressure in an oven (manufactured by Yamato Scientific Co., Ltd., product name: DKN402) to obtain a semiconductor device sample for evaluation.

(Comparative example 2)
A semiconductor device sample for evaluation was obtained in the same manner as in Comparative Example 1, except that the heating temperature for heating the temporary pressure-bonded body under atmospheric pressure was changed from 175°C to 260°C.

(Comparative Example 3)
A pressed body was obtained under the same conditions as in Example 1. The pressure-bonded body thus obtained was heated in an oven (manufactured by Yamato Scientific Co., Ltd., product name: DKN402) under atmospheric pressure at 175° C. for 10 minutes to obtain a semiconductor device sample for evaluation.

(Comparative Example 4)
A semiconductor device sample for evaluation was obtained in the same manner as in Comparative Example 3, except that the heating temperature when heating the pressure-bonded body using an oven apparatus was changed from 175°C to 260°C.

(1-3) Connection Evaluation Using a multimeter (manufactured by ADVANTEST, product name: R6871E), the initial continuity of the sample was measured. Connectivity was determined according to the following criteria. Table 2 shows the results.
A: The initial connection resistance value of the peripheral part is 30 Ω or more and 35 Ω or less B: The initial connection resistance value is less than 30 Ω or more than 35 Ω, or is not connected

(1-4) Void Evaluation An external image of the sample was taken with an ultrasonic imaging diagnostic device (product name: Insight-300, manufactured by Insight). From the obtained image, a scanner (product name: GT-9300UF, manufactured by Seiko Epson Corporation) was used to capture the adhesive layer on the chip. Using image processing software Adobe Photoshop, void portions were identified by color tone correction and two-gradation, and the percentage of void portions (void generation rate) was calculated from a histogram, with the area of the adhesive layer set to 100%. The void generation state was evaluated according to the following criteria. Table 2 shows the results.
A: Void generation rate is 5% or less B: Void generation rate is more than 5%

Examples 1 and 2 both showed good results in terms of void suppression and securing of connection. That is, according to the method of the present invention, it was confirmed that both suppression of voids and securing of connection are possible.

Consideration 2
(2-1) Film Adhesive A film adhesive having a composition shown in Table 3 (thickness: 0.040 to 0.045 mm) was prepared using the same material as that used for the preparation of the film adhesive in Study 1. ) was made.

(2-2) Fabrication and Evaluation of Semiconductor Device Under the same conditions as in Example 1, a semiconductor device sample for evaluation was obtained. The connections and voids of the obtained samples were evaluated in the same manner as in Study 1. Table 4 shows the results.

(2-3) Minimum Melt Viscosity A film adhesive is heated to 60° C. using a roll laminator (HOT DOG Leon 13DX, manufactured by Lamy Corporation) until the total thickness reaches 300 to 450 μm. Multiple sheets were laminated as shown. Using the obtained laminate as a test piece, a rotational rheometer (ARES G2, manufactured by TA) was used to measure the temperature range from 20°C to 300°C under the conditions of a temperature increase rate of 10°C/min, a frequency of 10Hz, and a rotation mode. The change in viscosity (complex viscosity) was measured. The minimum viscosity value in the measured viscosity changes was taken as the lowest melt viscosity.

(2-6) Curing reaction rate after the third pressure-bonding step A 10 mg sample was taken from the film-like adhesive before being used in the first pressure-bonding step, and a DSC (PerkinElmer DSC-7 model) was used. Differential scanning calorimetry was performed in the temperature range of 30 to 300° C. at a heating rate of 20° C./min. From the obtained DSC thermogram, the amount of heat generated by the initial curing reaction ΔH0 (J/g) was determined.
Using a hot plate and an oven, the film adhesive was subjected to a heat history corresponding to the first, second and third pressure bonding steps similar to those in Example 1. After that, a sample taken from the film-like adhesive was subjected to differential scanning calorimetry under the same conditions as above to determine the heat generation amount ΔH3 (J/g) due to the curing reaction of the corresponding adhesive after the third pressure-bonding step. . From the obtained ΔH0 and ΔH3, the curing reaction rate after the third pressure-bonding step was calculated by the following formula.
Curing reaction rate (%) after the third compression step: (ΔH0-ΔH3)/ΔH0×100

Examples 3 and 4 both showed good evaluation results in terms of void suppression and connection security.

Consideration 3
(3-1) Film Adhesive A film adhesive (thickness: 0.045 mm) having the composition shown in Table 5 was prepared using the same materials as those used in the preparation of the film adhesive in Study 1. .

(3-2) Fabrication of semiconductor device (Example 5)
A semiconductor device sample for evaluation was obtained in the same manner as in Example 1, except that the time for heating and pressurizing the laminate in the first press-bonding step was changed to 3 seconds.

(Example 6)
Evaluation was performed in the same manner as in Example 1 except that the time for heating and pressing the laminate in the first compression step was changed to 3 seconds, and the pressure in the oven was changed to 0.8 MPa in the third compression step. obtained a semiconductor device sample for

(Comparative Example 5)
A film-like adhesive having a size of 8 mm×8 mm×0.045 mm in thickness was prepared by cutting out the film-like adhesive. This was stuck on 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, bump melting point: about 220°C, bump height: about 45 μm in total for copper pillars and solder, number of bumps: 1048 pins , pitch 80 um, product name: WALTS-TEG CC80, manufactured by WALTS) was attached 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. By sandwiching between a stage and a pressure-bonding head, a temporary pressure-bonded body was obtained by hot-pressing at a temperature of 80° C. while applying pressure with a load of 25 N for 3 seconds. The obtained temporary press-bonded body was moved onto the stage of another flip chip bonder (FCB3, manufactured by Panasonic Corporation). The temporary pressure-bonded body was sandwiched between a stage and a pressure-bonding head, and heated at a temperature of 260° C. for 5 seconds while applying a load of 25 N to obtain a semiconductor device sample for evaluation.

(3-3) Evaluation By the same method as in Examination 1, connections and voids in the obtained semiconductor device samples were evaluated. Table 6 shows the results.

(3-4) Curing reaction rate after second pressure bonding step A 10 mg sample was taken from the film adhesive before being used in the first pressure bonding step, and DSC (Perkin Elmer DSC-7 type) was used. Differential scanning calorimetry was performed in the temperature range of 30 to 300° C. at a heating rate of 20° C./min. From the obtained DSC thermogram, the amount of heat generated by the initial curing reaction ΔH0 (J/g) was determined.
The film adhesive was subjected to a heat history corresponding to the first and second pressure bonding steps similar to Examples 5 and 6 using a hot plate and an oven. After that, a sample taken from the film-like adhesive was subjected to differential scanning calorimetry under the same conditions as above to determine the amount of heat generation ΔH2 (J/g) due to the curing reaction of the corresponding adhesive after the second pressure-bonding step. . From the obtained ΔH0 and ΔH2, the curing reaction rate after the second pressure-bonding step was calculated by the following formula.
Curing reaction rate (%) after the second compression step: (ΔH0-ΔH2)/ΔH0×100

(3-5) Fillet Evaluation Appearance images of semiconductor device samples were taken with a digital microscope (manufactured by KEYENCE, VHX-5000). From the obtained image, the length of the adhesive layer protruding from each of the four sides of the semiconductor chip (the length in the direction parallel to the main surface of the semiconductor chip) is measured, and the average value of the measured values is recorded as the fillet value. did.

Examples 1 and 2 both showed good evaluation results in terms of void suppression and connection security.

DESCRIPTION OF SYMBOLS 1... Semiconductor chip, 2... Wiring circuit board, 3... Laminate, 4... Temporary press-bonded body, 5... Interposer, 6... Press-bonded body, 10... Semiconductor chip body, 15, 16... Wiring, 20... Substrate body, 30 , 32, 33... Bump, 34... Penetrating electrode, 40... Adhesive layer, 41, 44... Crimp head, 42, 45... Stage, 43, 46... Pressing device, 50... Interposer main body, 60... Heating furnace, 100 , 200, 300, 400, 500 . . . semiconductor devices.

Claims (6)

A first member having a connection portion and a second member having a connection portion are sandwiched between a pair of first pressing members arranged to face each other, and a thermosetting adhesive is interposed between the first member and the second member. The connection portion of the first member and the connection portion of the second member are arranged to face each other by crimping at a temperature lower than the melting point of the connection portion of the member and the melting point of the connection portion of the second member. A step of obtaining a temporary crimped body with
By sandwiching the temporary pressure-bonded body between a pair of second pressing members arranged to face each other, at least one of the connecting portion of the first member and the connecting portion of the second member is heated to a temperature equal to or higher than the melting point of the connecting portion. A step of obtaining a crimped body by applying pressure while heating to
further heating the crimped body under a pressurized atmosphere;
with
The first member is a semiconductor chip or a semiconductor wafer, the second member is a wiring circuit board, a semiconductor chip or a semiconductor wafer,
In the step of obtaining the pressure-bonded body by applying pressure while heating the temporary pressure-bonded body, the thermosetting adhesive is partially cured until the curing reaction rate becomes 30% or less,
A method of manufacturing a semiconductor device, wherein the thermosetting adhesive is further cured in the step of heating the compressed body in a pressurized atmosphere. 2. The method according to claim 1, wherein in the step of heating the pressure-bonded body under pressure, the thermosetting adhesive is further cured until the curing reaction rate of the thermosetting adhesive reaches 85% or more. 3. The method according to claim 1, wherein in said step of heating said pressure-bonded bodies in a pressurized atmosphere, a plurality of said pressure-bonded bodies are collectively heated. The method according to any one of claims 1 to 3, wherein the heating temperature in the step of heating the pressure-bonded body in a pressurized atmosphere is 130°C or higher and 300°C or lower. Claim 1, wherein the thermosetting adhesive contains a thermosetting resin having a weight average molecular weight of less than 10,000, a curing agent for the thermosetting resin, and a polymer component having a weight average molecular weight of 10,000 or more. 5. The method of any one of 4. The method according to any one of claims 1 to 5, wherein the thermosetting adhesive has a minimum melt viscosity of 3000 Pa·s or less.

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