JP5145289B2 - Manufacturing method of semiconductor device - Google Patents

Description

The present invention relates to a method of manufacturing a semiconductor device according to a transfer molding using a resin composition for semiconductor encapsulation comprising a liquid or gel-like resin composition for semiconductor encapsulation was cooled and solidified.

  Generally, a semiconductor device has the following configuration. That is, a semiconductor element is mounted on a metal lead frame, and the semiconductor element and the inner lead of the metal lead frame are electrically connected by bonding a metal wire for the purpose of electrical connection with the outside. Such a semiconductor element and a lead frame are resin-sealed and packaged with a sealing material such as an epoxy resin composition.

  Resin sealing of the semiconductor element and the lead frame is usually performed by a transfer molding method using a solid tablet-shaped resin composition for semiconductor sealing. In this transfer molding method, a resin composition for encapsulating a semiconductor in the form of a solid tablet is put into a pot of a molding die, heated in this pot to be in a fluid state, and then extruded into a cavity by a plunger. Let it flow into. Then, the semiconductor element and the lead frame in the cavity are sealed with resin. Alternatively, in addition to the transfer molding method described above, for example, a resin composition for semiconductor encapsulation that is liquid or gel at room temperature (about 25 ° C.) is quantified with a spencer, and then encapsulated with a casting method or screen printing There is also a way to do it. Here, the resin composition for semiconductor encapsulation showing the gel-like high-viscosity non-solid substance is usually in a state diluted with a solvent or the like in the same state as the liquid semiconductor encapsulation resin composition. It is used for resin sealing.

  Furthermore, what solidified the resin composition for semiconductor sealing liquid or gel-like at the said normal temperature has been proposed conventionally (refer patent documents 1, 2). This uses a package body in which a liquid or gel-like resin composition for encapsulating a semiconductor is sealed in a container to form a pseudo tablet. The package, which is a semiconductor sealing resin composition enclosed in the container, is charged into the pot in the pot, and the package is compressed with a plunger at the molding temperature, as in normal transfer molding. Thus, a part of the enclosure is ruptured, and the resin composition for semiconductor sealing inside is pushed out to flow into the cavity.

Japanese Patent Laid-Open No. 9-174591 JP 2006-21788 A

  By the way, regarding the productivity of the semiconductor device, the manufacture by the transfer molding is superior to the casting method or the screen printing, and if possible regardless of the state of the sealing material used for the resin sealing, the transfer is possible. Resin sealing by molding is desired.

  However, the resin composition for semiconductor encapsulation that is liquid or gel at room temperature cannot be used for transfer molding because it cannot be converted into a tablet or other solid at room temperature.

  On the other hand, as described in Patent Documents 1 and 2 above, in a package formed by enclosing a liquid or gel-like resin composition for semiconductor encapsulation in a container, fragments are formed when a part of the encapsulated container is ruptured. In addition, there are concerns about the cost increase due to the use of the sealed container, the environmental load such as the discharge processing of the container after use, and the trouble of sealing the resin composition in the container.

  For these reasons, there is a demand for a technique that makes it possible to use a resin composition for semiconductor encapsulation that is liquid or gel-like at room temperature during transfer molding with high productivity.

The present invention has been made in view of such circumstances, and a semiconductor sealing resin composition that can be used for transfer molding a liquid or gel semiconductor sealing resin composition at room temperature as a sealing material . An object of the present invention is to provide a method for manufacturing a semiconductor device using the semiconductor device.

In order to achieve the above object, the present invention is a method of manufacturing a semiconductor device by resin-sealing a semiconductor element using a transfer molding machine, and cooling and solidifying a liquid or gel-like resin composition at room temperature The step of preparing a resin composition for semiconductor sealing in a cooled and solidified state filled into a mold and cooled and solidified into a tablet shape, and a cooled and solidified state while maintaining the above-mentioned cooled and solidified state in a pot of a transfer mold The semiconductor sealing resin composition is charged into the plunger after the thawing of the charged semiconductor sealing resin composition at a temperature of 150 to 175 ° C. or while thawing in the pot. A step of compressing and extruding the thawed liquid or gel semiconductor sealing resin composition and extruding it from the pot; The semiconductor device in the cavity by the composition and Abstract a method for manufacturing a semiconductor device comprising a step of resin encapsulation.

  The present inventors have intensively studied to obtain a technique for subjecting a liquid or gel-like resin composition for encapsulating a semiconductor to transfer molding. As a result, the inventors have found that the liquid or gel-like resin composition for encapsulating a semiconductor is cooled and solidified to obtain a cooled solidified body, which is used for transfer molding, and reached the present invention. That is, since a liquid or gel-like resin composition for encapsulating a semiconductor cannot be used for transfer molding as it is, various forms were examined. In the process, as a result of investigating an aspect that can be used for transfer molding without increasing the cost and without concern for environmental burden, and without requiring complicated work, a liquid or gel-like semiconductor encapsulation is obtained. It was recalled that the resin composition for cooling is solidified by cooling to a solid state (cooled solidified body). Thereby, the resin composition for semiconductor sealing cooled and solidified without incurring concern about cost increase and environmental burden and without requiring complicated work can be obtained.

  As described above, the present invention is a resin composition for encapsulating a semiconductor that is used in transfer molding and becomes a cooled and solidified resin composition in a liquid or gel form at room temperature. For this reason, even if it is a liquid or gel-like resin composition at normal temperature, it can be used for transfer molding. In addition, since a sealed container or the like is not required, the cost is not increased, and there is no need to worry about the environmental load due to disposal of the container after use or the like, the resin composition sealing work, and the like. In addition, since it is not used after being enclosed in a container, it is possible to perform highly reliable resin sealing without introducing fragments or the like of the container during transfer molding. Furthermore, compared with a sealing operation using a syringe, the loss of the sealing material is suppressed and the yield is improved.

  And in the method of manufacturing a semiconductor device by resin-sealing a semiconductor element using a transfer molding machine, after preparing the above-mentioned cooled and solidified resin composition for semiconductor sealing, it is transferred to a pot for transfer molding Into the inside while maintaining the above-mentioned cooling and solidification state. Next, after thawing the charged semiconductor sealing resin composition, or after thawing, the semiconductor sealing resin composition in liquid or gel form is extruded into the cavity by pushing it out with a plunger. A semiconductor device is manufactured by resin-sealing the semiconductor element in the cavity with the introduced resin composition for semiconductor sealing. For this reason, conventionally, the liquid or gel-like resin composition for semiconductor encapsulation that could not be used for transfer molding other than enclosing in a container can be subjected to a sealing process without going through complicated operations. In addition, since the semiconductor device is resin-sealed by a transfer molding method having excellent productivity, the productivity can be improved by using a liquid or gel-like resin composition for semiconductor sealing. And since the resin composition for semiconductor encapsulation which is a cooling solidified body is used for transfer molding, it is possible to use, for example, resin materials that have conventionally been difficult to solidify and B-stage (semi-curing) for transfer molding. Therefore, workability is improved, and high heat resistance and high reliability packages can be provided at a low price. For this reason, the semiconductor device in which the semiconductor element is encapsulated with the resin composition for encapsulating a semiconductor of the present invention is excellent in reliability and can sufficiently exhibit its function.

Further, the semiconductor encapsulating resin composition, since they are cooled and solidified into tablets by filling a liquid or gel-like resin composition for semiconductor encapsulation to cool and solidify mold, the conventional transfer molding machine It becomes easy to perform resin sealing with the same method and apparatus.

  Next, an embodiment for carrying out the present invention will be described in detail. However, the present invention is not limited to this embodiment.

<Resin composition for semiconductor encapsulation>
The resin composition for encapsulating a semiconductor according to the present invention is a resin composition that is liquid or gel at normal temperature, and various sealing materials that are liquid or gel (semi-solid) are used. And the resin composition for semiconductor sealing of this invention is the cooling solidification body which made this the cooling solidification state. In the present invention, the liquid means fluidity at room temperature, and the gel state specifically refers to a material that deforms when stress of 500 Pa is applied at room temperature. Moreover, in this invention, unless there is particular notice, normal temperature means the range of 20-25 degreeC.

  Examples of the semiconductor sealing resin composition include an epoxy resin composition using an epoxy resin as a main agent, a silicone resin composition using a silicone resin, or an epoxy resin / silicone resin hybrid resin composition. .

  As said epoxy resin composition, what mix | blended the epoxy resin, the hardening | curing agent, and other various additives is used, for example.

  Examples of the epoxy resin include various epoxy resins such as cresol novolac type epoxy resins, phenol novolac type epoxy resins, bisphenol A type epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins such as triglycidyl isocyanurate. Epoxy resin can be used. These may be used alone or in combination of two or more.

  The curing agent acts as a curing agent component of the epoxy resin, and in general, when considering transparency, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, etc. A colorless to light yellow acid anhydride curing agent is used.

  The mixing ratio of the epoxy resin and the curing agent is such that the active group (acid anhydride group or hydroxyl group) capable of reacting with the epoxy group in the curing agent is 0.5 to 1.5 with respect to 1 equivalent of the epoxy group in the epoxy resin. It is preferable to set the ratio so as to be equivalent, and more preferably 0.7 to 1.2 equivalent. That is, when there are too few active groups, the curing rate of the resin composition for semiconductor encapsulation becomes slow and the glass transition temperature tends to decrease, and conversely, the moisture resistance with too many active groups tends to decrease. Because it is.

  As the above various other additives, a curing accelerator, a silane coupling agent, a release agent, a low stress agent, an antioxidant, an inorganic filler, and the like can be appropriately blended.

  Examples of the curing accelerator include amine-based curing accelerators, imidazole-based curing accelerators, organic phosphorus-based curing accelerators, boron-based curing accelerators, and phosphorus-boron-based curing accelerators. These curing accelerators may be used alone or in combination of two or more.

  Examples of the silane coupling agent include amino silane coupling agents and epoxy silane coupling agents. Furthermore, a mercapto silane coupling agent can also be used as a coupling agent. These may be used alone or in combination of two or more. The content of the silane coupling agent is preferably set in the range of 0.05 to 2.0% by weight of the entire epoxy resin composition.

  As the mold release agent, for example, a polyethylene glycol compound can be used. The amount of the release agent used is preferably as small as possible.

  Next, examples of the silicone resin in the silicone resin composition using the silicone resin include non-reactive curable silicone resins, condensation reaction curable silicone resins, and peroxide curable silicone resins. Furthermore, as an additive, for example, a curing retarder, a silane coupling agent, and the like can be appropriately blended as necessary.

  As the above-mentioned epoxy resin / silicone resin hybrid resin composition, the same epoxy resin and silicone resin as those described above in the aspect of the epoxy resin are used.

The resin composition for semiconductor encapsulation according to the present invention is liquid or gel-like at room temperature, and is obtained by cooling and solidifying it to obtain a solid-state cooling solidified body. And as a resin composition for semiconductor sealing of this invention, since it solidifies by cooling and it is set as a solid state, it is preferable that the solidification start point is -196-0 degreeC. Especially preferably, it is -40-0 degreeC.

  Examples of the method for cooling and solidifying the resin composition for semiconductor encapsulation include, for example, a method of casting into a cooled mold, a method of cooling after casting into a mold, and compressing an ice flake-shaped resin composition for semiconductor encapsulation. Methods and the like.

  And as a cooling method in that case, the method of immersing in cooling media, such as liquid nitrogen, the method of exposing to cooling medium (liquefied gas etc.) atmosphere, the method of using cooling machines, such as a refrigerator, etc. are mention | raise | lifted, for example.

  The cooling and solidifying conditions may be set conditions that allow the semiconductor sealing resin composition that is liquid or gel at room temperature to be solidified by solidification. In consideration of the solidification start point of the resin composition, it is generally preferable to set it to about 1 to 24 hours in the range of −196 to 0 ° C., and particularly preferably in the range of −40 to 0 ° C. for 1 to 5 hours. is there.

  In the cooling operation, a filling mold for filling a liquid or gel-like semiconductor sealing resin composition is used. As a cooling and solidification mold used at this time, cooling and solidification is used. It is necessary to use one having heat resistance with respect to the temperature at the time of carrying out. For example, a metal mold made of aluminum or the like, a resin mold made of polyethylene, silicone resin, or the like can be used. Such a mold for filling and cooling and solidification is usually preferable because it can be used repeatedly. And as a filling type | mold, it is preferable from the point of filling work efficiency to use the thing of the state in which the some opening recessed part for filling was formed and connected.

  Furthermore, the shape of the mold may be appropriately set as long as the cooling and solidifying sealing material can be put into the pot of the transfer molding machine. From such a point, examples of the shape of the cooled and solidified body filled in the mold and cooled and solidified include various shapes such as a columnar shape (tablet shape) and a conical shape.

<Manufacture of semiconductor devices>
Next, a method for manufacturing a semiconductor device of the present invention using the above-described cooled and solidified resin composition for semiconductor encapsulation (cooled solidified body) will be described.

  First, the resin composition for semiconductor sealing which is a cooling solidified body is prepared as mentioned above. Subsequently, the resin composition for semiconductor encapsulation which is a cooling solidified body is thrown into the pot of the molding die of the transfer molding machine while maintaining the above-mentioned cooling solidified state. After charging, in the pot, after thawing or thawing the cooled and solidified semiconductor sealing resin composition, a liquid or gel-like semiconductor sealing resin composition is prepared, which is used as a plunger. Compressed and extruded to flow into the cavity. Next, the semiconductor device can be manufactured by resin-sealing the semiconductor element mounted on the lead frame in the cavity with the introduced resin composition for semiconductor sealing.

  As a method for charging the cooled and solidified semiconductor sealing resin composition into the pot of the transfer molding machine, the semiconductor sealing resin composition may be charged while maintaining the solidified state without melting. Any means may be used if possible. For this reason, it is possible to perform transfer molding by placing it in a pot for transfer molding by the same means as conventional solid tablets, and there is no need to install a new molding machine. have.

The thawing condition of the cooled and solidified resin composition for encapsulating a semiconductor charged in the pot is only required to be liquid or gelled by thawing , at a temperature of 150 to 175 ° C. for 5 to 30 seconds. It becomes possible to defrost at a degree.

  As a molding machine capable of the transfer molding, for example, various ordinary transfer molding machines such as a low-pressure transfer molding machine, a convention type, a multi-gang pot type, and a multi-plunger type can be used.

The manufacturing conditions of the semiconductor device by the transfer molding are appropriately set depending on the type of the resin composition for semiconductor encapsulation to be used. For example, the molding temperature is 130 to 175 ° C., the molding time is 3 to 10 minutes, the pressure is 1. It is set to 96-7.84 MPa (20-80 kg / cm < ² >).

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

  First, each epoxy resin composition showing liquid at normal temperature (25 ° C.) shown below was prepared.

[Epoxy resin composition a]
NT-8038-10000 (manufactured by Nitto Denko Corporation, liquid, solidification start point-38.4 ° C.)
[Epoxy resin composition b]
NT-S100B-10000 (manufactured by Nitto Denko Corporation, liquid, solidification start point-38.2 ° C.)
[Epoxy resin composition c]
NT-S100B-10500 (manufactured by Nitto Denko Corporation, liquid, solidification start point-38.2 ° C.)
[Epoxy resin composition d]
NT-S100B-10700 (manufactured by Nitto Denko Corporation, liquid, solidification start point-38.2 ° C.)

[Examples 1 to 4]
The epoxy resin compositions a to d were filled in a polyethylene cup. Thereafter, the cup filled with the epoxy resin compositions a to d was solidified by cooling in a refrigerator maintained at −40 ° C. for about 3 hours to form a solid (cooled solidified body).

[Comparative Examples 1-4]
The epoxy resin compositions a to d were filled in a 2 mL syringe manufactured by HENKE SASS WOLF.

  When producing five semiconductor sealing resin compositions (Examples 1 to 4) cooled and solidified by the above method and five semiconductor sealing resin compositions (Comparative Examples 1 to 4) filled in a syringe, respectively. The required work time was measured. In Examples 1 to 4, the time until cooling and solidification was used, and the working time required to measure 2 g ± 0.1 g five times was used. On the other hand, in Comparative Examples 1 to 4, the time for filling the syringe was used, and the working time required for weighing 2 g ± 0.1 g five times was used. The results are shown in Table 1 below together with the viscosities of the epoxy resin compositions a to d. The viscosity is a value obtained by measuring the viscosity at 25 ° C. using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TVE-22HT).

  From the above results, it can be seen that the working time is shorter in the example than in the comparative example. Further, in the case of the comparative example, the working time increases proportionally as the solution viscosity increases. However, in the examples, the working time does not change even when the solution viscosity increases, and thus it is understood that the productivity is excellent.

  Moreover, the loss amount of the resin which generate | occur | produces when producing the epoxy resin composition (Examples 1-4) cooled and solidified by the said method and the syringe (Comparative Examples 1-4) filled with the epoxy resin composition, respectively. Measured. In addition, the said resin loss amount is the loss amount of the resin produced when measuring 2g +/- 0.1g 3 times. The results are shown in Table 2 below.

  From the above results, it can be seen that when a syringe as a comparative example is used, the amount of loss resin is large because the epoxy resin composition adheres around the syringe. In particular, the higher the viscosity, the greater the amount of loss resin. In addition, in the comparative example, waste is generated after use by using a syringe, but in the example, the polyethylene cup used for cooling and solidification can be used repeatedly, reducing costs, and disposal processing There is no concern about environmental impact.

[Fabrication of semiconductor devices]
Next, using the epoxy resin compositions a to d produced in the above Examples 1 to 4 and solidified by cooling, a semiconductor device was produced as follows. That is, the epoxy resin compositions a to d, which are cooled and solidified bodies, are placed in a pot of a transfer molding machine (TDF-37 manufactured by Toho International Co., Ltd.) while maintaining the cooled and solidified state, and then in the pot. The above-mentioned semiconductor sealing resin composition was thawed (condition: 150 ° C. × 10 seconds). And the resin composition for semiconductor sealing which became liquid by thawing | decompression was made to flow in in a cavity by extruding with a plunger. The semiconductor element (size: 1.5 mm × 1.5 mm × thickness 370 μm) mounted on the lead frame in the cavity by the inflowing resin composition for semiconductor sealing is resin-sealed (condition: 150 ° C. × 4 minutes) ) To fabricate a semiconductor device. Thus, a semiconductor device (SOP) having a size: 4.9 mm × 3.9 mm × thickness 1.5 mm was obtained. The obtained semiconductor device was excellent in reliability with no particular problem.

The semiconductor sealing resin composition according to the present invention is a cooled and solidified body obtained by cooling and solidifying a liquid or gel-like resin composition at room temperature, and is useful as a sealing material for resin sealing by transfer molding. And by using the resin composition for semiconductor sealing which concerns on this invention, a cost reduction is implement | achieved with the improvement of sealing workability | operativity, and the concern of environmental impact is also eliminated.

Claims (3)

A method of manufacturing a semiconductor device by resin-sealing a semiconductor element using a transfer molding machine, in which a cooling or solidifying mold is filled with a liquid or gel-like resin composition at room temperature and cooled and solidified into a tablet shape. A step of preparing a solidified resin composition for encapsulating a semiconductor, and a step of introducing a cooled and solidified resin composition for encapsulating a semiconductor into a pot of a transfer molding mold while maintaining the above-mentioned cooled and solidified state; In a pot, after thawing the above-mentioned resin composition for encapsulating a semiconductor at a temperature of 150 to 175 ° C. or while thawing, the liquid or gel-like semiconductor encapsulated that has been thawed with a plunger A step of compressing and extruding the resin composition from the pot, and allowing the semiconductor element in the cavity to flow into the cavity by the injecting resin composition for semiconductor sealing. And a step of resin-sealing the child. Cooling and solidification conditions, method according to claim 1, wherein from 1 to 5 hours in the range of -40~0 ℃. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the cooling and solidifying means is a method of immersing in a cooling medium, a method of exposing to a cooling medium atmosphere, or a method of using a cooling machine.