JPH05283457A - Manufacture of resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing resin sealed semiconductor devices having high heat radiating properties which makes the sealing process suitable for automatic and inline processing and for increasing chip sizes following the increase in degree of integration of the semiconductor devices. CONSTITUTION:A sealing resin sheet 1 of an uncured resin is arranged on the active surface side of a semiconductor chip 4 connected to a lead 2d and, at the same time, a metallic material 5 is provided on the rear surface side of the chip 4 in a state where the material 5 is brought into contact with the rear surface. Then they are integrally formed by curing the uncured resin by applying a pressure from the outside of the material 5 and sheet 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a resin-encapsulated semiconductor device, and more particularly to a resin encapsulation method suitable for encapsulating a large-sized semiconductor chip that generates a large amount of heat.

[0002]

2. Description of the Related Art Conventionally, resin-sealed semiconductor devices have been obtained by a transfer molding method. In this method, an uncured resin such as an epoxy molding material mainly composed of an epoxy resin and a filler is heated and melted, and then transferred.
In this method, a semiconductor chip mounted on a lead frame is sealed by injecting it into a mold using a molding machine, molding in a high temperature and high pressure state, and curing. The resin-encapsulated semiconductor device manufactured by this method has excellent reliability because the semiconductor chip is completely covered with the epoxy resin composition, and the appearance of the package is good because it is densely molded with a mold. Therefore, most resin-encapsulated semiconductor devices are currently manufactured by this method.

However, in recent years, as the size of semiconductor chips has increased with the high integration of semiconductor devices, the package of resin-encapsulated semiconductor devices has increased in size. This trend is strengthening, and this trend is expected to grow stronger in the future. Also, the package
It is expected that the types of die will become more and more diverse in the future, and the conventional transfer molding method will not be able to adequately support them. Under such circumstances, it is desired to develop a flexible production mode capable of high-mix low-volume production.

Further, there is a problem of in-line manufacturing process. That is, the semiconductor device manufacturing process has been fully automated, and some have been automated by a single line. However, it is difficult to inline the semiconductor device encapsulation process with conventional transfer molding, and the production is done by batch processing after removing the line. Is required.

Further, in recent years, ASIC (Application Spec
As represented by ific IC), semiconductor devices are becoming highly integrated and operating at high speed, and the power consumption thereof is increasing.
Along with this, high heat dissipation is required for the package that seals the semiconductor chip.

[0006]

As described above, the conventional transfer molding method is not suitable for the in-line encapsulation process, and it is difficult to cope with the future increase in the size and thickness of the package. A new production method to replace this was desired.

The present invention has been made in view of the above circumstances, and is capable of automating the sealing process and making it in-line, and is also suitable for making the package large and thin, and also for the requirement of high heat dissipation of the package. It is an object of the present invention to provide a corresponding method for manufacturing a resin-sealed semiconductor device.

[0008]

Therefore, in the present invention, a sealing resin sheet made of uncured resin is arranged on the active surface side of a semiconductor chip connected to leads, and a metal material is provided on the back surface side. The metal material and the sealing resin sheet are arranged in contact with each other, and the uncured resin is cured while being pressed from the outside, and these are integrally molded.

The connection between the lead and the semiconductor chip is
TAB (Tape A
Utomated Bonding) or flip chip or other wireless bonding may be used, but wireless bonding such as TAB is more preferable because it is advantageous for thinning the package and is suitable for manufacturing a resin-sealed semiconductor device for surface mounting.

In the present invention, regarding the types of the lead structure such as the lead frame and the semiconductor chip,
There is no particular limitation. Examples of the material for the sealing resin sheet include uncured thermosetting resin, photocurable resin, engineering plastics, etc., but the lower the resin viscosity during integral molding, the more precise the sealing. Therefore, it is preferable to apply an uncured thermosetting resin. As a specific method for curing such an uncured resin, in the case of a thermosetting resin, a method of heating a mold used in integral molding, a method of selectively heating only the uncured resin by induction heating And so on. Further, in the case of a photocurable resin, a method in which the mold is made of a transparent member such as glass and the light is irradiated through the mold may be adopted.

The thermosetting resin used in the present invention includes epoxy resin, polyimide resin, maleimide resin,
Silicone resin, phenol resin, polyurethane resin,
Acrylic resin etc. are mentioned. These resins may be used alone or in combination, and in these resins, a curing agent, a catalyst, a plasticizer, a colorant, a flame retardant, a filler,
It may contain various other additives.

Further, in the present invention, it is desirable to strengthen the thermosetting resin with various woven cloths. As the material of the woven fabric, there are inorganic materials such as glass, quartz, carbon fiber, silicon carbide, silicon nitride, aluminum nitride, alumina, zirconia and potassium titanate fiber, and organic materials such as nylon, acrylic, vinylon and poly. Vinyl chloride type, polyester type, aramid type, phenol type, rayon type,
There are acetate, cotton, linen, silk, wool and so on. These may be used alone or in combination.

Further, as the material of the metal material, a metal having a high thermal conductivity is preferable, and examples of metals preferably used include, for example, iron, copper, aluminum, nickel, chromium, zinc, tin, silver, gold, Examples of alloys of these metals such as lead, magnesium, titanium, zirconia, tungsten, molybdenum, cobalt, stainless steel, 42 nickel-iron alloy, brass, and duralumin. The shape of the metal material is not particularly limited, and is appropriately selected from metal foils, metal plates, metal blocks, etc. according to the type of package.

For example, when it is used for a thin package,
It is desirable to use a metal foil as the metal plate, and as the material thereof, it is desirable to use a material that can be processed particularly thin and is lightweight. The thickness of the metal foil at this time is 1000μ
It is desirable to be m or less. Further, in the present invention, in order to prevent corrosion of the metal material and to prevent conduction between the metal material and the lead wire, an insulating resin layer is provided on at least one surface of the metal material excluding at least a region in contact with the semiconductor chip. Good.

The sealing resin sheet used in the present invention
For example, epoxy resin, curing agent, catalyst, filler,
It can be easily produced by crushing, mixing, melting and rolling other materials. When using a prepreg reinforced with woven glass cloth, dissolve the resin, curing agent, catalyst, filler, and other materials in a solvent such as acetone to prepare a solution with an appropriate concentration, and then add this solution to the woven cloth. Apply it to a cloth or impregnate a woven cloth in a solution and let it stand,
The solvent may be volatilized by heating or under reduced pressure.

In the present invention, as a concrete method for integrally molding the semiconductor chip, the sealing resin sheet and the metal sash, the active surface side of the semiconductor chip mounted on the film carrier or the like is sealed. A method in which a resin sheet is attached, a metal material is attached to the back surface of the semiconductor chip, and then compression molding is performed to integrally mold the semiconductor sheet, the sealing resin sheet and the metal material as described above. Examples include a method of installing in a mold and integrally compression-molding from the top and bottom. At this time, it is desirable to reduce the pressure in the mold in order to prevent the generation of voids. Furthermore, after-curing is desirable to improve various characteristics of the package after molding.

In the present invention, the lead structure such as a film carrier on which the semiconductor chip is mounted and the sealing resin sheet can be supplied by a reel system.
For example, by supplying with a reel so as to correspond to each other, and combining and sealing, the semiconductor device assembly to sealing can be performed in a continuous process.

[0018]

According to the present invention, in the state where the resin sheet is uniformly abutted against the semiconductor chip and the lead structure,
Since the uncured resin is melted by heat or light and then cured while being pressed, a dense resin sealing can be performed.

Further, as described above, since the encapsulating resin sheet is encapsulated in advance with the semiconductor chip and the lead already sealed, the encapsulating resin sheet is more suitable than the transfer molding method when the uncured resin is melted. Even if the viscosity is high, good sealing can be performed. Therefore, the semiconductor chip can be sealed by melting and curing the uncured resin by supplying a small amount of heat or light.

Further, since the uncured resin is melt-cured in a good state in this way, the mechanical strength of the obtained package is high, and when the package is small with respect to the semiconductor chip or in the case of an ultra-thin package. The semiconductor chip can be satisfactorily sealed without any cracks.

Further, in the conventional transfer method, it was extremely difficult and almost impossible to fix the heat sink to the back surface, especially in the case of a thin package, but according to the method of the present invention, the metal foil is used. By providing as a heat dissipation plate, a resin-encapsulated semiconductor device having high reliability and good heat dissipation can be obtained.

In addition, the method of manufacturing a resin-sealed semiconductor device of the present invention enables automatic manufacturing by the in-line encapsulation process, and is sufficiently compatible with high-mix low-volume production.

As described above, according to the present invention, it is possible to simplify the manufacturing process, and it is possible to manufacture a resin-sealed semiconductor device having good reliability for a long period of time.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings.

The resin-sealed semiconductor devices of Examples 1-12 and Comparative Examples 1-2 were manufactured by the following methods.

FIG. 1 shows a manufacturing process diagram of a resin-encapsulated semiconductor device of the first embodiment of the present invention, and FIG. 2 shows a schematic diagram of a semiconductor encapsulation device used for the same.

Example 1 First, a cresol novolac type epoxy resin (E
100 parts by weight of OCN-195XL, manufactured by Sumitomo Chemical Co., Ltd., 54 parts by weight of phenol resin as a curing agent, 350 parts by weight of fused silica as a filler, 0.5 parts by weight of benzyldimethylamine as a catalyst, and other additives. 3 parts by weight of carbon black and 3 parts by weight of a silane coupling agent are dissolved in 100 parts by weight of methyl cellosolve to prepare an epoxy impregnated varnish. The thus-prepared epoch-impregnated varnish was dipped in glass cloth, air-dried, and then heat-dried at 80 ° C. for 4 hours in a dryer to give a thickness of 1000 μm.
An encapsulating resin sheet having a size of m 3 was formed and cut into 13 × 13 mm to prepare an encapsulating resin sheet.

On the other hand, a copper foil 2d was adhered to the film 2S made of a polyimide resin and patterned to form a lead pattern, and a film carrier 2 was prepared by a usual method.

Using the semiconductor encapsulation device shown in FIG. 2, the film carrier 2 is moved between the supply reel 100 and the take-up reel 500 while the semiconductor chip is mounted and the resin is encapsulated in-line. It was It should be noted that this apparatus includes a supply reel 100 and a semiconductor chip mounting portion 200.
A sheet sticking section 300 for supplying and sticking the sealing resin sheet and the metal foil 5, a compression molding section 400, a take-up reel 500, and an after cure section (not shown). ..

First, while aligning with the chip mounting portion 200, 10 × 10 × 0.35 mm is placed on the film carrier 2.
The semiconductor chip 4 is connected face down with the leads 2d through the bumps 3.

Thereafter, the sheet attaching portion 300 attaches the encapsulating resin sheet 1 to the active surface side of the semiconductor chip 4 mounted on the film carrier 2 via the bumps 3, and 14 × 14 of 42 alloy is formed. A 0.5 mm metal foil 5 is attached to the back surface of the semiconductor chip 4 (FIG. 1 (a)).

Further, the resin molding type semiconductor device was manufactured as shown in FIG. 1 (b) by compression molding for 1 minute in the mold 401 heated to 170 ° C. in the compression molding part 400. In the figure, 402 is a heater, and 403 is a vacuum system for reducing the pressure inside the mold. The thickness of the package molded here was 0.9 mm. The molded package is removed from the mold, after-cured at 180 ° C. for 4 hours in the after-cure section 500, and wound by the take-up reel 600.

The shape of the recess of the mold 401 is shown in FIG.
As shown in the enlarged explanatory diagram in Fig. 1, the shape of the sealing resin sheet is almost the same as that of the sealing resin sheet, and the volume of the mold recess is slightly smaller than the total volume of the sealing resin sheet and the metal foil. A resin sheet for pressing is used so as to be pressed.

Finally, deburring is performed and the semiconductor device is divided into individual semiconductor devices to complete a thin resin-sealed semiconductor device.

The resin sealing device is not limited to the one used in the above-mentioned embodiment, and as shown in FIG. 4, sticking of the sealing resin sheet and pressure molding may be performed by the same device. You can

Further, as shown in FIG. 5, the sealing resin sheet may be placed on the tape carriers T1 and T2 and continuously supplied.

Example 2 Next, as a second example of the present invention, a resin-sealed semiconductor device was manufactured in exactly the same manner as in Example 1 except that the fused silica was changed to crystalline silica.

Example 3 Next, as a third example of the present invention, the material of the metal material is 42
A resin-sealed semiconductor device was manufactured in exactly the same manner as in Example 1 except that the alloy was changed to copper.

Example 4 Next, as a fourth example of the present invention, a resin-sealed semiconductor device was manufactured in the same manner as in Example 3 except that fused silica was replaced by crystalline silica.

Fifth Embodiment Next, as a fifth embodiment of the present invention, the metal material is 42
A resin-sealed semiconductor device was formed in exactly the same manner as in Example 1 except that the alloy was changed to Kovar.

Example 6 Next, as a sixth example of the present invention, a resin-sealed semiconductor device was manufactured in exactly the same manner as in Example 5 except that crystalline silica was used instead of fused silica.

Example 7 Next, as a seventh example of the present invention, an example in which a phenol novolac type epoxy resin is used instead of the cresol novolac type epoxy resin will be described.

In this example, a phenol novolac type epoxy resin (Epicote 154 Shell Chemical Co.) 1
00 parts by weight, 20 parts by weight of 3,3'-disiaminodiphenyl sulfone as a curing agent, and 2 parts of fused silica as a filler.
80 parts by weight and 1 part by weight of a BF ₃ -monoethylamine complex salt as a catalyst were crushed, mixed, melted, and rolled to prepare a sealing resin sheet. A resin-encapsulated semiconductor device was manufactured in exactly the same manner as in Example 2 except that this encapsulating resin sheet and a metal foil made of copper were used as the metal material, and after-curing was performed at 180 ° C. for 8 hours. did.
In addition, in the obtained resin-encapsulated semiconductor device, the package
The thickness of the die was 0.9 mm.

Example 8 Next, as an eighth example of the present invention, a resin-sealed semiconductor device was manufactured in exactly the same manner as in Example 7 except that crystalline silica was used in place of fused silica.

Example 9 Next, as a ninth example of the present invention, an example in which the composition of the uncured resin of the sealing resin sheet is changed will be described.

In this example, 100 parts by weight of a cresol novolac type epoxy resin (EOCN-195XL: manufactured by Sumitomo Chemical Co., Ltd.), 4 parts by weight of dicyandiamide as a curing agent, 240 parts by weight of silicon nitride as a filler, and a catalyst as a catalyst. 1 part by weight of BF ₃ -monoethylamine complex salt was crushed, mixed, melted, and rolled to produce a resin sheet for sealing. A resin-encapsulated semiconductor device was produced in exactly the same manner as in Example 1 except that this encapsulating resin sheet and a metal foil made of copper were used, and after-curing was performed at 180 ° C. for 8 hours. The thickness of the molded package is 0.9 mm. Molded package is 180 for 8
Time after cure was done.

Example 10 Next, as a tenth example of the present invention, an example in which the composition of the uncured resin of the sealing resin sheet is changed will be described.

100 parts by weight of a cresol novolac type epoxy resin (EOCN-195XL: manufactured by Sumitomo Chemical Co., Ltd.), and methylhexahydrophthalic anhydride 85 as a curing agent.
One part by weight of alumina, 430 parts by weight of alumina as a filler, and 1 part by weight of BF ₃ -monoethylamine complex salt as a catalyst were crushed, mixed, melted, and rolled to prepare a sealing resin sheet. A resin-encapsulated semiconductor device was produced in exactly the same manner as in Example 1 except that this encapsulating resin sheet and a metal foil made of copper were used, and after-curing was performed at 180 ° C. for 8 hours. The thickness of the molded package is 0.9 mm. Molded package is 180 for 8
Time after cure was done.

Example 11 Next, as an eleventh example of the present invention, an example in which an N, N-diphenylmethane bismaleimide resin is used instead of the cresol novolac type epoxy resin will be described.

100 parts by weight of N, N-diphenylmethane bismaleimide resin (MB-3000H, manufactured by Mitsubishi Petrochemical Co., Ltd.), 30 parts by weight of 4,4'-diaminodiphenylmethane as a curing agent, and 300 parts by weight of crystalline silica as a filler,
Then, 2 parts by weight of triphenylphosphine as a catalyst was pulverized, mixed, melted, and rolled to prepare a sealing resin sheet. A resin-encapsulated semiconductor device was produced in exactly the same manner as in Example 1 except that this encapsulating resin sheet and a metal foil made of copper were used, and after-curing was performed at 180 ° C. for 8 hours. The thickness of the molded package is 0.9 mm. Molded package is 180 for 8
Time after cure was done.

Example 12 Next, as a twelfth example of the present invention, an example in which the composition of the uncured resin of the sealing resin sheet is changed will be described.

In this example, 70 parts by weight of a cresol novolac type epoxy resin (EOCN-195XL, manufactured by Sumitomo Chemical Co., Ltd.) and 30 parts by weight of 4,4 'bromobisphenol A type epoxy resin as a flame retardant. , 54 parts by weight of phenolic resin as a curing agent, 33 of crystalline silica as a filler
0 parts by weight, 0.5 parts by weight of benzyldimethylamine as a catalyst, 3 parts by weight of carbon black as other additives, 3 parts by weight of silane coupling agent, and 20 parts by weight of antimony oxide, 100 parts by weight of methyl cellosolve. To prepare an epoxy impregnated varnish. Next, this epoxy resin-impregnated varnish was immersed in a glass cloth, air-dried, and dried by heating in a dryer at 80 ° C. for 4 hours to form a prepreg, which was used as a sealing resin sheet in this example. Using this sealing resin sheet and a metal foil made of copper, after-curing was performed at 180 ° C for 8 hours.
A resin-encapsulated semiconductor device was produced in exactly the same manner as in Example 1 except that the operation was performed for a time. The thickness of the molded package is 0.9 mm. The molded package is 18
After cure was performed at 0 for 8 hours.

For comparison, phenol novolac type epoxy resin (Epicote 154, Shell Chemical Co.)
100 parts by weight, 4 parts by weight of dicyanamide as a curing agent,
170 parts by weight of fused silica as a filler, 0.5 parts by weight of benzyldimethylamine as a catalyst, 3 parts by weight of carbon black as another filler, and 3 parts by weight of a silane coupling agent were pulverized, mixed and melted. The same semiconductor chip as in the example was sealed by the conventional transfer molding method using the above resin composition to manufacture a resin-sealed semiconductor device having the same package shape. The molding conditions were a molding temperature of 175 ° C., a molding time of 4 minutes, and an injection pressure of 80 kg / cm ² . Regarding the obtained resin-encapsulated semiconductor device,
After cure was performed at 180 ° C. for 8 hours.

Comparative Example 2 A resin-sealed semiconductor device was manufactured in exactly the same manner as Comparative Example 1 except that fused silica was changed to crystalline silica.

Table 1 shows Examples 1 to 12 and Comparative Example 1
Materials of the filler and the metal foil of the resin-encapsulated semiconductor device of Nos. 1 to 2 are collectively shown.

[0056] Evaluation test of resin-encapsulated semiconductor device Examples 1 to 12 and Comparative Examples 1 to 1 manufactured as described above.
The following evaluation tests were performed on the resin-sealed semiconductor devices of No. 2 respectively.

[1] In order to examine the heat dissipation property, a test device having a heat generation amount of 1 W was sealed as a semiconductor chip and then operated, and the steady temperature of the upper surface of the semiconductor chip was measured to calculate the thermal resistance.

[2] The following thermal cycle test (TCT test) was conducted to examine the thermal shock resistance. That is, after sealing the test device (6 mm x 6 mm), the temperature is -65 ° C.
(30 minutes) → room temperature (5 minutes) → 150 ° C. (30 minutes) A cooling / heating cycle as one cycle was repeated, and the defect occurrence rate was examined by checking the operating characteristics of the device.

[3] The following pressure cooker test (PCT) was conducted in order to investigate the moisture resistance reliability. After the test device was sealed, the device was left in a saturated steam atmosphere at 127 ° C. to examine the occurrence rate of defects (leak defect, open defect).

The above measurement results are summarized in Table 2, As is clear from Table 2, in Examples 1 to 12,
The thermal resistance is 1/2 to 1/4 of the comparative examples 1 and 2 sealed by the transfer method of the conventional example, and TCT, P
It can be seen that excellent thermal shock resistance and moisture resistance were obtained with almost no defects due to CT.

[0061]

As described above, according to the present invention, the heat dissipation is good, the heat reliability and the heat shock resistance are excellent, and the manufacturing is easy, and the semiconductor chip will be larger and thinner in the future. It is possible to provide a resin-encapsulated semiconductor device that can sufficiently cope with the demand for high-quality products.

[Brief description of drawings]

FIG. 1 is a sectional view showing a manufacturing process of a resin-sealed semiconductor device according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a semiconductor encapsulation device used in an embodiment of the present invention.

FIG. 3 is a sectional view showing a mold used in an example of the present invention.

FIG. 4 is a diagram showing another resin sealing device.

FIG. 5 is a view showing another resin sealing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing resin sheet 2 Film carrier 2S film 2d Lead 3 Bump 4 Semiconductor chip 5 Metal foil 100 Supply reel part 200 Semiconductor chip mounting part 300 Sheet sticking part 400 Compression molding part 500 Winding reel

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location H01L 23/36 (72) Inventor Akira Zensaku 1 Komukai Toshiba-cho, Kawasaki-shi, Kanagawa 1 Toshiba Corporation Inside the Research Institute (72) Inventor Tomoaki Takubo 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Toshiba Research Institute Co. Ltd. (72) Inventor Yasuhiro Yamaji Komu-shi Toshiba-cho, 1 Kawasaki-shi, Kanagawa Toshiba Research Institute In-house

Claims (1)

[Claims] 1. A sealing resin sheet made of uncured resin is arranged on the active surface side of a semiconductor chip connected to a lead, and a metal material is arranged in contact with the back surface side of the semiconductor chip. A method for manufacturing a resin-encapsulated semiconductor device, characterized in that the uncured resin is cured while being pressed from the outside of the encapsulating resin sheet, and these are integrally molded.