JPH10144827A - Resin sealed semiconductor device, production thereof and die therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a resin sealed semiconductor device in which reflow resistance is enhanced while decreasing thermal resistance by arranging a low stress and high thermally conductive sealing resins on the opposite sides of a lead frame die bonded with a semiconductor chip. SOLUTION: Since the upper and lower transfer molding dies 11, 12 are provided, respectively, with gates 13, 14 and pots 15, 16, a lead frame 2 can be sealed with different resins on the opposite sides thereof. More specifically, a resin sealed semiconductor device having low stress and low thermal resistance can be obtained by sealing a semiconductor chip 1 with a low stress resin 3 on the mounting side and with a high thermally conductive resin 4 on the opposite side. Consequently, stress is suppressed on the interface between the semiconductor chip and the low stress resin at the time of heating the resin sealed semiconductor device and reflow resistance can be enhanced while decreasing thermal resistance by dissipating heat to be generated on the semiconductor chip during operation efficiently through the high thermally conductive resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a resin-sealed semiconductor device, a method of manufacturing the same, and a mold thereof.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field include:
For example, literature title VLSI packaging technology (below),
Nikkei BP, P.K. 200. The P.S. 200, shown in FIG. 15.3.1, the thermal resistance has been reduced from two aspects of “material” and “structure”.

On the "material" side, Cu has been used as a lead frame material, or a filler in a molding resin has been devised to improve the thermal conductivity of the material. On the “structure” side, the lead frame shape has been devised, for example, by increasing the die pad size, or a method of incorporating a heat sink inside the device has been adopted.

[0004]

However, even the above-mentioned conventional methods have respective problems and disadvantages, and have not been technically satisfactory. This is described below. (1) When a material having high thermal conductivity is used, the stress generated in the device increases, and the reflow resistance and the T / C (Temperature Cycle) property are weak. Incidentally, as for the T / C test, one of the reliability tests of the semiconductor device is a temperature cycle test. In this temperature cycle test, the semiconductor device is placed in a high-temperature atmosphere (125 ° C.).
(150 ° C.) and a low-temperature atmosphere (−55 ° C. to −65 ° C.) alternately for 30 minutes to generate a thermal stress in the semiconductor device and check the quality.

(2) There is a limit to the enlargement of the die pad size, and when a heat sink is built in, there is a limit to the reduction in thickness. SUMMARY OF THE INVENTION An object of the present invention is to provide a resin-sealed semiconductor device capable of eliminating the above-mentioned problems and having high reflow resistance and low thermal resistance, a method of manufacturing the same, and a mold thereof.

[0006]

According to the present invention, there is provided a resin-encapsulated semiconductor device, comprising: a lead frame on which a semiconductor chip is die-bonded; And a high thermal conductive resin sealed on the side opposite to the side on which the semiconductor chip is mounted.

As described above, the low-stress resin is provided above the lead frame, that is, the side on which the semiconductor chip is mounted, and the high thermal conductive resin is provided below the lead frame.
A resin-sealed semiconductor device having high reflow resistance and low thermal resistance can be obtained. (2) In the method of manufacturing a resin-encapsulated semiconductor device, the side on which the semiconductor chip is mounted is sealed with a low-stress resin with the lead frame to which the semiconductor chip is die-bonded interposed therebetween, and the side opposite to the side on which the semiconductor chip is mounted is opposite. The side is sealed with a high thermal conductive resin.

As described above, the upper portion of the lead frame, that is, the side on which the semiconductor chip is mounted is sealed with a low stress resin, and the lower side of the lead frame is sealed with a high thermal conductive resin. Stress generated at the interface between the semiconductor chip and the low-stress resin at the time can be reduced, and the heat generated on the semiconductor chip during operation can be efficiently radiated through the high thermal conductive resin, and the reflow resistance is high, In addition, the thermal resistance can be reduced.

(3) In a mold for transfer molding of a resin-sealed semiconductor device, an upper mold having an upper mold pot, an upper mold gate, and an upper mold cavity, and a lower mold pot are provided. A lower mold having a lower mold gate and a lower mold cavity is provided, and a lead frame to which a semiconductor chip is die-bonded is sandwiched between the upper mold and the lower mold, and sealed with another resin. It is like that.

[0010] Therefore, by using a simple structure, separate resins are provided vertically above and below the lead frame, that is, the side on which the semiconductor chip is mounted is sealed with a low-stress resin and the opposite side is sealed with a high-thermal-conductivity resin. It is possible to obtain a mold capable of manufacturing a resin-encapsulated semiconductor device having high heat resistance and low heat resistance.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of a resin-sealed semiconductor device showing an embodiment of the present invention. As shown in this figure, the upper side (the semiconductor chip 1 side) of the lead frame 2 is sealed with a low stress resin 3, and the lower side of the lead frame 2 is sealed with a high thermal conductive resin 4. Note that the epoxy resin bonding is also performed between the low stress resin 3 and the high thermal conductive resin 4, and there is no gap.

Here, the low-stress resin 3 and the high-thermal-conductivity resin 4 will be described in detail. In general, a semiconductor encapsulating resin is composed of a skeleton epoxy resin mixed with various materials. The mixed materials of the low stress resin and the high thermal conductive resin are slightly different. For example, the low stress resin includes an epoxy resin, a filler (silica), a low stress material (silicone), a pigment, and the like. The high thermal conductive resin is made of an epoxy resin, a filler (alumina), a pigment, and others.

Incidentally, since the skeleton of the low-stress resin and the high-thermal-conductivity resin remains an epoxy resin, there is no interface. A low-stress resin region containing silica and silicone and a high-thermal-conductivity resin region containing alumina are formed on the border of the lead frame. Since the upper side of the lead frame 2 (semiconductor chip 1 side) is sealed with the low-stress resin 3 as described above, the stress generated at the interface between the semiconductor chip 1 and the low-stress resin 3 during heating, such as during reflow, can be reduced. Can be.

Further, since the lower side of the lead frame 2 is sealed with the high thermal conductive resin 4, it is possible to efficiently radiate heat generated on the semiconductor chip 1 during operation. As described above, according to this embodiment, the upper side (semiconductor chip 1 side) of the lead frame 2 is sealed with the low stress resin 3 and the lower side of the lead frame 2 is sealed with the high thermal conductive resin 4. When the semiconductor device is heated, the stress generated at the interface between the semiconductor chip 1 and the low stress resin 3 is reduced, and the heat generated on the semiconductor chip 1 during operation is reduced by the high thermal conductive resin 4.
, Heat can be efficiently dissipated, the reflow resistance is high, and the thermal resistance is low.

Next, a method of manufacturing a resin-sealed semiconductor device according to an embodiment of the present invention will be described. 2 is a cross-sectional view of a transfer mold for manufacturing a resin-encapsulated semiconductor device according to an embodiment of the present invention, FIG. 3 is a plan view of the transfer mold, and FIG. 4 is a transfer mold. It is a figure showing the state of transfer mold by a type.

In these figures, 11 is an upper mold, 12
Is a lower mold gate, 13 is an upper mold gate, 14 is a lower mold gate, 15 is an upper mold pot, 16 is a lower mold pot,
7 is a cavity. As described above, the upper die 11 and the lower die 12 are provided with the upper die gate 13, the lower die gate 14, and the upper die pot 15 and the lower die pot 16 connected thereto, respectively. Different resins can be poured above and below the lead frame 2 on which the die 1 is die-bonded.

From the upper mold pot 15, a low-stress resin 3
The high heat conductive resin 4 is simultaneously poured from the lower mold pot 16 and molded. As described above, according to this embodiment, the upper mold 11 and the lower mold 12 for the transfer mold are used.
Are provided with separate upper and lower mold gates 13, lower mold gates 14, upper mold pots 15, and lower mold pots 16, respectively. Can be sealed. That is, as shown in FIG. 4, the side on which the semiconductor chip 1 is mounted
By sealing the other side with the high thermal conductive resin 4,
A resin-encapsulated semiconductor device having low stress and low thermal resistance can be obtained.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0019]

As described above, according to the present invention, the following effects can be obtained. (1) According to the first aspect of the present invention, a low stress resin is provided on the upper side of the lead frame, that is, a side on which the semiconductor chip is mounted, and a high thermal conductive resin is provided on the lower side of the lead frame. It is possible to obtain a resin-encapsulated semiconductor device that is high and can reduce thermal resistance.

(2) According to the second aspect of the invention, the upper side of the lead frame, that is, the side on which the semiconductor chip is mounted, is sealed with a low stress resin, and the lower side of the lead frame is sealed with a high thermal conductive resin. Therefore, the stress generated at the interface between the semiconductor chip and the resin when the resin-encapsulated semiconductor device is heated is reduced,
The heat generated on the semiconductor chip during operation can be efficiently radiated through the high thermal conductive resin, and the reflow resistance can be high and the thermal resistance can be low.

(3) According to the third aspect of the invention, the upper and lower parts of the resin are separated by a simple structure,
In other words, the mold on which the semiconductor chip mounted side is sealed with a low-stress resin and the opposite side with a high-thermal-conductivity resin is used to manufacture a resin-encapsulated semiconductor device having low stress and low thermal resistance. Obtainable.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of a transfer mold for manufacturing a resin-sealed semiconductor device according to an embodiment of the present invention.

FIG. 3 is a plan view of a transfer molding die for manufacturing a resin-sealed semiconductor device according to an embodiment of the present invention.

FIG. 4 is a diagram showing a state of transfer molding of a semiconductor device using a transfer mold according to an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 semiconductor chip 2 lead frame 3 low stress resin 4 high thermal conductive resin 11 upper mold 12 lower mold 13 upper mold gate 14 lower mold gate 15 upper mold pot 16 lower mold pot 17 cavity

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29C 45/26 H01L 21/56 R H01L 21/56 // B29L 31:34

Claims (3)

[Claims] In a resin-encapsulated semiconductor device, a low-stress resin encapsulated on a side on which the semiconductor chip is mounted and a side opposite to the side on which the semiconductor chip is mounted are sandwiched by a lead frame to which the semiconductor chip is die-bonded. And a high thermal conductive resin sealed on the side. 2. A method for manufacturing a resin-encapsulated semiconductor device, comprising: a side on which the semiconductor chip is mounted is sealed with a low-stress resin; The other side of the semiconductor device is sealed with a high thermal conductive resin. 3. A transfer mold for a resin-encapsulated semiconductor device, comprising: (a) an upper mold having an upper mold pot, an upper mold gate, and an upper mold cavity;
(B) a lower mold having a lower mold pot, a lower mold gate, and a lower mold cavity; and (c) a lead frame to which a semiconductor chip is die-bonded. And sealing with another resin.