JPH06125029A - Lead frame for semiconductor device, resin sealed type semiconductor device, and manufacture of resin sealed type semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a lead frame which can prevent damage to a sealing resin even when the resin is exposed to heat at the time of mounting a semiconductor device on a circuit board, etc., and a semiconductor device using the frame. CONSTITUTION:Members constituting the title lead frame, such as leads 51, a bed 53, etc., are coated with and protected by a sealing resin body 3 made of an epoxy resin, etc., together with a semiconductor chip 1 fixed to the bed 53 with a mounting agent 4, bonding wires 2 connecting the leads 51 to the chip 1, etc. Since the lead frame is composed of a sintered porous metal, the steam which is generated from the inside of the lead frame when a semiconductor device is fitted to a circuit board, etc., can be discharged to the outside through the lead frame.

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 lead frame for a semiconductor device and a resin-sealed semiconductor device using the structure.

[0002]

2. Description of the Related Art A lead frame 5 used for forming a lead of a semiconductor device is generally shown in FIG.
Lead 51 and hanging pin 5 attached to frame 50
2 and a semiconductor chip mounting bed (hereinafter, referred to as bed) 53 supported by the fishing pins. The lead frame is usually made of Cu or 42 formed by rolling or the like.
It is obtained by shaping a metal foil made of an alloy (Fe-42Ni alloy) or the like by etching, punching or the like. In order to form the resin-sealed semiconductor device shown in FIG. 1 by using this lead frame, first, the semiconductor chip 1 on which an integrated circuit or the like is formed is remounted with a mount agent 4 such as epoxy resin.
It is fixed to the bed 53 of the dframe 5. Semiconductor chip 1
An electrode (not shown) such as a pad electrode electrically connected to the integrated circuit in the semiconductor chip is formed on the main surface of the semiconductor chip, and the other electrodes are covered with an insulating protective film (not shown). Protected. The tips of the leads 51 attached to the tie bar 50 face the electrodes of the semiconductor chip 1, respectively. The lead tip and the electrode are electrically connected by a bonding wire 2 made of aluminum or gold. Next, the semiconductor chip 1
Is covered with a resin sealing body 3 containing an epoxy resin or the like. The tip portion of the lead 51 connected to the electrode of the semiconductor chip 1 is naturally covered with the resin sealing body 3. After sealing with resin, remove unnecessary parts of the lead frame 5 and
The portion of the terminal 51 exposed to the outside of the resin encapsulation body 3 is shaped so as to be easily mounted.

In recent years, in the field of resin-encapsulated semiconductor devices, miniaturization of various functional units on the elements and enlargement of the elements themselves have been rapidly progressing with the high integration of the semiconductor devices. In addition, surface mount packages represented by gate arrays called ASICs (Application Specific ICs) and standard cell type LSIs are rapidly advancing. When mounting these surface mount type packages on a circuit board or the like, steps such as vapor phase reflow, infrared reflow, and solder dipping are adopted. In these steps, the package is exposed to high temperatures up to 215-260 ° C.

[0004]

Therefore, when a semiconductor device is mounted on a circuit board or the like, in a resin-sealed semiconductor device sealed with an epoxy resin or the like, a small amount of moisture that penetrates through the resin and enters the inside. Rapidly evaporates and cracks occur in the resin encapsulant. When this crack reaches the outside, the reliability against humidity cannot be guaranteed. In addition, the phenomenon that the resin cannot be mounted due to the bulging of the resin occurs. Further, PSG (phosphosilicate glass) or SiN used as a passivation film for wiring such as aluminum.
There are many problems such as cracks in (silicon nitride), peeling of the passivation polyimide film, and breaking of bonding wires such as gold. In order to solve such a problem, (1) the stress on the sealing material such as the semiconductor chip in the sealing resin is reduced, and the sealing resin and the PSG, SiN, the polyimide film and the lead frame on the semiconductor chip are Demands for increasing adhesion, (2) providing high-temperature strength and moisture-absorption high-temperature strength corresponding to the mounting temperature, and reducing the amount of moisture absorption are increasing, especially for sealing resins for large packages. ing.

From these viewpoints, for example, maleimide resin-based, PPS (polyphenylene sulfide) -based resin, PPO (polyhydroxyphenylene ether) -based resin, and liquid crystal polymers are being put into practical use as sealing resins. Furthermore, recently, a resin in which a maleimide resin and an epoxy resin are combined, or an aminobismaleimide resin in which a bismaleimide resin and 4.4-diaminodiphenylmethane are combined has been proposed as a sealing resin. On the other hand, a resin-encapsulated semiconductor device in which a problem in mounting is improved by a package structure (for example, JP-A-60-20884).
No. 7) is proposed. This semiconductor device
A cylindrical or polygonal hole is formed in the mold resin (sealing resin) under the die pad to form an extremely thin portion or a portion without the molding resin, and the package for mounting
It has a structure in which the gas generated by the evaporation of the water inside the mold resin when the resin is heated escapes from the above-mentioned extremely thin portion. In addition, a method of forming a metallic covering layer on the surface of the package has been proposed from a method of manufacturing a transfer mold semiconductor device. However, none of the resin-encapsulated semiconductor devices has been sufficiently satisfactory in terms of productivity and reliability against humidity.

Furthermore, in order to alleviate the above-mentioned problems at the time of mounting and prevent the displacement and disconnection of the aluminum wiring due to the influence of the sealing resin, a hollow plastic package or the like has been proposed. It was not sufficient in terms of low humidity reliability. The present invention has been made under such circumstances, and in order to eliminate damage to the sealing resin due to the influence of heat during mounting, the lead frame has excellent adhesion to the sealing resin, and at the time of mounting An object of the present invention is to provide a resin-encapsulated semiconductor device that is highly effective in discharging the generated water vapor and has high reliability. It is another object of the present invention to provide a lead frame that can be sufficiently applied to large-sized device packages and thin-type packages that will be accelerated in the future.

[0007]

The present invention is characterized by using a lead frame for a semiconductor device, at least a part of which is formed of a porous metal sintered body. That is,
A lead frame for a semiconductor device of the present invention comprises a bed for mounting a semiconductor chip, a hanging pin and a lead for supporting the bed for mounting a semiconductor chip, and a porous body having at least one hole led out to the outside. The first feature is that it is made of a porous metal sintered body, and a semiconductor chip mounting bed, a hanging pin and a lead for supporting the semiconductor chip mounting bed, and at least one hole led to the outside are provided. The second feature is that the porous metal sintered body having the inside is attached to at least the semiconductor chip mounting bed, the hanging pin, or both. The surface portion of the porous metal sintered body may be densely formed and the inner portion thereof may be sparsely formed.

The resin-encapsulated semiconductor device of the present invention comprises a semiconductor chip mounting bed, a semiconductor chip mounted on the semiconductor chip mounting bed, and electrodes formed on the main surface of the semiconductor chip. A lead having one end adjacent to the electrode and electrically connected to the electrode and the other end extending to the outside of the semiconductor chip; the semiconductor chip mounting bed; A semiconductor chip and a resin encapsulant that covers a portion of the lead excluding the other end, and the lead, the semiconductor chip mounting bed, or both are at least one empty space led to the outside. The first feature is that it is made of a porous metal sintered body having holes inside. Also, a semiconductor chip mounting bed, a semiconductor chip mounted on the semiconductor chip mounting bed, an electrode formed on the main surface of the semiconductor chip, and one end of the electrode being close to the electrode. Is electrically connected to
A lead having the other end extending to the outside of the semiconductor chip, and a resin encapsulation that covers the semiconductor chip mounting bed, the semiconductor chip and a portion of the lead excluding the other end. A body, and at least one hole that is led to the outside is provided on at least the surface of the lead or the surface of the semiconductor chip mounting bed opposite to the surface on which the semiconductor chips are mounted. The second characteristic is that the porous metal sintered body of the above is attached.

The semiconductor chip mounting bed has a suspending pin which is continuously connected to the bed and extends to the outside of the resin sealing body. The porous metal sintered body may be attached to the pin. The surface portion and the inner portion of the porous metal sintered body of the bed for mounting the semiconductor chip are formed sparsely, and the inner portion of the porous metal sintered body of the hanging pin portion is formed sparsely. And, the surface portion can be densely formed. A bed for mounting semiconductor chips,
A semiconductor chip mounted on the bed for mounting the semiconductor chip, an electrode formed on the main surface of the semiconductor chip, one end thereof being close to the electrode and electrically connected to the electrode, A lead having an end extending to the outside of the semiconductor chip, a semiconductor chip mounting bed, a resin encapsulant that covers the semiconductor chip and a portion of the lead excluding the other end. And a heat sink attached to a surface of the semiconductor chip mounting bed opposite to the surface on which the semiconductor chips are mounted, and partially exposed from the resin sealing body, A third feature is that the heat dissipation plate is made of a porous metal sintered body having at least one hole led out to the outside. The porous metal sintered body may be impregnated and coated with a thermoplastic resin.

Further, the method for manufacturing a resin-sealed semiconductor device of the present invention comprises a step of impregnating a thin plate of a porous metal sintered body with a resin, and an etching process of the porous metal sintered body thin plate with an etching solution. To form a lead frame, removing the resin impregnated in the lead frame, attaching a semiconductor chip to the lead frame, and the lead frame. A step of connecting the lead end of the frame and the electrode on the semiconductor chip with a bonding wire, and the semiconductor chip, a part of the lead of the lead frame and the bonding wire with a resin sealing body. And a coating step.

[0011]

By using the porous metal sintered body for the lead frame, the effect of discharging water vapor generated when the resin-sealed semiconductor device using the porous metal sintered body is mounted on a circuit board or the like is improved.
Further, when the lead frame is impregnated with a thermoplastic resin, the moisture resistance is improved.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a resin-sealed semiconductor device, which is structurally the same as the above-mentioned conventional example. That is, a semiconductor chip 1 such as a silicon substrate on which an integrated circuit or the like is formed is fixed to a bed 53 of a lead frame 5 with a mount material 4 such as epoxy resin. Electrodes (not shown) such as pad electrodes electrically connected to the integrated circuit in the semiconductor chip are formed on the main surface of the semiconductor chip 1. Other than this electrode, an insulating protective film such as SiO ₂ is formed. It is covered and protected by (not shown). The tips of the leads 51 face the electrodes of the semiconductor chip 1, respectively.
The lead tip and the electrode are electrically connected by a bonding wire 2 made of aluminum or gold. The semiconductor chip 1 is covered with a resin sealing body 3 containing an epoxy resin or the like. The tip portion of the lead 51 connected to the electrode of the semiconductor chip 1 is naturally covered with the resin sealing body 3. The sealing resin used in this example is an epoxy resin (which may contain a maleimide resin).

In addition to the above materials, maleimide resin and polyphenylene sulfide (P
PS) resin, polyhydroxyphenylene ether (P
PO) -based resins, liquid crystal polymers, amino bismaleimide resins and the like. In this resin-sealed semiconductor device, as shown in FIG.
The lead frame 5 shown in FIG. 2 is used, and the lead frame 5 and the bed 53 are used. The figure shows DIP (Dual In-Line P
ackage) type semiconductor device
A top view of the camera is shown. The lead frame 5 has a thickness of about 150 to 200 μm, and the lead 51 and the hanging pin 52 supported by the tie bar 50 and the semiconductor chip mounting bed (hereinafter, referred to as a supporting pin) supported by the hanging pin. 53). This embodiment is characterized in that the lead frame 5 is made of a porous metal sintered body having at least one hole led to the outside inside. The lead frame of this porous metal sintered body is obtained by press-molding metal powder and sintering this, and the inside of the sintered body is a porous body having a plurality of pores led to the outside. It is qualitative. Any metal powder may be used as the metal powder as long as it is conductive, and one having excellent corrosion resistance is particularly preferable.

Specific examples thereof are Fe, Cu, Ni and S.
n, Zn, Al, and the like, and alloys of these. For example, 42 alloy or copper alloy which is generally used as a frame material can be used. As a method for manufacturing the lead frame of these porous metal sintered bodies, it is possible to make it by punching or etching with a mold, but it is necessary that holes are formed inside and on the surface by the processing, In the case of etching, the etching solution containing a strong acid, etc. permeates through the holes and deeply overruns inside.
In order to suppress the etching, it is advantageous to use a method in which the holes are filled with resin before the etching. The resin only needs to impregnate the surface layer. The resin which has closed the pores can be completely removed by boiling with a solvent, and the final processed product needs to be in a completely porous state. Further, the surface can be made porous by electric discharge machining, etching, polishing or the like. The lead frame for a semiconductor device of the present invention serves to release the vapor pressure generated due to vaporization of moisture inside the absorbed moisture from the holes in the lead frame when the entire package is rapidly exposed to high temperature during mounting. It is necessary that the holes are internally connected.

FIG. 3 is an enlarged sectional view of the area A in FIG. This figure shows the internal structure of the lead 51 of the lead frame, showing the boundary area between the part embedded in the resin encapsulant 3 and the part exposed from it. There is. The metal powder uses relatively averaged particles. The particles are partially fused by sintering, and voids are partially formed between the particles, and these voids are continuously connected and exposed on the surface. The moisture inside the resin encapsulation body 3 absorbed by the high temperature generated when the completed resin encapsulation type semiconductor device is mounted on a circuit board is vaporized, and the water vapor is discharged to the outside through the holes in the lead 51. To be done. This water vapor is lead 5
1 is not discharged only from, for example, a hanging pin that supports the bed 53 not shown in FIG.
It is discharged to the outside through the bed 53.

Below, three samples in this embodiment will be shown. A lead frame of a porous metal sintered body using 42 alloy metal powder was prepared. The average pore diameter of the porous metal powder is 7 μm and the porosity is 70%. This metal powder is processed into a thin plate having a thickness of 150 μm, the holes in the surface layer are filled with a methyl methacrylate resin, and a QFP (Quad Flat Package) type 184-pin lead frame is formed by etching. Next, the methyl methacrylate filled in the holes is dissolved with a solvent, the semiconductor chip of the 15 mm square test element is mount-bonded, and the resin is sealed to prepare a first sample (No. 1).
A lead frame was made from a porous metal sintered body using phosphor bronze metal powder. The porous metal powder has an average pore diameter of 5 μm and a porosity of 25%.
Make a sample of (No.2). A lead frame was prepared by using porcerax (a porous metal sintered body using stainless steel powder) manufactured by Shinto Kogyo Co., Ltd. The average pore diameter of the porous metal is 8 μm, and the porosity is 24%. A third sample is prepared using this metal powder (No. 3). As a comparative example, a 15 mm square test element is mount-bonded using a QFP type 184-pin 42-alloy lead frame, followed by resin sealing to prepare a sample (No. 6).

Using the samples of the above-mentioned three examples and the comparative example, (1) moisture absorption treatment was performed at 85 ° C./85% for 168 hours, and then vapor phase reflow (VPS) treatment was performed.
It was carried out twice at 5 ° C. and the generation of cracks inside and the cracks reaching outside were observed, and peeling between the back of the bed and the sealing resin was observed. (2) After performing moisture absorption treatment at 85 ° C./85% for 168 hours, VPS treatment is performed twice at 215 ° C., and then 12
A reliability test against humidity (PCT) by a pressure cooker is performed under the condition of 5 ° C / 2.5 atm. (3) After performing the same pretreatment as in (2), -65 ° C to 2
A thermal cycle test (TCT) at 00 ° C was performed. The results are shown in Tables 1 and 2. In the observation of crack generation in (1) in the table, the number of occurrences / the number of observations is described,
In the VPS-PCT or TCT test of (2) and (3), the number of defects / the number of measurements is described.

[0018]

[Table 1]

[0019]

[Table 2]

Next, a second embodiment will be described with reference to FIGS. 4 shows a lead cross section of a boundary portion between the inside and the outside of the same resin sealing body as in FIG. 3, and FIG. 5 shows a cross sectional view of a portion exposed to the outside of the lead. In the previous example, the internal structure of the lead frame was a state in which the particle groups were sintered almost uniformly in both the surface region and the internal region, but the internal structure of the lead frame was not always uniform. do not have to. For example, the particle group on the surface portion of the lead frame may be made dense to minimize or eliminate the pores, and the inside may be made sparser than the surface portion to secure a sufficient space for water vapor to pass. it can. If you do this,
The water vapor passages can be oriented in any direction. Figure 4
The particles of the surface portion 511 of the lead 51 shown in FIG. 2 are made dense, and the inside 512 and the vicinity of the end 513 of the lead 51 exposed from the resin sealing body 3 shown in FIG. If the state is made dense, the lead 51 becomes like a pipe and efficiently discharges the internal water vapor to the outside. Further, if the particle state of the surface portion of the bed 53 (see FIG. 1) is made sparse and the pores are made large, the water vapor inside the resin sealing body 3 efficiently enters the bed 53 and is discharged to the outside through the hanging pin. It At this time, if the surface portion of the fishing pin is made to have a dense particle like the lead 51, the water vapor discharging effect is further improved.

The density of the inside of the lead frame can be made to be sparse and dense depending on its part, by the difference in particle size of the metal powder. If the particle size of the metal powder is small, it can be made dense, and if this particle size is large, it can be made sparse. Such a state can be adjusted at the time of molding the metal powder. The lead frame of the porous metal sintered body has a uniform internal structure at the beginning of formation, but the surface of the lead frame is formed by cutting or polishing treatments for aligning the shapes or for molding as shown in FIGS. 4 and 5. The particles are crushed and enter the holes in the surface area and fill the holes. Therefore,
That part is denser than the inside. This dense state of the surface can be easily eliminated by etching or electric discharge machining polishing. It is easy to make one part of the lead frame dense and the other part sparse.

Next, a third embodiment will be described with reference to FIGS. 6 to 8 are enlarged plan views of the bed 53 and the hanging pin 52 of the lead frame. This embodiment is characterized in that the conventional lead frame of rolled metal is combined with the lead frame of porous metal sintered body.
The lead frame of the sintered porous metal is the lead of the rolled metal.
The size may be the same as the dframe, but it may be partially used together. As a means for laminating, an adhesive can be used, and as the type of the adhesive, a silicone type, a polyimide type, an epoxy type, from the viewpoint of heat resistance and moisture resistance,
It can be appropriately selected from polyester type and the like. The thickness of the porous metal sintered body attached to the lead frame of the rolled metal is 50 μm in order to maintain the water vapor discharge effect during mounting without significantly lowering the strength of the lead frame. It must be below the level. The sticking position can be determined in consideration of the discharge effect except when sticking to the entire surface of the lead frame, and it is particularly preferable to stick the sticking pin at least on the back of the bed and the fishing pin portion continuous there. . FIG. 6 is applied to a DIP type semiconductor device. FIG. 6 (a) shows a case where the porous metal sintered body 6 is stuck on the entire surface of the lead frame, and the efficiency is obtained by simultaneously etching the composite of the rolled metal and the metal sintered body. Thus, a lead frame can be formed.

In the figure, the fishing pin 52 and the bed 53 are attached to the entire back surface. In FIG. 6B, the hanging pin 52
The porous metal sintered body 6 is attached in a straight line from the to the bed 53 with the same width as the hanging pin. In FIG. 6C, the porous metal sintered body 6 is attached in a circular shape to the center of the fishing pin 52 and the bed 53. In FIG. 6D, the porous metal sintered body 6 is formed so as to intersect the hanging pin 52 and the bed corner portion. In FIG. 6E, the porous metal sintered body 6 is formed along the periphery of the hanging pin 52 and the bed 53. 7 and 8 are applied to a QFP type semiconductor device. Figure 7 (a) shows
It shows a case where the porous metal sintered body 6 is attached to the entire surface of the dframe, and is attached to the entire rear surface of the hanging pin 52 and the bed 53. In FIG. 7B, the porous metal sintered body 6 is attached in a straight line with the same width as the hanging pin from the hanging pin 52 to the bed 53, and the straight lines intersect each other. In FIG. 7C, a circular porous metal sintered body 6 is attached to the center of the hanging pin 52 and the bed 53 in a circular shape. Figure 8
In (a), the porous metal sintered body 6 is formed so as to linearly project from the respective corner portions of the hanging pin 52 and the bed 53 to the center. In FIG. 8B, the porous metal sintered body 6 is formed along the periphery of the hanging pin 52 and the bed 53.

Next, a fourth embodiment will be described with reference to FIG. This embodiment is characterized in that a porous metal sintered body is used for the heat dissipation plate. The figure is a cross-sectional view of a resin-sealed semiconductor device. A semiconductor chip 1 is attached to a main surface of a bed 53 formed of a lead frame by a mount agent 4 such as epoxy resin. The bed 53, the semiconductor chip 1, a part of the lead 52, and the bonding wire 52 connecting the lead 51 and the electrode of the semiconductor chip 1 are
Both are covered with the resin sealing body 3. This bed 5
A heat radiating plate 7 made of a porous metal sintered body is attached to the back surface of 3, and is partially covered with the resin sealing body 3 and a part is exposed to the outside. Since the porous metal sintered body is used for the heat radiating plate 7, the water vapor generated at the time of mounting on the circuit board is discharged to the outside through this. In this embodiment, the lead frame
Although a conventional rolled metal is used for the frame, it is of course possible to use the porous metal sintered body. FIG. 9A is an example in which the heat dissipation plate 7 is attached to the entire back surface of the bed 53. If the lead frame is a porous metal sintered body, it is made of the same material as the heat sink, so it is integrated with the heat sink using the lead frame of the porous metal sintered body with only the bed thickened. You can also let it. In addition, in this case, without thickening the bed,
If the back surface of the bed portion is exposed from the resin sealing body, the bed portion also functions as a heat dissipation plate. 9 (b) and 9 (c)
In each of the examples, the heat dissipation plate 7 is attached to a part such as the center of the back surface of the bed 53.

Next, a fifth embodiment will be described. This embodiment is characterized in that the porous metal sintered body of the lead frame, which is at least partly a porous metal sintered body, is impregnated with a thermoplastic resin. Using this lead frame, a resin-sealed semiconductor device is formed. Then, when this semiconductor device is mounted on a substrate, the impregnated thermoplastic resin is melted by the high temperature at the time of mounting, and a water vapor discharge path inside the resin sealing body is formed in each part of the lead frame. Examples of the method for impregnating the lead frame of the porous metal sintered body with the thermoplastic resin include a method of dissolving the thermoplastic resin in a solvent and impregnating the porous metal sintered body, a vacuum impregnation method, and the like. After impregnation, the solvent is removed by heating or the like. The thermoplastic resin is pre-read
Since the resin is impregnated, it is possible to considerably prevent the infiltration of water from the outside into the inside of the resin sealing body. The impregnated thermoplastic resin acts as a kind of valve and can also help improve strength. It is also possible to impregnate only the surface region of the porous metal sintered body. Examples of the thermoplastic resin include polyethylene, polypropylene, polybutene, polyisobutylene, polystyrene, ABS resin, acrylic resin, vinyl acetate resin, butyral resin, polybutadiene, and polycarbonate.
Bonnet, nylon, polyester and the like can be mentioned. Since the mounting temperature is about 200 to 250 ° C., a material that melts at this temperature is selected. This porous metal sintered body impregnated with a thermoplastic resin is most suitable when applied to the heat dissipation plate of the fourth embodiment described above.

When the thin plate of the porous metal sintered body is processed by etching to form the lead frame, the thin plate is relatively deeply impregnated with resin in advance,
If this is not removed to the end, the above-mentioned lead frame impregnated with a thermoplastic resin can be easily obtained. Next, a sixth embodiment will be described with reference to FIG. The figure is
It is sectional drawing of a resin sealing type semiconductor device. The structure is almost the same as that of FIG. 1 for explaining the first embodiment, but the structure of the lead frame used is different. In this figure,
The bed 53 of the dframe is recessed from the lead 51, and the back of the bed is exposed from the resin encapsulant 3 so that it has a heat radiation effect. Also, the bonding wire 2 is not damaged much.

Below, two samples are prepared. A rolled 42-alloy lead frame and a 42-alloy porous metal-sintered lead frame are bonded together to form the structure shown in FIG.
The lead frame shown in (a) is formed, and the resin frame type semiconductor device as shown in FIG. 1 is formed by using the lead frame. The porosity of the porous metal sintered body was 10%, the average pore diameter was 5 μm, and the thickness was 30 μm (No. 4). Next, a lead frame made of a 42 alloy porous metal sintered body was impregnated with ABS resin to form a QFP184 pin type lead frame, which was used to seal the resin as shown in FIG. A static semiconductor device is formed (No. 5). The properties of this sample were measured and listed in Table 2 together with the properties of the conventional example (No. 6). From these measurement results, the effect of the present invention is recognized.

[0028]

As described above, in the resin-sealed semiconductor device using the lead frame of the present invention, the water vapor inside the resin-sealed body generated when the semiconductor device is mounted on the circuit board can be efficiently discharged to the outside. You can Since the lead frame has excellent adhesiveness with the sealing resin, no defect occurs and high reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a resin-sealed semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a plan view of a first embodiment and a conventional lead frame.

FIG. 3 is an enlarged cross-sectional view showing an interface A between the resin sealing body and the lead portion shown in FIG.

FIG. 4 is an enlarged cross-sectional view of a second embodiment showing an interface A between the resin sealing body and the lead portion of FIG.

5 is an enlarged cross-sectional view of a second embodiment showing an interface A between the resin sealing body and the lead portion of FIG.

FIG. 6 is a partially enlarged plan view of a lead frame according to a third embodiment.

FIG. 7 is a partially enlarged plan view of a lead frame according to a third embodiment.

FIG. 8 is a partially enlarged plan view of a lead frame according to a third embodiment.

FIG. 9 is a sectional view of a resin-encapsulated semiconductor device according to a fourth embodiment.

FIG. 10 is a sectional view of a resin-sealed semiconductor device of a sixth embodiment.

[Explanation of symbols]

 1 Semiconductor Chip 2 Bonding Wire 3 Resin Sealing Body 4 Mounting Agent 5 Lead Frame 6 Porous Metal Sintered Body 7 Heat Dissipating Plate 51 Lead 52 Fishing Pin 53 Bed

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Michiya Higashi 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki City, Kanagawa Prefecture, Toshiba Research Institute Co., Ltd. (72) Inventor Hiroshi Shimozawa, Komukai Toshiba, Kawasaki-shi, Kanagawa Town No. 1 Toshiba Corporation Research Institute

Claims (10)

[Claims] 1. A lead frame for a semiconductor device, comprising a porous metal sintered body. 2. A lead frame for a semiconductor device, wherein a porous metal sintered body is attached to at least a part of the surface thereof. 3. A semiconductor chip mounting bed, a hanging pin and a lead for supporting the semiconductor chip mounting bed, and a porous metal sintered body attached to at least one surface of these. A lead frame for a semiconductor device, which is characterized by: 4. The semiconductor according to claim 1, wherein a surface portion of the porous metal sintered body is densely formed and an inner portion thereof is sparsely formed. Lead frame for equipment. 5. A semiconductor chip mounting bed or a semiconductor chip mounting bed having hanging pins, and a semiconductor chip mounted on the semiconductor chip mounting bed or the semiconductor chip mounting bed having hanging pins. An electrode formed on the main surface of the semiconductor chip, one end of which is close to the electrode and electrically connected to the electrode, and the other end of which extends outside the semiconductor chip. A lead, a portion excluding the other end of the lead, a semiconductor chip mounting bed or a semiconductor chip mounting bed having a hanging pin, and a resin encapsulant covering the semiconductor chip. At least one of the lead, the hanging pin, and the semiconductor chip mounting bed is made of a porous metal sintered body, and a resin-sealed semiconductor device is provided. 6. A semiconductor chip mounting bed or a semiconductor chip mounting bed having a hanging pin, and a semiconductor chip mounted on the semiconductor chip mounting bed or a semiconductor chip mounting bed having a hanging pin. An electrode formed on the main surface of the semiconductor chip, one end of which is close to the electrode and electrically connected to the electrode, and the other end of which extends outside the semiconductor chip. And a portion other than the other end of the lead, the semiconductor chip and the resin sealing body that covers the semiconductor chip mounting bed or the semiconductor chip mounting bed having a hanging pin, A resin-sealed semiconductor device, wherein a porous metal sintered body is attached to at least one of the lead, the hanging pin, and the semiconductor chip mounting bed. 7. The surface of the porous metal sintered body at the one end portion electrically connected to the electrode of the lead is densely formed. 6
The resin-encapsulated semiconductor device according to. 8. A semiconductor chip mounting bed or a semiconductor chip mounting bed having a hanging pin, and a semiconductor chip mounted on the semiconductor chip mounting bed or a semiconductor chip mounting bed having a hanging pin. An electrode formed on the main surface of the semiconductor chip, one end of which is close to the electrode and electrically connected to the electrode, and the other end of which extends outside the semiconductor chip. A semiconductor chip mounting bed or a semiconductor chip mounting bed having a hanging pin, a resin sealing body that covers the semiconductor chip and a portion of the lead excluding the other end, and the semiconductor The chip mounting bed or the semiconductor chip mounting bed having a hanging pin is attached to the surface opposite to the surface on which the semiconductor chip is mounted, and is partially exposed from the resin sealing body. And a heat plate, the heat sink, a resin-encapsulated semiconductor device characterized by comprising a porous metal sintered body. 9. The resin-encapsulated semiconductor device according to claim 1, wherein the porous metal sintered body is impregnated with and coated with a thermoplastic resin. 10. A step of impregnating a thin plate of a porous metal sintered body with a resin; a step of etching the thin plate of the porous metal sintered body with an etching solution to form a lead frame; A step of removing the resin impregnated in the lead frame, a step of attaching a semiconductor chip to the lead frame, a lead tip of the lead frame and an electrode on the semiconductor chip. With a bonding wire, and a step of coating the semiconductor chip, a part of the lead of the lead frame and the bonding wire with a resin encapsulant. Manufacturing method of sealed semiconductor device.