JP2003068979A - Semiconductor device - Google Patents

Abstract

(57) [Problem] To provide an inexpensive power semiconductor device that can ensure a high withstand voltage of a semiconductor device, has a simple structure, and is inexpensive. SOLUTION: An insulating substrate 1a having conductors 1b bonded to both sides thereof is joined by solder 6 to a container bottom plate 4 of a container composed of a container side wall 5 and a container bottom plate 4, and is formed on one surface of the insulating substrate 1a. It is constituted by providing an Si chip 2 joined by solder and an external lead terminal 7. The upper surface of the container is sealed by a sealing plate 8a having a gel injection port 8d and a protruding structure portion 8b for pulling out the external lead-out terminal 7 to the outside. The structure 8b is configured to protrude below the sealing plate 8a. The inside of the container is filled with the gel agent 10 to a position in contact with the lower end of the protruding portion of the above-described structure portion 8b, and a space is formed from the upper surface of the gel agent 10 to the lower surface of the sealing plate 8a. The hole of the structural portion 8b is closed by the hard resin 12 so as to fix the external terminal, and the gel agent inlet 8d
Is closed by the silicone rubber cap 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a power semiconductor device which is provided in a case and is filled with an insulating gel agent and sealed.

[0002]

2. Description of the Related Art As a conventional technique relating to a power semiconductor device provided in a case and filled with an insulating gel agent and sealed,
For example, the technique described in JP-A-8-125071 is known.

FIG. 7 is a partial sectional view showing the structure of a power semiconductor device according to the prior art. The prior art will be described with reference to this figure. In FIG. 7, 1a is an insulating substrate,
2 is a Si chip, 3 is an aluminum wire, 4 is a container bottom plate, 5
Is a side wall of the container, 6 is a solder, 7 is an external lead terminal, 8f is a terminal block, 10 is a gel agent, and 12 is a hard resin.

As shown in FIG. 7, a semiconductor device according to the prior art is made up of a ceramic substrate or the like having a container bottom plate 4 as a base plate and solder 6 bonded on the container bottom plate 4 as a base plate, as shown in FIG. Insulating substrate 1a and Si chip 2 of a semiconductor element provided on insulating substrate 1a
And a terminal block 8f in which the external lead terminal 7 is resin-molded in advance, the Si chip 2 and the conductor on the insulating substrate 1a are connected by an aluminum wire, and the external lead terminal 7 is soldered to the conductor on the insulating substrate 1a. And cover the container, and the gel agent 10 is filled in the entire area of the insulating substrate 1a and the container bottom plate 4,
Further, it has a structure in which the hard resin 12 is filled in the gap between the upper surface of the gel agent 10 and the terminal block 8f and cured.

The above-described conventional semiconductor device has the above-described structure in which the gel material 10 is filled on the insulating substrate 1a and the hard resin 12 is further filled, whereby the container side wall 5 and the terminal block 8f are formed. The terminal block can be firmly fixed by suppressing peeling from the substrate, moisture can be prevented from entering from the outside, and the power semiconductor device can function as a high withstand voltage power semiconductor device that is free from deterioration in withstand voltage.

[0006]

In the prior art described above, the terminal block 8f is constructed by fixing the external lead terminal 7 with resin in advance.
The adhesiveness is weak in the portion where the resin is fixed, and the internal stress 16 is generated due to the difference in the thermal expansion coefficient between the resin agent and the terminal material due to the repeated rise and fall of the temperature during operation of the device, causing peeling and moisture. However, there is a problem in that the characteristics of the device are deteriorated by the intrusion of the. This phenomenon is caused by the container side wall 5
Is also likely to occur between the hard resin 12 and the hard resin 12. In general,
The adhesive force of the same type of resin agent is stronger than that of other structural materials.

Further, in the above-mentioned prior art, since the upper part is covered with the hard resin, the internal stress 16 is generated due to the expansion and contraction of the gel agent 10 due to the repeated rise and fall of the temperature during the operation of the apparatus, and There is a problem that defects such as cracks and voids may be generated inside the agent, and peeling may occur between the agent and the insulating substrate, which results in dielectric breakdown of the semiconductor device. is doing.

The object of the present invention is to solve the above-mentioned problems of the prior art, to make the resin sealing structure for taking out the external terminal a simple structure, and to secure a high withstand voltage withstand voltage inside. An object of the present invention is to provide a power semiconductor device.

[0009]

According to the present invention, the above object is to use, as a base plate, one or a plurality of insulating substrates on which a semiconductor element is mounted and external lead terminals are formed and on which a conductor is formed. It is mounted on a container bottom plate in a container configured by joining a container side wall to the outer peripheral portion of the container bottom plate, and the container is covered with a sealing plate for leading out the external lead terminal, and the inside of the container is filled with an insulating gel agent. In the semiconductor device configured as above, a space is formed between the upper surface of the gel agent and the lower surface of the sealing plate, and the structure portion for the external lead-out terminal of the sealing plate is molded by one kind of hard resin. It is achieved by being configured and configured.

In the above description, the structure for the external lead-out terminal is formed in a hole shape having a size that allows the external lead-out terminal to be pulled out to the outside with a margin, and below the sealing plate, the gel is formed. It is configured to have a protruding portion that comes into contact with the agent, or is formed in a two-stepped hole shape, and a nonwoven fabric is arranged in the hole.

Further, in the above description, the sealing plate and the hard resin are formed of a resin having a tracking resistance index of 400 V or more, and the container side wall is formed of PPS (polyparaphenylene sulfide), PBT (polybutylene terephthalate), The hard resin is made of SPS (syndiotactic polystyrene), polyamide resin, polyamideimide resin, or polyetheramide resin, and the hard resin is epoxy resin or phenol resin. It is made of polypropylene and fluorine resin.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a power semiconductor device according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an enlarged partial sectional view showing the structure of a power semiconductor device according to a first embodiment of the present invention, and FIG.
FIG. 6 is a diagram illustrating an assembling process of the power semiconductor device according to the embodiment. 1 and 5, 1b is a conductor, 8
Reference numeral a is a sealing plate, 8b is a protruding structure portion, 8d is a gel agent injection port, 9 is an adhesive agent, 13 is a silicone rubber cap, and 14 is a hollow portion, and other reference numerals are the same as those in FIG.

In the semiconductor device according to the first embodiment of the present invention, as shown in FIG. 1, the container bottom plate 4 of the container formed by the container side wall 5 and the container bottom plate 4 provided on the outer peripheral portion of the container bottom plate 4 is a base plate. As a result, the insulating substrate 1a having the conductors 1b made of Cu or the like adhered on both sides is joined by solder 6 on the base plate, and the Si chip 2 which is a semiconductor element and the outside are joined by soldering on one surface of the insulating substrate 1a. The lead terminal 7 is provided, and the Si chip 2 and the conductor 1b to which the external lead terminal 7 is solder-bonded are connected by the aluminum wire 3.

Then, the upper surface of the container is adhered by an adhesive 9
Sealing plate 8a having gel injection port 8d and hole-shaped protruding structure portion 8b for externally drawing out external terminal 7
It is sealed by. The protruding structure portion 8b is formed in a hole shape having a size that allows the external lead-out terminal 7 to be pulled out to the outside with a margin, and has a skirt-like portion as a protruding portion below the sealing plate 8a. Is configured. Further, the inside of the container containing the insulating substrate 1a to which the Si chip 2 and the external lead-out terminal 7 are joined is filled with the gel agent 10 up to a position in contact with the lower end of the protruding portion of the protruding structure portion 8b described above. A space is formed between the upper surface of the agent 10 and the lower surface of the sealing plate 8a. Further, the hole portion of the protruding structure portion 8b is closed by the hard resin so as to fix the external terminal, and the gel agent injection port 8d is closed by the silicone rubber cap 13.

Next, a method of manufacturing a semiconductor device having the above-described structure according to the first embodiment of the present invention will be described with reference to FIG.
Will be described with reference to.

In advance, the base plate serving as the container bottom plate 4 and the container side wall 5 are integrated with each other, or bonded and fixed with a silicone adhesive to form the container. The base plate serving as the container bottom plate 4 is, for example, Ni-plated Mo, Cu, A
l, Al-SiC composite material, CuCuO2 sintered material, etc., and the container side wall 5 has, for example, PPS (polyparaphenylene sulfide) having a CTI (tracking resistance index) of 400 V or more, PBT (polybutylene terephthalate). , SPS (syndiotactic polystyrene), polyamide-based resin, polyamide-imide-based resin,
It is made of a resin material selected from polyetheramide resins.

Next, the Si chip 2 is mounted on an insulating substrate 1a made of ALN (aluminum nitride) or the like on which a conductor 1b made of Cu foil or the like is formed, on a base plate serving as a container bottom plate 4 of the formed container. The insulating substrate 1a wired by the aluminum wire bonding 3 is soldered (for example, S
Bonded with n-40 wt% Pb) 6. At the same time, the external lead-out terminal 7 made of Ni-plated Cu material or the like is attached to the insulating substrate 1.
It is joined by soldering onto a (above, FIG. 5 (a)).

Next, a sealing plate 8a having a groove structure portion 8d having a gel agent injection hole 8d and an external lead-out terminal 7 and having a downwardly protruding structure portion 8b is previously formed on the upper surface of the container. Then, the end of the sealing plate 8a is bonded and fixed to the upper end of the container side wall 5 with, for example, a silicone adhesive 9. The sealing plate 8a has, for example, a CTI (tracking resistance index) 4
PPS (polyparaphenylene sulfide), PBT (polyethylene terephthalate), S having 00V or more
It is made of a resin material selected from PS (syndiotactic polystyrene), a polyamide resin, a polyamideimide resin, and a polyetheramide resin. Next, the silicone-based gel agent 10 is injected from the gel agent injection port 8d to the lower portion of the projecting shaped structure portion 8b, and the temperature is increased to, for example,
It is cured at 0 ° C. for 2 hours.

In the injection of the gel agent 10 described above, it is important to adjust the injection amount so that the lower portion of the protruding structure 8b is completely adhered to the silicone gel agent 10. In the next step, this is a structure 8 having a protruding shape.
This is to prevent the resin before curing from flowing into the upper surface of the gel agent 10 when the space between the external lead terminal 7b and the external lead terminal 7 is closed with a hard resin. To adjust the injection amount of the gel agent, for example, a container is made in advance with a transparent material, and S
The insulating substrate 1a on which the i-chip 2 is mounted is housed, the gel agent is injected while measuring the injection amount of the gel agent, and this is observed from the outside, and the lower part of the protruding structure portion 8b is the silicone gel agent 10. It suffices to determine the amount of the gel agent that completely adheres (above, FIG. 5B).

Next, a hard resin (for example, an epoxy resin or a phenol resin having a CTI of 400 V or more) 12 is injected into the inner groove of the structure portion 8b of the sealing plate 8a, and the temperature is, for example, 150 ° C. for 2 hours. It is cured under the conditions of.
As a result, the external lead terminal 7 and the sealing plate 8a are resin-fixed. Next, a cap 13 made of a silicone rubber material is inserted and fixed in a gel injection hole provided in the sealing plate in advance. In this case, the cap 13 may be coated with a silicone adhesive and then heat-cured. As described above, a semiconductor device having a hollow structure inside the container can be obtained, and the external lead-out terminal 7 is shaped by bending or the like (the above, FIG. 5C).

According to the above-described first embodiment of the present invention, the external lead-out terminal 7 can be easily sealed and fixed with one type of hard resin with a simple structure, and the hollow structure does not restrain the gel layer. Since the structure can be adopted, a highly reliable high breakdown voltage semiconductor device which does not cause defects in the gel layer can be obtained at low cost.

FIG. 2 is an enlarged partial sectional view showing the structure of the power semiconductor device according to the second embodiment of the present invention, and FIG.
FIG. 6 is a diagram illustrating an assembling process of the power semiconductor device according to the embodiment. In FIGS. 2 and 6, 8c is a two-step groove-shaped structure portion, 11a is a nonwoven fabric, and 11b is an opening portion,
Other reference numerals are the same as those in FIGS. 1 and 5.

In the semiconductor device according to the second embodiment of the present invention shown in FIG. 2, the shape of the structure portion for drawing out the external lead terminal 7 provided on the sealing plate 8a in the first embodiment described with reference to FIG. It is configured by differently.
That is, as shown in FIG. 2, the structure part for drawing out the external lead-out terminal 7 of the semiconductor device according to the second embodiment of the present invention has a two-step groove shape provided with a brim part such that the lower hole becomes smaller. The structure portion 8c is configured to hold the nonwoven fabric 11a that prevents the hard resin from leaking, as will be described later. Also in the second embodiment, a space is provided between the upper surface of the gel agent 10 and the sealing plate 8a, and the same effect as that of the first embodiment can be obtained.

Next, a method of manufacturing a semiconductor device having the above-described structure according to the second embodiment of the present invention will be described with reference to FIG.
Will be described with reference to.

In the same manner as described with reference to FIG. 5A, the base plate serving as the container bottom plate 4 and the container side wall 5 are previously formed as an integrated structure, or are bonded and fixed with a silicone adhesive to form the container. . Next, for example, an insulating substrate in which a Si chip 2 is mounted on an insulating substrate 1a on which a conductor 1b made of Cu foil or the like is formed on a base plate serving as a container bottom plate 4 of the formed container and wiring is performed by aluminum wire bonding 3. 1a,
Bonding is performed with solder 6, and at the same time, external lead-out terminal 7 made of a Ni-plated Cu material or the like is soldered onto insulating substrate 1a.

Next, the upper surface of the container is covered in advance with a sealing plate 8a having a gel material injection hole 8d and a structural portion 8c having a two-step groove structure that allows the external lead-out terminal 7, and the end of the sealing plate 8a is covered. The part is bonded and fixed to the upper end of the container side wall 5 with the adhesive 9. Next, the silicone-based gel agent 10 is injected from the gel agent injection port 8d to a predetermined position in the container and cured (see FIG. 6).
(A)).

Next, the two-step groove-shaped structure portion 8 of the sealing plate 8a.
A nonwoven fabric (made of polypropylene, for example) 11a having an opening 11b as shown in FIG.
Is inserted from the upper part of the external lead-out terminal 7 (see FIG.
(C)).

Then, a hard resin (for example, an epoxy resin having a CTI of 400 V or more) 12 is injected from above the non-woven fabric 11a and cured. As a result, the external lead-out terminal 7 and the sealing plate 8a are firmly fixed by resin. Next, the cap 13 made of a silicone rubber material is inserted and fixed in the gel injection hole 8d provided in the sealing plate 8a in advance. In this case, the cap 13 may be coated with a silicone adhesive and then heat-cured. As described above, a semiconductor device having a hollow structure inside the container can be obtained, and the external lead-out terminal 7 is shaped by bending or the like (the above, FIG. 6D).

According to the above-described second embodiment of the present invention, the external lead-out terminal 7 is easily sealed and fixed with one kind of hard resin by a simple structure in which the nonwoven fabric is inserted into the groove of the two-step groove shape. Further, since the gel layer can be formed into a hollow structure that is not constrained, a highly reliable high breakdown voltage semiconductor device that does not cause defects in the gel layer can be obtained at low cost.

FIG. 3 is a partially enlarged sectional view showing the structure of the power semiconductor device according to the third embodiment of the present invention, and shows the structure of the lead-out portion of the external lead-out terminal 7 in the sealing plate 8a. In FIG. 3, 8e is a groove structure portion, and other reference numerals are the same as those in FIG. The third embodiment of the present invention is an example of a case where a plurality of external lead-out terminals 7 are drawn out to the outside through the structure portion of the sealing plate 8a.
The protruding structure portion 8b for pulling out the external lead terminal 7 is
Basically, the configuration is similar to that of FIG.

The third embodiment of the present invention is shown in FIG.
As shown in, the resin on the upper surface of the sealing plate 8a is dug down,
The groove structure 8e is formed by connecting the holes of the plurality of protrusion structures 8b. That is, the groove structure portion 8e is
A shape that is much lower than the other parts of the upper surface of the sealing plate 8a so that the external lead-out terminals 7 at a plurality of locations can be fixed and sealed together by one injection and curing of one type of hard resin 12. It is said that.

The semiconductor device according to the third embodiment of the present invention may be manufactured in the same manner as described with reference to FIG. That is, the sealing plate 8 having the above-described structure
A is covered from the upper portion of the external lead terminal 7 and adhered to the container, and the silicone gel agent 10 is injected to a predetermined position and cured. In this case as well, as in the case described with reference to FIG.
It is necessary to adjust the injection amount of the gel agent so that it will be completely adhered. Next, one kind of hard resin 1 is added to the groove structure 8e having a shape one step lower than the other resin surface of the sealing plate 8a.
2 is injected and cured to seal and fix, and the external lead terminal is bent and shaped.

The structure of the lead-out terminal 7 lead-out portion having the groove structure portion as described above can also be applied to the structure of the external lead-out terminal 7 lead-out portion in the second embodiment of the present invention described above. it can.

According to the third embodiment of the present invention described above, the external lead-out terminals 7 at a plurality of positions can be collectively sealed and fixed by one type of hard resin 12, and the groove portion of the sealing plate 8a can be formed. Since it can be reinforced, there is no problem that the sealing plate 8a is cracked in the step of bending the terminal, and a highly reliable and high breakdown voltage semiconductor device can be obtained at low cost.

FIG. 4 is an enlarged partial sectional view showing the structure of the power semiconductor device according to the fourth embodiment of the present invention, and shows the structure of the lead-out portion of the external lead-out terminal 7 in the sealing plate 8a. In FIG. 4, 8 g is a groove structure portion, 15
Is a projecting structure, and other reference numerals are the same as those in FIG.

In the fourth embodiment of the present invention, as shown in FIG. 4, the fixing area portion of the external lead-out terminal 7 of the sealing plate 8a is formed by a groove structure portion 8g having an inclined gradient, and the inside thereof is formed. The external lead-out terminal 7 has a structure in which a protruding structure 15 having a through hole through which the external lead-out terminal 7 can pass with a margin is inserted and fixed with a silicone adhesive 9.

The semiconductor device according to the fourth embodiment of the present invention may be manufactured in the same manner as described with reference to FIG. That is, the sealing plate 8 having the above-described structure
A is covered from the upper portion of the external lead terminal 7 and adhered to the container, and the silicone gel agent 10 is injected to a predetermined position and cured. Also in this case, as described with reference to FIG. 5, it is necessary to adjust the injection amount of the gel agent so that the lower portion of the protruding structure 15 is completely adhered to the silicone gel agent 10. Next, to the through-hole portion of the protruding structure 15,
A type of hard resin 12 is injected and cured to seal and fix, and the external lead terminal is bent and shaped.

According to the above-described fourth embodiment of the present invention, the sealing plate 8a can be made thin, and the external lead-out terminal 7 is projected to form the through hole of the structure 15 in one kind of hard resin. It is possible to firmly seal and fix with 12, and there is no problem that the sealing plate 8a is cracked in the terminal bending process, and it is possible to obtain a highly reliable and high breakdown voltage semiconductor device at low cost.

In the above-described first to fourth embodiments of the present invention, the number of semiconductor elements provided on the insulating substrate 1a is 1.
Alternatively, a plurality of power elements may be provided in one chip. Further, in the present invention, a plurality of semiconductor elements as described above may be mounted on one insulating substrate 1a, and further, a plurality of insulating substrates on which the semiconductor elements are mounted as described above in a container. It can also be configured to accommodate.

Each of the above-described embodiments of the present invention is suitable for use in constructing a power converter such as an inverter device using a single unit or a plurality of units.

[0042]

As described above, according to the present invention, the power semiconductor device can have a mounting structure which is inexpensive and easy to manufacture, and can secure a high withstand voltage for a long period of time.

[Brief description of drawings]

FIG. 1 is an enlarged partial cross-sectional view showing the configuration of a power semiconductor device according to a first embodiment of the present invention.

FIG. 2 is an enlarged partial cross-sectional view showing the configuration of a power semiconductor device according to a second embodiment of the present invention.

FIG. 3 is a partial cross-sectional enlarged view showing the configuration of a power semiconductor device according to a third embodiment of the present invention.

FIG. 4 is an enlarged partial sectional view showing a configuration of a power semiconductor device according to a fourth embodiment of the present invention.

FIG. 5 is a diagram illustrating an assembly process of the power semiconductor device according to the first embodiment.

FIG. 6 is a diagram illustrating an assembly process of the power semiconductor device according to the second embodiment.

FIG. 7 is a partial cross-sectional view showing a configuration of a power semiconductor device according to a conventional technique.

[Explanation of symbols]

1a insulating substrate 1b conductor 2 Si chip 3 Aluminum wire 4 container bottom plate 5 container side wall 6 solder 7 External lead terminal 8a sealing plate 8b Projection structure part 8c 2-step groove-shaped structure 8d Gel injection port 8e Groove structure part 8f terminal block 8g groove structure 9 Adhesive 10 Gel agent 11a non-woven fabric 11b opening 12 hard resin 13 Silicone rubber cap 14 Hollow part 15 protruding structure

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuhiro Suzuki             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Hironori Kodama             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Rikuo Kamoshida             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Akira Bando             3-1-1 Sachimachi, Hitachi City, Ibaraki Prefecture Stock Association             Hitachi, Ltd., Hitachi Works (72) Inventor Tsuyoshi Hirai             3-1-1 Sachimachi, Hitachi City, Ibaraki Prefecture Stock Association             Hitachi, Ltd., Hitachi Works (72) Inventor Katsuaki Saito             3-1-1 Sachimachi, Hitachi City, Ibaraki Prefecture Stock Association             Hitachi, Ltd., Hitachi Works (72) Inventor Daisuke Kawase             3-1-1 Sachimachi, Hitachi City, Ibaraki Prefecture Stock Association             Hitachi, Ltd., Hitachi Works F-term (reference) 4M109 AA01 BA03 CA02 CA05 DA10                       DB02 DB10 EA02 EA10 EC07                       EE02 EE03 GA02

Claims (8)

[Claims] 1. A container side wall is bonded to an outer peripheral portion of a container bottom plate serving as a base plate, wherein one or a plurality of insulating substrates on which a semiconductor element is mounted and external lead terminals are connected and on which a conductor is formed. Mounted on a container bottom plate in the container, covered with a sealing plate for leading out the external lead-out terminal,
In a semiconductor device configured by filling the inside of the container with an insulating gel agent, a space is formed between the upper surface of the gel agent and the lower surface of the sealing plate, and is used for an external lead terminal of the sealing plate. The semiconductor device is characterized in that the structure part of (1) is molded by one kind of hard resin. 2. The structure for the external lead-out terminal is formed in a hole shape having a size that allows the external lead-out terminal to be pulled out to the outside with a margin, and below the sealing plate.
The semiconductor device according to claim 1, wherein the semiconductor device is configured to have a protruding portion that comes into contact with the gel agent. 3. The structure for the external lead-out terminal is formed in a two-stepped hole shape having a size that allows the external lead-out terminal to be pulled out to the outside with a margin, and a nonwoven fabric is placed in the hole. It is comprised, It is characterized by the above-mentioned.
The semiconductor device described. 4. The external lead terminal and a plurality of structural parts are provided, and the plurality of structural parts are connected by a groove provided on the outer surface of the sealing plate.
The semiconductor device described. 5. The semiconductor device according to claim 1, wherein the sealing plate and the hard resin are made of a resin having a tracking resistance index of 400 V or more. 6. The side wall of the container is made of PPS (polyparaphenylene sulfide), PBT (polybutylene terephthalate), SPS (syndiotactic polystyrene), polyamide resin, polyamideimide resin, or polyetheramide resin. 6. The semiconductor device according to claim 1, wherein the hard resin is formed and is made of an epoxy resin or a phenol resin. 7. The semiconductor device according to claim 3, wherein the non-woven fabric is made of polypropylene material or fluorine resin. 8. A power converter comprising one or a plurality of the semiconductor devices according to any one of claims 1 to 7.