JP2854192B2 - Hybrid integrated circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid integrated circuit device, and more particularly, to a silicon gel-filled hybrid integrated circuit device.

[0002]

2. Description of the Related Art As shown in FIG. 10, a conventional hybrid integrated circuit device has a first box-shaped case material (60), external leads (80), an integrated circuit element (82), etc., which are fixed and mounted. The insulating metal substrate (70) is mainly composed of a second insulating metal substrate (90) used for improving the insulating property.

[0003] The case material (60) has a wall (62) which comes into contact with the peripheral portion of the first insulating metal substrate (70). As shown in FIG. 10, a silicon gel introduction hole (64) is formed in one of the walls (62) formed in the direction in which the external lead is led out. Also, usually, the case material (60)
A step is formed at an end in the longitudinal direction, and a hole for a screw for connecting the hybrid integrated circuit device to a heat sink (not shown) is formed in the step. This case material (60) is obtained by injection molding, for example, fiberglass rain hose PET (FRPET).

First and second insulated metal substrates (70)
(90) is approximately 2 mm in consideration of heat radiation characteristics and workability.
Thick aluminum is used and its surface is anodized to improve insulation. First insulating metal substrate (7
0) is a rectangle, and when the hybrid integrated circuit device is substantially completed, the hybrid integrated circuit device substrate is divided into several units and several tens of units, and is divided into unit hybrid integrated circuit device sizes and pressed. The second insulating metal substrate (90) has substantially the same planar shape as the case material (60), and an adhesive layer (92) for bonding the second insulating metal substrate (90) to the first insulating metal substrate (70) is provided with a heat sink (not shown). And the first insulating metal substrate (70).

An external lead pad (74), a die bond pad (76), a wire bonding pad (78), and a conductive path (not shown) are made of a thermosetting insulating resin such as a polyimide resin having an adhesive property and having a thickness of about 35 μm. After the clad material with the copper foil is hot-pressed on the first insulating metal substrate (70) at a temperature of 150 ° C. to 170 ° C. and a pressure of 50 to 100 kg per square centimeter, the copper foil is subjected to a predetermined pattern by photoetching or the like. Formed. The thermosetting insulating resin is completely cured in this hot pressing step to form an insulating layer (72) having a thickness of about 35 μm.

Chip components are used for semiconductor elements such as the integrated circuit element (82) and other circuit elements, and the integrated circuit element (82) is formed of a die bond pad (70) on a first insulating metal substrate (70) using silver paste or the like. 76), chip capacitors or chip resistors, external leads (8
The odd-shaped parts such as 0) are fixed to predetermined pads by soldering. These circuit elements and components are provided with predetermined pads (74) (7).
6) After temporarily attaching to the solder paste screen-printed on (78), it is completely fixed by reflow. The peripheral portion of the first insulated metal substrate (70) is heat-pressed (125 ° C., 8
Time), and the mounted circuit element is sealed.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to an external lead (80) which may require reliability, and which may occur in silicon gel filled hybrid integrated circuit devices where special heat cycle tests are performed. This is made in the process of elucidating the cause of the separation of the pad (74). That is, according to the research of the inventor, when the hybrid integrated circuit device sealed with the resin case material (60) is subjected to the heat cycle test, as shown by the arrow in FIG. 10, the end of the case material (60) faces upward. It was known to bend. It has also been known that when the thermosetting resin (96) and the first insulating metal substrate (70) are completely fixed, the curvature is small.

The adhesive strength between the thermosetting resin (96) such as epoxy resin and the case material (60) filled in the area where the external leads (80) are fixed is extremely high, while the silicone gel (94) and other materials are used. When the silicon gel (94) adheres to the fixing portion of the external lead (80) due to the low adhesive strength of the material of the external lead (80), the thermosetting resin (96) and the external lead (80) was lifted from the first insulating metal substrate (70), and it was clarified that the pad (74) was eventually separated.

The reason why the silicon gel (94) adheres to the fixing portion of the external lead (80) is that in the conventional hybrid integrated circuit device, silicon in a sol state is injected from the fixing portion of the external lead (80). This is because the silicon sol that wets the outer wall of the injection pipe adheres to the fixing portion of the external lead (80). In addition, since the fluidity of the silicon sol to be injected is high, as shown in FIG. 10, the electrode pattern for the external lead (80) penetrates to wet the external lead (80) fixing portion with the silicon sol. This is because the silicon sol scattered when the silicon sol is injected at a high pressure adheres to the fixing portion of the external lead (80).

Further, in the hybrid integrated circuit device having the conventional structure, since a pair of external leads are led out from opposite surfaces, it is impossible to simultaneously fill and cure a thermosetting resin for reinforcing the external lead fixing portion. There is a problem that it is possible and the manufacturing process is complicated. Accordingly, a first object of the present invention is to provide a highly reliable silicon gel-filled hybrid integrated circuit device which does not cause pad separation even when a severe heat cycle is applied. It is an object of the present invention to provide a hybrid integrated circuit device capable of simultaneously filling and curing a thermosetting resin for reinforcing an external lead fixing portion.

[0011]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, a hybrid integrated circuit device according to the present invention includes an integrated circuit board having a plurality of integrated circuit elements and external lead terminals fixed and mounted on a circuit pattern formed on an insulated metal substrate, and an integrated circuit element mounting area. A substantially frame-shaped resin case material having at least a wall for dividing the external lead terminal fixing region, a silicon gel and a first thermosetting resin sequentially laminated in an integrated circuit element mounting space, and an external lead A second thermosetting resin filled in the space of the terminal lead-out side, a first protrusion for preventing the silicon gel from climbing up is provided on the inner surface of the wall, and a step above the first protrusion is provided. Is provided with a second projecting portion which is in a state of being engaged with the first thermosetting resin.

Further, a hybrid integrated circuit device according to the present invention provides an integrated circuit board having a plurality of integrated circuit elements and external lead terminals fixed and mounted on a circuit pattern formed on an insulated metal substrate; A substantially frame-like shape having at least a wall divided from an external lead terminal fixing region and arranged near the external lead terminal fixing pad, and an opening for filling the silicone gel and the thermosetting resin formed in the same direction; Resin case material, silicon gel and the first thermosetting resin sequentially laminated in the integrated circuit element mounting space, and the second thermosetting resin filled in the space of the lead-out side of the external lead terminal. A first protruding portion for intermittently providing a silicon gel at an inner surface of a wall at a position substantially flush with an interface of the silicon gel; It is characterized in that a second projecting portion to be the first thermosetting resin and 咬止 state in a region which is not and superimposed stages.

[0013]

In the hybrid integrated circuit device configured as described above, the external lead fixing region of the silicon sol injection pipe is formed by forming a wall dividing the integrated circuit element mounting region and the external lead fixing region in the case material. Thus, the problem that the silicon sol on the outer wall of the silicon sol injection pipe adheres to the external lead fixing region and the problem that the scattered silicon sol adheres to the external lead fixing region can be solved.

Further, a wall is formed in the case material to divide the integrated circuit element mounting area and the external lead fixing area, and an opening for filling the silicon gel and the thermosetting resin is formed in a single direction. In addition, the problem of contamination of the external lead fixing portion due to scattering of the silicon sol or the like can be solved, and the injection of the silicon sol and the filling of the thermosetting resin can be performed on a single jig.

Further, the thermosetting resin can be simultaneously filled into the outer lead fixing region of the case material having the opening for filling the silicone gel and the thermosetting resin in a single direction and the upper portion of the silicon gel, The problem of contamination of the external lead fixing part due to scattering of silicon sol is solved,
Thermosetting resin filling can be completed in one go. Further, by providing a first protrusion for preventing the silicone gel from rising and a second protrusion for engaging with the thermosetting resin on the inner surface of the wall, a very severe thermal shock test is performed. Even if the silicone gel expands and contracts and expands, the thermosetting resin on the silicone gel does not peel off.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. Referring to FIGS. 1 and 2, an embodiment illustrating a hybrid integrated circuit device in a dual in-line package includes a pair of walls (14) in a frame (12), the walls (14) providing an insulating metal. A case material (10) for dividing an area on the substrate (30) into an integrated circuit element mounting area (16) and an external lead fixing area (18), semiconductor elements such as an integrated circuit element (46), and external leads (44). A first insulating metal substrate (30) for fixing and mounting, etc., a second insulating metal substrate (50) mainly used for improving insulation properties, and a silicon gel filling the integrated circuit element mounting area (16). (56) A thermosetting resin (58) filled in the upper portion of the silicon gel (56) and the external lead fixing region (18).

The silicon gel (56) filled for the purpose of improving the weather resistance or the like is formed in a sol state by a pump or the like (not shown) in a predetermined area of the integrated circuit element mounting region (16) formed by the pair of walls (14). And then heat-treated after injection to gel. According to the present embodiment, at this time, the reason why the area of the integrated circuit element mounting area (16) is large, and the reason why the integrated circuit element mounting area (16) and the external lead fixing area (1)
8) Because of the formation of the separation wall (14) between the silicon sol injection pipe and the outer lead fixing area (18) of the silicon sol injection pipe is prevented from approaching, and the silicon sol on the outer wall of the silicon sol injection pipe is reduced. The problem of adhesion to the external lead fixing region (18) and the problem of scattering silicon sol adhering to the external lead fixing region (18) do not occur.

Then, a thermosetting resin (58) is filled into the upper portion of the silicon gel (56) and the pair of external lead fixing regions (18), and heat-treated to complete the structure of FIG.
This embodiment will be described in more detail with reference to FIGS. FIG. 3 is a perspective view of the case material (10), FIG.
FIG. 5 is a sectional view taken along line AA of FIG. The case member (10) is formed in a substantially frame shape as shown in FIGS. This case material is, for example, a fiberglass rain hose PET (F
It is formed by injection molding using an insulating resin material such as RPET).

The case material (10) is a wall (14) for dividing an external lead fixing area and an integrated circuit element mounting area.
Is provided. The bottom of the wall (14) is the first
Of the insulating metal substrate (30). That is, when the case material (10) and the first insulated metal substrate (30) are integrated, the space between the wall (14) and the substrate (30) is in a non-contact state, and a predetermined distance is provided between them. An interval space is formed. This space is formed on the peripheral edge of the substrate on the side to which the external lead terminals (44) are fixed, and the substrate surface on which the lead terminals are not formed comes into contact with the case material.

The wall (14) is connected to the first insulating metal substrate (3).
The reason for the non-contact state with 0) is to avoid adverse effects due to solder balls generated when external leads are fixed by soldering. Also, first and second protrusions (1) and (2) are provided on the inner surface of the wall (14) of the case material (10), that is, on the inner surface on the integrated circuit element mounting region side. The first protruding portion (1) is a protruding portion for preventing the silicon sol filling the integrated circuit element mounting area from going up.
And as shown in FIG. 5, it is intermittently provided on the inner surface of the wall (14). If the first protruding portion (1) is not provided, the silicon sol goes up the inner surface of the wall (14) due to surface tension when the silicon sol is filled, and the first thermosetting resin (58A) peels off. There is fear. That is, after the silicon sol is heat-treated and gelled, an epoxy resin is filled on the silicon gel to form the first thermosetting resin (58A). As described above, since the silicon gel adheres to the inner surface of the wall, the first thermosetting resin (58A) is adhered in a normal state, but a thermal shock test at −40 ° C. to + 150 ° C. is performed, for example. In this case, since the thermal expansion coefficient of the silicon gel is extremely large, the first thermosetting resin (58A) peels off from the wall (14), that is, the case material (10) due to expansion and contraction of the silicon gel. Was clarified by the experiment of the present inventors.

Therefore, a second protrusion (2) is provided on the upper part of the first protrusion (1), and the second protrusion (2) and the first thermosetting resin (58A) are connected to each other. The first thermosetting resin (58A) is prevented from peeling due to expansion and contraction / expansion of the silicone gel generated at the time of thermal shock by being engaged. The second protrusion (2) is formed in a region that does not overlap with the first protrusion (1), and has a triangular shape, for example, in order to improve the engagement state with the first thermosetting resin (58A). Is formed.

Next, the necessity of the second protrusion (2) will be described. FIG. 6 is an enlarged sectional view of the wall (14) of the case material (10) provided with the first and second protrusions (1) and (2). The second protrusion (2) is provided on the first substrate (3).
If the height H from 0) to the first protrusion (1) is sufficient, there is no need to provide it. That is, the first substrate (3
0) Even if silicon gel is filled enough to protect the circuit element mounted thereon, the rising of the silicon gel reaches the first protruding portion (1) but the tip portion of the first protruding portion (1), ie, , Silicon gel (56) interface (2 in FIG. 6)
This is because a region for engaging the first thermosetting resin (58A) is formed in the first projecting portion (1) and the first projecting portion (1). However, increasing the height H increases the thickness of the hybrid integrated circuit itself, and in recent years the thickness (height) of the hybrid integrated circuit itself has to be reduced as much as possible. .

Therefore, if the height H is minimized, the interface (solid line in FIG. 6) of the silicon gel (56) becomes substantially flush with the first protrusion (1). A first thermosetting resin (58) is provided at the interface between (1) and the silicon gel (56).
A region for engaging A) is not formed, and the first thermosetting resin (58A) is peeled off due to expansion and contraction and expansion of the silicon gel at the time of thermal shock as described above. Therefore, the presence of the second protrusion (2) is indispensable to provide a hybrid integrated circuit device having a minimum thickness.

More specifically, in this embodiment, the second protrusion (2) is formed on the upper side of the wall (14). This is because the second protrusion (2) and the first thermosetting resin (58)
In order to completely engage A), at least an interval of about 3 mm or more from the silicon gel (56) interface is required. Therefore, in order to minimize the thickness of the hybrid integrated circuit device itself, the thickness of the first thermosetting resin (58A) is set to about 3
mm, the second protrusion (2) needs to be formed on the upper surface side of the wall (14).

Although not shown in the figure, if a support is formed on the upper surface of the wall (14) so as to be substantially parallel to the interface between the first thermosetting resin, the first thermosetting resin is formed. Peel strength can be improved. FIG. 7 is a perspective view of a first insulated metal substrate (30) conforming to the present embodiment. Aluminum having a thickness of about 2 mm is formed on the first insulated metal substrate (30) in consideration of heat radiation characteristics and workability. It is used and its surface is anodized to improve insulation. This insulated metal substrate (30) is obtained when the hybrid integrated circuit device is substantially completed.
A plurality of units to several tens of units of the hybrid integrated circuit board are divided and pressed to the size of the unit hybrid integrated circuit device.

The external lead pad (38), the wire bonding pad (40), the die bond pad (42), and the conductive path (not shown) are made of a thermosetting insulating resin such as a polyimide resin having adhesiveness and having a thickness of about 35 μm. After hot-pressing the clad material with the copper foil on the first insulating metal substrate (30) at a temperature of 150 ° C. to 170 ° C. and a pressure of 50 to 100 kg per square centimeter, the copper foil is subjected to a predetermined pattern by photo-etching or the like. Formed. The thermosetting insulating resin is completely cured in this hot pressing step to form an insulating layer having a thickness of about 35 μm (reference numeral 32 in FIG. 2).
reference).

Chip components are used for semiconductor elements such as the integrated circuit element (46) and other circuit elements, and the integrated circuit element (46) is fixed to the die bond pad (42) with a silver paste or the like, and a chip capacitor or An odd-shaped component such as a chip resistor is fixed to a predetermined pad by soldering.
These circuit elements are temporarily adhered to a solder paste screen-printed on predetermined pads (40) (42) and then reflowed to be completely fixed.

Finally, the external lead terminals (44) are fixed to the fixing pads (38) by soldering. This external lead terminal (44) has about 3
A soldering iron heated to 00 to 350 ° C. is pressed for several seconds to melt the solder previously formed on the pad (38), and the lead terminal (44) is fixed on the pad (38) by soldering. When the soldering iron is pressed against the lead terminals (44), the solder balls are scattered from the solder onto conductive paths near the periphery and adhere to the surface. However, since the overcoat film is formed in advance in the vicinity of the periphery of the pad (38) by screen printing, the above-described solder balls actually adhere and remain on the overcoat film.

Referring to FIG. 8, the case material (1)
0) and the first insulating metal substrate (30) are overlapped as shown in the figure, and the peripheral portion of the first insulating metal substrate (30) and the frame (12) of the case material (10) are temporarily bonded by a silicone resin. Is done. At this time, as described above, since the bottom surface of the wall body (14) of the case material (10) and the surface of the first insulating metal substrate (30) are arranged in a non-contact state, the space between them is provided. When fixed, a predetermined space is formed. Therefore, even if the solder ball scatters in the region of the wall (14), the solder ball will be arranged in the space.

Incidentally, the integrated circuit element mounting area (16)
Since silicon sol is injected as described above,
Since the adhesive resin (57) is interposed in the space formed between the wall (14) and the substrate (30), the silicon sol does not flow out to the external lead fixing region (18). FIG. 9 is a perspective view of a second insulating metal substrate (50) mainly used for improving insulation. Second insulating metal substrate (50)
Is the same material as the first insulated metal substrate (30), and is a hole (2) for a screw to be coupled to a heat sink of the case material (10).
A hole (54) is formed at a position corresponding to (2). This second insulated metal substrate (50) is made of silicone resin (see reference numeral (52) in FIG. 2), and the frame (12) of the case material (10) is formed.
Is combined with Then, the silicone resin used for this bonding improves the insulation performance between the first insulating metal substrate (30) and the heat sink (not shown).

[0031]

As described in detail above, according to the present invention,
A wall that divides the integrated circuit element mounting area and the external lead fixing area is formed in the case material, so there is little risk of approaching the external lead fixing area of the silicon sol injection pipe, and the silicon sol on the silicon sol injection pipe outer wall is fixed to the external lead. The problem of adhesion to the area and the problem of scattering silicon sol adhering to the external lead fixing area do not occur. As a result, it is possible to provide a highly reliable silicon gel-filled hybrid integrated circuit device that does not cause pad separation even when a severe heat cycle is applied.

Further, according to the present invention, the thermosetting resin is provided on the outer lead fixing region of the case material in which the opening for filling the silicone gel and the thermosetting resin is formed in a single direction and on the upper portion of the silicon gel. Simultaneous filling is possible, and the problem of contamination of the external lead fixing portion due to scattering of silicon sol or the like can be solved, and filling of the thermosetting resin can be completed in a single operation.

Further, according to the present invention, the first protrusion for preventing the silicone gel from rising and the second protrusion for engaging with the thermosetting resin are provided on the inner surface of the wall. Accordingly, even when a thermal shock test under extremely severe conditions is performed, the thermosetting resin laminated on the silicon gel is not peeled off due to expansion and contraction and expansion of the silicon gel. As a result, a highly reliable hybrid integrated circuit device resistant to thermal shock can be provided.

Further, according to the present invention, by providing the first and second protrusions as described above, the thickness of the hybrid integrated circuit device having the structure in which the silicon gel and the thermosetting resin are laminated is reduced. Can be minimally thin.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view of a case member.

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a sectional view of a main part showing first and second protrusions;

FIG. 7 is a perspective view of a first insulating metal substrate.

FIG. 8 is a perspective view in which a case material and a first metal substrate are integrated.

FIG. 9 is a perspective view showing a second insulating metal substrate.

FIG. 10 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st projecting part 2 2nd projecting part 10 case material 12 frame 16 integrated circuit element mounting area 18 external lead fixing area 30 first insulating metal substrate 32 insulating layer 38 external lead pad 40 wire bonding pad 42 die bond pad 44 external lead terminal 46 integrated circuit element 50 second insulating metal substrate 52 insulating layer 56 silicon gel 57 silicon adhesive 58A first thermosetting resin 58B second thermosetting resin

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 23 / 28,23 / 24

Claims (2)

(57) [Claims] An integrated circuit board on which a plurality of integrated circuit elements and external lead terminals are fixed and mounted on a circuit pattern formed on an insulating metal substrate, and the integrated circuit element mounting area and the external lead terminal fixing area are divided. A substantially frame-shaped resin case material having a wall body to be formed, silicon gel and a first thermosetting resin sequentially laminated in the integrated circuit element mounting space, and filled in the space of the external lead terminal lead-out area. A second thermosetting resin, the surface of the insulating metal substrate corresponding to the bottom surface of the wall,
An overcoat film is coated, and the bottom surface of the wall is
Even if solder balls scatter between the insulating metal substrate surface
It is separated by the space where the solder balls are placed in this space
A hybrid integrated circuit device , wherein a space is provided, and an adhesive resin is provided in the space. 2. An integrated circuit board on which a plurality of integrated circuit elements and external lead terminals are fixed and mounted on a circuit pattern formed on an insulating metal substrate, and the integrated circuit element mounting area and the external lead terminal fixing area are divided. And at least a wall disposed near the external lead terminal fixing pad,
A substantially frame-shaped resin case material having an opening for filling the silicon gel and the thermosetting resin; a silicon gel and a first thermosetting resin sequentially laminated in the integrated circuit element mounting space; And a second thermosetting resin filled in the space of the external lead terminal lead-out region, and the surface of the insulating metal substrate corresponding to the bottom surface of the wall,
An overcoat film is coated, and the bottom surface of the wall is
Even if solder balls scatter between the insulating metal substrate surface
It is separated by the space where the solder balls are placed in this space
A space is provided, and an adhesive resin is provided in this space. The silicon gel is prevented from rising at a position on the inner surface of the wall which is substantially flush with the interface of the silicon gel. A first protruding portion provided intermittently, and a second protruding portion which is in a state of being engaged with the first thermosetting resin is provided in a region above the first protruding portion and not overlapping with the first protruding portion. A hybrid integrated circuit device characterized by the following.