JPH0334220B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a hybrid semiconductor device such as a semiconductor relay, and a method for manufacturing the same, and is particularly suitable for electrical insulation and heat dissipation of individual semiconductor elements having a large current capacity. The present invention relates to a structure and a method for assembling the same.

[Technical background of the invention]

FIG. 4 shows an example of a circuit block of a semiconductor relay (solid state relay) that controls ON/OFF of an AC circuit by DC input, and a specific example of the circuit is shown in FIG. Here, 1 and 2 are input terminals, 3,
4 is an output terminal, 5 is a triac (usually unitized), _Q1 to _Q3 are transistors, PH
is a photocoupler, R ₁ to _{R 6} are resistors, C ₁ and C ₂ are capacitors, and DB is a diode bridge.

The configuration and operation of the above circuit are well known and are not directly related to the present invention, so a description thereof will be omitted. The above-mentioned semiconductor relay usually has a structure housed in a single case, and a conventional example of the cross-sectional structure of a part thereof is shown in Fig. 6, and the structure is constructed by the method described below. was. That is, a wiring pattern (including soldering pads) is formed so that a circuit can be formed by soldering the individual semiconductor elements shown in the circuit diagram of FIG. 5 onto an aluminum substrate (or aluminum-based copper-clad laminate) 61. Provided by etching method. Then, a solder resist is coated on the part other than the soldering pad, and solder paste (Sn--Pb eutectic solder, also called solder cream) is screen printed on the soldering pad. Then, the resistor R, triax unit 5, output terminals 3 and 4, and other parts are placed on the substrate 61, and approximately
Perform solder reflow at 230℃. Next, the flux on the board 61 (mixed in the previous solder paste) is cleaned with triclean, the case is covered, silicone rubber (usually RTV) is coated from the hole in the case, and after curing, the hole is A label is attached to the product to make it a semiconductor relay product. In FIG. 6, ₅₁ is a fin-shaped heat sink of the triax unit 5, ₅₂ is a lead terminal of the triax unit 5, 62 is an insulating layer of the aluminum substrate 61, and 63 is a copper wiring pattern on the insulating layer 62. The foil and 64 are solder.

[Problems with background technology]

However, in the structure shown in FIG. 6, the insulating layer 62 of the aluminum substrate 61 is made of synthetic resin and has a high thermal resistance.If the resin layer is thinned to reduce this thermal resistance, the effect of voids may occur. The withstand pressure becomes low. Currently, the aluminum substrate that can guarantee voltage resistance of 3.5 kV AC for 1 minute has a layer thickness of 0.2 mm.
It has an epoxy resin insulating layer, and has a large thermal resistance Rth (j-c) of about 2 to 2.5°C/W.
Therefore, when using a triax unit 5 with a large current capacity (for example, 8 A or more), it is necessary to make the heat sink _{5 1 thick} . As a result, the warpage of the substrate 61 increases. Furthermore, when punching out the outline of the aluminum substrate 61 with a press, the insulating layer 62 made of synthetic resin and the aluminum plate 60 made of metal are punched out at the same time, so punching burrs on the aluminum plate 60 are likely to appear, making maintenance of the mold difficult and difficult to clean. It is necessary to perform this frequently (every 5,000 to 10,000 shots).

In addition, if an attempt was made to solve the above-mentioned problem by using a ceramic substrate of the same size instead of the aluminum substrate 61, the ceramic substrate would warp and break easily as the size increases, and the previous If the size is equivalent to that of an aluminum substrate, cracks will occur. To prevent this, it is necessary to divide the ceramic board into two or three pieces and connect them with metal plate terminals or wires after soldering reflow, which increases the number of assembly steps (especially the number of soldering steps). This results in an increase in costs.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and
A hybrid semiconductor device in which the thermal resistance of a heat dissipation path for a part of the individual semiconductors to be mounted can be reduced, and an individual semiconductor element with a large current capacity can be mounted on the same heat sink together with other individual semiconductor elements without any problem. It provides:

Furthermore, in the present invention, when assembling the semiconductor device, all the individual semiconductor elements including the circuit board and those with large current capacity to be mounted on the heat dissipation board can be mounted by one solder reflow, reducing the number of assembly steps. The present invention provides a method for manufacturing a hybrid semiconductor device that requires less.

[Summary of the invention]

That is, the hybrid semiconductor device of the present invention has the following features:
A circuit board is bonded to a heat sink made of a metal material via solder, and individual semiconductor elements are connected to wiring patterns on this circuit board via solder. A copper plate is inserted into the hole or notch and is attached to the heat sink with solder, and a double-sided metallized ceramic plate is placed on the copper plate and attached via solder. The device is characterized in that individual semiconductor elements having a large current capacity are mounted on the ceramic plate and are bonded to the ceramic plate through solder.

In this way, individual semiconductor elements with large current capacity are mounted on a heat sink in an electrically insulated state via a ceramic plate and a copper plate with low thermal resistance. Other individual semiconductor elements can be mounted on the same heat sink without any problem.

Further, in the method for manufacturing a hybrid semiconductor device of the present invention, a solder paste is printed on a heat sink made of a metal material, a hole or notch is formed in a part of the solder paste, a soldering part is formed on the lower surface, and a solder paste is formed on the upper surface. A circuit board with a wiring pattern formed thereon is stacked on top of the circuit board, and individual semiconductor components are placed on the wiring pattern of this circuit board via solder paste, and a copper plate or a ceramic plate is placed on the heat sink corresponding to the hole or notch. This method is characterized in that individual semiconductor elements with a large current capacity are mounted in order through the plates, and individual semiconductor elements with a large current capacity are mounted in order, and in this state, solder reflow is performed to perform solder bonding.

Therefore, all the individual semiconductor elements including the circuit board and those with large current capacity to be mounted on the heat dissipation board can be mounted by one solder reflow, and the number of assembly steps can be reduced.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

1a and 1b show the external appearance of the semiconductor relay as seen from the top and side, and FIG. 1c shows a schematic cross-sectional structure taken along line C-C' in FIG. 1a. That is, 10 is a heat sink (made of copper-based or aluminum-based metal material, for example, a copper plate or an aluminum plate with copper plating on one side).
It is. Reference numeral 11 denotes a circuit board in which a wiring pattern ₁₈ is formed on a glass epoxy double-sided copper-clad laminated board.For example, as shown in FIG. A cutout portion 11 ₂ is provided in the.
This circuit board 11 is provided with a copper foil portion 19 on at least a portion of its lower surface, and is placed on the heat sink 10 and the copper foil portion 19 is bonded onto the heat sink 10 with solder 12 ( pasted).
As shown in FIG. ₃ , a heat dissipating copper plate 14 (0.2 to 0.3 mm thicker than the circuit board 10) for the triax unit 13 is inserted into the hole 111 of the circuit board 11, and its lower surface is covered with solder 12. It is adhesively fixed on the heat sink 10. 15 is the above copper plate 1
4 is a double-sided metallized ceramic plate for insulating the triax unit, and ₁₃₂ is a lead terminal of the triax unit 13,
The tip part is soldered 12 on the wiring pattern part (copper foil) on the circuit board 10, and 13 ₁
is a fin-shaped heat sink of the triax unit 13. On the circuit board 11, there are individual semiconductor components (a capacitor C, a resistor R, and a photocoupler PH are representatively shown in FIG. 1) that constitute a circuit that drives a triax as shown in FIG. Input terminals 1 and 2 and output terminals 3 and 4 are soldered. A frame-shaped case 16 is provided that surrounds the sides of each of the above-mentioned components, input/output terminals, and triax unit, and a space surrounded by this case 16, the circuit board 11, and the heat sink 10 is filled with a sealing resin. 17 is filled. Note that the tips of the input terminals 1 and 2 and the output terminals 3 and 4 protrude outward from the resin 17 portion.

According to the above structure, the triax unit 13 generates a large amount of heat compared to other individual semiconductor components.
is designed to conduct heat to the heat sink 10 via the insulating ceramic plate 15 and the heat dissipating copper plate 14, and the ceramic plate 15 has a thermal resistance R _th(jc) =0.5 to 0.6 when a withstand voltage of 5 kV AC is applied for 1 minute. As it is as low as ℃/W,
The heat dissipation effect is significantly better than that of the conventional structure, which had a thermal resistance of 2 to 2.5° C./W.
Therefore, large-sized ceramic plates or 2
It is no longer necessary to use a ceramic plate divided into three pieces, and problems such as cracking of the ceramic and an increase in the number of soldering steps do not occur. Further, since it is no longer necessary to use a press to cut out the outline of the aluminum substrate having the resin insulating layer, the problem of having to frequently clean the mold does not occur.

Next, a method for manufacturing a semiconductor relay having the above structure according to the present invention will be explained in order of steps with reference to FIGS. 1 to 3. One side of an aluminum plate is coated with copper plating to a thickness of 6 to 10 μm, and a solder resist is coated on the plate except for the soldered part of the copper plate 14 corresponding to the triax unit mounting part and the soldered part of the circuit board 11. do. Next, the outer shape of the above-mentioned plate is cut out by press punching to obtain the desired heat sink plate 10. On the other hand, a circuit board 11 is prepared separately, and this circuit board 1
1, a wiring pattern 18 is provided on the upper surface of the glass epoxy double-sided copper-clad laminate for attaching each semiconductor element of the triac drive circuit, and a land 19 is provided on the lower surface for soldering to the heat sink 10.
will be established. In this case, the wiring pattern 18 and the land 19 are made by known screen printing and etching methods, and a solder resist is applied to areas other than the soldering parts on the upper and lower surfaces of the circuit board 11. On the other hand, input terminals 1 and 2 and output terminals 3 and 4 shall be prepared separately, and for this purpose a copper or brass rod is lathe-cut, threaded, knurled, etc., and then Ni-plated. administer. On the other hand, case 1
6 shall be prepared separately, and for this purpose a resin material that can withstand the soldering temperature of 230±5℃, such as
PPS (polyphenylene samphide) resin, FR−
PET (glass-filled polyethylene terephthalate,
Teijin Co., Ltd. product name) Resin molding with resin, etc. On the other hand, the triax unit 13 and the copper plate 14,
A ceramic plate 15 shall be prepared separately. In this case, the copper plate 14 is plated with Ni after press punching. Furthermore, the ceramic plate 15 is formed 1 to 2 mm smaller than the desired external dimension, and both sides of the ceramic plate 15 are
Ni plating is applied after Mo-Mn or W metallization. And the triax unit 13
Layer the ceramic plate 15 and copper plate 14 and solder 1.
I'll put 2 on it.

This soldering method uses a carbon jig and encapsulates the triac element by passing it through a furnace at 370±10° C. in the assembled state with Sn--Pb (10-90) high-temperature solder. In addition,
The triax unit 13 shown in FIG.
For example, it has a small capacity of 8A or less, and the triac element is mounted on the frame and bonded like the standard external shape TO-220 according to the American standard.
This is the semiconductor device itself obtained by transfer molding after applying an encap.

Next, a method of assembling each component prepared as described above and other individual semiconductor components on the heat sink 10 and the circuit board 11 will be described. First of all,
Solder cream (Sn-Pb, 63-37) on the heat sink 10
Similarly, solder cream is applied to the soldered portions on the circuit board 11. Next, the circuit board 11 is stacked on the heat sink 10, and the triax unit heat dissipation copper plate ₁₄ is inserted into the triax unit insertion hole 111 of the circuit board 11 and placed on the heat sink 10. Meanwhile, other individual semiconductor elements for the triac drive circuit are placed at predetermined positions on the circuit board 11, respectively. Further, a resin molding jig having input/output terminal guide holes having substantially the same shape as the case 16 is placed on the heat sink 10, and the input terminals 1 and 2 and the output terminals 3 and 4 are inserted into the guide holes of this jig. In this state, solder reflow (transferred on a conveyor over a heater. Temperature: 23°C ± 5°C) is performed. Next, the resin molding jig is removed, the solder flux (mixed in the solder cream) is cleaned with triclean, the case 16 is mounted on the heat sink 10, and in this state, a sealing resin (for example, epoxy ME266, Japanese (manufactured by Pernox) 17 to make a semiconductor relay product.

Note that, without soldering the triax unit 13, the ceramic board 15, and the copper plate 14 in advance, after printing solder cream on the upper surfaces of each of the copper plate 14 and the ceramic board 15, the copper plate is soldered when assembling the circuit board 11. 14, the ceramic plate 15, and the triax unit 13 may be stacked in this order and soldered at the same time during the solder reflow.

According to the above assembly method, the circuit board 11 is placed on the heat sink 10, the individual semiconductor elements are placed on this circuit board 11, and the copper plate ₁₄ and the ceramic plate are placed in the hole 111 previously provided in the circuit board 11. The triax unit 13 is mounted via the pin 15 and soldered using solder paste in a single solder reflow process, so that the number of assembly steps, especially the number of soldering steps, can be reduced. Furthermore, it is also possible to solder the copper plate 14, ceramic plate 15, and triax unit 13 at the same time during the solder reflow process.

The present invention is not limited to the semiconductor relay of the above embodiment, but is applicable to the structure and assembly method of general hybrid semiconductor devices having individual semiconductor elements that generate a relatively large amount of heat and other individual semiconductor elements. Further, in the above embodiment, the triax unit was mounted on the heat sink through the copper plate and ceramic plate in the hole of the circuit board, but a notch was provided in the circuit board instead of the hole, and the The triax unit may be mounted through a copper plate or ceramic plate such as the one shown in FIG.

〔Effect of the invention〕

As described above, according to the hybrid semiconductor device of the present invention, it is possible to reduce the thermal resistance of the heat dissipation path for some of the individual semiconductors to be mounted. Both can be mounted on the same heat sink. Furthermore, according to the method for manufacturing a hybrid semiconductor device of the present invention, all the individual semiconductor elements including the circuit board and those with large current capacity to be mounted on the heat sink when assembling the semiconductor device can be soldered at one time by reflow soldering. It has the advantage of being easy to mount and requiring less assembly man-hours.

[Brief explanation of drawings]

Figures 1a, b, and c are a top view, a side view, a sectional view, and a second
The figure is a top view showing an example of the circuit board in Figure 1 c, Figure 3 is a cross-sectional view showing an enlarged view of the main parts in Figure 1 c, and Figure 4 is a typical semiconductor relay. 5 is a circuit diagram showing a specific example of the circuit of FIG. 4, and FIG. 6 is a sectional view showing the sectional structure of a part of a conventional semiconductor relay. 1, 2... Input terminal, 4, 5... Output terminal, 1
0... Heat sink, 11... Circuit board, 11 ₁ ... Triack unit insertion hole, 11 ₂ ... Notch, 12... Solder, 13... Triack unit, 14... Copper plate, 15... ...Ceramic board, 16
... Case, 17 ... Sealing resin, 18 ... Wiring pattern, 19 ... Copper foil part (land), C ... Capacitor, R ... Resistor, PH ... Photocoupler.

Claims (1)

[Scope of Claims] 1. A heat dissipation plate made of a metal material, and an individual semiconductor element placed on the heat dissipation plate and bonded via solder, and connected via solder to a wiring pattern formed on the upper surface. a circuit board with a hole or cutout in a part thereof, and a copper plate inserted into the hole or cutout of the circuit board, placed on the heat sink, and bonded with solder. a double-sided metallized ceramic plate placed on this copper plate and bonded via solder; and an individual semiconductor placed on this ceramic plate and bonded with solder and having a larger current capacity than the individual semiconductor elements. 1. A hybrid semiconductor device comprising: an element. 2. The individual semiconductor element having a large current capacity is a triax unit, and the circuit board is a glass epoxy base copper clad laminate, and a circuit for driving the triax unit is configured on this circuit board. 2. The hybrid semiconductor device according to claim 1, wherein the hybrid semiconductor device is configured as a semiconductor relay. 3. The first aspect of claim 1, wherein the heat sink is made of a copper-based metal material or an aluminum-based metal material whose upper surface is plated with copper.
3. The hybrid semiconductor device according to item 1 or 2. 4. Solder paste is printed on a heat sink made of a metal material, and a circuit board having a hole or cutout in a part, a soldering part on the bottom surface, and a wiring pattern on the top surface is placed on top of this, Individual semiconductor components are placed on the wiring pattern of this circuit board via solder paste, and individual semiconductor elements with large current capacity are placed on the heat sink corresponding to the hole or notch via a copper plate and a ceramic plate in that order. Equipped with
A method for manufacturing a hybrid semiconductor device characterized by performing solder reflow in this state to perform solder bonding. 5. Insert the copper plate into the hole or notch and place it on a heat sink, place a double-sided metallized ceramic board on top of the copper plate with solder paste in between, and place the individual pieces of large current capacity on top of the ceramic board. 5. The method of manufacturing a hybrid semiconductor device according to claim 4, wherein a semiconductor element is mounted and the solder reflow is performed in this state.