JPH0638429Y2 - Semiconductor element mounting structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A semiconductor element mounting structure capable of preserving the geometrical arrangement of the lead terminals of the semiconductor element and mounting it on a radiator of a plurality of semiconductor elements. For the purpose of contributing to the mounting and improving the heat dissipation performance, the heat conductive fixing plate is installed in the same direction and separated from the base of the radiator with the heat dissipation fins, and the plate on the same side of the heat conductive fixing plate is installed. A semiconductor element having lead terminals of the same arrangement on the surface is mounted so that the lead terminals are arranged in a line, and the first semiconductor element or the second semiconductor element of the adjacent heat conductive fixing plates on which the semiconductor elements are mounted is attached. Of the second heat-conducting fixing plate or the plate portion of the first heat-conducting fixing plate which faces the semiconductor element of FIG. Reed While preserving the arrangement of terminals, it was bent toward the printed board and each lead terminal was connected to a corresponding circuit pattern portion on the printed board.

[Industrial application field]

The present invention relates to a semiconductor device mounting structure capable of mounting a plurality of semiconductor devices on a radiator by preserving the geometrical arrangement of the lead terminals of the semiconductor devices.

[Conventional technology]

As shown in FIG. 14, the mounting structure for improving heat dissipation of the semiconductor element mounted on the conventional printed circuit board is such that the semiconductor transistor 3a is held in close contact with the heat conductive fixing plate 1b of the radiator 1 by the metal fitting 4a. Fixed with, semiconductor transistor 3a
Was mounted on the mounting surface 2a side of the printed circuit board 2. However, if the number of semiconductor transistors 3a increases, mounting becomes impossible only on the mounting surface 2a side, and as shown in FIG. 15, it becomes necessary to mount on the back surface 2b side of the printed circuit board 2 as well. (Mounting surface) The semiconductor transistors 3a and 3b mounted on the back surface (solder surface) are mounted so that their back surfaces are aligned with each other.

[Problems to be solved by the device]

According to this back-to-back mounting, as shown in FIG. 12, the lead terminals 3al of the semiconductor transistor 3a and the lead terminal 3bl of the semiconductor transistor 3b are arranged at both ends.
Since the positions of al and the lead terminal 3bl are reversed by 180 °, the circuit pattern on the printed circuit board 2 must separate the emitter-like rounds E and e from the collector rounds C and c, respectively, as shown in FIG. The area of the pattern increases correspondingly, and the mounting efficiency of the semiconductor transistor deteriorates.

Moreover, Round E and c, Round B and b, Round C
Since and must be insulated by independent terminals, a gap d between the terminals is required, and the wiring area is increased accordingly.

Further, the thickness D of the heat transfer fixing plates 1b and 1c is the semiconductor transistor 3
It is determined by the length of the a and 3b leads (the lead must be bent to penetrate the lead insertion hole of the printed circuit board), and this heat conductive fixing plate 1b cannot be unnecessarily thick, so heat dissipation The heat flow to the fin 1a is a heat conductive fixed plate
It will be limited to a thickness D of 1b. Therefore, also in this point, it is desirable to increase the thickness of the heat conductive fixed plate 1b as much as possible so that the heat generated from the semiconductor transistors 3a and 3b can be quickly passed through the heat conductive fixed plate 1b.

An object of the present invention is to provide a semiconductor element mounting structure that contributes to high-density mounting of semiconductor elements and the like on a printed circuit board and can improve heat dissipation performance.

[Means for Solving the Problems]

FIG. 1 shows a block diagram of the principle of the present invention. As shown in this figure, the present invention is based on a radiator 1 having a radiation fin 1a.
1 ₁ from each other spaced apart from thermally conductive fixing plate 1b, to extend the 1c in the same direction, the thermally conductive fixing plate 1b, the semiconductor element 3a having a lead terminal of the same sequence to the plate surface of the same side of the 1c, 3b of The lead terminals are aligned and mounted, and the semiconductor element 3
a, 3b among the adjacent heat transfer fixing plates 1b, 1c, the semiconductor element 3a, or the heat transfer fixing plate 1b facing the semiconductor element 3b, or the plate portion of the heat transfer fixing plate 1c. The printed board 2 is attached and bent toward the printed board 2 while preserving the arrangement of the corresponding lead terminals of the semiconductor elements 3a and 3b having the same mounting positions on the heat conductive fixing plates 1b and 1c. And each lead terminal is connected to the corresponding circuit pattern portion 9 on the printed board 2.

[Action]

The heat transfer fixing plates 1b and 1c are separated from each other and the base portion 1 _{1 of the} radiator 1 is separated.
From the same direction. Semiconductor element having lead terminals of the same arrangement on the plate surface on the same side of the heat conductive fixing plates 1b, 1c
The lead terminals of 3a and 3b are aligned and mounted.

The printed board 2 is attached to the plate portion of the heat conductive fixing plate 1b or the heat conductive fixing plate 1c facing the semiconductor element 3a or the semiconductor element 3b.

The lead terminals bent toward the printed board 2 are retained on the printed board 2 while preserving the arrangement of the corresponding lead terminals of the semiconductor 3a and the semiconductor element 3b which are mounted at the same mounting position on the printed board 2. Corresponding circuit pattern part 9
Connect to.

By adopting such a mounting structure of the lead terminals of the semiconductor element to the printed board, the circuit pattern of the printed board 2 can be densified, and by extension, the printed board 2 of the semiconductor element.
Useful for high mounting density. Further, the heat conductive fixing plates 1b and 1c can be made thicker, and the heat dissipation can be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 2 to 7.

In the figure, the radiator 1 radiator base 1 ₁ of a pair of thermally conductive fixing plate 1b having a plurality of radiating fins 1a, 1c are spaced apart from each other, are extended and parallel. A notch 1B for mounting a printed circuit board is formed at both ends of the heat conductive fixing plate 1b, and a threaded hole 5a is screwed into each notch 1B. Further, a pair of through holes 6 for inserting a screw driver and a pair of screw holes 7ah are screwed into the heat transfer fixing plate 1b. on the other hand,
A pair of screw holes 7bh facing the respective through holes 6 are screwed in the heat transfer fixing plate 1c. On the same side plate surface of each heat conductive fixed plate 1b, 1c, as shown in FIG.
The l and 3bl are arranged in the same order. The transistors 3a, 3b are positioned by the protrusion (dough) 4c (see FIG. 5) of the pressing plate 4a, and the pair of transistors 3a, 3b face each other with the heat transfer fixing plate 1b in between. .
Then, the pressing plates 4a, 4b have screws 7a, 7b and screw holes 7ah, 7bh.
It is fixed to the heat transfer fixing plates 1b and 1c by fastening with. As a result, the transistors 3a and 3b are tightly joined to the heat conductive fixed plates 1b and 1c.

The printed circuit board 2 is arranged in the notch 1B of the heat transfer fixing plate 1b, and the printed circuit board 2 is fastened by fastening the screw 5 and the screw cut hole 5a.
Are fixed to the heat transfer fixing plate 1b. As shown in FIG. 9, circuit patterns for connecting the transistors 3a and 3b are formed on the mounting surface 2a and the back surface 2b of the printed circuit board 2. That is, the rounds E and e for the emitters of the transistors 3a and 3b, the rounds B and b for the bases, and the rounds C and c for the collectors are formed close to each other. A through hole 2h is formed at the center of these rounds.
Then, each lead terminal 3al of the transistor 3a is mounted on the mounting surface 2a.
Bend to the side, the tip is inserted into the through hole 2h,
Each lead terminal 3bl of the transistor 3b is bent to the back surface 2b side, the tip thereof is inserted into the through hole 2h, and the lead terminals 3al and 3bl protruding from each through hole 2h are soldered.
Is welded to each round E, B, C, e, b, c.

According to this embodiment, since the transistors 3a and 3b are mounted on the heat conductive fixing plates 1b and 1c in the same arrangement order of the lead terminals having the same function, the emitters, the bases, and the collectors of the paired transistors 3a and 3b are used. Rounds E and e, B and b, C and c can be close to each other, and the insulation gap d of the round can be set to d.
It becomes possible to set = 0, and the circuit pattern for bypass is not necessary. Therefore, the area occupied by the circuit pattern on the printed circuit board 2 can be significantly reduced,
It is possible to improve the component mounting efficiency of the printed circuit board 2.

Further, as shown in FIG. 8, the heat conductive fixing plates 1b, 1c are formed with inclined surfaces 1C, 1D, and the thickness of the heat conductive fixing plates 1b, 1c is within the length of the lead terminals 3al, 3bl. If the thickness is increased, the thermal resistance is reduced, and the heat of each of the transistors 3a and 3b can be sufficiently conducted to the radiation fin 1a side.

Here, as shown in FIG. 13, each of the transistors 3a, 3a
B lead terminal 3al, 3bl lead length is L, heat conductive fixing plate 1
If the thickness of b and 1c is D and the length of the bending position is l and m,
L is represented as L = l + m. In the case of the present embodiment, the insulation gap d can be set to 0, so that the bending position of the lead terminal can be shortened to l-d. This allows
The insertion height of the lead terminal 3al is m + d, and the thickness of the heat conductive fixing plate 1b can be D + d.

However, since the gap β is required between the heat conductive fixed plate 1b and the transistor 3b, the thickness of the heat conductive fixed plate must be reduced by this amount, and the thickness of the heat conductive fixed plate 1b is D + d. −
Beta. Here, if d = β, the thickness of the heat conductive fixed plate 1b becomes D, which is the same as that of the conventional heat conductive fixed plate 1b. In the conventional case, one set is provided on both sides of this heat conductive fixed plate 1b. In contrast to the case of radiating heat from the semiconductor of No. 1, in the present invention, the thickness of each of the pair of heat conductive fixing plates 1b and 1c is D, and the semiconductor is attached to only one surface of the fixing plate, so that the heat radiating effect is sufficient. Can be increased. Further, the thickness of one heat conductive fixing plate 1c can be set to D or more, and the heat radiation effect can be further enhanced.

[Effect of device]

As described above, according to the present invention, since the lead terminals having the same function of the pair of switching elements can be connected to the circuit pattern of the printed circuit board in close proximity to each other,
This serves to significantly reduce the area occupied by the circuit pattern on the printed circuit board and improve the component mounting efficiency on the printed circuit board. Further, the heat transfer fixing plate can be made thicker, and the heat dissipation performance can be improved.

[Brief description of drawings]

FIG. 1 is a structural view of the principle of the present invention, FIG. 2 is a perspective view showing an embodiment of the present invention, FIG. 3 is a side view, and FIG. 4 is a sectional view taken along the line III-III of FIG. FIG. 5 is a sectional view of an essential part of the pressing plate 4a, FIG. 6 is a structural view of a transistor, FIG. 7 is a plan view of an essential part, FIG. 8 is a sectional view of an essential part of another embodiment of the present invention, and FIG. Fig. 10 is a circuit pattern diagram of the present invention, Fig. 10 is a circuit pattern diagram of a conventional example, Fig. 11 is a transistor arrangement diagram of the present invention, Fig. 12 is a transistor arrangement diagram of a conventional example, and Fig. 13 is mounting of semiconductor transistors. FIG. 14 is a sectional view of a conventional example, and FIG. 15 is a sectional view of another conventional example. In Figure 1 to Figure 8, 1 radiator, 1 ₁ base, 2 a printed circuit board, 1b, 1c is thermally conductive fixing plate, 3a, 3b is a semiconductor device (power transistor), 9 is a wiring pattern portion is there.

Claims (1)

[Scope of utility model registration request] 1. A heat transfer fixing plate (1b, 1c) spaced apart from a base portion (1 ₁ ) of a radiator (1) having a radiation fin (1a).
Are installed in the same direction, and the lead terminals of the semiconductor elements (3a, 3b) having the lead terminals of the same arrangement are mounted on the same side plate surface of the heat transfer fixing plate (1b, 1c) in an aligned manner. At the same time, the adjacent heat conductive fixing plates (1b, 3b) on which the semiconductor elements (3a, 3b) are mounted are attached.
The printed board (2) is attached to the heat conductive fixing plate (1b) facing the semiconductor element (3a) or the semiconductor element (3b) or the plate portion of the heat conductive fixing plate (1c) in 1c). , Bending toward the printed board (2) while preserving the arrangement of corresponding lead terminals of the semiconductor elements (3a, 3b) having the same mounting position on each heat conductive fixing plate (1b, 1c) Then, each lead terminal is connected to a corresponding circuit pattern portion (9) on the printed board (2), which is a semiconductor element mounting structure.