JPH0412686Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a mounting tool for a heat sink for a printed circuit board for mounting a semiconductor device on a printed circuit board.

(Prior art) Conventionally, heat sinks for semiconductors used on printed circuit boards have been fixed to the printed circuit board by press fitting fittings from both ends of a mounting groove formed on the bottom of the heat sink. I try to do that.

FIG. 4 shows an example of such a radiator fixture. The mounting tool 11 has a rectangular plate shape made of metal, and includes a press-fitting part 11a having a wedge part 11b for wedge-fitting with the mounting groove 12a of the radiator 12, and a pair formed at one end of the press-fitting part 11a. leg terminal 11
c, and the leg terminal 11c contacts the entrance portion of the mounting groove 12a. The radiator 12 is fixed by press-fitting the mounting tools 11 from both ends of the mounting groove 12a and soldering each leg terminal 11c at a predetermined position on the printed circuit board. Note that 13 is a power transistor fixed to the side surface of the heat sink 12.

On the other hand, the semiconductors used in printed circuit boards used in the assembly and wiring of electronic device circuits include those that are attached directly to the board to control minute to small amounts of power, and those that control larger amounts of power that use heat generated during operation. Some are used while being cooled by radiating heat into the air with a heat radiator, and others are fixed to printed circuit boards along with electronic components such as resistive elements and capacitors by a soldering process using dip solder baths. Most parts of this process are usually automated, and in order to improve productivity in the board assembly process, it is important that the mounting dimensions of the board and mounting parts be accurate and have little variation. Required by assembly manufacturers.

(Problem to be solved by the invention) When attaching a heatsink to a printed circuit board, it is important to press fit the fixture 11 from both ends of the mounting groove 12a of the heatsink 12 and print the distance between the terminals 11c on both legs. It is to match the dimensions of the hole in the board. However, with this method, it is difficult to match the distance between the terminals with high precision, and when a large radiator is used, the distance between the leg terminals 11c increases, and the weight of the radiator 12 to be supported becomes large.
The force acting between the leg terminals 11c that directly support this heatsink and the printed circuit board becomes large under adverse conditions such as during transportation, and there is a risk that the mechanical strength will be insufficient. It cannot be used with this mounting method. For this reason, small-sized heat sinks are exclusively used as heat sinks for printed circuit boards.

Therefore, when using a large heat sink, a special process using screws, rivets, etc. is required, and this special process cannot be introduced into an automated line without reducing productivity. have.

The present invention has been made in view of these points, and provides a mounting tool for a printed circuit board heatsink that allows even a large heatsink to be mounted on a printed circuit board in the same manner as a conventional small heatsink. The purpose is to

(Means for Solving the Problem) According to the present invention, a mounting tool for a heat sink for a printed circuit board is formed by forming a mounting groove on the bottom surface of a semiconductor heat sink fixed to a printed circuit board, and is press-fitted from both ends of the mounting groove. In the present invention, there is provided a mounting fixture for a heat sink for a printed circuit board having leg terminals formed at both ends.

(Function) In the present invention, leg terminals are provided at both ends of the mounting fixture for the heat sink for printed circuit boards, so the number of leg terminals of the conventional fixture is doubled, and the mechanical strength of the heat sink for the printed circuit board is increased. The mounting strength is increased, and even a large radiator can be mounted in the same assembly process as a small one.

(Example) Next, an example to which the mounting tool according to the present invention is applied will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing the structure of a fixture 1 according to the present invention. FIG. 2 is a side view when applied to a large radiator 2, and FIG. 3 is a perspective view of the case shown in FIG. In these figures, 1 is a fixture according to the invention. The mounting 11 includes a press-fitting part 1a having a pair of wedge parts 1b provided at both edges for wedge-fitting to the mounting groove 2a of the radiator 2, and two leg terminals 1.
c, 1d. That is, at the front end in the press-fitting direction, a pair of leg terminals 1c for soldering and fixing to the printed circuit board are provided with an interval approximately equal to the distance between both edges of the press-fitting part 1a, and at the front end in the press-fitting direction, A pair of leg terminals 1d1 are provided at a distance that allows them to slide inside the opening of the mounting groove 12a of the radiator 12 when press-fitted.

The above-mentioned fixture 1 is made of metal, for example, a metal plate that is elastic and easy to solder, such as brass, is punched out into a shape in which the entire fixture 1 is developed in a plane, and the leg terminals 1c and 1d are provided at both ends. The wedge portion 1b is finished by bending the portion and plating the tip with solder, and the wedge portion 1b is also formed at the same time as punching during the press forming.

The distance between the leg terminals 1c and 1d can be set to the required length at the time of designing the fixture 1, and since they are generally made by press working as described above, they are highly accurate and have little variation in dimension. can be easily obtained. Further, this dimensional accuracy can be maintained well regardless of the press-fitting operation of the fixture 1. Furthermore, since the number of leg terminals 1c and 1d that the fixture 1 has is twice that of the conventional fixture, the weight of the radiator 2 can be reduced to approximately 1/2 per each leg end and distributed among the leg terminals.

Next, a case will be described in which the fixture 1 of the present invention is applied to a large radiator 2. FIGS. 2 and 3 are side views and perspective views in these cases. In FIG. 2, P1 and P3 are the distances between the leg terminals 1c and 1d, P2 is the distance between the press-fitted fixtures 1, and P1 and P3 are the distances between the fixtures 1 as described above. High precision can be obtained through manufacturing, and P2 can also obtain precision close to the dimensional precision of the heat sink 2. This is because the position of the fixture 1 when it is press-fitted is determined by the leg terminal 1e coming into contact with the entrance of the mounting groove 2a of the radiator 2. The weight of the large heat sink 2 to which a plurality of power transistors 3 are fixed is distributed by the increased leg terminals by using the fixture 1 of the present invention, and the distance P1 between the leg terminals is increased as described above. P2 and P3 can be precisely positioned, and the fixture 1 can be attached to the large radiator 2 and fixed to the printed circuit board only by press-fitting, without using screws or riveting. Further, there are advantages such as a high degree of coupling between the heat radiator 2 and the fixture 1.

(Effects of the invention) As described above, according to the invention, the mounting dimensions of the heatsink to the printed circuit board can be made with good accuracy regardless of the press-fitting work of the fixture. Even large heat sinks can be soldered and fixed at the same time as general electronic components without adding any special steps to the printed circuit board assembly process.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a fixture according to the present invention;
Fig. 2 is a side view showing an example in which the mounting according to the present invention is applied to a large heat sink, Fig. 3 is a perspective view of the embodiment shown in Fig. 2, and Fig. 4 shows a conventional mounting and heat dissipation device. FIG. 3 is a perspective view showing how it is attached to the device. 1...Mounting tool, 1a...Press-fitting part, 1b...Wedge part, 1c, 1d...Leg terminal, 2...Radiator, 2a
...Mounting groove, 3...Power transistor.

Claims (1)

[Scope of utility model registration request] A mounting tool for a heat sink for a printed circuit board that is press-fitted from both ends of a mounting groove formed on the bottom surface of a semiconductor heat sink fixed to a printed circuit board, characterized in that leg terminals are formed at both ends. Mounting bracket for heatsink for printed circuit board.