JPH0319397A - Heat sink installed on circuit board and manufacture thereof - Google Patents

Abstract

PURPOSE:To enable a foot pin to be easily and accurately fitted by a method wherein a heat sink is formed by bending a plate of prescribed shape, fitting holes are punched at prescribed positions in the base plate of the heat sink through a punching projection work done toward a side opposed to the side of the base plate in contact with a circuit board, and the root of the foot pin is press-fitted into the hole. CONSTITUTION:A heat sink main body 1 is formed by bending a plate of aluminum alloy or the like of prescribed shape and composed of a base 1a to which foot pins are fitted, an upright part 1b vertically bent and joined to the base 1a, and a zigzag bent part 1c joined to the part 1b. Two fitting holes 3 for foot pins 2 are provided to the base 1a separate from each other by a prescribed space corresponding to small holes bored in a board, where the holes 3 are punched through a punching projection work by a press making the side of the base 1b in contact with the board face upward, protrusions 4, fitting holes 5, and others are provided to the heat sink main body 1, and then the main body 1 is bent into a heat sink. Next, the bases 2a of the foot pins are press-fitted into the fitting holes 3 by a press to fix the foot pins 2. The foot pins 2 are inserted into the prescribed small holes bored in the circuit board and soldered at the rear side of the board.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical field The present invention is directed to each MW. This article relates to a heat sink with a simple structure and easy manufacture that can effectively dissipate the heat generated by electronic components fixed on circuit boards used in electronic equipment, and its manufacturing method. (Example) Conventional technology Some electronic components on a circuit board, such as electronic components that make up the power supply section, may generate high heat, shortening the life of the component or having a negative impact on the entire circuit. Therefore, conventionally, a heat sink with fins is installed and fixed on the board to hold the heat-generating electronic components to enhance the heat dissipation effect. However, as shown in FIG. 9, conventional heat sinks of this type are made by obtaining a long molded body with a plurality of fins formed by extruding or pultruding a material such as an aluminum alloy.
This is cut to an appropriate length to form the heatsink main body l, and a steel leg pin 2 is attached to the thick part 1z of the cut surface for insertion and fixation into a small hole drilled in the board. In this case, conventionally, in order to attach this leg pin 2 to the bottom surface of the radiator main body l, which is the cut surface, vertical holes 20 are drilled at a predetermined pitch at a predetermined location in the thick part 1z of the bottom surface. This is done by press-fitting the base 2a of the leg pin 2 into the holder using a press device. However, with this method, burrs are generated during the production of the connected body of the radiator body l by extrusion or pultrusion, so not only is it necessary to remove burrs after the fact, but also the leg pins 2 must be press-fitted. Burrs will also occur in the drill holes 20 of the drill hole 20, and if the deburring process is not done properly, the leg pins 2 will be bent or press-fitted at an angle.Furthermore, if the size and pitch of the drill holes 20 are inaccurate, it will cause damage to the entire body. Similar drawbacks occurred when press-fitting was performed automatically, resulting in a product radiator with an extremely low yield. (c) Disclosure of the invention In view of the problems in the production of conventional heat sinks of this type as described in (h), the manufacturing method has been completely changed and the heat sink can be manufactured in an extremely simple manner. In addition, the above-mentioned leg pin 2 can be installed accurately and easily. That is, the radiator of the present invention is made by bending a flat plate having a predetermined shape, and includes at least a bottom plate portion to which the leg pins are attached, a rising portion connected to the bottom plate portion, and a meander-shaped folded portion connected to the rising portion. At a predetermined location on the plate surface of the bottom plate, a hole protruding process is performed using a press machine toward the side opposite to the contact surface to the circuit board to form a fitting hole, and a fitting hole is formed in the fitting hole. It is manufactured by press-fitting the base of the leg pin. Hereinafter, embodiments of the present invention will be explained using figures. (2) Embodiment Figures 1 to 5 show heatsinks of various shapes manufactured by the method of the present invention. It is curved and has at least a bottom plate part 1 to which leg pins 2 are attached.
a, a rising part 1b that is newly curved at a right angle, which is connected to the bottom plate part 1a, and a meander-shaped bent part 1c, which is further connected to the rising part tb. In addition, FIGS. 1 to 2 show a heat sink in which the bent part 1c is folded in the same direction as the bottom plate part l&, and is used especially when the board (not shown) is used in an upright position. This is a heat sink in which the bent portion 1c is folded in a direction perpendicular to the bottom plate portion 1a, and is used with the board lying down. Therefore, the *a method will be explained below using the case of manufacturing the heat sink shown in Fig. 4 as an example. The wooden body l of the radiator in Fig. 4 is simply a single flat plate in the overall IIT shape as shown in Fig. There are two fitting holes for the leg pins 2 provided at a predetermined distance in 1a.The method for manufacturing the fitting holes 3 will be described below. Reference numeral 4 denotes a plurality of protrusions protruding from the left and right bending parts 1c at symmetrical positions across the rising part 1b. #I is located further ahead of the bending IC! It is press-fitted into a plurality of fitting holes 5 corresponding to the presser plate portions 1d provided therein. 6 is a screw hole for fixing electronic components made in the rising part 1b. Next, a method of manufacturing the front insertion hole 3 provided in the bottom slope portion 1a and a method of fixing the leg pin 2 to the insertion hole 3 will be explained with reference to Figures S7 and S8. This insertion hole 3 is not made with a drill as in the conventional method, but with the radiator main body 1 in a flat state, with the surface of the bottom slope 1b in contact with the substrate facing up, and the hole 3 is fixed using a press machine. First, on the tool 8, a thin guide hole 3a is made at a predetermined location on the bottom plate part la using a bunch 7a (FIG. 7 (a)), and then a punch with a slightly smaller diameter than the leg pin base 2a is used to punch the guide hole 3a at the tip. It is formed by replacing the punch 7b with a protrusion having the same diameter as the punch 7a and performing a so-called hole protruding process (burring process) in which the guide hole 38 portion is protruded and enlarged (Fig. 7 (e7)). ~(c)). In addition to the press-formed fitting hole 3, other protrusions 4 and fitting hole 5#! The radiator main body l on the flat plate shown in FIG. 6 with the radiator provided with the radiator is bent as shown in FIG. 4. Next, the leg pins 2 are inserted into the insertion holes 3 of the bottom plate portion 1a of the radiator body l.
Attach. In this case, place the jig 9 with the bottom plate l facing up.
, grip the leg pin 2 with another jig lO attached to the tip of the press device, and press-fit the leg pin base 2a facing downward into the protruding insertion hole 3 as described above (8th Figure (a)). Thereby, the leg pin 2 is firmly fixed in the insertion hole 3 (Fig. 8 (b)). Then, the heatsink manufactured in this way is combined with a predetermined electronic part, and the leg pins of the electronic part and the leg pins 2 of this heatsink are inserted into predetermined small holes drilled in the circuit board, and At the end, / \ danishing is done and fixed. (E) Effects of the Invention The radiator of the present invention is constructed as described above, and the radiator body can be formed by simply bending a single flat plate, so manufacturing is extremely simple and the thickness of the radiator can be reduced. Because it is thin and can be bent freely and in complex ways, it has a better heat dissipation effect than conventional products and is easier to reduce weight. In addition, this radiator is inserted into a small hole in the circuit board and fixed by soldering on the back side of the circuit board, so the leg pins are not press-fitted into drilled holes perpendicular to the thick wall part as in conventional methods. Since it is press-fitted into a fitting hole that has been drilled and protruded on the bottom plate surface of the radiator body, the fitting hole can be made deep even if the board is thin, and the leg pins can be press-fitted. Since the tube can be reliably installed in one piece and there is no need to worry about cracks appearing, the leg pins do not need to be bent or press-fitted diagonally like in drilled holes, making it possible to create extremely precise small heat sinks for circuit boards. It has the advantages that it can provide.

[Brief explanation of drawings]

Figures 1 to 5 are perspective views showing examples of various shapes of radiators manufactured by the method of the present invention, and Figure 6 is a plan view of the main body of the radiator shown in Figure 4 before being bent. Figures 7 (a) to (c) are explanatory diagrams showing the manufacturing process of the leg pin insertion holes provided in the bottom plate of the radiator body, and Figures 8 (a) to (b)
is an explanatory diagram showing how to attach the leg pin to the leg pin insertion hole. Description of symbols 1 - Heat sink body 2 - Monopod pin 3 - Monopod pin fitting hole 4 - protrusion 5 - protrusion fitting hole 6 - screw hole 7 - punch 8,9.
101 Jig 20 - Drill hole Figure 1 Figure 2 Figure 3 Figure 4 Patent application Person Mikado Technos Co., Ltd. Figure 5 Procedural amendment (Fang Gen Heisei September 29, 1999 Patent application Hei 1) -153670 No. 2, Title of the invention: A heat sink installed on a circuit board and its manufacturing method 3. Relationship with the case of the person making the amendment Name of the patent applicant: Mikado Technos Chichishiki Company 4. Agent 6 7. Details subject to amendment ``Brief explanation of the drawings'' column of the amendment.In the second line of page 9 of the statement of contents of the amendment, the statement ``This is an explanatory diagram showing how to attach the leg pins.'' was replaced with ``An explanatory diagram showing how to attach the leg pins.'' , Figure 9 is Figure 8 Figure 9

Claims (2)

[Claims] (1) A single flat plate is bent to include a bottom plate portion to which at least the leg pins are attached, a rising portion connected to the bottom plate portion, and a meander-like bent portion connected to the rising portion, A radiator installed on a circuit board, characterized in that the leg pins are press-fitted and fixed into insertion holes formed by drilling and projecting at predetermined locations on the plate surface of the bottom plate. (2) Analyze a single flat plate of a predetermined shape to form at least a bottom plate portion to which the leg pins are attached, a rising portion connected to the bottom plate portion, and a meander-shaped bent portion connected to the rising portion. At a predetermined location on the plate surface of the bottom plate, a hole protruding process is performed using a press machine toward the side opposite to the contact surface to the circuit board to form a fitting hole, and the base of the leg pin is inserted into the fitting hole. A method for manufacturing a heat sink installed on a circuit board, characterized by press-fitting the heat sink.