JP2007019377A - Heat sink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat sink improved in heat dissipation characteristics and mass-productivity. <P>SOLUTION: In a heat sink, a number of planar fins 3 are arrayed in parallel with each other at predetermined intervals. Fin pitch control units 4A, 4C which are bent outside to adjust the interval between the fins 3 are formed on both terminals of each of the fins 3, respectively. A snap 5 including a pawl 5A or 5C cut up to an upper side or lower side is formed in the top end of the fin pitch control units 4A, 4C, respectively. The pawls 5A, 5C are fitted and fixed, respectively with terminals of fin pitch control units 4B, 4D disposed in front of the fin pitch control units 4A, 4C, and in upper or lower parts of the fins 3, a notched part 7 is formed at a position where the fin pitch control units 4A, 4B, 4C, 4D are not formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat sink in which a large number of thin plate-like fins are arranged in parallel with each other at a predetermined interval.

  As is well known, the heat sink is for promoting heat dissipation and cooling, and generally has fins for increasing the heat radiation area as much as possible. If the fin is directly attached to the object to be cooled, the heat resistance between the two can be reduced (decreased) and the heat dissipation efficiency can be improved. However, some of the objects to be cooled inevitably generate heat, and such a heating element does not have a structure to which a heat radiating fin is attached because its original function is not heat generation. It is generally difficult to directly attach the fins for structural reasons and workability. Therefore, conventionally, in order to give versatility to the heat sink, a heat sink having a structure in which a base part to which a heating element can be brought into contact or attached and a large number of fins are attached is used. An example of such a heat sink is described in Patent Documents 1 and 2.

Conventionally, in order to improve the manufacturability of a heat sink in which a heat radiating fin is formed in a flat plate shape, a heat sink is formed by folding a single metal plate to cover the entire surface of the base portion. In addition, a heat sink having a structure attached to a base portion is known. This type of radiating fin is called a folded fin, and has a structure in which tunnel-like ventilation paths and ventilation paths opened upward are alternately formed, so that it is forced in the direction along the surface of the radiating fins. It is used as a heatsink that blows and cools. An example of this type of heat sink is described in Patent Document 3.
Japanese Patent Laid-Open No. 11-87961 Japanese Patent Laid-Open No. 2001-244677 US Pat. No. 6,288,899

  As a heat sink having a structure in which a large number of fins are erected on the base part as described in Patent Documents 1 and 2, a structure in which fins are attached to a base part prepared in advance and a structure in which both are integrally molded are known. It has been. In the former structure in which the base part and the fin are separate members, it is necessary to join the two together to integrate them. However, if a means such as brazing or soldering is used as the structure for the joining, a thin plate shape With this fin, a sufficient bonding area cannot be secured. For this reason, it is difficult to reliably and highly attach a thin plate-like fin capable of expanding the heat radiation area to the base portion. In addition, since work such as brazing and welding is required for the fin, if the manufacturing workability is poor and the fin and the base are different types of metals or alloys, either the fin or the base is used. One joint surface must be plated in advance, and when solder is used for this joint, there is a problem that a measure for lead-free must be taken. Therefore, the heat sink having such a structure is not suitable for mass production.

  In addition, as a method of manufacturing the fin and the base portion integrally, there are a casting method such as die casting and an extrusion molding method. In order to make the fin into a thin plate shape, a cavity for the fin or a molding die is used. Therefore, the molten metal does not reach the inside of the cavity enough to cause casting defects or breakage of the mold. In order to solve this problem, it is necessary to make the fins thicker or lower the height with respect to the thickness, but the heat capacity of the fins is increased, or a necessary and sufficient heat radiation area cannot be secured. Inconvenience occurs.

  In the heat sink using the folded fin as described in Patent Document 3 above, when the folded fin is joined to the base portion, it is joined at the bent edge of the folded fin. In addition, since the folding edges are not aligned on a plane, a gap is formed between one of the folding edges and the surface of the base portion, so that the heat between both There is a possibility that the resistance will be increased and the heat dissipation characteristics will be lowered.

  The present invention has been made paying attention to the above technical problem, and an object of the present invention is to provide a heat sink having improved heat dissipation characteristics and mass productivity.

  In order to achieve the above object, the invention of claim 1 is a heat sink in which a plurality of thin plate-like fins are arranged in parallel to each other at a predetermined interval, and at both ends of each of these fins, an outer side is provided. And a fin pitch control portion that adjusts the interval between the fins is formed, and a snap portion having a claw portion cut upward or downward at the tip of each fin pitch control portion is formed. Each of the claw portions and the end portions of the fin pitch control portions arranged in front of the fin pitch control portions are respectively fitted and fixed, and upper or lower portions of the fins. In addition, the heat sink is characterized in that a notch portion is formed at a place where each fin pitch control portion is not formed. It is.

  According to the first aspect of the present invention, since the interval between the fins (fin gap or fin pitch) is adjusted by each fin pitch control section, the fin gap (fin pitch) can be made narrower (smaller). it can. For this reason, the thermal resistance between the fins is reduced, so that a necessary bonding area can be sufficiently ensured. As a result, the heat sink can be easily assembled. Further, a snap portion having a claw portion cut upward and downward is formed at the tip of the fin pitch control portion, and each fin pitch disposed in front of each claw portion and each fin pitch control portion. Since the end part of the control part is fitted and fixed respectively, and the notch part is formed in the upper or lower part of each fin, and where each fin pitch control part is not formed The split flow can be generated downstream by the notch. Therefore, since air resistance becomes small, the heat dissipation efficiency of a heat sink improves.

  The best mode for carrying out the present invention will be described below. The heat sink 1 as an object of the present invention has a structure in which a large number of thin plate-like fins (radiating fins) are arranged in parallel with each other at a predetermined interval. FIG. 1 is a view showing a heat sink 1, and FIGS. 2 to 4 are views showing a part (fins 3) of the heat sink 1. The fin 3 is a thin metal plate having a high thermal conductivity such as aluminum, an aluminum alloy, or copper, and is formed into a predetermined shape by various processes such as stamping (embossing), wire cutting, and machining. . The fins 3A and 3C are bent at both ends (both sides) outward (toward the other fin 3B facing the fin 3A or the other fin 3D facing the fin 3C). Or flat fin pitch control portions 4A and 4C for adjusting (controlling) the spacing (fin gap or fin pitch) between the fins 3C and 3D. At the tip of each fin pitch control part 4A, 4C is formed a claw part 5A cut or raised upward or downward, respectively, or a snap part 5 having a claw part 5C, and above each fin 3A, 3C or Cutout portions (concave grooves) 7 are formed in the lower portion and at locations where the fin pitch control portions 4A and 4C are not formed. Each fin pitch control portion 4B, 4D is arranged in front of each fin pitch control portion 4A, 4C, and each fin pitch control portion 4A, 4B, 4C, 4D has a hole at the end thereof. 6 is formed. Each fin pitch control section 4A, 4B, 4C, 4D has a shape in which each cross section has a curve with a bending radius R and a straight line (horizontal line) with a length L, and the straight line length L is the fin gap G. This can be obtained by subtracting the bending radius R from. For example, if the fin gap G is 1.2 mm and the bending radius R is 0.4 mm, the straight line length L is 0.8 mm.

  Each fin pitch control part 4A, 4B and each fin pitch control part 4C, 4D are arranged in a line, and each claw part 5A, 5C is formed at the end of each fin pitch control part 4B, 4D. The holes 6B and 6D (hole 6) are fitted and fixed. Therefore, the said fin gap (fin pitch) G can be adjusted by changing the shape (size) of each fin pitch control part 4A, 4C. The fin gap G may be a value that reduces the thermal resistance between the fins, and may be a positive value such as 1.5 mm or 2.5 mm in addition to 1.2 mm. Further, each fin 3 (each fin 3A, 3B, 3C, 3D) may be joined to a base portion (not shown) by various coupling processes (soldering or the like). For example, when each fin 3 is erected on the base portion and an exhaust hole is formed between the notch portion 7 formed in each fin 3 and the base portion, each fin 3 functions as an exhaust valve. Therefore, a shunt can be generated on the downstream side.

  Next, the operation of the heat sink in the present invention will be described. When heat of a heat-generating component such as an arithmetic element is transmitted to each fin 3, the heat is dissipated from the fin 3 into the surrounding atmosphere. For example, when forced air cooling is performed by a blower fan or the like (not shown), a shunt is generated downstream by the notch portion 7 as shown in FIG. Therefore, the heat dissipation efficiency of the heat sink 1 is improved. More specifically, air (indicated by an arrow C1 in the figure) warmed by the heat flows inside the notch 7, and heat is released into the gap 10 between the fin 3C and the fin 3D to cool it. The air (shown by the arrow C2 in the figure) flows. And the flow direction of warm air or cold air is changed or controlled by the structure of each fin, and a mixed flow (indicated by an arrow C3 in the figure) is formed inside the fin 3A (fin pitch control portion 4A). Therefore, heat exchange is performed by this mixed flow, so that the heat dissipation characteristics of the heat sink 1 can be improved.

  Moreover, since the fin gap is adjusted to a predetermined width (mainly 1.2 mm) by changing the shape of each fin pitch control portion 4A, 4C, a wide coupling region between the fins 3 can be taken. Therefore, good soldering can be performed, and a plurality of fins 3 aligned with each other can be aligned. As a result, manufacturing workability can be improved. For example, the wider the coupling region between the fins 3, the narrower the fin gap (fin pitch) becomes. Therefore, the number of fins 3 is increased without taking into account the limit of the fin gap. be able to. Furthermore, since the thermal resistance between the fins 3 is reduced by narrowing the fin gap, a necessary junction area can be sufficiently ensured. Therefore, the heat sink 1 can be easily assembled.

  In the above-described specific example, the claw portions 5A and 5C of the snap portion 5 are fitted and fixed to the holes 6B and 6D formed at the end portions of the fin pitch control portions 4B and 4D, respectively. The snap portion in the invention is not limited to this specific example. In short, the snap portion may be in a shape that can be fitted and fixed to the fin pitch control portion. For example, the claw portion of the snap portion may be fitted and fixed to a recess formed in the fin pitch control portion.

It is a perspective view which shows one specific example of the heat sink in this invention. It is a figure which shows a part of heat sink of FIG. It is a front view which shows the fin of FIG. It is an AA cross-sectional perspective view showing the fin of FIG. It is a BB cross-sectional perspective view which shows the fin of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Heat sink, 3, 3A, 3B, 3C, 3D ... Fin, 4A, 4B, 4C, 4D ... Fin pitch control part, 5A, 5C ... Claw part, 5 ... Snap part, 6, 6B, 6D ... Hole part 7: Notch part, 10 ... Gap.

Claims (1)

A plurality of thin plate-like fins are heat sinks arranged in parallel with each other at a predetermined interval,
A fin pitch control part is formed at each end of each fin to bend outward and adjust the spacing between the fins. The fin pitch control part is cut upward and downward at the tip of each fin pitch control part. Snap portions each having a claw portion are formed, and each claw portion and the end portion of each fin pitch control portion disposed in front of each fin pitch control portion are respectively fitted and fixed, and A heat sink, characterized in that a notch is formed in a portion on the upper side or the lower side of each fin and where each fin pitch control portion is not formed.

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