JP2007305649A - Means for fixing radiator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive, reliable, and easily attaching/detaching means for fixing a radiator where a load to a circuit board is reduced, and restriction in the arrangement of a circuit pattern is reduced. <P>SOLUTION: The means comprises: the circuit board 105 connected to an electronic component 10, a means for transmitting the heat generated from the electronic component 101 to a heat receiver in a radiator 103, the heat receiver of the radiator 103, the circuit board 105, a fixing tool 106, and a fixing screw 104. A complete screw 104b of the fixing screw 104 passes through a fixing tool screw hole 106c for racing at a fixing screw incomplete screw 104a for adhering the electronic component to the radiator with a fixed load, thus reducing the load to the circuit board and the restriction in the arrangement of the circuit pattern. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fixing means for a radiator attached to an electronic component.

  In recent years, the amount of heat generated by electronic components tends to increase as the electronic components are densely integrated and the operation speed is increased. As a means for preventing an unstable operation of the electronic component due to heat generation, it is common to connect the electronic component and a radiator. In order to efficiently transmit heat to the heatsink, it is important to reduce the gap between the electronic component and the heatsink and fix it firmly, and consider service and maintenance, or improving performance by replacing electronic components. Thus, there is a demand for a structure in which the radiator can be removed.

  As a means for fixing the radiator, the circuit board, radiator, electronic component, and coil spring are passed through with a stepped screw and tightened with a nut. The portion where the diameter of the screw step is large cannot penetrate the hole of the radiator, so the nut prevents the coil spring from compressing too much, and as a result, the coil spring load is stabilized at the set value, and the radiator is uniformly electronic. There is a fixing means for the radiator that is in close contact with the component (for example, see Patent Document 1).

  Moreover, although it is the same as that of patent document 1, there exists a fixing means via a supporting member between a heat radiator and a circuit board (for example, refer patent document 2).

Furthermore, two hook-shaped locking claws are provided on the support portion mounted with the electronic component on the circuit board, and the heat sink is brought into close contact with the electronic component by being fixed to the heat radiator with a linear spring or a plate spring. There is a fixing means (see, for example, Patent Document 3).
JP-A-5-243439 (paragraphs (0014-0015), FIGS. 1 and 2) Japanese Unexamined Patent Publication No. 2004-235482 (paragraphs (0023 to 0033), FIGS. 1 to 8) JP 2002-217345 A (paragraphs (0025 to 0043), FIGS. 1 to 13)

  However, in the configuration in which the heat sink is fixed together with the circuit board using a stepped screw using the coil spring of Patent Document 1, the warpage of the circuit board caused by the load of the coil spring deteriorates the reliability of the connection part between the electronic component and the circuit board. There were problems of increased product defects and shortened product life. In addition, the screw head of the radiator is in direct contact with the circuit board, thereby reducing the area for arranging the wiring pattern.

  Further, in the radiator fixing means of Patent Document 2 and Patent Document 3, the load due to the spring is reduced by the support member, but there is a problem of an increase in cost due to the support member. There is a problem that the reduction of the number of parts and the arrangement of parts are limited.

  In addition, the circuit board wiring pattern is also densely arranged around the high-density electronic components, and if the wiring pattern cannot be arranged due to the reduction of the wiring area, the circuit board needs to be multi-layered and the cost increases. Had problems.

  Especially in the case of electronic components that need to consider the copper foil width and wiring length on the circuit board or the distance between the copper foils, the proven wiring pattern is often used as it is, but the screw head and supporting member If it is not possible to avoid placement, it will be necessary to redesign and verify the wiring pattern from the beginning, which will require a lot of time and effort. Was.

  The present invention solves the above-mentioned conventional problems by providing a heat-dissipating fixing means that reduces the load on the circuit board, reduces the circuit pattern placement limit, is inexpensive, highly reliable, and can be easily attached and detached. The purpose is to provide.

  In order to achieve this object, the radiator fixing means of the present invention comprises a fixture, a circuit board disposed on a fixture support portion of the fixture, an electronic component disposed on the circuit board, A heat transfer body disposed on the heat generating portion of the electronic component, a radiator having the heat receiving portion disposed on the heat transfer body, and a fixing screw head locked by a radiator fixing hole of the heat radiator A fixing screw in which the complete screw portion is inserted through the radiator fixing hole of the radiator, the circuit board fixing hole of the circuit board, and the fixing screw hole portion of the fixing tool, and the fixing screw incomplete screw portion is idle It has the composition provided with.

  The fixing screw hole is a speed nut.

  Furthermore, the fixture has a configuration in which a plurality of fixture elastic portions are provided around the fixture support portion.

  Further, when fixing the fixture, the fixture elastic portion is deformed, and the radiator or the heat receiving portion of the radiator is biased to the electronic component by the restoring force of the deformation. ing.

  Furthermore, the heat radiator has a configuration in which the heat receiving portion and the heat radiating portion are integrated.

  Moreover, the said heat radiator has the structure by which the said heat receiving part and a thermal radiation part are connected through a heat-transfer means.

  As described above, the present invention can provide a heat-dissipating means that can reduce the load on the circuit board and reduce the restrictions on the arrangement of circuit patterns, is inexpensive, highly reliable, and can be easily mounted and removed. Excellent effect is obtained.

The best mode for carrying out the present invention will be described below with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals and the description thereof is omitted.
(Embodiment 1)
FIG. 1 is a perspective view showing the configuration of the radiator fixing means according to Embodiment 1 of the present invention. The electronic component 101 in FIG. 1 is an integrated circuit made of a semiconductor, and the heat transfer body 102 is a sheet for efficiently transmitting the heat generated by the electronic component 101 to the heat receiving portion of the radiator 103. The material of the heat transfer body 102 is soft, such as silicon rubber, to improve the adhesion to the electronic component 101, and a material with low thermal resistance is preferable to transfer heat well. The radiator 103 is made of a metal having a high thermal conductivity such as aluminum or copper, and is provided with a radiator fixing hole 103a for penetrating the fixing screw 104. 103b is provided. The circuit board 105 is provided with an electric circuit that is electrically connected to the electronic component 101 and performs a desired function, and is provided with a circuit board fixing hole 105a through which the fixing screw 104 passes. A heat transfer body 107 is disposed directly behind the circuit board 105 on which the electronic component 101 is mounted. The heat transfer body 107 is in close contact with the circuit board 105 and the fixture support portion 106 a of the fixture 106. Yes. The fixing device 106 does not necessarily need to be a material with excellent heat dissipation when the radiator 103 has a sufficient heat dissipation capability. Therefore, the heat transfer body 107 disposed on the back side of the circuit board includes the electronic component 101 and the circuit board. For the purpose of transmitting the heat transmitted from the connecting portion to 105 to the fixture 106, it may be an auxiliary role and is not always necessary. However, when the fixture 106 is made of metal and a circuit pattern other than GND exists in a portion in contact with the circuit board 105, the fixture 106 may be arranged for the purpose of electrical insulation. The fixture 106 includes a fixture support portion 106 a, a fixture elastic portion 106 b, and a fixture screw hole portion 106 c, and the fixture screw hole portion 106 c is screwed to the fixation screw 104. The fixing screw 104 includes a fixing screw incomplete screw portion 104a, a fixing screw complete screw portion 104b, a fixing screw head 104c, and a fixing screw thick shaft 104d. The fixing screw 104 includes a radiator fixing hole 103a and a circuit board fixing hole 105a. And is screwed to the fixture screw hole 106c.

  This will be described in more detail with reference to FIGS. FIG. 2 is a cross-sectional view of the radiator fixing portion according to Embodiment 1 of the present invention, and shows a case where the radiator is fixed with the configuration of FIG. 2 is mounted on the circuit board 105 by a small board 101a and solder balls 101b. The fixing screw incomplete screw portion 104a is formed thinner than the fixing screw complete screw portion 104b and the fixing screw thick shaft 104d. In FIG. 2, the fixing screw 104 penetrates the radiator fixing hole 103a and the circuit board fixing hole 105a, and the fixing screw head 104c is used for fixing the radiator while the fixing screw complete screw portion 104b passes through the fixing screw hole portion 106c. It is in a state in contact with the hole 103a.

  FIG. 3 is a cross-sectional view of the radiator fixing portion according to Embodiment 1 of the present invention, and is a cross-sectional view of the radiator fixing portion when the fixing screw 104 is further tightened as compared with the case of FIG. The fixture elastic portion 106b is elastically deformed, and the fixture screw hole portion 106c reaches the fixed screw incomplete screw portion 104a. The radiator 103 is fixed to the electronic component 101 by tightening the fixing screws 104 at four places until they are idle. At this time, a desired spring force is determined by the material, thickness, width, length, shape, and deformation amount of the elastic portion 106b of the fixture 106. That is, the adhesion strength between the electronic component 101 and the heat transfer body 102 can be set appropriately. The example of the fixture 106 in FIG. 1 is a general leaf spring and its calculation is easy, but the strength of the fixture elastic portion 106b is insufficient due to the size of the electronic component 101 and the radiator 103 and other reasons. In that case, the strength may be increased appropriately by adding flange bending or the like.

  Although the sheet material of the heat transfer body 102 is generally excellent in handleability, it has high thermal resistance or high cost. Instead, it is coated with a thin film of heat conductive material or a thin film of a heat-meltable material. It is possible to reduce the resistance.

  In FIG. 1, the heat radiator 103 and the heat radiating portion 103b are integrally formed, but the same kind of metal may be connected by welding, pressure welding, or adhesion.

  Further, when it is desired to dissipate heat at a location away from the electronic component 101, or to dissipate heat at a location where the ambient temperature is lower, the heat dissipating part 103b is configured separately from the radiator 103, and heat is dissipated at a location away from the electronic component 101. Is possible. In that case, it is desirable to connect the heat radiator 103 and the heat radiating portion 103b by a high heat transfer means such as a heat pipe, a heat lane, or copper.

  4 is a cross-sectional view of another radiator fixing portion according to Embodiment 1 of the present invention. The fixing screw 104 eliminates the fixing screw thick shaft 104d of FIG. 2 and directly fixes the incomplete screw portion 404a. It is good also as a shape connected to 104c. FIG. 4 is a cross-sectional view of the radiator fixing portion according to Embodiment 1 of the present invention.

  Further, the fixing tool screw hole portion 106c in FIG. 2 is subjected to burring processing by a press. However, if the fixing screw complete screw portion 104b is a tapping screw or a tap tight screw, it is not necessary to perform the screw processing in advance. . Of course, screw holes may be formed in advance by tapping.

  FIG. 5 is a cross-sectional view of another radiator fixing portion according to Embodiment 1 of the present invention, and the fixture hole portion 106c is a fixed screw complete screw portion like the fixture screw hole portion 506c shown in FIG. You may form only with the aperture shape and the through-hole matched with the pitch of 104b.

  FIG. 6 is a perspective view showing a configuration of another radiator fixing unit according to Embodiment 1 of the present invention. The fixture hole 106c may have a speed nut shape represented by the fixture screw hole 606c of FIG.

  FIG. 7 is a cross-sectional view of another radiator fixing portion according to the first embodiment of the present invention. The boundary between the fixing screw thick shaft 104d and the fixing screw incomplete screw portion 104a is fixed to the fixing screw from the circuit board fixing hole 105a. If it is configured on the head 104c side and the diameter of the circuit board fixing hole 105a is made narrower than the direct system of the fixed screw thick shaft 104d, the fixed screw thick shaft 104d can be used even if a temporary load is applied to the radiator 103. Becomes a stopper, and the radiator 103 can be more closely attached to the electronic component 101 and the heat transfer body 102 in a stable manner.

  Note that the fixture elastic portion 106b may use only the elasticity inherent in the substance, not the shape intended for elasticity.

  As described above, the thermal resistance can be reduced by bringing the radiator, the electronic component, and the heat transfer member into close contact with each other.

And the heat radiator fixing means which has the following characteristic can be provided by making a fixing screw idle.
(1) A fixed load is kept constant.
(2) Since it is the fixture that is elastically deformed, a long-term reliability in the mounting part of the electronic component is good without applying a load that warps the circuit board.
(3) The dead space on the circuit board is only a hole through which the fixing screw penetrates, thereby reducing the restrictions on the pattern design.
(4) Due to the elastic spring, there is tolerance for variations in the height direction of the parts.
(5) Since an excessive load due to screw tightening is not applied, work management becomes easy and workability is good. (6) Since the radiator is fixed by screws, it cannot be easily detached by vibration or impact, and can be easily removed by a general tool.
(7) The number of parts is small.
(8) The parts themselves can be produced at low cost by general pressing or forging, and are economical.
(9) When the material can be made of metal, long-term reliability is good with respect to a load caused by heat generation of electronic parts and adhesion of a radiator, and aging characteristics are good.

  As described above, according to the first embodiment, the fixing means for the radiator that reduces the load on the circuit board and reduces the circuit pattern arrangement restriction, is inexpensive, reliable, and can be easily attached and detached. Can be provided.

  The radiator fixing means of the present invention can provide an inexpensive and highly reliable radiator fixing means that can reduce the load on the circuit board and reduce the circuit pattern arrangement restriction, and can be easily mounted and removed. Therefore, it is useful in a radiator fixing means or the like.

The perspective view which shows the structure of the radiator fixing means in Embodiment 1 of this invention. Sectional drawing of the radiator fixing part in Embodiment 1 of this invention Sectional drawing of the radiator fixing part in Embodiment 1 of this invention Sectional drawing of the other heat sink fixing | fixed part in Embodiment 1 of this invention Sectional drawing of the other heat sink fixing | fixed part in Embodiment 1 of this invention The perspective view which shows the structure of the other heat radiator fixing means in Embodiment 1 of this invention. Sectional drawing of the other heat sink fixing | fixed part in Embodiment 1 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Electronic component 101a Small board | substrate 101b Solder ball | bowl 102,107 Heat-transfer body 103 Radiator 103a Radiator fixing hole 103b Heat sink 104 Fixing screw 104a, 704a Fixing screw incomplete screw part 104b Fixing screw complete screw part 104c Fixing screw head 104d 704d Fixing screw shaft 105 Circuit board 105a Circuit board fixing hole 106 Fixing tool 106a Fixing tool supporting part 106b Fixing tool elastic part 106c Fixing tool hole part 506c, 606c Fixing tool screw hole part

Claims (6)

A fixture,
A circuit board disposed on a fixture support portion of the fixture;
An electronic component disposed on the circuit board;
A heat transfer body disposed on the heat generating portion of the electronic component;
A radiator in which a heat receiving portion is disposed on the heat transfer body;
The fixing screw head is locked in the radiator fixing hole of the radiator, and the fixing screw complete screw portion is the radiator fixing hole of the radiator, the circuit board fixing hole of the circuit board, and the fixing screw hole of the fixing tool. A fixing screw that passes through the part and the fixing screw incomplete thread part is idled,
A radiator fixing means. The radiator fixing means according to claim 1, wherein the fixing screw hole is a speed nut. The radiator fixing means according to claim 1, wherein the fixture includes a plurality of fixture elastic portions around the fixture support portion. The fixing device elastic portion is deformed when the fixing device is fixed, and the radiator or the heat receiving portion of the radiator is urged to the electronic component by a restoring force of the deformation. A radiator fixing means. The radiator fixing means according to any one of claims 1 to 4, wherein in the radiator, the heat receiving portion and the heat radiating portion are integrated. The heat radiator fixing means according to any one of claims 1 to 4, wherein the heat receiving section and the heat radiation section are connected via a heat transfer section.

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