JPH04343253A - Heat dissipating fin mounting structure of ic - Google Patents

Abstract

PURPOSE:To provide a heat dissipating fin mounting structure which can be easily and surely mounted on an IC to enhance it in heat dissipating property. CONSTITUTION:An IC 3 is sandwiched between a heat dissipating fin 1 which is thermally engaged with the upside of the IC 3 so as to conduct the heat released from the IC 3 and a prescribed member 2 engaged with the underside of the IC 3, and the IC 3 and the heat dissipating fin 1 are mechanically joined together.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation fin mounting structure for an IC.

0002

2. Description of the Related Art Conventionally, in order to effectively cool a heat-generating IC, aluminum heat dissipation fins are attached directly to the outer surface of an IC package. As an example of this attachment method, there is a method of simply joining an IC package (made of ceramic) and a radiation fin with a thermally conductive adhesive.

0003

However, in the above bonding method using an adhesive, there is a risk that the adhesive may peel off and the radiation fin may fall off from the IC due to the difference in coefficient of thermal expansion. Therefore, without using adhesive, I
It is an object of the present invention to provide a mounting structure capable of mechanically coupling C and a radiation fin together safely, reliably, and easily.

0004

[Means for Solving the Problems] In order to solve the above problems, an IC heat dissipation fin mounting structure according to the present invention is provided.
The IC is sandwiched between a heat dissipation fin that thermally conductively engages the upper surface of C and a predetermined member that engages the lower surface of the IC.
The structural feature is that C and the radiation fins are mechanically connected.

[0005]

[Operation] Since the heat dissipation fins are sandwiched between the heat dissipation fins and the predetermined member, the heat dissipation fins are firmly fixed to the IC.
Therefore, its reliability is improved. In addition, the heat radiation fin is
Since it is thermally conductively engaged with C, heat radiation efficiency is improved.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As can be seen from FIG. 1, which is an exploded perspective view, the mounting structure of this embodiment has four side walls cut out in a comb-like shape in order to secure heat dissipation area. A box-shaped heat dissipation fin 1 that is open at the top, and a sandwiching member 2 that can elastically sandwich something between them, such as a U-shape formed by bending a single plate spring in two, It basically consists of: At the time of installation, the DIP type IC (package) 3 and the heat dissipation fin 1 are firmly sandwiched between the opposing flat parts of the sandwiching member 2, and are fixed in a state of close engagement with each other (Fig. 2).

One side (upper side) forming the U-shape of the sandwiching member 2
As shown in FIG. 3, the tip of the flat portion is bent and expanded diagonally to facilitate attachment of the sandwiching member 2 to the radiation fin 1. A round hole 6 into which two protrusions 5 provided on the bottom inner surface (upper surface) of the radiation fin 1 can fit is bored in the middle part of the upper flat part by so-called dowel molding. This protrusion 5 and hole 6
When they are fitted together (attached), the relative movement of the radiation fins 1 and the sandwiching member 2 is thereby restricted.

As shown in FIG. 4, a locking portion 8 similar to the hook at the tip of a fishhook (not shown) is provided on the inside of the tip of the other (lower) flat portion of the pinching member 2. This is formed, for example, by cutting a portion of it and partially raising it. Further, a protrusion 9 is provided at an inner position located a predetermined distance from the locking portion 8 in the longitudinal direction. By these locking portions 8 and projections 9, both end surfaces of the IC package 3 are restrained during installation.
This restricts the relative movement of the IC package 3 and the sandwiching member 2 in the longitudinal direction.

As shown in FIG. 5 when viewed from below, the bottom outer surface (lower surface) of the heat dissipation fin 1 is provided with a metal plate in order to prevent relative movement (displacement) between the heat dissipation fin 1 and the IC package 3 as much as possible. A plurality of protrusions 11 that can be engaged with both side surfaces and one end surface of the IC package 3 are provided. However, in the illustrated embodiment, such a protrusion is not provided at a portion corresponding to the remaining (other) end surface of the IC package 3. This is so that the two can be easily assembled by sliding the radiation fin 1 along the top surface of the IC package 3.

That is, in this embodiment, it is planned that the sandwiching member 2 is attached to the heat radiation fin 1 first, and then the sandwiching member 2 is attached to the IC package 3 while the heat dissipation fin is kept as it is and the sandwiching member 2 is pushed out. This is because, without such protrusions, the radiation fins 1 (sandwich members 2) can be slid along both the upper and lower surfaces of the IC package 3, and therefore, both can be easily assembled. .

[0011] It should be noted that there is no practical problem in constructing a structure in which such a protrusion is provided so that the entire outer periphery of the IC package 3 can be held down, but in such a case, the pinching part may be larger than in the case of the above embodiment. It is necessary to assemble (install) the parts by pushing them apart. Here, referring to FIGS. 6 and 7 showing the state in which the IC 3 to which the heat dissipation fin 1 is attached as described above is actually mounted on the board 13, the heat dissipation fin 1 is attached to the male and female fitting portions (protrusions 5 and holes). 6), it is integrally connected to the sandwiching member 2. Further, the heat dissipation fin 1 is substantially integrally connected to the IC 3 in close contact with the IC 3 by the projections 11 of the heat dissipation fin 1 that engage with both side surfaces and one end surface of the IC 3. Sandwich member 2
is generally integrally connected to the IC 3 by a locking portion 8 and a protrusion 9 that engage with both end surfaces of the IC 3. That is, these three members 1, 2, and 3 will be integrally interconnected as a whole. Note that a predetermined insulating sheet 15 is interposed between the sandwiching member 2 and the substrate 13 for insulation.

As described above, according to the structure of this embodiment, the heat dissipating fin 1 can be securely fixed to the IC 3 with one touch using the sandwiching member 2, and the number of assembly steps can be reduced. Furthermore, the elastic restoring force of the sandwiching member 2 causes the radiation fins 1 and the IC 3 to always (over a long period of time) stably and closely engage with each other, so that the heat radiation efficiency can be improved. Furthermore, since the structure is compactly integrated, the restraint area that would otherwise be wasted on the mounting area of the board 13 on which the IC 3 is mounted can be minimized to the necessary minimum, making pattern design easier. The degree of freedom and implementation efficiency can be improved. Furthermore, the IC 3 to which the heat dissipation fin 1 is attached can be soldered as is in a so-called dip method, thereby reducing the number of IC mounting steps. Also, I
Since the structure is such that only the C3 and the radiation fins 1 are restrained and fixed, there is no need to exert any physical load (influence) on the leads of the IC3, which is preferable in terms of the reliability of the IC3.

Finally, another embodiment of the present invention will be briefly explained with reference to FIGS. 8 to 10. Parts and portions common to the above embodiments will be given the same reference numerals and their explanation will be omitted. do. Two holes 22 for set screws are bored at predetermined positions on the bottom of the radiation fin 21 located on the upper side of the IC package 3, and on the other hand, two holes 22 for set screws are bored in the bottom of the heat dissipation fin 21 located on the upper side of the IC package 3. A female thread 24 is cut in a corresponding position of the fixing plate 23. Therefore, when the set screw 25 is screwed into the fixing plate 23 through the hole 22 of the heat dissipation fin 21, the IC package 3 is attached to the heat dissipation fin 21.
and the fixed plate 23, and due to the frictional force, I
The C package 3 and the radiation fin 21 are firmly fixed with the upper surface of the IC package and the lower surface of the radiation fin in close contact with each other.

The IC 3 to which the radiation fins 21 are attached in this manner is mounted on the substrate 26. At this time, an insulating sheet 27 is placed under the fixed plate 23.

[0015]

As described above, according to the present invention, an IC and a radiation fin can be integrally mechanically coupled safely, reliably, and easily without the inconveniences of the conventional method. In addition, since the mounting is compactly integrated, the restricted area of the IC mounting area of the board can be minimized, and the degree of freedom in pattern design and mounting efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a mounting structure according to an embodiment of the present invention.

FIG. 2 is a cutaway perspective view of essential parts of the embodiment.

FIG. 3 is a diagram for explaining the attachment relationship between the radiation fins and the sandwiching member.

FIG. 4 is a diagram for explaining the attachment relationship between the sandwich member and the IC.

FIG. 5 is a diagram for explaining the attachment relationship between heat dissipation fins and ICs.

FIG. 6 is a side sectional view of the embodiment.

FIG. 7 is a front sectional view of the embodiment.

FIG. 8 is an exploded perspective view of another embodiment.

FIG. 9 is a side cross-sectional view of the embodiment of FIG. 8;

FIG. 10 is a front sectional view of the embodiment of FIG. 8;

[Explanation of symbols]

1, 21...radiating fin 2...Pinch member 3...IC (package) 5...Protrusion 6...hole 8...Locking part 9...Protrusion 13, 26...Substrate 15, 27...Insulating sheet 11...Protrusion 23...Fixing plate

Claims (1)

[Claims] [Claim 1] The IC is equipped with a radiation fin (1, 21) that thermally conductively engages with the upper surface of the IC (3), and a predetermined member (2, 23) that engages with the lower surface of the IC (3). A radiation fin mounting structure for an IC, characterized in that the IC (3) and the radiation fin (1, 21) are mechanically connected by sandwiching the IC (3).