JP2020113620A - Heat sink and electronic component package - Google Patents

Abstract

To obtain good heat dissipation performance due to space-saving shape.SOLUTION: A heat sink includes a plate-shaped base portion 10 whose one surface is defined as an electronic component contact surface 11, and a surrounding portion 20 whose other side with the base portion 10 as a boundary is defined as an internal space S2, and that projects from the peripheral side of the base portion 10 so as to surround the internal space S2, and a beam-shaped piece 31 that extends from a portion of the surrounding portion 20 in the circumferential direction to the inner space S2 side is provided on the projecting end side of the surrounding portion 20.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat sink and an electronic component package that radiate heat from electronic components and the like.

Conventionally, in this type of invention, as described in Patent Document 1, for example, a plate-shaped base portion capable of contacting an electronic component and four protrusions surrounding a space on one side in the thickness direction of the base portion. There is a heat sink having a piece, a plurality of cylindrical projections protruding from the respective projection pieces to the outside opposite to the space, and a plurality of grooves formed inside the four projection pieces.
In this heat sink, good heat dissipation performance can be obtained by the plurality of cylindrical protrusions and the plurality of grooves.

JP, 2018-14539, A

However, according to the above-mentioned conventional technique, since the plurality of protrusions horizontally protrude from the contour of the base portion, the overall horizontal area tends to increase. Therefore, it may be difficult to deal with the case where the horizontal mounting space is predetermined or when other electronic components are located around the four protruding pieces. Therefore, it is conceivable to omit the plurality of cylindrical protrusions, but there is a concern that the heat dissipation performance may deteriorate.

In view of such a problem, the present invention has the following configurations.
A plate-shaped base portion whose one side surface is an electronic component contact surface, and the other side with the base portion as a boundary is an internal space, and a surrounding portion protruding from the peripheral side of the base portion so as to surround the internal space. A heat sink, comprising: a beam-shaped piece that extends from a portion of a circumferential direction of the surrounding portion toward the internal space, and is provided on the projecting end side of the surrounding portion.

Since the present invention is configured as described above, good heat dissipation performance can be obtained with a space-saving shape.

It is a perspective view showing an example of a heat sink concerning the present invention. It is an exploded perspective view of the heat sink. It is sectional drawing which follows the line (III)-(III) of the same heat sink. It is a perspective view showing the state where the base part was turned sideways about the same heat sink. It is a figure which shows the flow and heat distribution of the air by computer analysis in the cross section shown in FIG. 3 of the same heat sink. FIG. 4 is a diagram showing an air flow and a heat distribution by computer analysis in a state where the base portion is turned sideways in the cross section shown in FIG. 3 of the heat sink. It is a perspective view which shows the other example of the heat sink which concerns on this invention. It is a perspective view which shows the other example of the heat sink which concerns on this invention. It is a perspective view which shows the other example of the heat sink which concerns on this invention. It is a perspective view which shows the other example of the heat sink which concerns on this invention. It is a perspective view which shows the other example of the heat sink which concerns on this invention. It is a perspective view which shows the other example of the heat sink which concerns on this invention. It is a perspective view which shows the other example of the heat sink which concerns on this invention. It is a perspective view which shows an example of the heat sink which concerns on another invention. It is a perspective view which shows an example of the conventional heat sink.

The following features are disclosed in the present embodiment.
A first feature is that a plate-shaped base portion whose one side surface is an electronic component contact surface and the other side with the base portion as a boundary are an internal space, and the peripheral side of the base portion is surrounded by the internal space. And a beam-shaped piece extending from the circumferential portion of the surrounding portion to the inner space side is provided on the projecting end side of the surrounding portion (FIGS. 1 to 1). 13).
According to this configuration, when the heat of the electronic component causes the base portion to generate heat, an ascending air current is generated in the inner space of the surrounding portion due to the heat effect, and the air current contacts the beam-shaped piece and the inner surface of the surrounding portion to efficiently Heat is released.

As a second feature, the beam-like piece is characterized in that one end side is connected to a part of the surrounding portion and the other end side is located in the internal space away from the surrounding portion (FIG. 10, (See FIGS. 11 and 12).

As a third feature, in order to increase the strength of the surrounding portion, one end side of the beam-shaped piece is connected to a part of the surrounding portion and the other end side is connected to another portion of the surrounding portion (Fig. 1, FIG. 7, FIG. 8, FIG. 9, and FIG. 13).

As a fourth feature, the surrounding portion is provided with a ventilation portion that penetrates in the thickness direction and communicates the internal space with an external space (see FIGS. 1 to 12 ).
According to this structure, the relatively low temperature air outside penetrates into the internal space through the ventilation portion so as to be drawn into the rising airflow of the internal space. For this reason, heat dissipation by the beam-shaped piece and the surrounding portion is performed more efficiently.

As a fifth feature, in order to further improve heat dissipation, the ventilation portion continuously extends in a direction in which the surrounding portion projects from the base portion and penetrates the surrounding portion (FIGS. 1 to 1). (See FIG. 12).

A sixth feature is that an electronic component package in which an electronic component is in contact with the electronic component contact surface of the base portion is configured (see FIGS. 1, 3 and 4).

In addition, in the embodiments described below, an independent invention which does not have the above-mentioned features but in which only the following constituent elements are essential is also disclosed.
The heat sink according to the present invention includes a plate-shaped base portion having a surface on one side as an electronic component contact surface and an inner space on the other side with the base portion as a boundary, the surrounding portion protruding from the peripheral side of the base portion. The surrounding portion is provided with a ventilation portion that penetrates in the thickness direction and communicates the internal space with an external space, and the upper end portion of the surrounding portion covers the entire circumference of the upper end inner edge of the surrounding portion. One surface and the other surface in the thickness direction of the surrounding portion are formed in a flat shape without a protruding portion (see FIG. 14).

<First embodiment>
Next, specific embodiments having the above characteristics will be described in detail with reference to the drawings.

The heat sink A shown in FIGS. 1 to 6 has a plate-shaped base portion 10 having an electronic component contact surface 11 on one side (lower side according to FIG. 1) and the other side with the base portion 10 as a boundary ( 1, the upper side) is defined as an internal space S2, and the surrounding portion 20 is provided upright from the peripheral side of the base portion 10 so as to surround the internal space S2, and the projecting end side of the surrounding portion 20 is extended to the internal space S2 side. The beam-like piece 31 is integrally provided, and has a substantially cage shape.

The raw material of the heat sink A includes a pure metal composed of a single metal element, a plurality of metal elements or an alloy composed of a metal element and a non-metal element. Here, specific examples of the metal element include aluminum, copper, stainless steel, nickel, magnesium, and the like.
Further, the heat sink A may be formed of a single material or a composite material in which two or more different materials are integrally combined.
Then, in the heat sink A of the illustrated example, the electronic component contact surface 11 is brought into contact with the electronic component X (for example, CPU, transistor, thyristor, other semiconductor or electronic component, etc.), and the electronic component package P (see FIG. 1) is obtained. Constitute.

The base portion 10 is formed in a rectangular flat plate shape (square flat plate shape in the illustrated example), and a surface located on one side in the thickness direction (lower side in FIG. 1) is formed in a flat shape to form the electronic component X. The electronic component contact surface 11 for contacting with.
The surface on the other side (upper side in FIG. 1) of the base portion 10 is formed in a flat shape without through holes or irregularities, but it is possible to provide a heat radiation fin or the like having an appropriate shape as necessary. ..

The surrounding portion 20 is configured in a rectangular tube shape (a regular square tube shape in the illustrated example) that surrounds the internal space S2 from a plurality of directions by the plurality of surrounding pieces 21, and has an opening on the side opposite to the base portion (upper side in the drawing). Have.

Each surrounding piece 21 rises substantially vertically from the edge portion along each side of the base portion 10 toward the anti-heat source side (the side opposite to the electronic component X side).
Each surrounding piece 21 is provided with a plurality of ventilation portions 21 a arranged in a direction along the surface of the base portion 10 (horizontal direction according to the illustrated example).
Each surrounding piece 21 is formed by bending a flat plate-like member that protrudes from each piece of the base portion 10 in a direction in which the surface of the base portion 10 is continuous, and its outer corner portion is formed into a curved surface.
Then, the surface of each surrounding piece 21 on the inner space S2 side and the surface of the outer space S1 side are formed into a flat surface shape without a protruding portion.

In addition, as another example, it is possible to adopt a mode in which each surrounding piece 21 is connected to the base portion 10 by welding or the like as a member separate from the base portion 10.
Further, as another example of the surrounding portion, it is also possible to have a rectangular tube shape, a cylindrical shape, an elliptic tube shape or the like having a shape other than the illustrated example.

Each ventilation part 21a is a through-hole that penetrates the surrounding piece 21 in the thickness direction continuously in the lengthwise direction (rectangular shape according to the illustrated example) in the rising direction of the surrounding piece 21, and the internal space S2 and the surrounding portion. It communicates with the external space S1 on the side of 20.

In addition, the beam-shaped piece 31 projects into the internal space S2 from a part of the inner edge of the surrounding portion 20 in the circumferential direction on the upper end side of the surrounding portion 20, and according to the illustrated example, is fixed to the inner edge of the upper end portion of the surrounding portion 20. The frame-shaped member 30 is formed as a part of the frame-shaped member 30.

The frame-shaped member 30 is integrally configured from a rectangular frame-shaped frame portion 32 connected to the inner edge of the surrounding portion 20 and the plurality of beam-shaped pieces 31.

The frame portion 32 is fixed to the inner edge of the surrounding portion 20 by fixing means such as welding or fitting.

A plurality of beam-shaped pieces 31 are provided in parallel with each other at intervals.
Each beam-shaped piece 31 has one end and the other end connected to a part of the surrounding part 20 and another part via a frame part 32 so as to extend between the upper ends of the facing surrounding parts 21 and 21, and both ends are supported. It has a beam shape.
Although the cross-sectional shape of each beam-shaped piece 31 is quadrangular according to the illustrated example, it can be circular or other cross-sectional shape.

With the above configuration, the openings that connect the internal space S2 and the upper external space are secured on both sides of each beam-shaped piece 31.

Next, the characteristic effects of the heat sink A having the above structure will be described in detail.
As shown in FIG. 3, when the heat sink A is in a posture in which the base portion 10 faces downward and the electronic component contact surface 11 of the base portion 10 is brought into contact with the electronic component X serving as a heat source, the heat of the electronic component X is It is transmitted to the base unit 10. Then, in the internal space S2 above the base portion 10, an air flow rising due to the heat of the base portion 10 is formed. Therefore, the air in the external space S1 having a relatively low temperature is drawn into the ascending airflow to form a continuous air flow F.
That is, the air in the external space S1 enters the internal space S2 through the respective ventilation portions 21a of the surrounding portion 20, rises, passes through the openings on both sides of the beam-shaped piece 31, and escapes to the upper external space (FIG. 1). And FIG. 3).

Further, as shown in FIG. 4, with the heat sink A in a posture in which the base portion 10 faces sideways, the air in the external space S1 enters the internal space S2 through the openings on both sides of the beam-shaped piece 31 and rises. It passes through the upper ventilation part 21a and exits to the upper external space. Further, in this posture, a flow F of air that enters the internal space S2 from the lower external space through the lower ventilation portion 21a is also formed.

According to the heat sink A, the flow is continuous as described above in both the posture in which the base portion 10 faces downward (see FIG. 1) and the posture in which the base portion 10 faces sideways (see FIG. 4 ). The air comes into contact with the surrounding portion 20 and the beam-shaped piece 31 to perform efficient heat exchange, and suppress the temperature rise of the base portion 10 and the electronic component X. Therefore, good heat dissipation performance can be obtained due to the space-saving shape without fins protruding to the outside.

Next, with respect to the heat sink A (see FIGS. 1 to 4) having the above-described configuration, a result of a computer analysis in which an air flow is visualized by an arrow-shaped graphic and a temperature distribution is visualized by colors and shades in an image is shown. explain. In this computer analysis, it is assumed that the heat source is in contact with the electronic component contact surface 11 of the base portion 10.

As a result of this analysis, as shown in FIG. 5, in the posture in which the base portion 10 is directed downward, the air flow F1 flowing from the external space S1 to the internal space S2 through the ventilation portion 21a and both sides of the beam-shaped piece 31. It was confirmed that the air flow F2 from the internal space S2 to the upper external space through the opening of No.
Further, as shown in FIG. 6, in the posture in which the base portion 10 is directed sideways (the posture in which the Y direction in the drawing is vertical), the external space S1 is passed through the openings on both sides of the beam-shaped piece 31 to the internal space S2. An air flow F1 that flows toward the inside, an air flow F2 that flows from the internal space S2 to the upper external space through the upper ventilation portion 21a, and a lower external space that flows from the internal space S2 to the internal space S2 through the lower ventilation portion 21a. The air flow F3 was confirmed.

Note that, in FIGS. 5 and 6, two-dot chain lines (F1 to F3) are curves drawn along arrow-shaped figures (white arrows) obtained by computer analysis.
Further, in FIG. 5, the range of the gray color indicated by the symbol H indicates a portion having a relatively high temperature in the internal space S2.

In addition, when the heat sink A and the conventional heat sink 100 (see FIG. 15) were subjected to computer analysis to obtain and compare temperature rise values at the same location (base portion 10) under the same conditions, the following results were obtained.
The heat sink A has a temperature of 67.2° C. in a posture in which the Z direction is vertical (see FIG. 1) and 76.4° C. in a posture in which the X direction is vertical (see FIG. 4 ).
On the other hand, in the heat sink 100, the temperature was 74.0° C. when the Z direction was vertical, and the temperature was 88.7° C. when the X direction was vertical.
That is, in the heat sink A, the temperature difference due to the difference in posture in the ZX direction was relatively small, and in any of the postures, a lower temperature than the conventional product was obtained.
These results suggest that the heat sink A has less air retention in the internal space than the heat sink 100.

In the conventional heat sink 100, a large number of columnar heat radiation fins are provided on the upper surface of the base portion, and the contour (outer shape) of the dimension (25×25×15 mm) in the XYZ directions is substantially the same as that of the heat sink A. It is a thing.

<Second embodiment>
Next, another embodiment of the heat sink according to the present invention will be described. Since the embodiment described below is a partial modification of the above-described embodiment, the modified part will be mainly described in detail, and the description of the common part will be appropriately omitted by using the same reference numerals or the like.

In the heat sink B shown in FIG. 7, the number of beam-shaped pieces 31 closer to the center in the intersecting direction with respect to the plurality of beam-shaped pieces 31 is increased with respect to the heat sink A having the above-described configuration so that both ends in the intersecting direction (enclosing piece 21 The air passage closer to the center is wider than the air passage closer to the center.

That is, in the heat sink A described above, as shown in FIG. 5, an updraft with a relatively large flow velocity was observed near the center in the intersecting direction with respect to the plurality of beam-shaped pieces 31. Therefore, in the heat sink B, the density (number) of the beam-shaped pieces 31 is increased near the center so that more efficient heat exchange is performed.

<Third embodiment>
The heat sink C shown in FIG. 8 is obtained by replacing the heat sink A with a plurality of beam-shaped pieces 31 replaced by cross-shaped beam-shaped pieces 33.

The beam-shaped piece 33 has an intersecting portion arranged near the center in the plane direction in the internal space S2, and each end portion is connected to the facing surrounding piece 21.
Similar to the heat sink A, the heat sink C can obtain good heat dissipation in any posture. Further, the strength of the surrounding portion 20 can be improved by the cross-shaped beam-shaped piece 33.

<Fourth Embodiment>
A heat sink D shown in FIG. 9 is obtained by replacing the heat sink A with a plurality of beam-shaped pieces 31 replaced with beam-shaped beam-shaped pieces 34.

The beam-shaped piece 34 has a cross-shaped crossing portion arranged near the center in the plane direction in the internal space S2, and each end portion is connected to the facing surrounding piece 21.

According to the heat sink D, similar to the heat sink A, good heat dissipation can be obtained in any posture. In particular, in the case where the base portion 10 is in the downward posture, efficient heat exchange can be performed by the cross-beam-shaped beam-shaped pieces 34 on the center side of the surrounding portion 20. In addition, the strength of the surrounding portion 20 can be improved by the beam-shaped pieces 34 having a cross beam shape.

<Fifth Embodiment>
A heat sink E shown in FIG. 10 is different from the above heat sink A in that the surrounding portion 20 is replaced with a surrounding portion 20′ composed of a plurality of surrounding pieces 22, and the frame-shaped member 30 (beam-shaped piece 31) is replaced by a beam-shaped piece 34, 35 is substituted.

Each surrounding piece 22 has a plurality of projecting piece portions 22b that rise substantially vertically from each side of the base portion 10 to the side opposite to the heat source (the side opposite to the electronic component X side), and between the upper end portions of these projecting piece portions 22b. The connecting portion 22c for connecting is integrally provided, and the adjacent protruding piece portions 22b, 22b are made into the ventilation portion 22a.
Each projecting piece 22b is formed by bending so as to be substantially perpendicular to the base 10.

Note that, as another example of the protruding piece portion 22b, it is possible to adopt a mode in which a separate member is connected to the base portion 10.
Furthermore, as another example, it is possible to replace the entire surrounding piece 22 with the surrounding piece 21 of the heat sink A described above.

Among the plurality of ventilation portions 22a, the ventilation portion 22a located at the corner portion where the adjacent surrounding pieces 22, 22 intersect each other has a larger opening area than the other ventilation portions 22a. The ventilation portion 22a prevents air from accumulating in the inside corner portion.

A beam-shaped piece 34 and a beam-shaped piece 35 are provided in a pair of facing surrounding pieces 22 and 22, respectively, of the plurality of surrounding pieces 22 surrounding the internal space S2.

The one beam-like piece 34 is connected to the upper end side of the one surrounding piece 22 in a cantilevered manner, and the projecting end side thereof is arranged near the center of the internal space S2 in the plane direction. A plurality of the beam-like pieces 34 are provided at intervals in a direction intersecting the extending direction of the beam-like pieces 34.

The other beam-like piece 35 is connected to the upper end side of the other surrounding piece 22 in a cantilever manner, and its projecting end side is arranged near the center of the internal space S2 in the plane direction. A plurality of the beam-like pieces 35 are provided at intervals in a direction intersecting the extending direction of the beam-like pieces 35.

Each of the beam-shaped pieces 34, 35 is formed, for example, by bending a projecting piece (see a two-dot chain line in FIG. 10) projecting upward from the upper end of the surrounding piece 22 into the inner space S2 at a substantially right angle.
One beam-shaped piece 34 and the other beam-shaped piece 35 face each other with a gap, as shown in FIG.

Therefore, according to the heat sink E, similar to the heat sink A, good heat dissipation can be obtained in any posture. In particular, in the case where the base portion 10 is oriented downward, efficient heat exchange can be performed on the center side of the surrounding portion 20. Further, each surrounding piece 22 and each beam-like piece 34 can be formed by bending, and the productivity is good.

<Sixth embodiment>
The heat sink F shown in FIG. 11 is obtained by replacing the heat sink C with the beam-shaped pieces 34, 35 replaced with a plurality of beam-shaped pieces 36.

The beam-shaped piece 36 is configured in a cantilever shape, one end side of which is connected to a part of the surrounding portion 20 (specifically, the surrounding piece 22). The other end side of the beam-like piece 36 is close to the other part of the surrounding portion 20 (specifically, the upper end portion of the facing surrounding piece 22).
The beam-like piece 36 is formed, for example, by bending a projecting piece protruding upward from the upper end of the surrounding piece 22 into the inside of the internal space S2 at a substantially right angle.

Therefore, according to the heat sink F, similar to the heat sink A, good heat dissipation can be obtained in any posture. Further, each surrounding piece 22 and each beam-like piece 36 can be formed by bending, and the productivity is good.

<Seventh embodiment>
A heat sink G shown in FIG. 12 is obtained by replacing the heat sink A with the frame member 30 (beam-shaped piece 31) by a plurality of beam-shaped pieces 37.
The beam-shaped piece 37 is provided in the shape of a cantilever beam that projects toward the internal space S2 side slightly below the upper end of each surrounding piece 21 near one end in the lateral width direction of each surrounding piece 21.
Each beam-like piece 37 extends toward the side portion of the other beam-like piece 37 and is positioned so as not to interfere with the other beam-like piece 37.

Each beam-shaped piece 37 can be, for example, a mode in which a part of the surrounding piece 21 is bent, a mode in which a separate member is connected to the surrounding piece 21, or the like.

According to the heat sink G configured as described above, similar to the heat sink A, good heat dissipation can be obtained in any posture, and moreover, productivity is excellent.

<Eighth Embodiment>
In the above-mentioned heat sinks A to F, as a particularly preferable embodiment, the ventilation pieces 21a and 22a are provided in the surrounding piece 21 (or 22), but as another example, a heat sink H shown in FIG. 13 can be used. Is.
The heat sink H is obtained by replacing the heat sink A having the above structure with the surrounding portion 20 replaced by a surrounding portion 40 having no ventilation portion.

The surrounding portion 40 is configured in a rectangular tube shape surrounding the internal space S2 by the plurality of surrounding pieces 41 that respectively project upward from the plurality of sides of the base portion 10.
Each surrounding piece 41 is obtained by omitting the ventilation part 21a from the surrounding piece 21, and is formed in a rectangular flat plate shape according to the illustrated example.

According to this heat sink H, as shown by the chain double-dashed line in FIG. 13, the air flow F1 entering the inside space S2 from the outside through a part of the openings on both sides of the beam-like piece 31 and the inside space S2. Through the other part of the opening to a flow F2 of the air discharged to the outside. Therefore, in addition to the heat radiation effect on the front and back surfaces of each surrounding piece 41, the heat radiation effect by each beam-shaped piece 31 can be obtained.

<Other inventions>
Although the heat sinks A to H are each provided with the beam-shaped piece, the heat sink I shown in FIG. 14 has a configuration in which the beam-shaped piece is omitted.
The heat sink I projects from the peripheral side of the base portion 10 so as to surround the plate-shaped base portion 10 having the electronic component contact surface 11 on one side and the internal space S2 on the other side with the base portion 10 as a boundary. The surrounding portion 20 is provided with a ventilation portion 21a that penetrates in the thickness direction and communicates the inner space S2 with the outer space S1. The surface of the surrounding portion 20 is formed in a flat shape without any protruding portion.

According to this heat sink I, as shown in FIG. 14, a flow F of air that enters from the outside into the internal space S2 through the ventilation portion 21a and escapes to the outside through the upper opening is formed. The heat radiation effect of each surrounding piece 21 can be improved.

In each of the above-described embodiments, natural convection of the ambient air is promoted, but as another example, a blower may be provided at an appropriate location to force the ambient air to flow. ..

Further, the present invention is not limited to the above-described embodiments, and can be appropriately modified without changing the gist of the present invention.

10: Base part 11: Electronic component contact surface 20, 20', 40: Enclosure part 21, 22, 41: Enclosure piece 21a, 22a: Ventilation part 31, 33, 34: Beam-shaped piece A-I: Heat sink P: Electronic Component package S1: External space S2: Internal space F, F1, F2, F3: Air flow X: Electronic component

Claims (6)

A plate-shaped base portion whose one side surface is an electronic component contact surface, and the other side with the base portion as a boundary is an internal space, and a surrounding portion which projects from the peripheral side of the base portion so as to surround the internal space. Equipped with
The heat sink characterized in that a beam-shaped piece is provided on the projecting end side of the surrounding portion so as to extend from a portion of the surrounding portion in the circumferential direction toward the internal space side. The heat sink according to claim 1, wherein one end of the beam-like piece is connected to a part of the surrounding portion, and the other end of the beam-like piece is located in the internal space away from the surrounding portion. The heat sink according to claim 1, wherein one end side of the beam-shaped piece is connected to a part of the surrounding portion and the other end side is connected to another portion of the surrounding portion. The heat sink according to any one of claims 1 to 3, wherein the surrounding portion is provided with a ventilation portion that penetrates in the thickness direction and communicates the internal space with an external space. The heat sink according to claim 4, wherein the ventilation portion extends in a long shape in a direction in which the surrounding portion projects from the base portion, and penetrates the surrounding portion. An electronic component package using a heat sink according to any one of claims 1 to 5, wherein an electronic component is in contact with an electronic component contact surface of the base portion.

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