1. Field of the Invention
The present invention relates to an art of radiating heat generated by electronic components mounted on a printed board. The invention relates particularly to an art suitable for use in a plug-in unit which is inserted in a sub-rack apparatus.
2. Description of the Related Art
There is an art of radiating heat generated by electronic components (for example, LSI; Large Scale Integration) mounted on a printed board by means of radiating fins, and this art is applied to a communication apparatus as shown in
The communication apparatus 1 of
In the communication apparatus 1, as shown in FIG. 44, plug-in units 2 are inserted into the sub-rack 3 in the c1-c2 direction, and connectors 2b of the plug-in units 2 are connected to back plane connectors (not shown) inside the sub-rack 3, whereby an electric connection is established between the plug-in units 2 and the sub-rack 3.
Here, referring to
In this manner, radiating fins 5 directly fixed on LSIs 2c with an adhesive agent are advantaged in that radiation efficiency is high, but on the other hand it is disadvantaged in that model numbers and manufacturers' names printed or attached on the upper surface of the LSIs 2c cannot be read. Thus, if a necessity arises of checking the model number or the manufacturer's name of an electronic component 2c, which information is described on the upper surface of the electronic component 2c, for the purpose of modification or repair to be added to the printed board 2a, the radiating fins 5 fixed on the LSI 2c with an adhesive agent must be removed, which is a difficult operation.
Therefore, in the example of
In this manner, in cases where radiating fins 5 are mounted on the LSIs 2c via the radiating fin mounting hardware 5a, it is possible to easily detach the radiating fins 5 so that letters printed on the LSIs 2c can be easily read unless the letters are hidden by the radiating fin mounting hardware 5a.
However, in the example of
With recent progress in down-sizing of electronic components and dense integration, dense mounting of electronic components 2c on the printed board 2a is progressed in the plug-in units 2 of the communication apparatus 1. Under such circumstances, power consumption of the printed board 2a tends to be increased, and the amount of heat radiated from the printed board 2a is also increased.
Further, with increase in operation speed of LSIs 2c mounted on the printed board 2a, power consumption is more and more increased, and the amount of heat radiated from LSIs 2c themselves is increased.
As a result, in the above art described referring to
Further, the height of the radiating fins 5 is limited when the sheet pitches of the plug-in units 2 are small, and when the plug-in units 2 are covered by shield covers. Thus, the art in which radiating fins 5 are provided, one for each LSI 2c, has difficulty in satisfying the permissible junction temperature value.
Here, when the height of the radiating fins 5 is limited, it is possible that the diameter of the radiating fins 5 is increased for improving the heat radiation efficiency. However, if the diameters of the radiating fins 5 are increased, mounting of other electronic components 2c in the vicinity of the LSIs 2c needs to be limited, so that high-density mounting becomes unavailable.
Therefore, there have been arts for radiating heat generated by electronic components (LSIs) by using radiating boards as well as radiating fins. In an example, each component (electronic component) mounted on a printed board is provided with a heat conductive piece (heat radiating fin), and on the heat conductive piece is provided a heat conductive board (heat radiating board) (for example, see the following patent document 1). In another example, bellows are provided for electronic components mounted on a printed board via heat conductive mats, and such bellows are mounted with lids (radiating board) (for example, see the following patent document 2).
However, in the art of the following patent document 1, if the heights of the electronic components mounted on the printed board are not uniform, the distance between the upper surfaces of the electronic components and the radiating board differs among the electronic components. Thus, the height of each of the radiating fins must be adjusted corresponding to the height of each of the electronic components, so that manufacturing process of the radiating fins becomes complicated and the manufacturing cost is increased.
Accordingly, in patent document 1, flat springs are formed on the radiating board at positions corresponding to electronic components. With this arrangement, if the heights of the radiating fins are equal, errors in height of the electronic components are absorbed.
However, such formation of flat springs, which are made by processing the radiating board, makes the connection parts between the whole radiating board and the radiating fins small, so that the heat conductive efficiency from the radiating fins to the radiating board is deteriorated, whereby the heat radiation efficiency is decreased.
Further, patent document 1 also discloses that heat conductive rubber, instead of heat radiating fins, is used for the purpose of absorbing errors in height among various electronic components. This technique absorbs the errors in height among the electronic components only by means of the compressibility of the heat conductive rubber. Thus, this technique is applicable only to cases where errors in height of the electronic components are small, and cannot be applied to cases where the errors in height are large.
In addition, since the art in patent document 2 utilizes hollow bellows, instead of radiating fins, the heat conductive efficiency to a radiating board is low, and thus the heat radiation efficiency is low.
[Patent Document 1] Japanese Patent Application Publication No. HEI 5-315777
[Patent Document 2] Japanese Patent Application Publication No. HEI 5-53293
With the foregoing problems in view, it is an object of the present invention to provide a heat radiator device which exhibits a high heat radiation efficiency while absorbing errors in height among various electronic components mounted on a printed board.
In order to accomplish the above object, according to the present invention, there is provided a radiator device, comprising: a radiating board which is connected to an electronic component side of a printed board mounted with one or more electronic components thereon, with a specific space between the radiating board and the printed board; and a heat conductive block which is connected to a side of the radiating board that faces the printed board in such a manner that the position of the heat conductive block is adjustable along a direction crossing the printed board, the heat conductive block making intimate contact with an electronic component mounted on the printed board.
As one preferred feature, the heat conductive block is grooved on its peripheral surface, and the heat conductive block is screwed in a tapped hole provided on the radiating board.
As another preferred feature, the heat conductive block includes: a heat conductive member which makes intimate contact with the electronic component mounted on the printed board; and a cushion member interposed between the heat conductive member and the radiating board, the cushion member being heat conductive. In this instance, the heat conductive member and the radiating board are combined by means of a screw mechanism, and the cushion member is sandwiched between the heat conductive member and the radiating board.
As yet another preferred feature, the heat conductive member has a wall part thereof so that the heat conductive member has a concave part thereof relative to the radiating board, and the cushion member is placed in the concave part which is formed by the wall part of the heat conductive member, and the radiating board has a mating part which mates with the concave part formed by the wall part of the heat conductive member. In this instance, a heat-conductive intimate contact member is provided between an inner peripheral surface of the wall part of the heat conductive member and an outer peripheral surface of the mating part of the radiating board so as to fill a gap therebetween.
As a further preferred feature, the wall part of the heat conductive member is provided on an outside edge of the heat conductive member.
As a yet further preferred feature, the heat conductive block has one or more projections extending toward the radiating board, and one or more through holes are formed, for letting the projections pass therethrough, on the radiating board at positions corresponding to the one or more projections of the conductive block.
As a furthermore preferred feature, the radiating board has two or more connection parts which connect the radiating board with the printed board, and the radiating board has a cut formed thereon so that the radiating board has a spring force which presses the heat conductive block against the printed board with the two or more connection parts as fulcrums.
As another generic feature, there is provided a plug-in unit, comprising: a printed board on which one or more electronic components are mounted; a radiating board which is connected to an electronic component side of the printed board, with a specific space between the radiating board and the printed board; and a heat conductive block which is connected to a side of the radiating board that faces the printed board in such a manner that the position of the heat conductive block is adjustable along a direction crossing the printed board, the heat conductive block making intimate contact with an electronic component mounted on the printed board.
According to the present invention, since heat generated by electronic components mounted on a printed board is transferred to a radiating board having a large area via heat conductive blocks which make intimate contact with the electronic components, a high heat radiation efficiency is realized.
Further, even if the heights of the electronic components mounted on the printed board are not equal, the heat conductive block is connected in such a manner that the position of the heat conductive block is adjustable along a direction crossing the printed board, so that errors in height among various electronic components are reliably absorbed by adjusting the position of the heat conductive block.
Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.
Preferred embodiments of the present invention will now be described with reference to the relevant accompanying drawings.
First of all, referring to
As shown in
In the plug-in unit 6, a front panel 6d is provided on the front edge of a printed board 6a on which electronic components are mounted, and connectors 6b are provided on the rear edge of the printed board 6a. When the plug-in unit 6 is inserted into the sub-rack 3, connectors 6b are connected to backplane connectors (not shown) provided inside the sub-rack 3, thereby establishing an electric connection between the plug-in unit 6 and the sub-rack 3.
Here, the sub-rack 3 has fans 3a, which have air flow inside the sub-rack 3, and the plug-in units 6 stored in the sub-rack 3 are cooled by the air flow.
Further, as shown in
As shown in
Further, each heat conductive sheet 22 is interposed between a heat conductive member 21 and the radiating board 11. The heat conductive sheets 22 are sandwiched between the heat conductive members 21 and the radiating board 11, when the heat conductive members 21 are connected with the radiating board 11.
The radiating board 11 is connected with the printed board 6a at its four corners, with spacing bolts 12, which are attached to the printed board 6a, and screws 13. With this arrangement, the radiating board 11 is connected to an electronic component side of the printed board 6a with the spacing bolts 12, leaving a specific space therebetween, and as a result, a space for mounting the heat conductive blocks 20 on the printed board 6a is reserved. Here, mating parts 15 are provided on the radiating board 11 at positions where the heat conductive blocks 20 are to be connected. These mating parts 15 will be detailed later, referring to e.g.,
The radiating board 11 and the heat conductive block 20 are connected by the engaging screw 14. That is, a tapped hole is provided at the center of the heat conductive member 21, and a tapped hole is also provided for the radiating board 11 at the corresponding position. The engaging screw 14 is screwed into these tapped holes, whereby the radiating board 11 is connected with the heat conductive block 20. As a result, the heat conductive block 20 is connected to a side of the radiating board 11 that faces the printed board 6a, in such manner that the position of the heat conductive block 20 is adjustable along a direction crossing the printed board 6a (preferably, a direction perpendicular to the printed board 6a).
The heat conductive member 21 and the heat conductive sheet 22 of the heat conductive block 20 and the radiating board 11 will be detailed hereinbelow.
As shown in
Further, the heat conductive member 21 has a wall part 21c on its outside edge so that the heat conductive member 21 forms a concave part relative to the radiating board 11.
The heat conductive member 21 is made of a heat conductive material, and it is preferably made of aluminum, copper, or stainless steel.
As shown in
Further, the heat conductive sheet 22 is formed so that it is accommodated (placed) within the concave part formed by the heat conductive member 21c of the heat conductive member 21. In this example, the heat conductive sheet 22 has a circular shape with a diameter smaller than the diameter of a circle that is formed by the inner face of the heat conductive member 21c.
The heat conductive sheet 22 is made of a material which is not only heat conductive but also compressive (in particular, with respect to the heat conductive member 21), and it is preferably made of elastic rubber, a resin sheet which is made of silicone filled with ceramics filler, or gel resin. Further, the heat conductive sheet 22 is preferably heat resistant.
Next, referring to
Likewise, in the drawings which will be described hereinafter in the present embodiment and in the second through fourth embodiments, for simplicity of illustration, only two connection parts with the printed board 6a are illustrated, and further, only one heat conductive block 20 or only one heat conductive block 23 is illustrated. Note that the number of connections with the printed board 6a and the numbers of heat conductive blocks 20 and heat conductive blocks 23 which are provided, one for each of the electronic components 6c mounted on the printed board 6a, should not be limited.
As shown in
The mating part 15 is formed by processing (pressing) the shape of the radiating board 11. The outer size (here, diameter) of the mating part 15 which projects toward the heat conductive block 20 is slightly smaller than the diameter of a circle formed by the inner face of the wall part 21c so that the mating part 15 can mate with the concave part formed by the wall part 21c. When the mating part 15 mates with the concave part formed by the wall part 21c, the outer peripheral surface of the mating part 15 preferably makes intimate contact with the inner peripheral surface of the wall part 21c. Accordingly, the outer size (here, diameter) of the mating part 15 is preferably approximately the same as the inner size (here, diameter) of the concave part formed by the wall part 21c.
In this manner, the mating part 15 mates with the concave part, with its outer peripheral surface making intimate contact with the inner peripheral surface of the wall part 21c. This arrangement makes it possible to transfer heat, which has been transferred from the electronic components 6c to the heat conductive member 21, to the mating part 15 (that is, the radiating board 11) via the wall part 21c, whereby the heat radiation efficiency of the radiator device 10 is improved.
In addition, since the radiating board 11 is processed so that it has the mating part 15, as a concave part, on its upper surface, the upper portion of the engaging screw 14 and the upper edge of the rotation preventing projections 21b are prevented from projecting beyond the upper surface of the radiating board 11, so that the height of the whole radiator device 10 is reduced. Therefore, even if the height of the plug-in unit 6 is limited, the radiator device 10 is applicable.
Here, the radiating board 11 is made of a heat conductive material, and it is preferably made of aluminum, copper or stainless steal.
Next, referring to
Further, as indicated by arrow β, the engaging screw 14 is put into the tapped hole 11b from the upper surface of the radiating board 11, and passes through the hole 22a of the heat conductive sheet 22, and is crewed into the tapped hole 21a of the heat conductive member 21, whereby the radiating board 11 is connected with the heat conductive member 21 (see
Furthermore, as indicated by arrow γ in
In this case, as shown in
Here, if the heat conductive sheet 22 is compressed in a direction crossing the printed board 6a, the heat conductive sheet 22 spreads in the lateral direction. However, due to the wall part 21c of the heat conductive member 21, the laterally spreading heat conductive sheet 22 is prevented from overlapping the edge of the heat conductive member 21 and from hanging down over the electronic component 6c.
When the heat conductive sheet 22 is compressed, pressure of the radiating board 11 against the printed board 6a, caused by the screws 13 screwed into the spacing bolts 12, is uniformly transferred to the heat conductive member 21, and as a result, the heat conductive member 21 uniformly makes intimate contact with the electronic component 6c. That is, the electronic component 6c and the heat conductive member 21 make intimate contact with each other with equal force at any part thereof.
If the gaps S are not removed only by compressing the heat conductive sheet 22, the engaging screw 14 is further tightened, thereby adjusting the position of the heat conductive member 21 so as to be closer to the radiating board 11. This makes it possible to remove the gaps S so that the radiating board 11 is completely connected with the spacing bolts 12.
Further, adjustment of the engaging screw 14 makes it possible to control the contact between the heat conductive member 21 and the electronic component 6c, so that the heat conductive member 21 can be adjusted to an optimal contact height. Accordingly, it is possible to reliably prevent the heat conductive member 21 from pressing the electronic component 6c so strongly that the electronic component 6c is broken.
If the heat conductive member 21 does not make intimate contact with the corresponding electronic component 6c, with the radiating board 11 being connected to the spacing bolts 12 with the screws 13, the engaging screw 14 is loosened, thereby realizing intimate contact between the heat conductive member 21 and the electronic component 6c.
In this manner, the printed board 6a is connected with the radiating board 11 to which the heat conductive block 20 is attached. As a result, as shown in
As shown in
In this manner, according to the radiator device 10 of the first embodiment of the present invention, the heat generated by the electronic components 6c mounted on the printed board 6a is transferred to the radiating board 11 via the heat conductive block 20 which makes intimate contact with the upper surface of the electronic components 6c, so that a high heat radiation efficiency is realized.
What is more, since the heat conductive sheet 22 interposed between the mating part 15 of the radiating board 11 and the heat conductive member 21 is compressed by connecting the radiating board 11 and the heat conductive member 21, the pressure against the printed board 6a is evenly transferred to the heat conductive member 21, so that the heat conductive member 21 makes even contact with the electronic component 6c. This increases the heat conductivity from the electronic component 6c to the heat conductive member 21, thereby realizing a high heat radiation efficiency.
Further, as shown in
Further, since an error in height among the electronic components 6c and 6c′, can be reliably absorbed, heat radiation of the electronic components 6c and 6c′ can be equalized.
Even if a necessity arises of checking the model number or the manufacturer's name of an electronic component 6c, which information is described on the upper surface of the electronic component 6c, for modification or repair to be added to the printed board 6a, it is possible to remove the radiator device 10 from the printed board 6a only by removing the screws 13 which are screwed into the spacing bolts 12 on the radiating board 11. Thus, the model number and the manufacturer's name described on the printed board 6a can be easily recognized.
Next, referring to
In contrast to the radiator device 10 of the first embodiment, in which the heat conductive block 20 is connected by the engaging screw 14 with a side of the radiating board 11 that faces the printed board 6a, in the radiator device 10a, as shown in
That is, as shown in
As shown in
Further, as shown in
By processing the radiating board 11 so as to have the mating part 15 as a concave part on the upper surface of the radiating board 11, it is possible to prevent the upper edge of the male screw 21d of the heat conductive member 21 from projecting beyond the upper surface of the radiating board 11, so that the height of the whole radiator device 10a is reduced. Thus, the radiator device 10a is applicable in cases where the height of the plug-in unit 6 is limited.
Now, referring to
First of all, as indicated by arrow α in
Further, as indicated by arrow β, the male screw 21d of the heat conductive member 21 passes through the through hole 22c of the heat conductive sheet 22, and also passes through the through hole lid of the radiating board 11, and projects beyond the upper surface of the radiating board 11. The adjustment nut 16a is screwed onto the projecting male screw 21d, whereby the heat conductive block 20 is connected with the radiating board 11 (see
Then, as indicated by arrow γ in
Subsequently, by adjusting the adjustment nut 16a as indicated by arrow δ in
That is, when gaps S are present between the spacing bolts 12 and the radiating board 11 under a condition where the heat conductive member 21 makes intimate contact with the electronic components 6c, as shown in
If the heat conductive member 21 does not make intimate contact with the corresponding electronic component 6c under a condition where the radiating board 11 is connected to the spacing bolts 12 with the screws 13, the adjustment nut 16a can be loosened to realize intimate contact between the heat conductive member 21 and the electronic component 6c.
Accordingly, as shown in
In this manner, the radiator device 10a of the second embodiment of the present invention realizes like effects and benefits to those of the first embodiment.
Next, referring to
In contrast to the radiator device 10 of the first embodiment, in which the mating part 15 is formed by processing the shape of the radiating board 11, in the radiator device 10b of the third embodiment, as shown in
That is, as shown in
In addition, as shown in
Further, as shown in
Here, the mating part 17 is made of a heat conductive material. It is preferably made of aluminum, copper, or stainless steel.
Since the mating part 17 and the radiating board 11 are connected by means of more than one screw 17a, displacement between the mating part 17 and the heat conductive block 20 connected to the mating part 17 is prevented.
Further, as with the mating part 15 of the radiator device 10 of the first embodiment, when the mating part 17 is mated with the heat conductive member 21, the outer peripheral surface of the mating part 17 makes intimate contact with the inner surface of the concave part formed by the wall part 21c of the heat conductive member 21. Accordingly, the outer size (here, diameter) of the mating part 17 is preferably the same or approximately the same as the inner size (here, diameter) of the concave part formed by the wall part 21c.
As shown in
Here, referring to
First of all, as indicated by arrow α in
Then, as indicated by arrow β, the engaging screw 14a is put into the countersunk hole 17c from the upper surface of the mating part 17, and passes through the hole 22a of the heat conductive sheet 22, and is screwed into the tapped hole 21a of the heat conductive member 21. As a result, the mating part 17 and the heat conductive member 21 are connected, sandwiching the heat conductive sheet 22 therebetween (see
At that time, the end portion of the engaging screw 14a is fixed to the tapped hole 21a of the heat conductive member 21 with a locking agent (an adhesive agent) (see the solidly shaded area F in
Further, in this instance, a heat conductive thermal compound (intimate contact member) T is applied to the outer peripheral surface of the mating part 17 and/or the inner peripheral surface of the wall part 21c of the heat conductive member 21, so that the outer peripheral surface of the mating part 17 makes intimate contact with the inner peripheral surface of the wall part 21c, without leaving any gap therebetween, when the mating part 17 is connected to the heat conductive member 21 (see
Then, as indicated by arrow γ in
Further, as indicated by arrow δ, the radiating board 11 is connected to the spacing bolts 12, whereby the printed board 6a is connected with the radiating board 11 to which the mating part 17 and the heat conductive block 20 are connected (see
Here, as indicated by a solidly shaded part F in
Accordingly, as shown in
In this manner, according to the radiator device 10b of the third embodiment of the present invention, like effects and benefits to those of the first embodiment are realized.
That is, as shown in
What is more, according to the radiator device 10b, as shown in
Further, according to the radiator device 10b, the mating part 17 is not formed by processing the shape of the radiating board 11, but is formed independently of the radiating board 11. Thus, the shape and the size of the mating part 17 can be realized more easily than in the first embodiment, in which the shape of the radiating board 11 is processed for formation. That is, it is easy to manufacture a mating part 17 having the same or approximately the same size (here, diameter) as the inner peripheral size of the concave part formed by the wall part 21c of the heat conductive member 21.
Next, referring to
As shown in
In addition, as shown in
Here, the heat conductive block 23 is made of a heat conductive material, and it is preferably made of aluminum, copper, or stainless steel.
As shown in
As shown in
Here, referring to
First of all, as indicated by arrow α in
Then, as indicated by arrow β, the radiating board 11′ is connected to the spacing bolts 12 by means of the screws 13 (see
Next, as indicated by arrow γ in
In this instance, as indicated by arrow δ, utilizing the cut 23a provided for the heat conductive block 23, a screw driver (in this example, as the cut 23a is plus-shaped, a plus-type screw driver) is used to turn the heat conductive block 23, so that the heat conductive block 23 is screwed into the tapped hole 11h of the radiating board 11′.
As shown in
In this instance, as shown in
With the two or more (here, two) connection parts as fulcrums, a spring force is generated at positions K indicated by the broken lines in
Accordingly, in the radiator device 10c, since such a spring force presses the heat conductive block 23 against the printed board 6a, all the parts of the bottom surface of the heat conductive block 23 uniformly make contact with the electronic component 6c.
That is, according to the radiator device 10c, the radiating board 11′ has more than one connection part with the printed board 6a, and there are cuts 11g, each extending toward an edge of the radiating board 11′, on the radiating board 11′ at positions near the connection parts of the radiating board 11′ so that the radiating board 11′ has a spring force which presses the heat conductive block 23 against the printed board 6a, with the connection parts as fulcrums.
In this manner, according to the radiator device 10c of the fourth embodiment of the present invention, as shown in
Further, since the cuts 11g are provided for the radiating board 11′, the radiating board 11′ has a spring force which presses the heat conductive block 23 against the printed board 6a. This spring force causes the heat conductive block 23 to make uniform contact with the electronic component 6c. Therefore, a high heat conductivity is realized, thereby improving radiation efficiency.
Furthermore, even if two or more electronic components 6c with different heights are mounted on the printed board 6a, the heat conductive block 23 can be tightened or loosened to easily adjust the position of the heat conductive block 23 along a direction crossing the printed board 6a. Therefore, it is possible to reliably absorb errors in height of the electronic components 6c.
Further, the present invention should by no means be limited to the above-illustrated embodiments, but various changes or modifications may be suggested without departing from the gist of the invention.
For example, in the above-described embodiments, the radiating boards 11 and 11′ are connected with the printed board 6a via the spacing bolts 12, so that the radiating boards 11 and 11′ and the printed board 6a are connected, with a specific space therebetween. The present invention should not be limited to this, and spacers, instead of the spacing bolts 12, can be used to realize such a specific space between the radiating board 11 and 11′ and the printed board 6a.
Further, in the above embodiments, although the heat conductive block 20 and 23 and the mating part 15 and 17 have circular shapes, the present invention should not be limited to this.
Furthermore, in the above third embodiment of the present invention, the engaging screw 14a is fixed to the heat conductive member 21. However, as in the case of the first and the second embodiment of the present invention, the spacing bolts 12 can be adjustably attached to the heat conductive member 21, and the position of the heat conductive member 21 can be adjustable relative to the radiating board 11.
Still further, in the first and the second embodiment, also, a thermal compound T can be applied between the outer peripheral surface of the mating part 15 and the inner peripheral surface of the wall part 21c of the heat conductive member 21. This arrangement makes it possible to have the mating part 15 make intimate contact with the concave part formed by the wall part 21c of the heat conductive member 21 without leaving any gap therebetween, so that heat conductivity from the heat conductive member 21 to the mating part 15 (radiating board 11) is improved, whereby an improved heat radiation efficiency is realized.
In addition, in the above first through third embodiments, the heat conductive sheet 22 is shaped like a sheet. The present invention should not be limited to this, and as the heat conductive sheet 22, a paste-like object or a liquid-like object can be used as long as it is heat conductive and compressive.
Here, if any paste-like or liquid-like thing is used as heat conductive sheet 22, the wall part 21c of the heat conductive member 21 becomes more effective.
In the above first through third embodiments, the heat conductive member 21 has the wall part 21c. The present invention should not be limited to this. If a sheet-like object is used as a heat conductive sheet 22, and this heat conductive sheet 22 will not deform so as to stick out of the heat conductive member 21 when being sandwiched between the heat conductive member 21 and the radiating board 11 (mating part 15), the wall part 21c of the heat conductive member 21 can be omitted as shown in
Moreover, in the above first through third embodiments, the cuts 11g can be provided for the radiating board 11 as in the fourth embodiment.
Number | Date | Country | Kind |
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2005-099057 | Mar 2005 | JP | national |