JP2021018996A - Electronic substrate and electronic apparatus - Google Patents

Abstract

To provide an electronic substrate and an electronic apparatus that can efficiently cool a heat-generating component even when the electronic substrate and the electronic apparatus cannot come into contact with the heat-generating components.SOLUTION: An electronic substrate 30 includes a substrate 40, a heat generating component 51 provided on a first surface 40a of the substrate 40, and a heat pipe 33 provided on the second surface 40b opposite to the first surface 40a of the substrate 40. A groove 41 is formed in at least a part of a back surface region 60 of the heat generating component 51 on the second surface 40b of the substrate 40, and at least a part of the heat pipe 33 is arranged in the groove 41.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electronic substrate and an electronic device.

As an electronic device, for example, a portable notebook personal computer includes an electronic board on which electronic components are mounted. Among the electronic components, the heat generating component (CPU or the like) that generates a particularly large amount of heat is brought into contact with a heat radiating plate that diffuses and dissipates heat (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-227925

By the way, it is effective to place the heat radiating plate on top of the heat generating parts, but if there is a shield on the heat generating parts and the heat generating parts cannot be contacted, the heat generating parts cannot be cooled efficiently. There's a problem.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic substrate and an electronic device capable of efficiently cooling a heat-generating component even when the heat-generating component cannot be contacted.

In order to solve the above problems, the electronic substrate according to one aspect of the present invention includes a substrate, heat-generating components provided on the first surface of the substrate, and a second surface opposite to the first surface of the substrate. A groove is formed in at least a part of the back surface region of the heat generating component on the second surface of the substrate, and at least a part of the heat radiating component is arranged in the groove. Adopt the configuration that is.

Further, the electronic substrate may include a laminated component arranged so as to cover the heat generating component on the first surface.
Further, in the electronic substrate, the heat generating component may be a CPU, and the laminated component may be a DRAM.
Further, in the electronic substrate, the groove portion is a long groove passing through the back surface region of the substrate, and a heat pipe may be arranged as the heat radiating component in the groove portion.
Further, in the electronic substrate, the groove portion is a recess formed in the back surface region of the substrate, and a metal block may be arranged as the heat radiating component in the groove portion.
Further, in the electronic substrate, a metal layer may be formed on the surface of the groove portion.
Further, in the electronic substrate, a second groove portion may be formed on the first surface of the substrate, and the heat generating component may be arranged in the second groove portion.

Further, the electronic device according to one aspect of the present invention adopts a configuration including the electronic substrate described above and a housing for accommodating the electronic substrate.

According to the present invention, the heat generating component can be efficiently cooled even when the heat generating component cannot be contacted.

It is a perspective view of the electronic device in 1st Embodiment of this invention. It is sectional drawing of the electronic substrate in 1st Embodiment of this invention. It is sectional drawing of the electronic substrate in 2nd Embodiment of this invention. It is sectional drawing of the electronic substrate in 3rd Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment)
FIG. 1 is a perspective view of the electronic device 1 according to the first embodiment of the present invention.
The electronic device 1 includes a housing 10 and a lid 20. The electronic device 1 is a clamshell type laptop personal computer (so-called notebook type personal computer).

The housing 10 is formed in a flat box shape. A keyboard 11 and a touch pad 12 are provided on the upper surface 10a of the housing 10. The keyboard 11 is arranged on the back side of the upper surface 10a, and the touch pad 12 is arranged on the front side of the upper surface 10a. Further, palm rest portions 13 are formed on both left and right sides of the touch pad 12 on the upper surface 10a.

The lid 20 is provided with a display device 21 on a surface of the housing 10 facing the upper surface 10a. The display device 21 is formed of, for example, a liquid crystal display or an organic EL display. The lower end of the lid 20 is rotatably connected to a hinge (not shown) provided on the back side of the housing 10 around an axis extending in the left-right direction.

When the lid 20 is opened as shown in FIG. 1, the display device 21 faces the front side, and the upper surface 10a of the housing 10 is opened. On the other hand, when the lid 20 is closed, the lid 20 becomes a cover that covers the display device 21 and the upper surface 10a of the housing 10.

An electronic substrate 30, a centrifugal fan 31, a heat pipe 33 (heat dissipation component), and the like are provided in the housing 10. An exhaust port 14 of the centrifugal fan 31 and a USB (Universal Serial Bus) receptacle 32 are opened on the left side surface 10b of the housing 10.

The electronic substrate 30 is fixed to a plurality of bosses (not shown) of the housing 10 by screwing, and is arranged so as to face the bottom portion substantially in parallel with a space. The electronic board 30 is arranged on the back surface side of the keyboard 11.

The heat pipe 33 transports the heat received from the electronic substrate 30 to the centrifugal fan 31. The centrifugal fan 31 cools the heat pipe 33 by the exhaust flow, and discharges the exhaust flow from the exhaust port 14 to the outside of the housing 10. An air intake port or a gap (not shown) for taking in external air into the housing 10 is formed on the upper surface 10a and the bottom surface of the housing 10.

FIG. 2 is a cross-sectional configuration diagram of the electronic substrate 30 according to the first embodiment of the present invention.
As shown in FIG. 2, the electronic substrate 30 includes a substrate 40 (main substrate), and a laminated electronic component 50 is mounted on a first surface 40a of the substrate 40. The substrate 40 is a rigid substrate such as glass epoxy. The laminated electronic component 50 is, for example, an electronic component package such as a BGA (Ball grid array) or an LGA (Land grid array), and is bonded to the first surface 40a of the substrate 40 via a solder 56.

The laminated electronic component 50 has a PoP (Package on Package) structure, includes a CPU (Central Processing Unit) as a heat generating component 51, and a DRAM (Dynamic Random Access Memory) as a laminated component 52 on the heat generating component 51. ) Is provided. The heat generating component 51 and the laminated component 52 are not limited to the CPU and DRAM, and may be, for example, other memories, chargers, DC / DC capacitors, SSDs (Solid State Drives), various antennas, and the like.

The heat generating component 51 is mounted on the first substrate 53. The first substrate 53 is formed in a rectangular shape that is one size larger than the heat generating component 51 in a plan view, and is joined to the first surface 40a of the substrate 40 via a solder 56. A relay board 54 is joined to the peripheral edge of the first board 53 via a solder 56. The relay board 54 is formed in a rectangular frame shape in a plan view and surrounds all four sides of the heat generating component 51.

A second substrate 55 is joined to the upper opening edge of the relay substrate 54 via a solder 56. The laminated component 52 is mounted on the second substrate 54. The second substrate 54 (laminated component 52) closes the upper opening of the relay substrate 54. That is, the laminated component 52 is arranged so as to cover the heat generating component 51 on the first surface 40a. A slight gap is formed between the relay board 54 and the heat generating component 51. The laminated component 52 is electrically connected to the substrate 40 via the second substrate 55, the relay substrate 54, and the first substrate 54. The heat generating component 51 is electrically connected to the substrate 40 via the first substrate 54.

A groove 41 is formed on the second surface 40b opposite to the first surface 40a of the substrate 40. The groove 41 is formed in at least a part of the back surface region 60 of the heat generating component 51. Here, the back surface region 60 of the heat generating component 51 means a region on the second surface 40b of the substrate 40 that overlaps with the heat generating component 51 in a plan view. The back surface region 60 of the present embodiment has a rectangular shape corresponding to the plan view shape of the heat generating component 51.

At least a part of the heat pipe 33 described above is arranged in the groove 41. The groove portion 41 is a long groove that passes through the back surface region 60 of the heat generating component 51. The groove 41 of the present embodiment is formed along the second surface 40b of the substrate 40 with a constant width and a constant depth, and is formed so as to pass through the back surface region 60 of the heat generating component 51. A metal layer such as copper is formed on the surface of the groove 41. The metal layer may be a conductor layer inside the substrate 40, a plating layer formed later, or the like.

The gap between the groove 41 and the heat pipe 33 is filled with an adhesive, thermal paste, or the like. The thickness T1 (also referred to as the depth of the groove 41 from the surface of the second surface 40b) on which the groove 41 is formed with respect to the second surface 40b is preferably 1/2 or less of the thickness T of the substrate 40. For example, when the thickness T of the substrate 40 is 0.6 mm, the thickness T1 in which the groove 41 is formed is preferably 0.3 mm or less. If the thickness T1 on which the groove 41 is formed is 1/2 or less of the thickness T of the substrate 40, there is no problem in the strength of the substrate 40.

As described above, according to the electronic substrate 30 having the above configuration, the substrate 40, the heat generating component 51 provided on the first surface 40a of the substrate 40, and the second surface 40b opposite to the first surface 40a of the substrate 40 are provided. A groove 41 is formed in at least a part of the back surface region 60 of the heat generating component 51 on the second surface 40b of the substrate 40, and at least a part of the heat pipe 33 is formed in the groove 41. By adopting the configuration of being arranged, the heat pipe 33 can be indirectly applied to the heat generating component 51 from the opposite second surface 40b side instead of the first surface 40a side to perform cooling. .. Since the groove 41 for reducing the thermal resistance of the substrate 40 is formed between the heat generating component 51 and the heat pipe 33, the heat generating component 51 can be efficiently cooled. Specifically, it was confirmed from the experimental results that the heat generation of the heat generating component 51 was reduced by 11.4% by forming the groove portion 41.

Further, in the present embodiment, since the laminated component 52 arranged so as to cover the heat generating component 51 is provided on the first surface 40a, the heat generating component is generated even when the laminated component 52 cannot contact the heat generating component 51. 51 can be cooled efficiently. Further, in the experimental results of the structure shown in FIG. 2, 70% of the heat of the heat generating component 51 is transferred to the substrate 40 and 30% to the laminated component 52. Therefore, by forming the groove 41 in the substrate 40, the heat generating component 51 is made more efficient. It turned out that it can be cooled well.

Further, in the present embodiment, since the heat generating component 51 is a CPU and the laminated component 52 is a DRAM, the CPU can be efficiently cooled even when the DRAM cannot contact the CPU.

Further, in the present embodiment, the groove portion 41 is a long groove passing through the back surface region 60 of the heat generating component 51, and since the heat pipe 33 is arranged in the groove portion 41, heat is efficiently generated from the back surface region 60 of the heat generating component 51. Can be diffused.

Further, in the present embodiment, since the metal layer is formed on the surface of the groove portion 41, the heat received by the substrate 40 can be efficiently transferred to the heat pipe 33.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent configurations as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 3 is a cross-sectional configuration diagram of the electronic substrate 30 according to the second embodiment of the present invention.
As shown in FIG. 3, in the second embodiment, the groove portion 41A is a recess formed in the back surface region 60 of the heat generating component 51, and the groove portion 41A is provided with a metal block 34 as a heat radiating component. , Different from the above embodiment.

The groove portion 41A is a rectangular recess in a plan view formed in the back surface region 60 of the heat generating component 51. The groove portion 41A may be formed inside the back surface region 60, or may protrude outside the back surface region 60. The thickness T1 at which the groove portion 41A is formed with respect to the second surface 40b is preferably 1/2 or less of the thickness T of the substrate 40, as in the above embodiment.

The metal block 34 is made of a material having good thermal conductivity such as a copper block. The metal block 34 has substantially the same (slightly smaller) volume as the internal volume of the groove portion 41A. The metal block 34 arranged in the groove 41A is in contact with the heat pipe 33 extending along the second surface 40b of the substrate 40. It is preferable that a metal layer such as copper is formed on the surface of the groove portion 41A, and the gap between the groove portion 41A and the metal block 34 is filled with an adhesive, thermal paste, or the like.

As described above, according to the second embodiment described above, the groove portion 41A is a recess formed in the back surface region 60 of the heat generating component 51, and the metal block 34 is arranged in the groove portion 41A as a heat radiating component. The thermal resistance of the substrate 40 can be reduced, and the metal block 34 can be indirectly applied to the heat generating component 51 from the second surface 40b side for cooling. Therefore, the heat generating component 51 can be efficiently cooled even when the heat generating component 51 cannot be contacted.

(Third Embodiment)
Next, a third embodiment of the present invention will be described. In the following description, the same or equivalent configurations as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 4 is a cross-sectional configuration diagram of the electronic substrate 30 according to the third embodiment of the present invention.
As shown in FIG. 4, in the third embodiment, the second groove portion 42 is formed on the first surface 40a of the substrate 40, and the heat generating component 51 is arranged in the second groove portion 42. Different from the embodiment.

The second groove 42 is formed to include a mounting region of the laminated electronic component 50. Here, the mounting region of the laminated electronic component 50 means a region on the first surface 40a of the substrate 40 that overlaps with the first substrate 53 in a plan view. The mounting area of the laminated electronic component 50 of the present embodiment has a rectangular shape corresponding to the plan view shape of the first substrate 53.

The thickness T2 (also referred to as the depth of the second groove 42 from the surface of the first surface 40a) on which the second groove 42 is formed with respect to the first surface 40a is 1/4 or less of the thickness T of the substrate 40. It is good. Further, in this case, the thickness T1 at which the above-mentioned groove portion 41 (which may be referred to as the first groove portion) is formed is also preferably 1/4 or less of the thickness T of the substrate 40. For example, when the thickness T of the substrate 40 is 0.6 mm, the thickness T1 at which the groove 41 is formed and the thickness T2 at which the second groove 42 is formed are preferably 0.15 mm or less. As a result, the thickness of the thinnest portion of the substrate 40 is not less than 1/2, so that there is no problem in the strength of the substrate 40.

As described above, according to the third embodiment described above, the second groove portion 42 is formed on the first surface 40a of the substrate 40, and the heat generating component 51 is arranged in the second groove portion 42. The thermal resistance of the substrate 40 can also be reduced from the first surface 40a side. Further, since the depth (processing amount) per of the groove portion 41 and the second groove portion 42 is also reduced, the formation becomes easy.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the above embodiments, and includes designs and the like within a range that does not deviate from the gist of the present invention. The configurations described in the above embodiments can be arbitrarily combined as long as they do not conflict with each other.

Further, for example, in the above embodiment, the heat pipe 33 and the metal block 34 are exemplified as the heat radiating component, but a heat radiating plate or the like may be used.

Further, for example, in the above embodiment, a notebook personal computer has been described as an example of an electronic device, but the present invention is not limited to this, and can be applied to other electronic devices such as tablets. Is.

1 Electronic device 10 Housing 30 Electronic board 33 Heat pipe (heat dissipation component)
34 Metal block (heat dissipation parts)
40 Substrate 40a First surface 40b Second surface 41 Groove 41A Groove 42 Second groove 51 Heat-generating component 52 Laminated component 60 Back area

Claims (8)

With the board
The heat-generating component provided on the first surface of the substrate and
A heat radiating component provided on a second surface opposite to the first surface of the substrate is provided.
A groove is formed in at least a part of the back surface region of the heat generating component on the second surface of the substrate.
An electronic substrate in which at least a part of the heat radiating component is arranged in the groove. The electronic substrate according to claim 1, further comprising a laminated component arranged so as to cover the heat generating component on the first surface. The heat generating component is a CPU.
The electronic substrate according to claim 2, wherein the laminated component is a DRAM. The groove portion is a long groove that passes through the back surface region of the heat generating component.
The electronic substrate according to any one of claims 1 to 3, wherein a heat pipe is arranged in the groove as the heat radiating component. The groove portion is a recess formed in the back surface region of the heat generating component.
The electronic substrate according to any one of claims 1 to 3, wherein a metal block is arranged in the groove as the heat radiating component. The electronic substrate according to any one of claims 1 to 5, wherein a metal layer is formed on the surface of the groove. A second groove is formed on the first surface of the substrate.
The electronic substrate according to any one of claims 1 to 6, wherein the heat generating component is arranged in the second groove portion. The electronic substrate according to claims 1 to 7 and
An electronic device including a housing for accommodating the electronic substrate.

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