Cooling motherboard and optical module

Abstract

The present application relates to the field of optical communication technology, and in particular to a heat dissipation motherboard and an optical module. A heat dissipation motherboard is used to package a chip, comprising a circuit board and a heat sink, the heat sink is located on one side of the circuit board, and the chip is arranged on the other side of the circuit board. A heat dissipation through hole is provided at the position corresponding to the chip on the circuit board, and the heat dissipation through hole runs through both sides of the circuit board. At least part of the heat sink extends into the heat dissipation through hole and can contact the chip, so that the heat generated by the chip when working can be transferred out, reducing the heat transfer thermal resistance, thereby effectively dissipating the heat of the chip, and solving the problem of heat dissipation difficulties of COB bare chips. An optical module comprises the heat dissipation motherboard, chip and shell, the heat dissipation motherboard and chip are located in the shell, and the heat sink of the heat dissipation motherboard contacts the chip and the shell respectively, so as to quickly transfer the heat generated by the chip to the shell, thereby achieving the effect of efficient heat dissipation.

Description

Technical Field

[0001] The present invention relates to the technical field of optical communications, and in particular to a heat dissipation mainboard and an optical module. Background Art

[0002] In the field of optical communications, the COB (chip on board) process is often used to package chips with specific functions on PCB boards (printed circuit boards), and the current mainstream practice is to attach the chip to a specific area on the PCB board. However, after the chip is attached to the PCB board, the heat cannot be directly transferred to the corresponding metal shell using thermal interface materials or metal heat sinks, which makes this process have a large heat dissipation disadvantage.

[0003] To address the above issues, the current conventional approach is to drill through holes in the COB area of ​​the PCB board and use overheating holes for heat dissipation. However, due to the limited content of thermal conductive materials at the overheating holes, the heat transfer effect is poor, which can easily cause heat concentration and increase the chip temperature. Summary of the invention

[0004] The purpose of the present application is to provide a heat dissipation motherboard and an optical module to solve the technical problem in the prior art that the heat dissipation effect of the chip is poor when the chip is packaged on a PCB board using the COB process.

[0005] The present application provides a heat dissipation mainboard for packaging chips, including a circuit board and a heat dissipation element;

[0006] A heat dissipation through hole is provided on the circuit board at a packaging position corresponding to the chip; the heat sink is located on one side of the circuit board, and at least part of the heat sink extends into the heat dissipation through hole and can contact the chip on the other side of the circuit board.

[0007] In the above technical solution, preferably, a protrusion is formed on the heat sink, and the protrusion extends into the heat dissipation through hole and can contact the chip;

[0008] An end surface of the heat sink facing the circuit board is in contact with the circuit board.

[0009] In any of the above technical solutions, preferably, the heat dissipation mainboard further includes a first thermally conductive adhesive layer, and the first thermally conductive adhesive layer is arranged between the raised portion of the heat dissipation component and the chip.

[0010] In any of the above technical solutions, preferably, the heat dissipation mainboard further includes a metal layer, and the metal layer is located between the heat dissipation element and the circuit board, or the metal layer is located between the protruding portion of the heat dissipation element and the chip.

[0011] In any of the above technical solutions, preferably, the heat dissipation mainboard further includes a second thermally conductive adhesive layer, and the second thermally conductive adhesive layer is located between the metal layer and the raised portion of the heat dissipation component.

[0012] In any of the above technical solutions, preferably, a vent hole is formed on the heat sink, and the vent hole is connected to the second thermally conductive adhesive layer and / or the first thermally conductive adhesive layer.

[0013] In any of the above technical solutions, preferably, a thermal interface material layer is provided on a side of the heat sink facing away from the circuit board.

[0014] In any of the above technical solutions, preferably, the thermal conductivity of the heat sink and the thermal conductivity of the metal layer are both greater than 15 W / (m·K).

[0015] The present application also provides an optical module, comprising the heat dissipation mainboard and the chip described in any of the above technical solutions, wherein the chip is located on one side of the circuit board and in contact with the heat dissipation component.

[0016] In the above technical solution, preferably, the optical module further comprises a shell, a containing space is formed in the shell, the chip and the heat dissipation mainboard are both located in the containing space, and the heat dissipation element is in contact with the shell.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present application provides a heat dissipation motherboard for packaging chips, including a circuit board and a heat sink; wherein the heat sink is located on one side of the circuit board, and the chip is arranged on the other side of the circuit board. A heat dissipation through hole is provided at the position corresponding to the chip on the circuit board, and the heat dissipation through hole runs through both sides of the circuit board. At least part of the heat sink extends into the heat dissipation through hole and can contact the chip, so that the heat generated by the chip when working can be transferred out with the maximum efficiency, reducing the heat transfer resistance, and then effectively dissipating the heat of the chip, solving the problem of heat dissipation difficulties of COB bare chips. In addition, the heat sink of the heat dissipation motherboard of the present application is easy to assemble, and the heat sink can be bonded after the circuit board is processed.

[0019] The present application also provides an optical module, including the heat dissipation mainboard, chip and shell, the heat dissipation mainboard and chip are located in the shell, and the heat dissipation parts of the heat dissipation mainboard are in contact with the chip and the shell respectively, so as to quickly transfer the heat generated by the chip to the shell, thereby achieving the effect of efficient heat dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the exploded structure of the first optical module provided by an embodiment of the present invention;

[0022] Figure 2 A schematic cross-sectional structural diagram of a first optical module provided by an embodiment of the present invention;

[0023] Figure 3 for Figure 2 The enlarged view of point A in the middle;

[0024] Figure 4 A schematic diagram of an exploded structure of a second optical module provided by an embodiment of the present invention;

[0025] Figure 5 A schematic cross-sectional view of a second optical module provided by an embodiment of the present invention;

[0026] Figure 6 for Figure 5 Enlarged view of point B in the middle.

[0027] Reference numerals:

[0028] 1-circuit board, 101-heat dissipation through hole, 2-heat dissipation element, 201-protrusion, 202-vent, 3-chip, 4-metal layer, 5-thermal interface material layer, 6-upper cover, 7-lower cover. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0031] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Refer to the following Figures 1 to 6 A heat dissipation mainboard and an optical module including the heat dissipation mainboard according to some embodiments of the present invention are described.

[0035] See also Figures 1 to 6 As shown, the present application provides a heat dissipation motherboard for packaging a chip 3, including a circuit board 1 and a heat sink 2; wherein the heat sink 2 is located on one side of the circuit board 1, and the chip 3 is arranged on the other side of the circuit board 1. A heat dissipation through hole 101 is provided at a position corresponding to the chip 3 on the circuit board 1, and the heat dissipation through hole 101 runs through both sides of the circuit board 1. At least part of the heat sink 2 extends into the heat dissipation through hole 101 and contacts the chip 3, that is, the heat sink 2 can be completely embedded in the heat dissipation through hole 101 in a block or strip shape, directly contacting the chip 3, or a convex portion extending into the heat dissipation through hole 101 can be formed on the heat sink 2, and the convex portion contacts the chip 3 and transfers heat.

[0036] Preferably, a protrusion 201 is formed on the side of the heat sink 2 facing the circuit board 1, and the protrusion 201 can pass through the heat dissipation through hole 101 to contact the chip 3, so that the heat generated by the chip 3 when working can be transferred out with the maximum efficiency, reducing the heat transfer resistance, thereby achieving the purpose of effectively dissipating the heat of the chip 3, and solving the problem of heat dissipation difficulties of COB bare chips. In addition, the heat sink 2 is easy to assemble, and the heat sink 2 can be bonded after the circuit board 1 is processed, without affecting the bonding of the chip 3.

[0037] In this embodiment, preferably, the raised portion 201 of the heat sink 2 is adapted to the shape of the heat dissipation hole 101, and the end surface of the heat sink 2 in contact with the chip 3 is flat, so that the heat sink 2 can better fit and contact with the chip 3, thereby improving the heat dissipation efficiency of the heat sink 2 to the chip 3.

[0038] In this embodiment, preferably, Figure 2 , Figure 3 and Figure 5 , Figure 6 As shown, the end surface of the heat sink 2 facing the circuit board 1 is in contact with the circuit board 1, and the end surface can be bonded to the circuit board 1 by a thermally conductive adhesive material, so that the heat sink 2 and the circuit board 1 are firmly connected and not prone to loosening; and the side wall of the protrusion 201 can be in contact with the inner wall of the heat dissipation hole 101, so as to further stabilize the connection between the heat sink 2 and the circuit board 1.

[0039] In the embodiment of the present application, the heat sink 2 can be made of pure copper, copper alloy, pure aluminum, aluminum alloy and other metal and non-metal materials with thermal conductivity greater than 15 W / (m·K) or aluminum nitride ceramics and other ceramic materials to ensure heat dissipation efficiency.

[0040] It should be noted that the number of the heat dissipation through holes 101 on the circuit board 1 is one or more, so as to package different numbers of chips 3 .

[0041] The heat dissipation motherboard of the embodiment of the present application further includes a metal layer 4, which is a grounding layer and is arranged between the chip 3 and the heat sink 2, or between the heat sink 2 and the circuit board 1. Preferably, the metal layer 4 is arranged between the chip 3 and the raised portion 201 of the heat sink 2, or between the end surface of the heat sink 2 facing the circuit board 1 and the circuit board 1. The following describes two preferred implementations of the heat dissipation motherboard of the present application using these two preferred configurations of the metal layer 4.

[0042] like Figures 1 to 3 As shown, when the metal layer 4 is arranged between the chip 3 and the raised portion 201 of the heat sink 2, a first thermally conductive adhesive layer is arranged on one side of the metal layer 4, and the metal layer 4 is bonded and fixed to the chip 3 through the first thermally conductive adhesive layer; a second thermally conductive adhesive layer is arranged on the other side of the metal layer 4, and the metal layer 4 is bonded and fixed to the raised portion 201 of the heat sink 2 through the second thermally conductive adhesive layer.

[0043] like Figures 4 to 6 As shown, when the metal layer 4 is located between the end surface of the heat sink 2 facing the circuit board 1 and the circuit board 1, the metal layer 4 is arranged in a ring shape, and the metal layer 4 is arranged around the raised portion 201 of the heat sink 2. In this structure, the metal layer 4 can also be bonded and fixed to the heat sink 2 and the circuit board 1 through a thermally conductive adhesive material. The chip 3 is directly bonded and fixed to the raised portion 201 of the heat sink 2 through the first thermally conductive adhesive layer.

[0044] It should be noted that in order not to affect the heat dissipation effect, the thermal conductivity of the metal layer is greater than 15W / (m·K); preferably, the material of the metal layer 4 is copper; the thermally conductive adhesive material is a material with good thermal conductivity, such as silver paste; in addition, the thermally conductive adhesive material can have conductive properties or electrical insulation properties.

[0045] In the embodiments of the present application, preferably, Figure 2 and Figure 3 As shown, in order to prevent the bubbles generated on the bonding surface from causing the metal layer 4 to swell and deform when the metal layer 4 is bonded to the heat sink 2 and the chip 3, a vent hole 202 is provided on the heat sink 2 in the embodiment of the present application, and the vent hole 202 is connected to the second thermal conductive adhesive layer or the first thermal conductive adhesive layer. When the first thermal conductive adhesive layer and the second thermal conductive adhesive layer are respectively provided on both sides of the metal layer 4, the vent hole 202 can pass through the metal layer 4 and connect the first thermal conductive adhesive layer and the second thermal conductive adhesive layer at the same time. By providing the vent hole 202 connected to the thermal conductive adhesive layer, the air in the adhesive layer can be discharged to the vent hole 202, so it is not easy to cause the metal layer 4 to swell and deform.

[0046] It should be noted that the first thermally conductive adhesive layer and the second thermally conductive adhesive layer are adhesive layers formed by a thermally conductive adhesive or an adhesive layer formed by a solder.

[0047] In the embodiments of the present application, preferably, Figures 1 to 6 As shown, a thermal interface material layer 5 is provided on the side of the heat sink 2 facing away from the circuit board 1. The heat sink 2 is in contact with the housing of the optical module through the thermal interface material layer 5 to transfer the heat of the chip 3 absorbed by the heat sink 2 to the housing of the optical module. Since the housing of the optical module is generally made of metal, the heat can be quickly dissipated.

[0048] Preferably, the material of the thermal interface material layer 5 includes but is not limited to thermal pads, thermal paste, graphene, etc.

[0049] In addition, it should be noted that when a thermal interface material layer 5 is arranged between the heat sink 2 and the housing of the optical module, the stepped surface formed on the heat sink 2 can also play a role of limiting and supporting. When installing the circuit board 1 (which has been bonded to the heat sink 2 as a whole), it will be subjected to the extrusion force of the thermal interface material layer 5. The extrusion force acts on the heat sink 2, but because the circuit board 1 will limit the stepped surface formed on the heat sink 2, the raised portion 201 of the heat sink 2 will not produce relative displacement relative to the circuit board 1 and protrude from the side surface of the circuit board 1 facing the chip 3. Therefore, it can avoid the breakage or deformation of the gold wire of the circuit board 1 or the chip 3 due to the displacement of the heat sink 2, and at the same time, it can also effectively avoid the risk of the chip 3 falling off due to the bulge in the bottom area of ​​the chip 3.

[0050] An embodiment of the present application also provides an optical module, comprising a heat dissipation mainboard of any of the above embodiments, a chip 3 and a shell, the heat dissipation mainboard and the chip 3 are located in the shell, and the heat dissipation component 2 of the heat dissipation mainboard is in contact with the chip 3 and the shell respectively, so as to quickly transfer the heat generated by the chip 3 to the shell, thereby achieving the purpose of efficient heat dissipation.

[0051] Preferably, for easy disassembly and assembly, Figures 1 to 6 As shown, the housing includes an upper cover 6 and a lower cover 7, which can be snap-fitted and connected to enclose a receiving space. The heat sink 2 of the heat dissipation mainboard can contact the lower cover 7 of the housing to quickly transfer the heat generated by the chip 3 to the lower cover 7.

[0052] Further preferably, the material of the lower cover 7 is metal, so that the lower cover 7 has better heat dissipation and strength.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat dissipation motherboard for packaging chips, characterized in that: Including circuit boards and heat sinks; A heat dissipation through hole is provided on the circuit board at a packaging position corresponding to the chip; the heat sink is located on one side of the circuit board, and at least a portion of the heat sink extends into the heat dissipation through hole and can contact the chip on the other side of the circuit board; A protrusion is formed on the heat sink, the protrusion extends into the heat dissipation through hole and can contact the chip, and the end surface of the heat sink facing the circuit board is in contact with the circuit board; The heat dissipation mainboard further includes a metal layer, a first heat conductive adhesive layer and a second heat conductive adhesive layer, wherein the metal layer is arranged between the chip and the raised portion of the heat dissipation member, the first heat conductive adhesive layer is arranged on one side of the metal layer, and the metal layer is bonded and fixed to the chip through the first heat conductive adhesive layer; the second heat conductive adhesive layer is arranged on the other side of the metal layer, and the metal layer is bonded and fixed to the raised portion of the heat dissipation member through the second heat conductive adhesive layer; A vent hole is formed on the heat sink, and the vent hole passes through the metal layer to connect the second thermal conductive adhesive layer and the first thermal conductive adhesive layer.

2. The heat dissipation mainboard according to claim 1, characterized in that: A thermal interface material layer is arranged on a side of the heat sink facing away from the circuit board.

3. The heat dissipation mainboard according to claim 1, characterized in that: The thermal conductivity of the heat sink and the thermal conductivity of the metal layer are both greater than 15 W / (m·K).

4. An optical module, characterized in that: It comprises the heat dissipation mainboard according to any one of claims 1 to 3 and the chip, wherein the chip is located on one side of the circuit board and contacts the heat dissipation element.

5. The optical module according to claim 4, characterized in that: It also includes a shell, a containing space is formed in the shell, the chip and the heat dissipation mainboard are both located in the containing space, and the heat dissipation element is in contact with the shell.

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