CPO optical module, heat dissipation structure thereof and installation method of heat dissipation structure

Abstract

The invention relates to a CPO optical module, a heat dissipation structure thereof and an installation method of the heat dissipation structure, the heat dissipation structure comprises a heat dissipation medium, and the heat dissipation medium is provided with a first working surface, a second working surface and a third working surface; the first working face is used for being arranged opposite to the upper surface of a chip needing heat dissipation, a preset gap is formed between the first working face and the upper surface of the chip needing heat dissipation, and the preset gap is filled with a soft heat conduction material; the second working face is located above the first working face and used for being in contact with a module upper cover of the CPO optical module or being connected with the module upper cover through a soft heat conduction material, and a heat conduction path from the first working face to the second working face is formed in the heat dissipation medium; the third working face is used for being fixed to a PCBA board, and the fixing position is located on one side of the chip. Through the three-working-face heat dissipation structure and the installation method thereof, the key technical bottlenecks of the CPO optical module in the aspects of multi-packaging compatibility, efficient heat dissipation, high-density integration and reliable assembly are systematically solved.

Description

Technical Field

[0001] This invention belongs to the field of optical module technology, specifically relating to a CPO optical module, its heat dissipation structure, and a method for installing the heat dissipation structure. Background Technology

[0002] With the rapid development of high-bandwidth applications such as 5G, live streaming, ultra-high-definition video (4K / 8K), virtual reality (VR), cloud computing, the Internet of Things (IoT), and artificial intelligence, data transmission capacity is experiencing explosive growth. Optical modules, as photoelectric conversion modules in the data transmission link, face demands for higher bandwidth, higher packaging density, and lower power consumption. As transmission rates gradually shift from 400G / 800G to 1.6T / 3.2T, the packaging form of optical modules is gradually shifting from OSFP to CPO packaging, which offers higher packaging density and lower link loss. The CPO package volume is only about 1 / 3 to 1 / 2 of that of OSFP. The internal circuitry, optical path, and heat dissipation layout of the module become more complex. Faced with a smaller package volume, the packaging trend of optoelectronic chips has to shift from 2D planar arrangement to 3D vertical layout, which brings greater challenges to heat dissipation.

[0003] Traditional pluggable optical modules typically heat up the bare EIC chips such as TIA, DIVER, and ODSP (TIA: transimpedance amplifier; DIVER: driver; ODSP: optical digital signal processor) by conducting heat from the back of the chip to the back of the PCBA. However, with the increase in internal packaging density and the shortening of transmission links, the CPO optical module protocol requires that the interfaces of high-speed signals be placed on the back of the PCBA. This means that the heat dissipation of bare EIC chips such as TIA and DIVER can no longer follow the traditional path of conducting heat from the back of the chip to the back of the PCBA.

[0004] To address the heat dissipation issue of the high-heat electrical chip die inside the CPO, current technology still largely adopts a strategy similar to that of pluggable optical modules. This involves using a heat dissipation channel at the bottom of the chip to guide heat through the side of the module cover, thus avoiding damage to the active layer on the surface of the bare chip.

[0005] (1) For expensive 2.5D / 3D packaging technologies: such as Figure 1 As shown, the PIC chip 4 is mounted upright on the PCBA board 1, and an optical fiber 6 is connected to the PIC chip 4. Electrical contact points 2 are located at the bottom of the PCBA board 1. The EIC chip 5 is flipped over and mounted on top of the PIC chip 4, with its back facing upwards and in contact with the heat dissipation medium 8. The heat dissipation medium 8 receives heat from the EIC chip 5 through its bottom heat dissipation surface and then conducts the heat upwards through its top heat dissipation surface to the module cover 3 above (heat dissipation direction as shown). Figure 1 (As shown by the middle arrow), at the same time, the heat dissipation surface on the top of the heat dissipation medium 8 is fixed on the module cover 3 as a support surface for the heat dissipation structure, which facilitates assembly when the module cover 3 is assembled.

[0006] In this context, "front-mounted" means that the active side (i.e., wiring layer) of the chip faces upwards, while the back side (i.e., matrix layer) is mounted on the substrate; "flip-mounted" means that the active side of the chip faces downwards and is connected to the substrate.

[0007] (2) In 2D encapsulation scenarios: such as Figure 2 As shown, the upper surface of the heat dissipation medium 8 has two heat dissipation surfaces of different heights. The upright EIC chip 5 is mounted on the heat dissipation surface below the heat dissipation medium 8. Heat is conducted through the heat dissipation surface below the heat dissipation medium 8 to the body of the heat dissipation medium 8, then conducted to the side of the EIC chip 5, and then conducted upwards to the heat dissipation surface above the heat dissipation medium 8. Finally, the heat dissipation surface above the heat dissipation medium 8 directs the heat to the module cover 3 in contact with it (heat dissipation direction as shown). Figure 2 (As shown by the middle arrow), the bottom surface of the heat dissipation medium 8 is fixed on the PCBA board 1. However, in this solution, the EIC chip 5 needs to be mounted on the heat dissipation surface below the heat dissipation medium 8. The thickness of the heat dissipation medium will increase the WB line length, resulting in a performance penalty. In addition, the heat needs to pass through the side body of the heat dissipation medium 8. The side body forms a barrier between the EIC chip 5 and the PCBA board 1, resulting in a decrease in the fan-out density of the EIC chip 5.

[0008] Therefore, the following technical problems exist in the prior art: (1) Poor packaging compatibility: Existing heat dissipation structures cannot simultaneously adapt to packaging scenarios of 2D packaging (EIC upright) and 2.5D / 3D packaging (EIC flip-chip); (2) Long heat dissipation path and low efficiency: In 2D packaging, heat needs to be conducted from the back of the chip through the side heat sink to the top cover, and the heat dissipation path is roundabout; the increased thickness of the heat dissipation medium causes the chip to be raised, the length of the gold wire bonding increases, and the signal loss increases. (3) Limited local space: In order to ensure heat dissipation efficiency, the heat dissipation structure with lateral extension in 2D packaging has a large area, which will block the fan-out space around the EIC chip, affecting the gold wire bonding and PCB wiring density, which is not conducive to the layout optimization of high-density, high-performance CPO modules. (4) The assembly process is complex and risky: In 2.5D / 3D packaging, the heat dissipation structure is often fixed to the top cover. During assembly, there is a risk of interference with internal optical fibers, chips and other components. There is a blind spot in the process of aligning the heat dissipation medium with the back of the chip, which can easily cause assembly damage. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a CPO optical module, its heat dissipation structure, and its installation method. Through an innovative three-working-surface heat dissipation structure and its installation method, it systematically solves the key technical bottlenecks of CPO optical modules in terms of multi-package compatibility, efficient heat dissipation, high-density integration, and reliable assembly, providing a reliable heat dissipation solution for next-generation high-speed, high-density optical communication modules.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is: a heat dissipation structure for a CPO optical module, comprising a heat dissipation medium, wherein the heat dissipation medium has a first working surface, a second working surface and a third working surface; The first working surface is set parallel to the upper surface of the chip that needs heat dissipation, and a preset gap is formed between them. The preset gap is filled with a soft thermally conductive material. The second working surface is located above the first working surface and is used to contact the module cover of the CPO optical module or to be connected through a soft thermally conductive material, forming a thermally conductive path from the first working surface to the second working surface within the heat dissipation medium; The third working surface is used to fix it on the PCBA board, and the fixing position is located on one side of the chip.

[0011] Its beneficial effects are: (1) The first and second working surfaces are heat-conducting surfaces, and the heat is directly conducted from the upper surface of the chip to the upper cover of the module. The path is the shortest and the thermal resistance is small, which improves the heat dissipation efficiency; (2) The third working surface is a fixed surface, which is fixed on the PCBA board, so that the heat dissipation medium has independent support and does not depend on the upper cover of the module for fixation. The heat dissipation medium can be assembled before the CPO optical engine is coupled to avoid the upper cover assembly touching the functional components; (3) The structure is not sensitive to the orientation of the chip (upright / flipped) and can be compatible with different packaging forms; (4) The heat dissipation medium is prevented from directly contacting the chip surface through the preset gap, which prevents damage to the fragile chip wiring layer or surface structure.

[0012] Furthermore, the heat dissipation medium is a thermally conductive metal block.

[0013] Its beneficial effects are: metallic materials (such as copper and aluminum) have excellent thermal conductivity, ensuring rapid heat transfer; the metal block has good structural strength, which can stably support and withstand mechanical stress during assembly and use.

[0014] Furthermore, the soft thermally conductive material is a soft thermally conductive gel or an elastic thermally conductive pad.

[0015] Its beneficial effects are: soft materials can fill microscopic uneven surfaces and reduce contact thermal resistance; elastic materials can absorb thermal expansion stress and reduce mechanical damage to the chip.

[0016] Furthermore, the heat dissipation medium is provided with a support leg structure, the bottom surface of the support leg structure is the third working surface, and an avoidance groove is provided between the support leg and the first working surface to avoid the fan-out traces or gold wire bonding space of the chip.

[0017] Its advantages are: the clearance slot design provides space for gold wire bonding or fan-out routing, supporting high-density wiring.

[0018] Furthermore, the heat dissipation structure is a single-chip heat dissipation structure used to dissipate heat for a single chip, and its heat dissipation medium includes a first working surface, a second working surface, and at least one third working surface.

[0019] Its advantages are: it is suitable for single-chip scenarios, has a compact structure, and is easy to manufacture and assemble.

[0020] Furthermore, the heat dissipation structure is a multi-chip heat dissipation structure, used to dissipate heat for multiple chips simultaneously. Its heat dissipation medium includes multiple first working surfaces, one second working surface, and at least one third working surface. The number of first working surfaces is the same as the number of chips that need to be dissipated, and the distance between adjacent first working surfaces is adapted to the distance between two corresponding chips.

[0021] Its beneficial effects are: it can dissipate heat for multiple chips at the same time, reduce the number of heat dissipation structures, and improve space utilization.

[0022] Furthermore, the first working surface is a plane or an inclined plane.

[0023] Its beneficial effects are: it can meet different chip mounting methods and ensure that the first working surface and the upper surface of the chip are arranged in parallel.

[0024] Based on the above-mentioned heat dissipation structure technical solution, the present invention further proposes an installation method for the heat dissipation structure, including the following steps: (1) placing the first working surface of the heat dissipation medium opposite to the upper surface of the chip that needs to be dissipated, and ensuring that a preset gap is formed between the first working surface and the upper surface of the chip; (2) filling the preset gap with a soft thermally conductive material; (3) fixing the third working surface to the PCBA board; (4) making the second working surface thermally connected to the module cover of the CPO optical module through the soft thermally conductive material.

[0025] Its beneficial effects are: clear steps, strong operability, and help to ensure assembly consistency and quality.

[0026] Furthermore, step (3) includes first using UV adhesive for temporary fixation, and then using structural adhesive for permanent fixation.

[0027] Its beneficial effects are: UV adhesive enables rapid and accurate temporary positioning, avoiding assembly misalignment; structural adhesive provides durable and firm mechanical fixation, improving product durability.

[0028] Based on the above-mentioned heat dissipation structure, this invention further proposes a CPO optical module, characterized in that it includes a PCBA board, an EIC chip, a PIC chip, a housing, and the aforementioned heat dissipation structure, wherein the heat dissipation structure is used for heat dissipation of the EIC chip.

[0029] Its beneficial effect is that the heat dissipation structure is integrated as a standard component into the CPO optical module, thereby improving the overall heat dissipation performance.

[0030] Furthermore, the EIC chip has a top-mounted or flip-chip structure, with its upper surface being a thermally conductive surface, which is either the wiring layer on the front side of the chip or the substrate layer on the back side.

[0031] Its beneficial effects are: it clearly supports both upright and flip-chip mounting of EIC chips, and it is clear that both sides of the chip can be used as effective heat dissipation surfaces, demonstrating its wide applicability.

[0032] Furthermore, the CPO optical module has a 2D, 2.5D, or 3D packaging structure.

[0033] Its beneficial effects are: it covers mainstream packaging types, has strong compatibility, can meet the packaging needs of different customers and different scenarios, and enhances product competitiveness.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention has 2D, 2.5D and 3D packaging compatibility: By controlling the height difference between the second and third working surfaces, this invention ensures that after the heat dissipation structure is assembled, a stable gap is formed between the first working surface and the upper surface of the EIC chip, and a soft thermally conductive material is provided to avoid surface damage caused by adhesive contact with the heat dissipation surface. Therefore, the heat dissipation structure of this invention is not sensitive to whether the thermally conductive surface is the front (wiring layer) or the back (matrix layer) of the chip. Consequently, it is not sensitive to whether the front (wiring layer) of the EIC chip is placed upwards in the 2D packaging process or the back (matrix layer) of the EIC chip is placed upwards in the 2.5D / 3D packaging process, thus improving the compatibility of the solution and being compatible with 2.5D / 3D packaging and 2D packaging.

[0035] 2. The heat dissipation path of this invention extends from the top surface of the EIC chip upwards to the top cover of the module, eliminating the need for heat dissipation from the back of the chip to the sides and top. The heat dissipation path is comparable to that of 3D packaged CPO. Compared with the existing 2D packaged CPO heat dissipation solution, it can shorten the heat dissipation path length, improve heat dissipation efficiency, and avoid the increased circuit loss caused by the increased gold wire bonding length due to raising the chip.

[0036] 3. Maximized EIC Fan-out Density: In existing 2D packaging CPO technologies, heat is conducted from the bottom of the EIC chip, then laterally, and then upwards. The heat dissipation medium on the chip's side obstructs the fan-out of the EIC portion. In this invention, a clearance groove is provided between the third working surface and the first working surface. This ensures that the heat dissipation structure does not completely block the EIC chip's lateral direction, leaving the EIC's fan-out space unaffected. This is more conducive to the fan-out of interconnects, especially when 2D packaging uses gold wire bonding, which provides more space for the gold wire connection between the PCBA and the EIC.

[0037] 4. Convenient assembly of heat dissipation structure: The present invention is fixedly connected to the PCBA board through the third working surface, and there is no need to fix the heat dissipation structure from the top cover of the module. Therefore, the heat dissipation structure can be installed during the device production stage, and then the top cover of the module can be assembled, avoiding the risk of interference between the tube shell boss and the internal components of the module. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the layout of a 2.5D / 3D packaged CPO heat dissipation structure in the prior art; Figure 2 This is a schematic diagram of the layout of a 2D packaged CPO heat dissipation structure in the prior art. Figure 3 This is a schematic diagram of the heat dissipation structure of the CPO optical module described in Example 1; Figure 4 This is a schematic diagram of the single-chip heat dissipation structure described in Example 2; Figure 5 This is a schematic diagram of the installation of the single-chip heat dissipation structure described in Example 2; Figure 6 This is a schematic diagram of the dual-chip heat dissipation structure described in Example 3; Figure 7 This is a schematic diagram of the installation of the dual-chip heat dissipation structure described in Example 3; The diagram is labeled as follows: 1. PCBA board, 2. Electrical connection contact point, 3. Module cover, 4. PIC chip, 5. EIC chip, 5-1. First EIC chip, 5-2. Second EIC chip, 6. Fiber optic cable, 7. Wiring layer, 8. Heat dissipation medium, 801. First working surface, 802. Second working surface, 803. Third working surface, 8-1. First single-chip heat dissipation structure, 8-2. Second single-chip heat dissipation structure, 8-3. Dual-chip heat dissipation structure. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the embodiments, but this should not be construed as limiting the invention in any way.

[0040] Example 1 like Figure 3As shown, a heat dissipation structure for a CPO optical module includes a heat dissipation medium 8, which has three working surfaces: a first working surface 801, a second working surface 802, and a third working surface 803. The first and second working surfaces 801 and 802 are the heat dissipation surfaces of the heat dissipation medium 8, used for heat conduction. The third working surface 803 is a structural fixing surface used to fix the heat dissipation medium 8 onto the PCBA board 1 of the CPO optical module. The heat dissipation medium 8 is a copper block, an aluminum block, or other heat sink with a high thermal conductivity.

[0041] The first working surface 801 is located above the upper surface of the EIC chip 5, and the two are arranged parallel to each other, forming a preset gap. Soft thermally conductive gel is filled within this preset gap to provide a heat conduction path, while avoiding damage to the chip contact surface caused by hard contact with the heat dissipation medium 8. Furthermore, the parallel arrangement of the first working surface 801 and the upper surface of the EIC chip 5 ensures uniform thickness of the soft thermally conductive gel, which is beneficial for uniform heat dissipation. The EIC chip 5 is mounted on the PCBA board 1 in either a top-mounted or flip-chip configuration, with its upper surface serving as its thermally conductive surface. When the EIC chip 5 is top-mounted, the thermally conductive surface is the wiring layer on the front side of the chip; when the EIC chip 5 is flip-chipped, the thermally conductive surface is the matrix layer on the back side of the chip. This invention does not require a specific orientation for the thermally conductive surface of the EIC chip 5; either the front or back side of the EIC chip 5 can serve as a heat transfer interface. Therefore, this invention liberates the thermally conductive surface from the back side of the EIC chip 5, making it compatible with 2.5D / 3D packaging and 2D packaging.

[0042] The second working surface 802 is located on the upper surface of the heat dissipation medium 8 and above the first working surface 801. It is used to directly contact the upper part of the module cover 3 of the CPO optical module or to conduct heat to the upper part of the module cover 3 through soft thermal conductive materials such as soft thermal conductive gel and elastic thermal conductive pad, thereby forming an upward heat conduction path from the first working surface 801 to the second working surface 802 and then to the upper part of the module cover 3.

[0043] The third working surface 803 is fixed to the PCBA board 1 by adhesive or welding, and the fixing position is located on one side of the EIC chip 5. In the heat dissipation structure design, a support leg structure can be formed on one side of the first working surface 801. The bottom surface of this support leg structure is the third working surface 803. Furthermore, according to design requirements, a clearance groove of appropriate shape and size is left between the support leg structure and the first working surface 801 to avoid space for the fan-out traces or gold wire bonding space of the EIC chip.

[0044] Since the upper surface of the EIC chip 5 is higher than that of the PCBA board 1, there is a certain height difference between the first working surface 801 and the third working surface 803. This height difference ensures that the heat dissipation structure, after being installed on the PCBA board 1, can form a preset gap between the first working surface 801 and the upper surface of the EIC chip 5. Therefore, this height difference can be controlled during the design process according to product requirements to meet the installation needs of different products.

[0045] In this invention, the heat dissipation path of the CPO optical module through the heat dissipation structure is as follows: upper surface of EIC chip 5 → soft thermally conductive material between EIC chip 5 and first working surface 801 → first working surface 801 → heat dissipation medium 8 body → second working surface 802 → soft thermally conductive material between second working surface 802 and module cover 3 → module cover 3.

[0046] In this invention, the heat of the EIC chip 5 is directly conducted upward from the upper surface of the chip to the module cover 3, without the need for heat dissipation to the sides and top through the back of the chip. The heat dissipation path is comparable to that of 3D packaged CPO. Compared with the existing 2D packaged CPO heat dissipation solution, the heat dissipation path length is reduced and the heat dissipation efficiency is improved. At the same time, it avoids the increase in the length of gold wire bonding caused by raising the chip, which leads to increased circuit loss.

[0047] The heat dissipation structure in the installation of the CPO optical module includes the following steps: (1) Place the first working surface 801 of the heat dissipation medium 8 parallel to the upper surface of the EIC chip 5, and ensure that a preset gap is formed between the first working surface 801 and the upper surface of the EIC chip 5. (2) Fill the preset gap with a soft thermally conductive material, such as a soft thermally conductive gel; (3) The third working surface 803 is fixed to the PCBA board 1 by adhesive. During the adhesive process, UV glue is used for temporary fixation first, and then structural glue is used for permanent fixation. (4) Install an elastic thermal pad or apply a soft thermal gel on the second working surface 802, and press down the module cover 3 so that it forms a thermally conductive connection with the second working surface 802 through the elastic thermal pad or the soft thermal gel.

[0048] Example 2 In this embodiment, the heat dissipation structure described in Example 1 is a single-chip heat dissipation structure, that is, each heat dissipation structure is used to dissipate heat from a corresponding EIC chip 5.

[0049] like Figure 4 , 5As shown, in this embodiment, the heat dissipation medium of the single-chip heat dissipation structure is a copper heat dissipation block, and the number of the first working surface 801, the second working surface 802, and the third working surface 803 is one. In the optical module, the EIC chip 5 is sometimes installed at an angle, in which case its upper surface is an inclined plane. The first working surface 801 needs to be parallel to the upper surface of the EIC chip 5. Therefore, the first working surface 801 needs to be set as an inclined plane relative to the third working surface 803 to meet the installation scenario. If the EIC chip 5 is not installed at an angle, then its upper surface is parallel to the PCBA board, and the first working surface 801 is a plane parallel to the third working surface 803.

[0050] like Figure 5 As shown, when there are two EIC chips 5 on the PCBA board, each EIC chip 5 is equipped with a corresponding single-chip heat dissipation structure. Specifically, the first EIC chip 5-1 is cooled by the corresponding first single-chip heat dissipation structure 8-1, and the second EIC chip 5-2 is cooled by the corresponding second single-chip heat dissipation structure 8-2.

[0051] In this embodiment, the two EIC chips 5 have two independent heat dissipation paths. Taking the first EIC chip 5-1 as an example, its heat dissipation path is as follows: the upper surface of the first EIC chip 5-1 → the soft thermally conductive material between the first EIC chip 5-1 and the first working surface 801 on the first single-chip heat dissipation structure 8-1 → the first working surface 801 → the heat dissipation medium 8 body of the first single-chip heat dissipation structure 8-1 → the second working surface 802 of the first single-chip heat dissipation structure 8-1 → the soft thermally conductive material between the second working surface 802 and the module cover 3 → the module cover 3.

[0052] Example 3 In this embodiment, the heat dissipation structure described in Example 1 is a dual-chip heat dissipation structure 8-3, that is, each heat dissipation structure is used for the heat dissipation of two EIC chips 5.

[0053] like Figure 6 As shown, the dual-chip heat dissipation structure 8-3 includes two first working surfaces 801, a second working surface 802, and a third working surface 803. There is a gap between the two first working surfaces 801, and the size of the gap is adapted to the gap between the two EIC chips 5.

[0054] like Figure 7 As shown, when there are two EIC chips 5 on the PCBA board, the first EIC chip 5-1 and the second EIC chip 5-2 conduct heat through the two first working surfaces 801 of the dual-chip heat dissipation structure 8-3, thereby realizing the heat dissipation of the two EIC chips 5 by a dual-chip heat dissipation structure 8-3.

[0055] It is understood that in other embodiments, when heat dissipation is required for two or more EIC chips 5, the heat dissipation structure can be a multi-chip heat dissipation structure, with the same number of first working surfaces 801 as the EIC chips 5 on its heat dissipation medium. Moreover, in embodiments 2 and 3, the third working surfaces 803 can also be arranged in multiple intervals.

[0056] In this embodiment, the heat dissipation path of the two EIC chips 5 is as follows: the upper surface of the first EIC chip 5-1 and the second EIC chip 5-2 → the soft thermally conductive material between the first EIC chip 5-1 / the second EIC chip 5-2 and the dual-chip heat dissipation structure 8-3 → the two first working surfaces 801 → the heat dissipation medium 8 body of the dual-chip heat dissipation structure 8-3 → the second working surface 802 of the dual-chip heat dissipation structure 8-3 → the soft thermally conductive material between the second working surface 802 and the module cover 3 → the module cover 3.

[0057] Example 4 like Figure 3 As shown, a CPO optical module includes a PCBA board 1, an EIC chip 5, a PIC chip 4, a housing, and the heat dissipation structure described in embodiments 1-3. The PCBA board 1 has electrical contact points on its bottom and the EIC chip 5 and PIC chip 4 are mounted on its front side. An optical fiber 6 is connected to the PIC chip 4. In this embodiment, the EIC chip 5 is flip-chip, with its wiring layer facing downwards and its substrate layer serving as a thermally conductive surface. In other embodiments, the EIC chip 5 can also be mounted upright. The housing includes a base and a module cover 3. The PCBA board 1, EIC chip 5, PIC chip 4, and the heat dissipation structure are disposed within the housing, and the second working surface 802 of the heat dissipation structure is thermally connected to the module cover 3.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the specific implementation of the present invention with reference to the above embodiments. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the pending claims.

Claims

1. A heat dissipation structure for a CPO optical module, comprising a heat dissipation medium (8), characterized in that, The heat dissipation medium (8) has a first working surface (801), a second working surface (802) and a third working surface (803); The first working surface (801) is set opposite to the upper surface of the chip that needs to dissipate heat, and a preset gap is formed between the two, the preset gap being filled with a soft thermally conductive material; The second working surface (802) is located above the first working surface (801) and is used to contact the module cover (3) of the CPO optical module or to be connected through a soft thermally conductive material, forming a thermally conductive path from the first working surface (801) to the second working surface (802) in the heat dissipation medium (8); The third working surface (803) contacts the PCBA board (1), and the contact position is located on one side of the chip.

2. The heat dissipation structure of the CPO optical module according to claim 1, characterized in that, The heat dissipation medium (8) is a thermally conductive metal block.

3. The heat dissipation structure of the CPO optical module according to claim 1, characterized in that, The soft thermally conductive material is a soft thermally conductive gel or an elastic thermally conductive pad.

4. The heat dissipation structure of the CPO optical module according to claim 1, characterized in that, The heat dissipation medium (8) is provided with a support leg structure. The bottom surface of the support leg structure is the third working surface (803). An avoidance groove is provided between the support leg and the first working surface (801) to avoid the fan-out traces or gold wire bonding space of the chip.

5. The heat dissipation structure of the CPO optical module according to claim 1, characterized in that, The heat dissipation structure is a single-chip heat dissipation structure used to dissipate heat for a single chip. Its heat dissipation medium (8) includes a first working surface (801), a second working surface (802), and at least one third working surface (803).

6. The heat dissipation structure of the CPO optical module according to claim 1, characterized in that, The heat dissipation structure is a multi-chip heat dissipation structure, which is used to dissipate heat for multiple chips at the same time. Its heat dissipation medium (8) includes at least two first working surfaces (801), one second working surface (802) and one third working surface (803). The number of first working surfaces (801) is the same as the number of chips that need to be dissipated, and the distance between adjacent first working surfaces (801) is adapted to the distance between two corresponding chips.

7. The heat dissipation structure of the CPO optical module according to claim 1, characterized in that, The first working surface (801) is a plane or an inclined plane.

8. A method for installing the heat dissipation structure according to any one of claims 1-7, characterized in that, The steps include: (1) placing the first working surface (801) of the heat dissipation medium (8) opposite to the upper surface of the chip, and ensuring that a preset gap is formed between the first working surface (801) and the upper surface of the chip; (2) filling the preset gap with a soft thermally conductive material; (3) fixing the third working surface (803) onto the PCBA board (1); (4) making the second working surface (802) thermally connected to the module cover (3) of the CPO optical module through the soft thermally conductive material.

9. The installation method according to claim 8, characterized in that, Step (3) involves first using UV adhesive for temporary fixation, and then using structural adhesive for permanent fixation.

10. A CPO optical module, characterized in that, It includes a PCBA board (1), an EIC chip (5), a PIC chip (4), a housing, and a heat dissipation structure as described in any one of claims 1-7, wherein the heat dissipation structure is used for heat dissipation of the EIC chip (5).

11. The CPO optical module according to claim 10, characterized in that, The EIC chip (5) is a top-mounted or flip-mounted structure, with its upper surface being a heat-conducting surface, which is either the wiring layer (7) on the front side of the chip or the matrix layer on the back side.

12. The CPO optical module according to claim 10, characterized in that, The CPO optical module has a 2D, 2.5D, or 3D packaging structure.

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