A high power chip diamond composite material welding packaging process

Abstract

The application relates to the technical field of semiconductor packaging, in particular to a high-power chip diamond composite material welding packaging process, S1: liquid cooling plates and high-thermal-conductivity uniform temperature materials or devices are cleaned; S2: silver-copper composite solder is coated on the liquid cooling plates and the high-thermal-conductivity uniform temperature materials or devices; S3: the high-thermal-conductivity uniform temperature materials or devices are covered and attached on the liquid cooling plates to obtain a prefabricated attachment; S4: the prefabricated attachment is clamped on a constant-temperature stage, a bonding head is aligned, pre-tightening pressure is applied to the prefabricated attachment, and protective gas is injected; S5: the bonding temperature is set as a segmented stepwise heating mode, and the highest temperature is 200-300 DEG C; during the period, the bonding head continuously applies a constant pressing force of 0.1-0.2 MPa to the prefabricated attachment, and constant-temperature pressure maintaining is performed for 20-30 min to complete metallurgical combination; S6: after the constant-temperature pressure maintaining is completed, the furnace is gradually cooled to room temperature, and the workpiece is taken out to complete bonding; the low-temperature silver-copper hot-press bonding process is adopted to cover or embed the high-thermal-conductivity uniform temperature materials or devices on the heat conduction contact surface of the liquid cooling plate, and the heat conduction efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and more specifically to a high-power chip diamond composite material welding and packaging process. Background Technology

[0002] With the development of artificial intelligence, large model training and high-performance computing, the thermal design power (TDP) of GPUs, CPUs and Chiplet heterogeneous integrated packaged chips has continued to increase and has exceeded 2000W, with local hot spot heat flux density exceeding 1000W / cm².

[0003] Currently, the mainstream heat dissipation solution uses liquid cooling plates, which typically use copper or aluminum as the heat-conducting substrate and rely on a toothed structure to improve heat dissipation efficiency. However, the thermal conductivity of copper is about 400 W / (m·K), while there is obvious uneven heat generation inside multi-core heterogeneous integrated packaged chips. Moreover, the heat is mainly conducted along the thickness direction, and the lateral diffusion ability is limited, resulting in local hot spot temperatures that are significantly higher than the average temperature, which limits the operating frequency and reliability.

[0004] While there are solutions to improve heat dissipation efficiency by adding vapor chambers or heat spreaders to liquid cooling plates, these solutions generally employ high-temperature brazing or conventional soldering processes. High-temperature brazing, with temperatures exceeding 600°C, can easily cause graphitization at the diamond interface and material cracking. Conventional soldering processes result in thick solder layers, high void ratios, and large interfacial thermal resistance, failing to fully leverage the uniform temperature advantage of highly thermally conductive materials.

[0005] Therefore, the applicant hereby proposes a high-power chip diamond composite material welding and packaging process to solve the aforementioned problems. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a high-power chip diamond composite material welding and packaging process to solve the technical problems of low thermal conductivity, high interfacial thermal resistance, and insufficient heat dissipation capacity of existing liquid cooling plates.

[0007] The technical solution of this invention is as follows: This invention provides a high-power chip diamond composite material welding and packaging process, which specifically includes the following steps: S1: Plasma cleaning pretreatment is performed on the heat conduction contact surfaces of liquid cooling plates and high thermal conductivity homogeneous materials or devices. S2: A layer of silver-copper composite solder is uniformly coated on the heat conduction contact surface between the pretreated liquid cooling plate and the high thermal conductivity homogeneous material or device. S3: Completely cover and bond a high thermal conductivity uniform temperature material or device onto the heat conduction contact surface of the liquid cooling plate to obtain a pre-fabricated bonding part; S4: Position and clamp the pre-fabricated bonding component on the constant temperature stage of the hot press bonding equipment. After the bonding head of the hot press bonding equipment is precisely aligned, apply pre-tightening pressure to the pre-fabricated bonding component and inject protective gas. S5: Start the hot press bonding equipment and set the bonding temperature to segmented step heating mode, with the bonding temperature rising to a maximum of 200-300℃. During this period, the bonding head continuously applies a constant pressing force of 0.1-0.2MPa to the pre-fabricated bonding parts and maintains constant temperature and pressure for 20-30 minutes to complete the metallurgical bonding. S6: After the constant temperature and pressure holding is completed, the furnace is cooled down to room temperature in stages to eliminate interfacial thermal stress, and the workpiece is removed to complete the bonding.

[0008] Furthermore, the high thermal conductivity uniform temperature material or device has a plate-like structure.

[0009] Furthermore, the high thermal conductivity heat-equalizing material or device is one of diamond copper, diamond aluminum, diamond, or a heat-equalizing plate.

[0010] Furthermore, the coating thickness of the silver-copper composite solder is 30-60 μm.

[0011] This invention also provides a high-power chip diamond composite material welding and packaging process, which specifically includes the following steps: S1: An embedded groove is made on the heat conduction contact surface of the liquid cooling plate; S2: Plasma cleaning pretreatment is performed on the inner wall of the embedded groove and the heat conduction contact surface of high thermal conductivity uniform temperature material or device. S3: Apply a layer of silver-copper composite solder evenly to the inner wall of the pre-treated embedding groove and the thermal conductivity contact surface of the high thermal conductivity homogeneous material or device.

[0012] S4: Embed a high thermal conductivity uniform temperature material or device into the embedding groove to obtain a pre-fabricated bonding part; S5: Position and clamp the pre-fabricated bonding component on the constant temperature stage of the hot press bonding equipment. After the bonding head of the hot press bonding equipment is precisely aligned, apply pre-tightening pressure to the pre-fabricated bonding component and inject protective gas. S6: Start the hot press bonding equipment and set the bonding temperature to segmented step heating mode, with the bonding temperature rising to a maximum of 200-300℃. During this period, the bonding head continuously applies a constant pressing force of 0.1-0.2MPa to the pre-fabricated bonding parts and maintains constant temperature and pressure for 20-30 minutes to complete the metallurgical bonding. S7: After the constant temperature and pressure holding is completed, the furnace is cooled down to room temperature in a stepwise manner to eliminate interfacial thermal stress, and the workpiece is removed to complete the bonding.

[0013] The beneficial effects achieved by this invention are as follows: The present invention provides a high-power chip diamond composite material welding and packaging process, which uses a low-temperature silver-copper hot-press bonding process to cover or embed a high thermal conductivity homogeneous material or device onto the heat conduction contact surface of a liquid cooling plate, and the silver-copper composite solder coated between the two forms a low thermal resistance connection interface, which greatly improves the thermal conductivity efficiency and realizes rapid lateral diffusion and homogeneous conduction of heat in the hot spot area of ​​the chip. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the process flow of Embodiment 1 of the present invention.

[0015] Figure 2 This is a schematic diagram of the process flow of Embodiment 2 of the present invention.

[0016] Figure 3 This is a three-dimensional schematic diagram of the liquid cooling plate in Example 1.

[0017] Figure 4 This is a three-dimensional assembly diagram of the liquid cooling plate in Example 1.

[0018] Figure 5 This is a three-dimensional schematic diagram of the liquid cooling plate in Example 2.

[0019] Figure 6 This is a three-dimensional assembly diagram of the liquid cooling plate in Example 2. Detailed Implementation

[0020] To facilitate understanding of the present invention by those skilled in the art, specific embodiments of the present invention are clearly described below with reference to the accompanying drawings. Obviously, the specific embodiments described are merely preferred embodiments of the present invention, and not all embodiments.

[0021] Example 1: like Figure 1-6 As shown, the present invention provides a high-power chip diamond composite material welding and packaging process for preparing a liquid cooling plate embedded with a high thermal conductivity homogenizing material or device 2; the packaging process specifically includes the following steps: S1: Perform plasma cleaning pretreatment on the heat conduction contact surface of liquid cooling plate 1 and high thermal conductivity uniform temperature material or device 2; remove oxide layer, oil and other contaminants, thereby improving solder wettability.

[0022] The high thermal conductivity heat-equalizing material or device 2 has a plate-like structure. The high thermal conductivity heat-equalizing material or device 2 includes, but is not limited to, diamond copper, diamond aluminum, diamond, and heat-equalizing plates. In this embodiment, diamond copper is preferred. The thermal conductivity of diamond is 1200-2600W / (m·K), which greatly improves the thermal conductivity.

[0023] S2: A layer of silver-copper composite solder is uniformly coated on the thermal conduction contact surface of the pretreated liquid cooling plate 1 and the high thermal conductivity homogeneous material or device 2. The coating thickness of the silver-copper composite solder is 30-60μm. It replaces traditional thermal interface materials such as thermal conductive silicone grease (TIM), significantly reduces interface thermal resistance, and further improves thermal conductivity.

[0024] The silver-copper composite solder is composed of silver particles and ultrafine copper powder, combined with a low-temperature organic active flux carrier. The silver particles provide ultra-high thermal conductivity channels, while the copper powder further improves thermal conductivity, reduces material costs, and enhances metallurgical compatibility with copper cold plates. The solder body has a thermal conductivity >200 W / (m²). K); It has strong wetting and spreading ability in the low temperature range of 200-300℃, and forms a continuous and dense metal bonding layer after pressure curing, without delamination gaps.

[0025] S3: Completely cover and adhere the high thermal conductivity uniform temperature material or device 2 to the heat conduction contact surface of the liquid cooling plate 1 to obtain a pre-fabricated bonding part; S4: Position and clamp the pre-fabricated bonding component on the constant temperature stage of the hot press bonding equipment. After the bonding head of the hot press bonding equipment is precisely aligned, apply pre-tightening pressure to the pre-fabricated bonding component and inject protective gas. In this example, the protective gas is preferably nitrogen to avoid high-temperature oxidation.

[0026] S5: Start the hot press bonding equipment and set the bonding temperature to a segmented step heating mode, with the bonding temperature rising to a maximum of 200-300℃. During this period, the bonding head continuously applies a constant pressure of 0.1-0.2MPa to the pre-fabricated bonding parts and maintains constant temperature and pressure for 20-30 minutes to complete the metallurgical bonding. The weld layer thickness can be precisely controlled to be stable at 20-50 μm, the overall interface void rate is less than 1%, and the batch processing consistency is good.

[0027] S6: After the constant temperature and pressure holding is completed, the furnace is cooled down to room temperature in stages to eliminate interfacial thermal stress, and the workpiece is removed to complete the bonding.

[0028] Example 2: like Figure 1-6 As shown, this embodiment is an optimization based on embodiment 1: S1: An embedded groove 11 is opened on the heat conduction contact surface of the liquid cooling plate 1 to facilitate the positioning and installation of high thermal conductivity uniform temperature material or device 2.

[0029] S2: Perform plasma cleaning pretreatment on the inner wall surface of the embedded groove 11 and the heat conduction contact surface of the high thermal conductivity uniform temperature material or device 2; remove oxide layer, oil and other contaminants, thereby improving solder wettability.

[0030] S3: A layer of silver-copper composite solder is uniformly coated on the inner wall of the pre-treated embedding groove 11 and the thermal conduction contact surface of the high thermal conductivity uniform temperature material or device 2. The coating thickness of the silver-copper composite solder is 30-60μm. It replaces traditional thermal interface materials such as thermal conductive silicone grease (TIM), significantly reduces interface thermal resistance, and further improves thermal conductivity.

[0031] S4: Embed the high thermal conductivity uniform temperature material or device 2 into the embedding groove 11 to obtain the pre-fabricated bonding part; S5: Position and clamp the pre-fabricated bonding component on the constant temperature stage of the hot press bonding equipment. After the bonding head of the hot press bonding equipment is accurately aligned, apply pre-tightening pressure to the pre-fabricated bonding component and inject protective gas. In this example, the protective gas is preferably nitrogen to avoid high-temperature oxidation.

[0032] S6: Start the hot press bonding equipment and set the bonding temperature to a segmented stepped heating mode, with the bonding temperature rising to a maximum of 200-300℃. During this period, the bonding head continuously applies a constant pressure of 0.1-0.2MPa to the pre-fabricated bonding parts and maintains constant temperature and pressure for 20-30 minutes to complete the metallurgical bonding. The weld layer thickness can be precisely controlled to be stable at 20-50 μm, the overall interface void rate is less than 1%, and the batch processing consistency is good.

[0033] S7: After the constant temperature and pressure holding is completed, the furnace is cooled down to room temperature in a stepwise manner to eliminate interfacial thermal stress, and the workpiece is removed to complete the bonding.

[0034] The embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A high-power chip diamond composite material welding and packaging process, characterized in that: S1: Plasma cleaning pretreatment is performed on the heat conduction contact surfaces of liquid cooling plates and high thermal conductivity homogeneous materials or devices. S2: A layer of silver-copper composite solder is uniformly coated on the heat conduction contact surface between the pretreated liquid cooling plate and the high thermal conductivity homogeneous material or device. S3: A pre-fabricated bonding component is obtained by completely covering and bonding a high thermal conductivity uniform temperature material or device onto the heat conduction contact surface of the liquid cooling plate; S4: Position and clamp the pre-fabricated bonding component on the constant temperature stage of the hot press bonding equipment. After the bonding head of the hot press bonding equipment is precisely aligned, apply pre-tightening pressure to the pre-fabricated bonding component and inject protective gas. S5: Start the hot press bonding equipment and set the bonding temperature to segmented step heating mode, with the bonding temperature rising to a maximum of 200-300℃. During this period, the bonding head continuously applies a constant pressing force of 0.1-0.2MPa to the pre-fabricated bonding parts and maintains constant temperature and pressure for 20-30 minutes to complete the metallurgical bonding. S6: After the constant temperature and pressure holding is completed, the furnace is cooled down to room temperature in stages to eliminate interfacial thermal stress, and the workpiece is removed to complete the bonding.

2. The high-power chip diamond composite material welding and packaging process according to claim 1, characterized in that... In S1-S3: the high thermal conductivity uniform temperature material or device is a plate-like structure.

3. A high-power chip diamond composite material welding and packaging process according to claim 1 or 2, characterized in that... In S1-S3: the high thermal conductivity heat-equalizing material or device is one of diamond copper, diamond aluminum, diamond, or a heat-equalizing plate.

4. The high-power chip diamond composite material welding and packaging process according to claim 3, characterized in that... In S2: the coating thickness of the silver-copper composite solder is 30-60μm.

5. A high-power chip diamond composite material welding and packaging process, characterized in that: S1: An embedded groove is made on the heat conduction contact surface of the liquid cooling plate; S2: Plasma cleaning pretreatment is performed on the inner wall of the embedded groove and the heat conduction contact surface of high thermal conductivity uniform temperature material or device. S3: A layer of silver-copper composite solder is uniformly coated on the inner wall of the pre-treated embedding groove and the thermal conduction contact surface of the high thermal conductivity uniform temperature material or device. S4: Embed a high thermal conductivity uniform temperature material or device into the embedding groove to obtain a pre-fabricated bonding part; S5: Position and clamp the pre-fabricated bonding component on the constant temperature stage of the hot press bonding equipment. After the bonding head of the hot press bonding equipment is precisely aligned, apply pre-tightening pressure to the pre-fabricated bonding component and inject protective gas. S6: Start the hot press bonding equipment and set the bonding temperature to segmented step heating mode, with the bonding temperature rising to a maximum of 200-300℃. During this period, the bonding head continuously applies a constant pressing force of 0.1-0.2MPa to the pre-fabricated bonding parts and maintains constant temperature and pressure for 20-30 minutes to complete the metallurgical bonding. S7: After the constant temperature and pressure holding is completed, the furnace is cooled down to room temperature in a stepwise manner to eliminate interfacial thermal stress, and the workpiece is removed to complete the bonding.

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