Chip with heat dissipation structure and preparation process

Abstract

The present invention relates to the field of semiconductor technology, and specifically discloses a chip with a heat dissipation structure and a preparation process, comprising: a circuit board for connecting components, a heat sink connected to a side of the circuit board away from the components, and the heat sink and the circuit board connected by pressing. The thermal conductivity of the circuit board of the present invention is greater than that of a traditional PCB circuit board, and the circuit board and the heat sink are formed into an integrated structure by pressing. Pressing is to tightly connect the heat sink and the circuit board without a gap under a certain pressure, avoiding the presence of gaps in the contact surface due to the uneven surface of the heat sink, and the contact surface between the two will not generate gaps under the action of vibration, which can prevent the contact surface between the two from generating gaps and increasing thermal resistance, thereby improving the heat dissipation effect of the components.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and more particularly to a chip with a heat dissipation structure and a preparation process thereof. Background Art

[0002] With the rapid development of science and technology, the power of various electronic devices is increasing, especially power modules, which are becoming smaller and smaller. Due to the close arrangement of electronic components, heat generation is relatively concentrated in the equipment. If the heat cannot be effectively dissipated outward in a timely manner, the electronic equipment will cause various forms of failure due to long-term operation at high temperatures, which greatly limits the scope of use, service life and performance stability of electronic devices.

[0003] The most efficient way to transfer heat from a chip is through the solder pad, PCB, interface material, and heat sink. Traditional PCBs have a thermal conductivity of 0.2-5 W / m·K. Heat from the chip is transferred to the heat sink through the PCB and thermal interface material.

[0004] Under magnified observation, the heat sink's surface clearly shows significant unevenness. When the PCB and heat sink come into contact, there's a gap between them. Due to the poor heat transfer performance of air, this creates contact thermal resistance. When a large amount of heat passes through the contact surface, a large temperature difference is generated. Currently, thermal interface materials fill the contact surface, expelling air from it and thus reducing contact thermal resistance. However, thermal interface materials, such as thermal grease (thermal conductivity 1-8W / m·K), have limited thermal conductivity. Vibration between the power device and the housing can cause slight variations in the gap between the contact surfaces. This change in gap increases the thermal resistance.

[0005] For high-power device cooling applications such as IGBTs (insulated-gate bipolar transistors), heat flux density tends to increase with higher power and higher integration. The modules also generate significant amounts of concentrated heat due to their high-frequency conduction and switching. Overheating is a key weakness of IGBT power semiconductor modules, making thermal management a key issue. The thermal conductivity of PCB materials and their thermal interface materials are bottlenecks in thermal management of power devices.

[0006] Therefore, it is necessary to propose a chip with a heat dissipation structure and a preparation process to at least partially solve the problems existing in the prior art. Summary of the Invention

[0007] The Summary of the Invention introduces a series of simplified concepts that will be further described in the Detailed Description of the Invention. The Summary of the Invention is not intended to limit the key features and essential features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0008] To at least partially solve the above problems, the present invention provides a chip with a heat dissipation structure, comprising: a circuit board for connecting components, a heat sink connected to the side of the circuit board away from the components, and the heat sink and the circuit board are connected by pressing.

[0009] Preferably, the circuit board comprises: an insulating layer and a circuit layer connected to each other, and the components are connected to the circuit layer via a solder paste layer.

[0010] Preferably, the radiator is provided with a heat dissipation channel, and the heat dissipation medium passing through the heat dissipation channel is gas or liquid.

[0011] Preferably, the pressing method of the heat sink and the circuit board includes: a hot pressing method or a cold pressing method.

[0012] Preferably, when the heat sink and the circuit board are cold pressed together, an adhesive layer is provided between the circuit board and the heat sink.

[0013] A process for preparing a chip with a heat dissipation structure, comprising:

[0014] Laying the circuit board and the heat sink between the upper pressing part and the lower pressing part;

[0015] The upper and lower pressing parts are used to sequentially apply pressure to the circuit board and the heat sink in three stages. The actual pressure applied by the upper pressing part on the circuit board is detected in real time. The pressure application process is controlled by comparing the actual pressure with the set pressure corresponding to each stage.

[0016] Among them, the upper pressure part adopts pneumatic operation;

[0017] A pressure sensor for detecting actual pressure is provided on the upper pressure part.

[0018] Preferably, the upper pressing portion comprises: a plurality of pressing heads arranged in sequence from the middle to the edge, and the plurality of pressing heads can be controlled individually or simultaneously;

[0019] The three-stage pressure process includes:

[0020] In the first pressure application stage, the movements of multiple pressure heads are controlled simultaneously to detect whether the multiple pressure heads are in effective contact with the circuit board;

[0021] In the second pressure application stage, the movement of multiple pressure heads is independently controlled to remove air between the circuit board and the heat sink;

[0022] In the third pressure application stage, the movements of multiple pressure heads are controlled simultaneously to press the circuit board and the heat sink together;

[0023] The first set pressure corresponding to the first pressure application stage is smaller than the second set pressure corresponding to the second pressure application stage; and the second set pressure is smaller than the third set pressure corresponding to the third pressure application stage.

[0024] Preferably, the first pressure application stage includes:

[0025] Simultaneously controlling the movements of multiple pressure applying heads and detecting in real time the first actual pressure applied by each pressure applying head to the circuit board;

[0026] Compare the first actual pressure with the first set pressure. If the first actual pressures corresponding to multiple pressure heads all reach the first set pressure, it means that the multiple pressure heads effectively apply pressure to the circuit board, and then proceed to the second pressure stage; if the first actual pressure of at least one pressure head among the multiple pressure heads does not reach the first set pressure, it means that the multiple pressure heads do not effectively apply pressure to the circuit board.

[0027] Preferably, the second pressure application stage includes:

[0028] Divide the multiple pressure heads into multiple pressure groups from the middle to the edge, each pressure group including at least one pressure head;

[0029] Based on the pressure group to which each pressure head belongs, multiple pressure heads are controlled to move in sequence from the middle to the edge. The pressure heads in each pressure group move synchronously. Each pressure head in the moving pressure group is tested to obtain a second actual pressure applied by each pressure head to the circuit board.

[0030] The second actual pressure is compared with the second set pressure. If the second actual pressure corresponding to the pressure head in the pressure group that is in action does not reach the second set pressure, the pressure heads in this pressure group are continuously controlled to move until the second actual pressure reaches the second set pressure. If the second actual pressure corresponding to the pressure head in the pressure group that is in action reaches the second set pressure, the pressure head in this pressure group stops moving, and simultaneously controls the pressure head in the next pressure group to start moving.

[0031] When the second actual pressures of all the pressure applying heads reach the second set pressure, the plurality of pressure applying heads are controlled to apply pressure to the circuit board at the second set pressure and maintain the pressure for the first set time.

[0032] Preferably, the third pressure application stage includes:

[0033] Simultaneously control the movement of multiple pressure heads and detect in real time the third actual pressure applied by each pressure head to the circuit board;

[0034] The third actual pressure is compared with the third set pressure. If the third actual pressure of at least one of the multiple pressure heads does not reach the third set pressure, the corresponding pressure head is adjusted until the third actual pressures of all pressure heads reach the third set pressure. If the third actual pressures corresponding to multiple pressure heads all reach the third set pressure, the multiple pressure heads are controlled to apply pressure to the circuit board with the third set pressure and maintain the pressure for the second set time.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] In the chip with a heat dissipation structure and the preparation process described in the present invention, the thermal conductivity of the circuit board is greater than that of a traditional PCB circuit board, and the thermal conductivity effect is good. The circuit board and the heat sink are formed into an integrated structure by pressing. Pressing is to tightly connect the heat sink and the circuit board without a gap under a certain pressure, avoiding the presence of gaps in the contact surface due to the uneven surface of the heat sink. The contact surface between the two will not produce gaps under the action of vibration, which can prevent the formation of gaps in the contact surface between the two and increase the thermal resistance, thereby improving the heat dissipation effect of the components.

[0037] The chip with heat dissipation structure and preparation process described in the present invention, as well as other advantages, objectives and features of the present invention will be partially reflected in the following description, and will also be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 A schematic diagram of the connection structure between the heat dissipation structure and the chip in the prior art;

[0040] Figure 2 This is a schematic diagram of the structure of the chip with a heat dissipation structure according to the present invention using cold pressing and air cooling;

[0041] Figure 3 This is a schematic diagram of the structure of the chip with a heat dissipation structure according to the present invention using cold pressing and liquid cooling;

[0042] Figure 4 This is a schematic diagram of the structure of the chip with a heat dissipation structure according to the present invention using hot pressing and air cooling;

[0043] Figure 5This is a schematic diagram of the structure of the chip with a heat dissipation structure according to the present invention using hot pressing and liquid cooling;

[0044] Figure 6 This is a structural diagram of the heat sink and the circuit board being pressed together in the manufacturing process of the chip with the heat dissipation structure according to the present invention;

[0045] Figure 7 This is a schematic diagram of the actions of multiple pressure heads during the first pressure application stage in the manufacturing process of the chip with a heat dissipation structure according to the present invention;

[0046] Figure 8 This is a schematic diagram of the actions of multiple pressure heads during the second pressure application stage in the manufacturing process of the chip with a heat dissipation structure according to the present invention;

[0047] Figure 9 This is a schematic diagram of the actions of multiple pressure heads during the third pressure application stage in the manufacturing process of the chip with a heat dissipation structure according to the present invention. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description.

[0049] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0050] like Figure 1 As shown, in the prior art, the PCB circuit board includes a circuit layer 22, a PCB thermal insulation layer 11 and a PCB metal base 12. The component 1 is connected to the PCB circuit board through a solder paste layer 4, and the PCB circuit board is connected to the heat sink 3 through an interface material 13. The interface material 13 is generally thermal grease. The disadvantage of this connection method is that gaps are easily generated on the contact surface between the radiator 3 and the PCB circuit board, thereby increasing the thermal resistance and affecting the heat dissipation effect of the component 1.

[0051] like Figure 2-Figure 5 As shown, the present invention provides a chip with a heat dissipation structure, including: a circuit board 2 for connecting components 1, a heat sink 3 is connected to the side of the circuit board 2 away from the components 1, and the heat sink 3 and the circuit board 2 are connected by pressing.

[0052] The circuit board 2 includes single-layer, double-layer or multi-layer circuits, and the material of the circuit board 2 includes one or more of the flame-resistant material FR4 (grade code for flame-resistant materials), IMS (insulated metal substrate), ceramic board and glass substrate; the thermal conductivity coefficient of the circuit board 2 is 0.2-200W / m·K.

[0053] In the present invention, the circuit board 2 and the heat sink 3 are connected by pressing, and then the component 1 is electrically connected to the circuit board 2; the heat generated by the component 1 during operation is transferred to the heat sink 3 through the circuit board 2 and dissipated through the heat sink 3.

[0054] In the above technical solution, the thermal conductivity of the circuit board 2 is greater than that of the traditional PCB circuit board, and the circuit board 2 and the heat sink 3 are made into an integrated structure by pressing. Pressing is to make the heat sink 3 and the circuit board 2 tightly connected without a gap under a certain pressure, avoiding the presence of gaps in the contact surface due to the uneven surface of the heat sink 3, and the contact surface between the two will not produce gaps under the action of vibration, which can prevent the contact surface between the two from producing gaps and increasing the thermal resistance, thereby improving the heat dissipation effect of the component 1.

[0055] like Figure 4 As shown, in one embodiment, the circuit board 2 includes: an insulating layer 21 and a circuit layer 22 connected to each other, and the component 1 is connected to the circuit layer 22 through a solder paste layer 4.

[0056] In this embodiment, the insulating layer 21 is preferably IMS (insulated metal substrate), which has a higher thermal conductivity; the circuit layer 22 is a PCB copper foil layer, which is a single-layer, double-layer or multi-layer circuit; the component 1 is soldered to the circuit board 2 through the solder paste layer 4.

[0057] like Figure 2 As shown, further, a metal layer 23 is selectively provided on a side of the insulating layer 21 away from the circuit layer 22 .

[0058] The metal layer 23 is made of copper or aluminum to improve heat dissipation.

[0059] In one embodiment, a heat dissipation channel 31 is provided on the radiator 3 , and the heat dissipation medium passing through the heat dissipation channel 31 is gas or liquid.

[0060] The radiator 3 can be cooled by air or liquid; Figure 2 and Figure 4 The air cooling method is shown as the selected one, and the side of the heat dissipation channel 31 away from the circuit board 2 is opened; Figure 3 and Figure 5 The liquid cooling method is selected. The heat dissipation channel 31 is closed on the side away from the circuit board 2. The heat dissipation channel 31 is formed inside the radiator 3 to facilitate liquid flow to achieve heat dissipation.

[0061] In one embodiment, the pressing method of the heat sink 3 and the circuit board 2 includes: a hot pressing method or a cold pressing method.

[0062] like Figure 2 and Figure 3 As shown, the circuit board 2 and the heat sink 3 are connected as one by cold pressing. At this time, the circuit board 2 includes a circuit layer 22, an insulating layer 21 and a metal layer 23 that are interconnected. The metal layer 23 is made of copper or aluminum. During pressing, it is tightly connected to the heat sink 3 through the metal layer 23.

[0063] Furthermore, when the heat sink 3 and the circuit board 2 are cold pressed together, an adhesive layer 5 is provided between the circuit board 2 and the heat sink 3 .

[0064] Among them, the adhesive layer 5 is made of pure adhesive.

[0065] When cold pressing is used, a glue layer 5 is first set between the heat sink 3 and the circuit board 2, that is, pure glue is applied to the surface of the heat sink 3 or the surface of the metal layer 23, and then the heat sink 3 and the circuit board 2 are stacked and pressed together. The heat sink 3 and the metal layer 23 of the circuit board 2 are in close contact under pressure, and the two are bonded together under the action of pure glue. During cold pressing, since the hardness of the materials selected for the metal layer 23 and the heat sink 3 are similar or the same, the uneven parts of the surfaces of the two can be flattened after being pressed, and then the pure glue is used to press the metal layer 23 and the heat sink 3 together. The metal layer 23 and the heat sink 3 are tightly connected together. After cold pressing, the gap between the metal layer 23 and the heat sink 3 is very small (which can be observed at the microscopic level), and the adhesive layer 5 is very thin (filling a very small gap to increase the bonding strength between the metal layer 23 and the heat sink 3), so that the metal layer 23 and the heat sink 3 are almost in direct contact. Therefore, the adhesive layer 5 has little effect on the thermal conductivity. Therefore, the cold pressing method can reduce the gap on the contact surface between the circuit board 2 and the heat sink 3, connect the two as a whole, and improve the heat dissipation effect of the component 1.

[0066] like Figure 4 and Figure 5 The circuit board 2 and the heat sink 3 are connected as one body by heat pressing. In this case, the circuit board 2 includes a circuit layer 22 and an insulating layer 21 connected to each other. The insulating layer 21 is made of a material with good bonding ability and high thermal conductivity when heat-pressed with the heat sink 3.

[0067] By means of thermal compression, the insulating layer 21 of the circuit board 2 can be combined with the heat sink 3, thereby reducing or preventing the gap between the circuit board 2 and the heat sink 3, reducing the contact thermal resistance, and the two have a strong bonding ability, and no gap will be generated due to external vibration, thereby improving the heat dissipation effect of the component 1.

[0068] like Figure 6 As shown, the present invention also provides a process for preparing a chip with a heat dissipation structure, comprising:

[0069] The circuit board 2 and the heat sink 3 are stacked and placed between the upper pressing part 6 and the lower pressing part 7;

[0070] The upper pressing part 6 and the lower pressing part 7 sequentially apply pressure to the circuit board 2 and the heat sink 3 in three stages, and the actual pressure applied by the upper pressing part 6 on the circuit board 2 is detected in real time. The pressure application process is controlled by comparing the actual pressure with the set pressure corresponding to each stage;

[0071] Among them, the upper pressing part 6 is operated pneumatically;

[0072] The upper pressing portion 6 is provided with a pressure sensor for detecting actual pressure.

[0073] An upper rubber pad 8 is provided between the circuit board 2 and the upper pressing part 6, and a lower rubber pad 9 is provided between the lower pressing part 7 and the heat sink 3. The upper pressing part 6 applies pressure to the circuit board 2 by pneumatic drive (for example, a cylinder and piston drive mode);

[0074] When applying pressure, the upper pressing part 6 is controlled to move, and the applied pressure is detected in real time by the pressure sensor. The applied pressure is controlled by comparing the actual pressure with the set pressure to achieve cold or hot pressing of the circuit board 2 and the heat sink 3.

[0075] The entire pressing process can be carried out in a vacuum environment, which is conducive to removing the air between the heat sink and the circuit board 2 and preventing the formation of gaps; when thermal pressing is adopted, the circuit board 2 and / or the heat sink 3 need to be heated.

[0076] like Figure 7-Figure 9 As shown, further, the upper pressing portion 6 includes: a plurality of pressing heads 61 arranged in sequence from the middle to the edge, and the plurality of pressing heads 61 can be controlled individually or simultaneously;

[0077] Each pressure head 61 corresponds to a pneumatic control mechanism, and the upper pressure part 6 also includes a lifting part for driving all the pneumatic control mechanisms and the pressure heads 61 to operate simultaneously; the lifting part drives all the pressure heads 61 to descend until they contact the upper rubber pad 8, and then the pneumatic control mechanism drives the pressure heads 61 to operate again to adjust the pressure applied by the pressure heads 61;

[0078] The pneumatic control mechanism includes a cylinder and a piston arranged in the cylinder. The piston is connected to the pressure head 61. A proportional valve is provided on the pipeline connected to the cylinder. The precise control of the air pressure in the cylinder is achieved by controlling the opening of the proportional valve; the air pressure in the cylinder is controlled by inflating or exhausting air into the cylinder, thereby achieving control of the pressure applied by each pressure head 61.

[0079] The three-stage pressure process includes:

[0080] In the first pressure application stage, the multiple pressure applying heads 61 are controlled to move simultaneously to detect whether the multiple pressure applying heads 61 are in effective contact with the circuit board 2;

[0081] In the second pressure application stage, the multiple pressure applying heads 61 are individually controlled to remove the air between the circuit board 2 and the heat sink 3;

[0082] In the third pressure application stage, the plurality of pressure applying heads 61 are controlled to move simultaneously to press the circuit board 2 and the heat sink 3 together;

[0083] The first set pressure corresponding to the first pressure application stage is smaller than the second set pressure corresponding to the second pressure application stage; and the second set pressure is smaller than the third set pressure corresponding to the third pressure application stage.

[0084] During the first pressure application stage, the contact between the multiple pressure heads 61 and the circuit board 2 can be detected (actually, the pressure heads 61 are in direct contact with the adhesive pad 8), thereby preventing the position of the circuit board 2 from deviating and causing a portion of the circuit board 2 to not be pressurized, thereby ensuring the accuracy of the pressure application position. By detecting and controlling the pressure application of each pressure head 61, the uniformity of the pressure applied by the multiple pressure heads 61 to the circuit board 2 can be ensured, thereby ensuring the stability of the connection between the circuit board 2 and the heat sink 3 and preventing the presence of gaps between the two.

[0085] During the second pressure application stage, the multiple pressure applying heads 61 are individually controlled to apply pressure from the middle of the circuit board 2 to the edge in sequence, which can effectively expel air and prevent some air from remaining between the circuit board 2 and the heat sink 3 to form thermal resistance, thereby further improving the heat dissipation effect.

[0086] Through the third pressure application stage, the circuit board 2 and the heat sink 3 are pressed together to make them tightly combined;

[0087] The above three stages are used to press the circuit board 2 and the heat sink 3 together, which can ensure that the force applied to the contact surfaces of the two is uniform during pressing, and can effectively discharge air to prevent the generation of gaps.

[0088] like Figure 7 As shown, in one embodiment, the first pressure application stage includes:

[0089] Simultaneously controlling the actions of the plurality of pressure applying heads 61 and detecting in real time the first actual pressure applied by each pressure applying head 61 to the circuit board 2;

[0090] Compare the first actual pressure with the first set pressure. If the first actual pressures corresponding to the multiple pressure heads 61 all reach the first set pressure, it means that the multiple pressure heads 61 effectively apply pressure to the circuit board 2, and then the second pressure stage is carried out; if the first actual pressure of at least one pressure head 61 among the multiple pressure heads 61 does not reach the first set pressure, it means that the multiple pressure heads 61 do not effectively apply pressure to the circuit board 2.

[0091] The first set pressure is: when the pressure head 61 applies pressure to the circuit board 2, there is still a gap between the circuit board 2 and the radiator 3, and the minimum pressure value that the pressure sensor can detect; the first set pressure of the pressure sensor corresponding to each pressure head 61 is the same.

[0092] During the first pressure application stage, the cylinder corresponding to each pressure applying head 61 is first filled with gas of the same set pressure (corresponding to the first set pressure), and then all the pressure applying heads 61 are driven down by the lifting part until they come into contact with the upper rubber pad 8 (the descending distance can be set), and then the first actual pressure detected by the pressure sensor is obtained;

[0093] The first actual pressure reaching the first set pressure can be understood as: the difference between the first actual pressure and the first set pressure is within the first error threshold; when the first actual pressure detected by all pressure sensors reaches the first set pressure, it indicates that multiple pressure heads 61 have effectively applied pressure to the circuit board 2, and the second pressure stage can be carried out; if the first actual pressure detected by at least one pressure sensor does not reach the first set pressure, the air pressure in the corresponding cylinder should be adjusted within the set adjustment range to make the first actual pressure reach the first set pressure. If, after adjustment, the first actual pressure still does not reach the first set pressure, it indicates that the pressure position may deviate or other abnormal conditions may occur, and the pressure should be stopped.

[0094] Through the first pressure stage, the pressure head 61 performs a preliminary detection on whether the circuit board 2 is effectively pressed, so as to facilitate the effective implementation of the subsequent pressure stage and prevent the subsequent pressure stage from being affected so that the pressing effect cannot reach the expected level.

[0095] like Figure 8 As shown, in one embodiment, the second pressure application stage includes:

[0096] The plurality of pressure heads 61 are divided into a plurality of pressure groups from the middle to the edge, each pressure group including at least one pressure head 61;

[0097] Based on the pressure group to which each pressure head 61 belongs, the multiple pressure heads 61 are sequentially controlled from the center to the edge to operate. The pressure heads 61 in each pressure group operate synchronously. Each pressure head 61 in the operating pressure group is tested to obtain a second actual pressure applied by each pressure head 61 to the circuit board 2.

[0098] The second actual pressure is compared with the second set pressure. If the second actual pressure corresponding to the pressure head 61 in the pressure group in operation does not reach the second set pressure, the pressure head 61 in this pressure group is controlled to continue to operate until the second actual pressure reaches the second set pressure. If the second actual pressure corresponding to the pressure head 61 in the pressure group in operation reaches the second set pressure, the pressure head 61 in this pressure group stops operating, and simultaneously controls the pressure head 61 in the next pressure group to start operating.

[0099] The second actual pressure reaching the second set pressure can be understood as: the difference between the second actual pressure and the second set pressure is within the second error threshold;

[0100] When the second actual pressure of all the pressure applying heads 61 reaches the second set pressure, the plurality of pressure applying heads 61 are controlled to apply pressure to the circuit board 2 at the second set pressure and maintain the pressure for the first set time.

[0101] When all the pressure applying heads 61 effectively apply pressure to the circuit board 2 , the second pressure applying stage is continued;

[0102] like Figure 8 As shown in the figure, there are five pressure heads 61 in total, the pressure head 61 located in the middle is the first pressure group, the two pressure heads 61 adjacent to the pressure head 61 in the middle are the second pressure group, and the two pressure heads 61 adjacent to the two pressure heads 61 of the second pressure group are the third pressure group.

[0103] When controlling the actions of multiple pressure heads 61, first control the action of one pressure head 61 of the first pressure group, that is, control the air pressure in the corresponding cylinder to increase. When its second actual pressure reaches the second set pressure, stop the action of the pressure head 61 of the first pressure group, and simultaneously control the action of two pressure heads 61 of the second pressure group, that is, control the air pressure in the corresponding cylinder to increase. Similarly, when the second actual pressures corresponding to these two pressure heads 61 reach the second set pressure, stop the second pressure group from continuing to act, and simultaneously control the action of two pressure heads 61 of the third pressure group, that is, control the air pressure in the corresponding cylinder to increase. When the second actual pressures corresponding to these two pressure heads 61 reach the second set pressure, stop the third pressure group from continuing to act. At this point, the second actual pressures of all pressure heads 61 reach the second set pressure, and after maintaining for the first set time, the third pressure stage can be continued.

[0104] By controlling the movement of multiple pressure groups in sequence from the middle to the edge, the air can be discharged from the middle to the edge, effectively emptying the air. If the movement of multiple pressure heads 61 is controlled at the same time, the same force is applied to each contact position between the circuit board 2 and the heat sink 3. The air in the middle may not have time to be discharged, and bubbles or gaps will be formed between the two, thereby increasing the thermal resistance. Therefore, the above method can ensure the tightness of the contact between the circuit board 2 and the heat sink 3, reduce the contact thermal resistance, and further improve the heat dissipation effect.

[0105] like Figure 9 As shown, in one embodiment, the third pressure application stage includes:

[0106] Simultaneously controlling the actions of the multiple pressure applying heads 61 and detecting in real time the third actual pressure applied by each pressure applying head 61 to the circuit board 2;

[0107] The third actual pressure is compared with the third set pressure. If the third actual pressure of at least one pressure head 61 among the multiple pressure heads 61 does not reach the third set pressure, the corresponding pressure head 61 is adjusted until the third actual pressures of all pressure heads 61 reach the third set pressure. If the third actual pressures corresponding to the multiple pressure heads 61 all reach the third set pressure, the multiple pressure heads 61 are controlled to apply pressure to the circuit board 2 with the third set pressure and maintain the pressure for the second set time.

[0108] The third actual pressure reaching the third set pressure can be understood as: the difference between the third actual pressure and the third set pressure is within a third error threshold;

[0109] After the second pressure application stage is completed, the third pressure application stage is continued, which mainly controls the movement of multiple pressure application heads 61 at the same time to further increase the applied pressure to ensure the bonding ability of the circuit board 2 and the heat sink 3;

[0110] When applying pressure, the cylinder corresponding to each pressure head 61 is controlled at the same time to ensure that the pressure applied by each pressure head 61 to the circuit board 2 is balanced during the pressure application process, that is, the deviation between the third actual pressures corresponding to each pressure head 61 is within the set deviation range to ensure that the bonding effect of each contact point between the circuit board 2 and the radiator 3 is the same.

[0111] The cylinder corresponding to each pressure head 61 is controlled simultaneously, including:

[0112] According to the pressure difference between the third set pressure and the second set pressure, and the set time required for pressure increase, the proportional valve is controlled to steadily increase the gas pressure in the cylinder;

[0113] As the air pressure in the cylinder increases, the opening information of the proportional valve is obtained in real time, and the control instructions for the proportional valve are obtained based on the opening information;

[0114] The opening information includes: the opening of the proportional valve is less than or equal to the set opening, and the opening of the proportional valve is greater than the set opening; when the opening information indicates that the opening of the proportional valve is less than or equal to the set opening, a control instruction for the proportional valve is obtained according to a first unit step length; when the opening information indicates that the opening of the proportional valve is greater than the set opening, a control instruction for the proportional valve is obtained according to a second unit step length; wherein the first unit step length is greater than the second unit step length;

[0115] The proportional valve is controlled according to the control command to increase the air pressure in the cylinder steadily.

[0116] If you want to ensure that the pressure applied by each pressure head 61 to the circuit board 2 is balanced during the pressure application process, you need to control the pressure increase process of the air pressure in the cylinder. The control of the pressure increase process is mainly achieved by controlling the proportional valve. When inflating the cylinder, you need to adjust the opening of the proportional valve. When its opening is less than or equal to the set opening, it indicates that its opening is small. Then, you can obtain the control instruction through a larger unit step, that is, synchronously control multiple proportional valves through the first unit step, so as to increase the air pressure adjustment speed. When the opening is small, the proportional valve can be fine-tuned more quickly through the first unit step to ensure the adjustment The overall efficiency is improved, and multiple proportional valves can execute control instructions synchronously; when the opening is greater than the set opening, it indicates that the opening of the proportional valve is large, and the control instruction is obtained through a smaller unit step, that is, multiple proportional valves are synchronously controlled through the second unit step, thereby avoiding the adjustment range of the proportional valve opening being too large, which causes the air pressure in the cylinder to increase suddenly, and causes the pressure applied by multiple cylinders to have an instantaneous deviation under a larger adjustment range, resulting in uneven pressure in various places, and also prevents the pressure applied by the pressure head 61 on the circuit board 2 from suddenly increasing, thereby ensuring the stability of the pressure process and preventing damage to the circuit board 2.

[0117] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying 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 should not be understood as limiting the present invention.

[0118] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0119] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with this field, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the present invention, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A process for preparing a chip with a heat dissipation structure, characterized in that: include: The circuit board (2) and the heat sink (3) are stacked and placed between the upper pressing portion (6) and the lower pressing portion (7); The upper pressing part (6) and the lower pressing part (7) are used to sequentially apply pressure to the circuit board (2) and the heat sink (3) in three stages, and the actual pressure applied by the upper pressing part (6) to the circuit board (2) is detected in real time. The pressure application process is controlled by comparing the actual pressure with the set pressure corresponding to each stage; The upper pressing part (6) is operated pneumatically; The upper pressure portion (6) is provided with a pressure sensor for detecting actual pressure; The upper pressure portion (6) comprises: a plurality of pressure heads (61) arranged in sequence from the middle to the edge, and the plurality of pressure heads (61) can be controlled individually or simultaneously; The three-stage pressure process includes: In the first pressure application stage, the multiple pressure application heads (61) are simultaneously controlled to move, so as to detect whether the multiple pressure application heads (61) are in effective contact with the circuit board (2); In the second pressure application stage, the plurality of pressure application heads (61) are individually controlled to operate to remove air between the circuit board (2) and the heat sink (3); In the third pressure application stage, the plurality of pressure application heads (61) are controlled to move simultaneously to press the circuit board (2) and the heat sink (3) together; The first set pressure corresponding to the first pressure application stage is smaller than the second set pressure corresponding to the second pressure application stage; and the second set pressure is smaller than the third set pressure corresponding to the third pressure application stage.

2. The process for preparing a chip with a heat dissipation structure according to claim 1, characterized in that: The first pressure application stage includes: Simultaneously controlling the actions of multiple pressure applying heads (61) and detecting in real time the first actual pressure applied by each pressure applying head (61) to the circuit board (2); The first actual pressure is compared with the first set pressure. If the first actual pressures corresponding to the multiple pressure applying heads (61) all reach the first set pressure, the second pressure application stage is performed. If the first actual pressure of at least one pressure applying head (61) among the multiple pressure applying heads (61) does not reach the first set pressure, it indicates that the multiple pressure applying heads (61) do not effectively apply pressure to the circuit board (2).

3. The process for preparing a chip with a heat dissipation structure according to claim 1, wherein: The second pressure stage includes: The plurality of pressure heads (61) are divided into a plurality of pressure groups from the middle to the edge, each pressure group including at least one pressure head (61); According to the pressure group to which each pressure head (61) belongs, the plurality of pressure heads (61) are sequentially controlled from the middle to the edge to operate, the pressure heads (61) in each pressure group operate synchronously, and each pressure head (61) in the operating pressure group is detected to obtain a second actual pressure applied by each pressure head (61) to the circuit board (2); The second actual pressure is compared with the second set pressure. If the second actual pressure corresponding to the pressure head (61) in the pressure group in operation does not reach the second set pressure, the pressure head (61) in the pressure group is continuously controlled to operate until the second actual pressure reaches the second set pressure. If the second actual pressure corresponding to the pressure head (61) in the pressure group in operation reaches the second set pressure, the pressure head (61) in the pressure group stops operating and simultaneously controls the pressure head (61) in the next pressure group to start operating. When the second actual pressure of all the pressure applying heads (61) reaches the second set pressure, the plurality of pressure applying heads (61) are controlled to apply pressure to the circuit board (2) at the second set pressure and maintain the pressure for the first set time.

4. The process for preparing a chip with a heat dissipation structure according to claim 1, wherein: The third pressure stage includes: Simultaneously controlling the actions of multiple pressure applying heads (61) and detecting in real time the third actual pressure applied by each pressure applying head (61) to the circuit board (2); The third actual pressure is compared with the third set pressure. If the third actual pressure of at least one pressure applying head (61) among the multiple pressure applying heads (61) does not reach the third set pressure, the corresponding pressure applying head (61) is adjusted until the third actual pressures of all pressure applying heads (61) reach the third set pressure. If the third actual pressures corresponding to the multiple pressure applying heads (61) all reach the third set pressure, the multiple pressure applying heads (61) are controlled to apply pressure to the circuit board (2) at the third set pressure and maintain the pressure for a second set time.

5. A chip with a heat dissipation structure, characterized in that: The chip with a heat dissipation structure is manufactured according to the preparation process of any one of claims 1 to 4, comprising: a circuit board (2) for connecting components (1), a heat sink (3) being connected to a side of the circuit board (2) away from the components (1), and the heat sink (3) and the circuit board (2) being connected by pressing.

6. The chip with a heat dissipation structure according to claim 5, characterized in that: The circuit board (2) comprises an insulating layer (21) and a circuit layer (22) connected to each other, and the component (1) is connected to the circuit layer (22) via a solder paste layer (4).

7. The chip with a heat dissipation structure according to claim 5, characterized in that: The radiator (3) is provided with a heat dissipation channel (31), and the heat dissipation medium passing through the heat dissipation channel (31) is gas or liquid.

8. The chip with a heat dissipation structure according to claim 5, characterized in that: The pressing method of the heat sink (3) and the circuit board (2) includes: a hot pressing method or a cold pressing method.

9. The chip with a heat dissipation structure according to claim 8, characterized in that: When the heat sink (3) and the circuit board (2) are cold pressed together, a glue layer (5) is provided between the circuit board (2) and the heat sink (3).

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