Manufacturing method of circuit board with micro-channel structure and circuit board

Abstract

The invention discloses a manufacturing method of a circuit board with a micro-channel structure and the circuit board, the circuit board is provided with a first substrate and a second substrate, the manufacturing method comprises the following steps: a plurality of heat dissipation channels are milled on the first substrate, and the heat dissipation channels are used for circulation of a cooling medium; communicating holes are milled, the communicating holes are milled in the second substrate, and the positions of the communicating holes correspond to the positions of the two ends of the heat dissipation channel one to one; and laminating the core board, wherein the first substrate and the second substrate are laminated to form the circuit board in a laminating manner. A heat dissipation channel is milled on one of the substrates, and then a communication hole communicated with the heat dissipation channel is milled on the circuit board and can be used for introducing a cooling medium for cooling into the circuit board, so that a micro-channel structure for circulating cooling liquid is formed in the circuit board, and the effect of cooling the circuit board is further achieved; and finally, the operation reliability of the circuit board can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit board manufacturing technology, and in particular to a manufacturing method of a circuit board with a microchannel structure and a circuit board. Background Art

[0002] With the development of microelectronics technology and electronic packaging technology, the integration of integrated circuits and devices has been continuously improved, and the operating speed and output power of various electronic components have been continuously improved, resulting in a large amount of heat generated inside, which in turn affects the reliability of electronic components. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method for manufacturing a circuit board with a microchannel structure, which can manufacture a circuit board with a microchannel structure, and achieve the purpose of reducing the temperature of the circuit board by passing a circulating coolant into the microchannel.

[0004] The present invention also provides a circuit board with a microchannel structure manufactured by the above manufacturing method.

[0005] According to a method for manufacturing a circuit board having a microfluidic structure according to a first aspect of an embodiment of the present invention, the circuit board has a first substrate and a second substrate, and the manufacturing method comprises the following steps:

[0006] Milling out heat dissipation channels, and milling out a plurality of heat dissipation channels on the first substrate, wherein the heat dissipation channels are used for the circulation of cooling medium;

[0007] Milling a connecting hole, milling the connecting hole on the second substrate, the position of the connecting hole is set in one-to-one correspondence with the positions of the two ends of the heat dissipation channel, the connecting hole is connected to the heat dissipation channel, and the connecting hole is used for the cooling medium to flow into or out of the heat dissipation channel; and

[0008] A pressed core board is formed by pressing the first substrate and the second substrate together to form the circuit board.

[0009] The method for manufacturing a circuit board with a microfluidic structure according to an embodiment of the present invention has at least the following beneficial effects: a heat dissipation channel is milled out on one of the substrates, and then the connecting hole connected to the heat dissipation channel is milled out on the circuit board, which can be used to introduce a cooling medium for cooling into the interior of the circuit board, so that the circuit board has a microfluidic structure for circulating coolant, thereby achieving the effect of cooling the circuit board, and ultimately ensuring the reliability of the operation of the circuit board.

[0010] According to some embodiments of the present invention, the step of pressing the core board together further includes the following steps: copper plating on the groove wall of the heat dissipation channel and / or on the hole wall of the connecting hole.

[0011] According to some embodiments of the present invention, the step of milling out the connecting holes further includes the following steps:

[0012] Milling out process holes, milling out the process holes on the first substrate and the second substrate according to product requirements; and

[0013] The process hole is blocked by using a blocking object.

[0014] According to some embodiments of the present invention, the first substrate includes several pieces, the second substrate includes several pieces, and the manufacturing method includes the following steps:

[0015] Laminating the substrates, laminating the first substrate and the second substrate into a first core board and a second core board respectively;

[0016] Milling out heat dissipation channels, wherein the first core board includes a third substrate, and before the step of pressing the substrates, a plurality of heat dissipation channels are milled out on the third substrate, wherein the heat dissipation channels are used for the circulation of cooling medium;

[0017] Milling a connecting hole, milling the connecting hole on the second core plate, the position of the connecting hole is set in one-to-one correspondence with the positions of the two ends of the heat dissipation channel, the connecting hole is connected to the heat dissipation channel, and the connecting hole is used for the cooling medium to flow into or out of the heat dissipation channel; and

[0018] The core board is pressed together, and after the third substrate on the first core board is stacked with the second core board according to the stacking requirements, the first core board and the second core board are pressed together by pressing to form the circuit board.

[0019] According to some embodiments of the present invention, the thickness of the first core plate and the second core plate is ≤1.5 mm.

[0020] According to some embodiments of the present invention, the distance between adjacent heat dissipation channels is ≥1 mm.

[0021] According to some embodiments of the present invention, the step of milling out the connecting hole further comprises:

[0022] Milling out process holes, milling out the process holes on the first core plate or the second core plate according to product requirements; and

[0023] The process hole is blocked by using a blocking object.

[0024] According to some embodiments of the present invention, the sealing material is copper paste or resin.

[0025] According to some embodiments of the present invention, the adhesive in the step of laminating the core panels is a no-flow prepreg.

[0026] According to the second aspect of the present invention, the circuit board with a microfluidic structure is manufactured by the method for manufacturing a circuit board with a microfluidic structure described in any one of the embodiments of the first aspect.

[0027] The circuit board with a microchannel structure according to the embodiment of the present invention has at least the following beneficial effects: the circuit board with a microchannel structure can pass a cooling medium for cooling into the microchannel inside the circuit board, so that the circuit board has a good operating environment during operation, thereby ensuring the reliability of the circuit board operation.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 A half-section schematic diagram of a first substrate in the step of milling out a heat dissipation channel according to an embodiment of the present invention;

[0031] Figure 2 A half-section schematic diagram of a second substrate in the step of milling a connecting hole according to an embodiment of the present invention;

[0032] Figure 3 A half-section schematic diagram of a circuit board showing the steps of pressing a core board according to an embodiment of the present invention;

[0033] Figure 4 for Figure 3 The circuit board is shown in a cross-sectional view taken along the AA direction.

[0034] Reference numerals:

[0035] A first substrate 1; a second substrate 2; a heat dissipation channel 3; a communication hole 4; and a prepreg 5. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0037] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are 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, and do not indicate or imply 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 a limitation on the present invention.

[0038] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0039] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0040] Reference Figures 1 to 4 According to a method for manufacturing a circuit board with a microfluidic structure in accordance with an embodiment of the first aspect of the present invention, the circuit board has a first substrate 1 and a second substrate 2, and the manufacturing method comprises the following steps: milling out heat dissipation channels, milling out a plurality of heat dissipation channels 3 on the first substrate 1, and the heat dissipation channels 3 are used for the circulation of cooling medium; milling out connecting holes 4, milling out connecting holes 4 on the second substrate 2, the positions of the connecting holes 4 are arranged in a one-to-one correspondence with the positions of the two ends of the heat dissipation channels 3, the connecting holes 4 are connected to the heat dissipation channels 3, and the connecting holes 4 are used for the cooling medium to flow into or out of the heat dissipation channels 3; and pressing the core board, pressing the first substrate 1 and the second substrate 2 together to form a circuit board.

[0041] Specifically, refer to Figure 1 First, select an appropriate material for the first substrate 1, such as a metal substrate or a ceramic substrate with high thermal conductivity. Then, at a predetermined position of the first substrate 1, use a controlled depth milling process to mill out a number of heat dissipation channels 3. These heat dissipation channels 3 are used for the circulation of cooling medium. The width, depth and length of the heat dissipation channels 3 need to be precisely controlled during the milling process to ensure that the cooling medium can flow smoothly and effectively remove heat from the electronic components. Figure 2Next, select the material of the second substrate 2, which can be the same as or different from the material of the first substrate 1, according to the specific application requirements. Then, accurately mill the connecting holes 4 on the second substrate 2. The positions of these connecting holes 4 need to be set one by one corresponding to the positions of the two ends of the heat dissipation channel 3 on the first substrate 1. The function of the connecting holes 4 is to allow the cooling medium to flow in from one side of the circuit board, pass through the heat dissipation channel 3, and then flow out from the other side, forming an effective cooling cycle. Figure 3 as well as Figure 4 After the milling of the heat dissipation channel 3 and the connecting hole 4 is completed, the first substrate 1 and the second substrate 2 are precisely aligned to ensure that the connecting hole 4 completely corresponds to the two ends of the heat dissipation channel 3. Then, the first substrate 1 and the second substrate 2 are pressed together by pressing to form a circuit board with a microchannel structure. Appropriate pressure and temperature need to be controlled during the pressing process to ensure a firm bond between the substrates and avoid damage to the heat dissipation channel 3 and the connecting hole 4.

[0042] After the circuit board is formed by pressing, electronic components can be installed on the circuit board as needed, and a cooling medium, such as water, air or other appropriate coolant, can be injected into the heat dissipation channel 3 through the connecting hole 4. When the cooling medium flows in the heat dissipation channel 3, it can effectively take away the heat generated by the electronic components and discharge the circuit board through the connecting hole 4, thereby achieving an efficient heat dissipation effect. In addition, in order to improve the heat dissipation efficiency, a heat conductive layer can be set on the inner wall of the heat dissipation channel 3 or structures such as heat dissipation fins can be added to increase the heat dissipation area and thermal conductivity. At the same time, different heat dissipation channel 3 layouts and connecting hole 4 shapes can be designed on the circuit board according to specific application requirements to meet the heat dissipation requirements of different electronic components. In summary, the method for manufacturing a circuit board with a microfluidic structure of the embodiment of the present invention forms an efficient and reliable heat dissipation structure by precisely milling the heat dissipation channel 3 and the connecting hole 4, and pressing the substrate together using a pressing process. This method can effectively solve the heat dissipation problem of high-performance electronic components and improve the stability and reliability of the electronic system.

[0043] Therefore, it can be understood that the method for manufacturing a circuit board with a microchannel structure according to an embodiment of the present invention has at least the following beneficial effects: a heat dissipation channel 3 is milled out on one of the substrates, and then a connecting hole 4 connected to the heat dissipation channel 3 is milled out on the circuit board, which can be used to introduce a cooling medium for cooling into the interior of the circuit board, so that the circuit board has a microchannel structure for circulating the coolant, thereby achieving the effect of cooling the circuit board, and ultimately ensuring the reliability of the operation of the circuit board.

[0044] In some embodiments of the present invention, the step of pressing the core board further includes the following steps: copper plating, copper plating on the groove wall of the heat dissipation channel 3 and / or on the hole wall of the connecting hole 4. After the heat dissipation channel 3 and the connecting hole 4 are milled out, the copper plating step can be performed according to the specific actual product requirements. In addition to meeting the copper plating requirements of the product, copper plating can also enhance the thermal conductivity of the heat dissipation channel 3 and the connecting hole 4, while improving the bonding force between the substrates during the subsequent pressing process. Copper plating can be performed on the groove wall of the heat dissipation channel 3 and / or on the hole wall of the connecting hole 4, and the specific copper plating area can be determined according to actual needs.

[0045] In some embodiments of the present invention, before the step of milling out the connecting hole 4, the following steps are also included: milling out process holes, milling process holes on the first substrate 1 and the second substrate 2 according to product requirements; and sealing the process holes, using sealing objects to seal the process holes.

[0046] Before milling the connecting hole 4, it is first necessary to mill process holes on the first substrate 1 and the second substrate 2 according to product requirements. The process hole can be a product requirement, or it can be for the convenience of positioning, fixing or detection during subsequent processing, assembly or testing. The position, size and number of the process holes can be determined according to the specific product design and process requirements. When milling the process holes, use precision milling tools and perform milling according to predetermined process parameters to ensure the accuracy and position of the process holes. At the same time, care should be taken to avoid damage to other parts of the first substrate 1 and the second substrate 2. In addition, after milling the process holes, in order to protect the process holes from contamination or damage during subsequent processing and to ensure the overall performance and appearance of the circuit board, it is necessary to use a plugging material to plug the process holes. The plugging material can be selected from appropriate materials, such as plastic, rubber, metal, etc., and customized according to the size and shape of the process hole. The plugging material needs to have good sealing performance and corrosion resistance to ensure that it will not fall off or be damaged during subsequent processing and use.

[0047] In some embodiments of the present invention, the first substrate 1 includes several blocks, and the second substrate 2 includes several blocks, and the manufacturing method includes the following steps: pressing the substrates, pressing the first substrate 1 and the second substrate 2 into a first core board and a second core board respectively by pressing; milling out the heat dissipation channel 3, taking the third substrate, and milling out several heat dissipation channels 3 on the third substrate for the circulation of cooling medium; milling out connecting holes 4, milling connecting holes 4 on the first core board or the second core board, and the positions of the connecting holes 4 are set one by one corresponding to the positions of the two ends of the heat dissipation channel 3; and pressing the core boards, after stacking the first core board, the third substrate and the second core board in the stacking order, using pressing to press together to form a circuit board.

[0048] According to the method for manufacturing a circuit board with a microfluidic structure in the first embodiment described above, the embodiment of the present invention further provides an implementation method for processing multiple substrates. Specifically, the first substrate 1 includes several pieces, that is, it can be one or more pieces. If it is multiple pieces, it needs to be pressed into a first core board using a pressing process. The second substrate 2 also includes several pieces. Similarly, the second substrate 2 is also the same. The specific steps of this implementation method will be described in detail below.

[0049] First, select appropriate materials for the first substrate 1 and the second substrate 2, such as a metal substrate or a ceramic substrate with high thermal conductivity. Then, multiple first substrates 1 and multiple second substrates 2 are pressed together into a first core board and a second core board by pressing, wherein the first core board includes a third substrate, and the third substrate is located on the outer layer of the first core board. Appropriate pressure and temperature need to be controlled during the pressing process to ensure a firm bond between the substrates and avoid damage to the substrates.

[0050] Next, select the third substrate material, which can be the same or different from the materials of the first substrate 1 and the second substrate 2, and is selected according to the specific application requirements. Specifically, a core board with no copper foil on both sides can be used. Then, a number of heat dissipation channels 3 are milled out on the third substrate using a precise milling process. These heat dissipation channels 3 will be used for the circulation of cooling medium. During the milling process, it is not necessary to precisely control the depth of the heat dissipation channel 3. The third substrate can be directly milled through. After the subsequent pressing process, the heat dissipation channel 3 is defined between the first substrate 1 on the first core board and the second substrate of the second core board, so that the cooling medium can flow smoothly in the heat dissipation channel and effectively take away the heat from the first core board and the second core board (electronic components).

[0051] On the second core board, the connecting holes 4 are precisely milled according to the positions of the heat dissipation channels 3. The positions of these connecting holes 4 need to be set in a one-to-one correspondence with the positions of the two ends of the heat dissipation channels 3 on the third substrate on the first core board. The function of the connecting holes 4 is to allow the cooling medium to flow in from one side of the circuit board, pass through the heat dissipation channels 3, and then flow out from the other side, forming an effective cooling cycle.

[0052] After completing the milling of the heat dissipation channel 3 and the connecting hole 4, align them precisely according to the stacking order of the first core board and the second core board. At this time, it should be noted that the third substrate on the first core board should fit one side of the second core board. Then, the three layers of substrates are pressed together by lamination to form a circuit board with a microchannel structure. During the lamination process, it is necessary to ensure the precise alignment and firm bonding between the layers of substrates, while avoiding damage to the heat dissipation channel 3 and the connecting hole 4. After lamination, the connecting hole 4 on the second core board can be connected to the heat dissipation channel 3 on the third substrate in the middle, thereby forming a heat dissipation channel 3 for heat dissipation of the circuit board.

[0053] Through this embodiment, a circuit board with a microfluidic structure including a multi-layer substrate can be manufactured. The design of the multi-layer substrate can not only improve the overall strength and stability of the circuit board, but also arrange different circuits and components on different substrate layers as needed to achieve more complex functions. At the same time, the design of the heat dissipation channel 3 and the connecting hole 4 in this embodiment can effectively take away the heat generated by the electronic components and improve the heat dissipation performance of the circuit board. When the cooling medium flows in the heat dissipation channel 3, it can form a cooling cycle inside the circuit board through the connecting hole 4, thereby achieving an efficient heat dissipation effect. In addition, in order to further improve the heat dissipation efficiency, a heat conductive layer or a heat dissipation fin or other structures can be provided on the inner wall of the heat dissipation channel 3. At the same time, different heat dissipation channel 3 layouts and connecting hole 4 shapes can be designed on the circuit board according to specific application requirements to meet the heat dissipation requirements of different electronic components. In summary, the method for manufacturing a circuit board with a microfluidic structure provided in the embodiment of the present invention, through the steps of pressing the substrate, milling out the heat dissipation channel 3 and the connecting hole 4, and pressing the core board, a circuit board with a multi-layer core board with an efficient and reliable heat dissipation structure is manufactured.

[0054] Furthermore, in some embodiments of the present invention, the thickness of the first core board and the second core board is ≤1.5mm. Limiting the thickness of the first core board and the second core board to within 1.5mm, the thinner core board is not only conducive to reducing the overall thickness and weight of the circuit board, improving the portability and aesthetics of the electronic device, but also helps to improve the heat dissipation performance of the circuit board, because the thinner substrate is more conducive to the rapid conduction and dissipation of heat.

[0055] In some embodiments of the present invention, the spacing between adjacent heat dissipation channels 3 is ≥1 mm. The purpose is that, firstly, sufficient spacing can ensure that the cooling medium flows smoothly in the heat dissipation channel 3 and improve the heat dissipation efficiency; secondly, appropriate spacing can maintain the structural strength and stability of the circuit board and avoid deformation or cracking during processing and use; thirdly, setting clear spacing requirements helps to accurately control the milling path and width during processing, improve processing accuracy and consistency; finally, sufficient spacing can avoid thermal interference and fluid dynamic interference between adjacent heat dissipation channels 3, ensuring the performance stability of the circuit board.

[0056] In some embodiments of the present invention, similar to the above embodiments, in the method for manufacturing a circuit board with a microfluidic structure including a multi-layer substrate, the step of milling out the connecting hole 4 may also include: milling out the process hole, milling out the process hole on the first core board or the second core board according to product requirements; and plugging the process hole, plugging the process hole with a plugging object. Therefore, it can be seen that in the method for manufacturing a circuit board with a microfluidic structure including a multi-layer substrate, the step of milling out the connecting hole 4 is no longer repeated in this embodiment.

[0057] Specifically, in some embodiments of the present invention, the plugging material is copper paste or resin. When selecting the plugging material, it is necessary to select it according to the specific requirements and purpose of the process hole. If a plugging material with good electrical connection or thermal conductivity is required, copper paste can be selected; if a plugging material with good insulation or sealing performance is required, resin can be selected.

[0058] In some embodiments of the present invention, the adhesive in the step of pressing the core board is a no-flow prepreg 5. The no-flow prepreg 5 can firmly bond the various layers of the substrate to form a stable microchannel structure; ensure the electrical insulation between the various layers of the circuit board, improve the reliability and safety of the circuit board; maintain stable performance under high temperature conditions, and meet the requirements of long-term use of the circuit board; the no-flow prepreg 5 is easy to cut and stack, which is convenient for the processing and manufacturing of the circuit board.

[0059] According to the circuit board with a microfluidic structure in the second aspect of the present invention, the circuit board with a microfluidic structure is manufactured by the method for manufacturing a circuit board with a microfluidic structure in any one of the first aspects. The circuit board with a microfluidic structure can pass a cooling medium for cooling into the microfluidic channel inside the circuit board, so that the circuit board has a good operating environment during operation, thereby ensuring the reliability of the operation of the circuit board.

[0060] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for manufacturing a circuit board having a microfluidic channel structure, characterized in that: The circuit board has a first substrate and a second substrate, and the manufacturing method comprises the following steps: Milling out heat dissipation channels, and milling out a plurality of heat dissipation channels on the first substrate, wherein the heat dissipation channels are used for the circulation of cooling medium; Milling a connecting hole, milling the connecting hole on the second substrate, the position of the connecting hole is set in one-to-one correspondence with the positions of the two ends of the heat dissipation channel, the connecting hole is connected to the heat dissipation channel, and the connecting hole is used for the cooling medium to flow into or out of the heat dissipation channel; and A pressed core board is formed by pressing the first substrate and the second substrate together to form the circuit board.

2. The method for manufacturing a circuit board having a microchannel structure according to claim 1, characterized in that: The step of pressing the core board may also include the following steps: copper plating on the groove wall of the heat dissipation channel and / or on the hole wall of the connecting hole.

3. The method for manufacturing a circuit board having a microchannel structure according to claim 1, characterized in that: The step of milling the connecting hole also includes the following steps: Milling out process holes, milling out the process holes on the first substrate and the second substrate according to product requirements; and The process hole is blocked by using a blocking object.

4. The method for manufacturing a circuit board having a microchannel structure according to claim 1, characterized in that: The first substrate includes a plurality of blocks, the second substrate includes a plurality of blocks, and the manufacturing method includes the following steps: Laminating the substrates, laminating the first substrate and the second substrate into a first core board and a second core board respectively; Milling out heat dissipation channels, wherein the first core board includes a third substrate, and before the step of pressing the substrates, a plurality of heat dissipation channels are milled out on the third substrate, wherein the heat dissipation channels are used for the circulation of cooling medium; Milling a connecting hole, milling the connecting hole on the second core plate, the position of the connecting hole is set in one-to-one correspondence with the positions of the two ends of the heat dissipation channel, the connecting hole is connected to the heat dissipation channel, and the connecting hole is used for the cooling medium to flow into or out of the heat dissipation channel; and The core board is pressed together, and after the third substrate on the first core board is stacked with the second core board according to the stacking requirements, the first core board and the second core board are pressed together by pressing to form the circuit board.

5. The method for manufacturing a circuit board having a microfluidic structure according to claim 4, characterized in that: The thickness of the first core plate and the second core plate is ≤1.5 mm.

6. The method for manufacturing a circuit board having a microchannel structure according to claim 4, characterized in that: The distance between adjacent heat dissipation channels is ≥1 mm.

7. The method for manufacturing a circuit board having a microchannel structure according to claim 4, characterized in that: The step of milling out the connecting hole also includes: Milling out process holes, milling out the process holes on the first core plate or the second core plate according to product requirements; and The process hole is blocked by using a blocking object.

8. The method for manufacturing a circuit board having a microfluidic channel structure according to claim 3 or 7, characterized in that: The sealing material is copper paste or resin.

9. The method for manufacturing a circuit board having a microchannel structure according to claim 4, characterized in that: The adhesive in the step of pressing the core board is a non-flowing prepreg.

10. A circuit board with a microfluidic structure, characterized in that: The circuit board is manufactured by the method for manufacturing a circuit board with a microfluidic structure as described in any one of claims 1 to 9.

Images