Manufacturing method of circuit board with exchange chip, circuit board and steel mesh

Abstract

The invention discloses a manufacturing method of a circuit board with an exchange chip, the circuit board and a steel mesh, and relates to the technical field of circuit boards, and the manufacturing method of the circuit board with the exchange chip comprises the steps: forming a green oil combination layer outside a circuit board body through a secondary green oil technology, a plurality of stepped mounting holes in one-to-one correspondence with a plurality of circuit board bonding pads in a chip bonding area of the circuit board body are formed in the green oil combination layer; solder paste is put into each stepped mounting hole; a supporting column is inserted into at least one of the step mounting holes; a switching chip is attached to the outside of the green oil combination layer and is arranged corresponding to the chip welding area; according to the invention, the solder paste is firstly melted and then cooled through the reflow soldering process, so that the switching chip and the circuit board body are welded and connected to form the circuit board, and the problem that the printed circuit board with the switching chip in the related technology is easy to cause poor welding and deformation in the reflow soldering process is solved; the technical effect of remarkably improving the welding yield of the circuit board is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit boards, in particular to a manufacturing method of a circuit board with a switching chip, a circuit board and a steel mesh. BACKGROUND

[0002] With the deep penetration of artificial intelligence (AI) and machine learning (ML) technologies in various industries, the demand for high-performance servers and computing power is expanding like a snowball, giving rise to the rise of generative intelligent servers, and further promoting the large-scale deployment of intelligent server clusters to meet the demand for massive computing power for complex tasks such as logical reasoning and image recognition. To meet this challenge, data center networks are experiencing unprecedented bandwidth demand, prompting 112G, 224G and even 800G switches to become industry standards, and the widespread use of 800G switches marks the entry of network infrastructure into a new era of ultra-high-speed development.

[0003] Specifically, the switching chip of the 800G switch is large in size (both length and width are greater than 85mm), heavy (more than 135g), and the number of layers of the circuit board is increasing (at least 32 layers), the line density is approaching the limit (not less than 20μm / 20μm) and the impedance control is precise (within ±5%), which will cause significant thermal deformation (more than 100μm / m), and the printed circuit board faces the challenges of high board temperature difference (≥10℃) and thermal deformation during reflow soldering, which makes it prone to welding defects such as short circuit, cold welding and pillow effect during reflow soldering, significantly increasing production and maintenance costs and slowing down production pace. SUMMARY

[0004] The present application provides a manufacturing method of a circuit board with a switching chip, a circuit board and a steel mesh to at least solve the problem of welding defects and deformation of the printed circuit board with the switching chip in the related art during reflow soldering.

[0005] The present application provides a manufacturing method of a circuit board with a switching chip, comprising: forming a green oil combination layer outside the circuit board body by a secondary green oil process, and opening a plurality of stepped mounting holes corresponding to a plurality of circuit board pads of a chip welding area located in the circuit board body on the green oil combination layer; putting tin paste into each stepped mounting hole; inserting a support column into at least one of the plurality of stepped mounting holes; placing the switching chip outside the green oil combination layer and corresponding to the chip welding area; melting and then cooling the tin paste by a reflow soldering process to weld and connect the switching chip and the circuit board body to form the circuit board.

[0006] Furthermore, the step of forming a green solder mask layer on the outside of the circuit board body through a secondary green solder mask process, and opening multiple stepped mounting holes on the green solder mask layer that correspond one-to-one with multiple circuit board pads located in the chip soldering area of ​​the circuit board body includes: brushing a layer of green solder mask on the outside of the circuit board body to form a first green solder mask layer covering the circuit board body and multiple circuit board pads located on the circuit board body, and opening holes in the first green solder mask layer to form multiple first clearance holes that correspond one-to-one with multiple circuit board pads.

[0007] Furthermore, the step of forming a solder mask layer on the circuit board body through a secondary solder mask process, and opening multiple stepped mounting holes on the solder mask layer that correspond one-to-one with the multiple circuit board pads in the chip soldering area of ​​the circuit board body, further includes: brushing another layer of solder mask on the first solder mask layer to form a second solder mask layer covering the first solder mask layer; opening holes in the second solder mask layer to form multiple second clearance holes that correspond one-to-one with the multiple first clearance holes, and making the cross-sectional area of ​​the second clearance holes larger than the cross-sectional area of ​​the corresponding first clearance holes; wherein, the multiple first clearance holes and the multiple second clearance holes correspond one-to-one to form multiple stepped mounting holes.

[0008] Furthermore, the step of placing solder paste into each stepped mounting hole includes: placing a stencil outside the green solder mask layer, setting multiple connecting holes on the stencil to correspond one-to-one with multiple stepped mounting holes, and placing solder paste on the stencil so that the solder paste flows into the multiple stepped mounting holes through the multiple connecting holes one-to-one.

[0009] Furthermore, the step of inserting a support post into at least one of the plurality of stepped mounting holes includes: inserting four support posts into four stepped mounting holes respectively provided in a one-to-one correspondence with the four corners of the chip soldering area.

[0010] Furthermore, in the reflow soldering process, the temperature rise slope is 0.5℃ / s to 1.5℃ / s; and / or, the duration of the soldering temperature between 150℃ and 200℃ is 90s to 130s; and / or, the duration of the soldering temperature above 217℃ is 90s to 140s; and / or, the temperature fall slope is -1.5℃ / s to -0.5℃ / s; and / or, the circuit board exit temperature is less than or equal to 150℃.

[0011] This application provides a circuit board with a switching chip, manufactured using the above-described method for manufacturing a circuit board with a switching chip. The circuit board with the switching chip includes: a circuit board body and a plurality of circuit board pads disposed on the circuit board body in a chip soldering area; a solder mask layer covering the circuit board body, wherein a plurality of stepped mounting holes are formed on the solder mask layer to avoid the plurality of circuit board pads in a one-to-one correspondence; a switching chip located on the side of the solder mask layer away from the circuit board body; and a support post located in at least one of the plurality of stepped mounting holes, wherein one end of the support post is connected to the circuit board pad and the other end of the support post is connected to the switching chip.

[0012] Furthermore, the solder mask layer includes a first solder mask layer covering the circuit board body, and each stepped mounting hole includes a first clearance hole formed on the first solder mask layer; the solder mask layer also includes a second solder mask layer covering the first solder mask layer, and each stepped mounting hole also includes a second clearance hole formed on the second solder mask layer and communicating with the corresponding first clearance hole; wherein, the cross-sectional area of ​​the second clearance hole is larger than the cross-sectional area of ​​the corresponding first clearance hole.

[0013] Furthermore, the chip bonding area is a rectangular area, the first clearance hole is a circular hole with a height of a and a diameter of d1; the second clearance hole is a circular hole with a height of c and a diameter of d2; the support pillar is a cylinder with a height of h and a diameter of d0, and the distance between the center line of the support pillar and the edge of the chip bonding area is L; wherein, a≤c; and / or, a+c≥25μm; and / or, 10μm≤a≤(a+c) / 2; and / or, d2-d1≥100μm; and / or, d1>d0; and / or, 0.23mm≤h≤0.27mm; and / or, 0.08mm≤d0≤0.12mm; and / or, 4.98mm≤L≤5.02mm.

[0014] This application also provides a stencil applicable to the above-described method for manufacturing a circuit board with a switching chip. The stencil includes a stencil body and a switching chip area located on the stencil body. The switching chip area includes a plurality of interconnecting holes spaced apart, with each interconnecting hole corresponding to a plurality of circuit board pads for allowing solder paste to pass through. The thickness of the switching chip area is 0.13 mm to 0.17 mm; and / or the diameter of the interconnecting holes is 17 mil to 20 mil.

[0015] This application provides a method for manufacturing a circuit board with a switching chip, comprising: forming a solder mask layer on the outside of the circuit board body using a secondary solder mask process; opening multiple stepped mounting holes on the solder mask layer that correspond one-to-one with multiple circuit board pads located in the chip soldering area of ​​the circuit board body; placing solder paste into each stepped mounting hole; inserting a support post into at least one of the multiple stepped mounting holes; placing the switching chip on the outside of the solder mask layer and corresponding to the chip soldering area; and using a reflow soldering process to melt and then cool the solder paste to solder the switching chip to the circuit board body to form a circuit board. Technically, this method for manufacturing a circuit board with a switching chip, by forming a solder mask layer on the circuit board body and opening stepped mounting holes on the solder mask layer, can increase the effective solder space of the circuit board pads, improve the soldering stability between the circuit board pads and the switching chip, and reduce short circuits and pillow effects during the soldering process. In principle, the method for manufacturing a circuit board with a switching chip in this application utilizes the insulation of solder paste and the stepped mounting holes formed after a secondary solder paste process to ensure the stability and uniformity of solder paste during the soldering process between the switching chip and the circuit board body. Simultaneously, the addition of support pillars provides strong support for the switching chip, preventing deformation during soldering. In terms of effectiveness, the method for manufacturing a circuit board with a switching chip in this application solves the problem of poor soldering and deformation that easily occurs during reflow soldering of printed circuit boards with switching chips in related technologies. It significantly improves the soldering yield of the circuit board during reflow soldering, reduces cold solder joints and short circuits, thereby lowering the production cost of circuit boards with switching chips and enhancing the product's market competitiveness. Attached Figure Description

[0016] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart illustrating a method for manufacturing a circuit board with a switching chip, provided in an embodiment of this application;

[0018] Figure 2 A schematic diagram of the structure of a circuit board body with a switching chip provided in an embodiment of this application;

[0019] Figure 3 for Figure 2 A magnified view of the chip soldering area of ​​the circuit board body shown;

[0020] Figure 4 forFigure 3 The chip soldering area of ​​the circuit board body shown is a partial cross-sectional view through the first clearance hole when the first solder mask layer and the first clearance hole are provided.

[0021] Figure 5 for Figure 4 The chip soldering area of ​​the circuit board body shown is partially cross-sectionally viewed through the second clearance hole when the second solder mask layer and the second clearance hole are provided.

[0022] Figure 6 for Figure 3 A schematic diagram of the support pillars installed in the chip soldering area shown;

[0023] Figure 7 For use in installation Figure 2 A schematic diagram of the switching chip on the circuit board body shown;

[0024] Figure 8 For use Figure 1 A schematic diagram of the stencil structure used in the fabrication of a circuit board with a switching chip is shown.

[0025] Figure 9 for Figure 8 A magnified view of a portion of the switching chip area of ​​the stencil shown.

[0026] The above figures include the following reference numerals:

[0027] 1. Circuit board body; 2. Circuit board pads;

[0028] 3. Switching chip;

[0029] 4. First green oil layer; 5. First clearance hole;

[0030] 6. Second green oil layer; 7. Second clearance hole;

[0031] 8. Support columns;

[0032] 9. Stepped mounting holes; 10. Chip soldering area;

[0033] 11. Steel mesh; 12. Connecting hole; 13. Steel mesh body; 14. Switching chip area. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0035] It should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; they can be internal connections between two elements. The terms "parallel," "perpendicular," and "equal" include the described situation and situations similar to the described situation, the range of which is within an acceptable deviation range, wherein the acceptable deviation range is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where an acceptable deviation range for approximate parallelism can be, for example, within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where an acceptable deviation range for approximate perpendicularity can also be, for example, within 5°. "Equal" includes absolute equality and approximate equality, where an acceptable deviation range for approximate equality can be, for example, a difference between the two equal items being less than or equal to 5% of either one. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] like Figure 1 As shown, this application provides a method for manufacturing a circuit board with a switching chip, comprising: forming a solder mask layer on the outside of the circuit board body 1 by a secondary solder mask process, and opening a plurality of stepped mounting holes 9 on the solder mask layer, which are respectively arranged in a plurality of circuit board pads 2 located in the chip soldering area 10 of the circuit board body 1; placing solder paste in each stepped mounting hole 9; inserting a support post 8 into at least one of the plurality of stepped mounting holes 9; placing the switching chip 3 on the outside of the solder mask layer and corresponding to the chip soldering area 10; and using a reflow soldering process to melt and then cool the solder paste to solder the switching chip 3 to the circuit board body 1 to form a circuit board.

[0038] Technically, the method for manufacturing a circuit board with a switching chip in this application increases the effective solder space of the circuit board pads 2 by forming a solder paste layer on the circuit board body 1 and opening stepped mounting holes 9 on the solder paste layer, thereby improving the soldering stability between the circuit board pads 2 and the switching chip 3 and reducing short circuits and pillow effect defects during the soldering process. In principle, the method utilizes the insulation of the solder paste and the stepped mounting holes 9 formed after the secondary solder paste process to ensure the stability and uniformity of the solder paste during the soldering process between the switching chip 3 and the circuit board body 1. Simultaneously, the addition of support pillars 8 provides strong support for the switching chip 3, preventing deformation during the soldering process. Effectively, the method solves the problem of poor soldering and deformation of printed circuit boards with switching chips during reflow soldering in related technologies, significantly improving the soldering yield of the circuit board during reflow soldering, reducing cold solder joints and short circuits, thereby reducing the production cost of circuit boards with switching chips and enhancing the market competitiveness of the product.

[0039] Furthermore, the method for manufacturing a circuit board with a switching chip in this application can further enhance the heat resistance of the solder mask by optimizing its formulation, thereby improving the soldering quality of the circuit board during reflow soldering and solving the instability problem that the solder mask may cause in high-temperature environments. Optimizing the formulation of the solder mask is one of the key strategies for improving the soldering quality and thermal stability of the circuit board during reflow soldering. In the method for manufacturing a circuit board with a switching chip in this application, a solder mask formulation with better high-temperature resistance is used, which can effectively cope with the high-temperature environment during reflow soldering and avoid soldering defects caused by solder mask instability. High-temperature resistant solder mask can maintain its chemical and physical properties at higher temperatures, reducing the softening, flow, and bubble generation of the solder mask during the high-temperature soldering stage, thereby ensuring the accuracy and cleanliness of the pad area, preventing solder overflow or poor solder joint formation, such as short circuits, cold solder joints, or pillow effect, and thus significantly improving the soldering yield and the overall reliability of the circuit board. This optimization is not limited to formula adjustments, but may also involve improvements to the curing temperature, time, and method of the green solder mask, as well as matching pretreatment and post-treatment processes. Together, they constitute a comprehensive thermal management solution to ensure that the circuit board maintains a high level of soldering quality even under complex and harsh soldering conditions, meeting the stringent requirements for the soldering stability and reliability of switching chips in electronic devices.

[0040] In the method for manufacturing a circuit board with a switching chip according to this application, the steps of forming a green solder mask layer on the outside of the circuit board body 1 by a secondary green solder mask process, and opening a plurality of stepped mounting holes 9 on the green solder mask layer corresponding to a plurality of circuit board pads 2 located in the chip soldering area 10 of the circuit board body 1, include: brushing a layer of green solder mask on the outside of the circuit board body 1 to form a first green solder mask layer 4 covering the circuit board body 1 and the plurality of circuit board pads 2 located on the circuit board body 1; and opening holes in the first green solder mask layer 4 to form a plurality of first clearance holes 5 corresponding to a plurality of circuit board pads 2.

[0041] Technically, the method for manufacturing a circuit board with a switching chip in this application involves forming a first solder mask layer 4 above the circuit board pads, and then creating a first clearance hole 5 on the first solder mask layer 4 to provide a foundation for the subsequent second application of solder mask. In principle, the first solder mask layer 4 serves as a base layer, and the size and depth of the first clearance hole 5 directly affect the effect of the second application of solder mask, ensuring the efficient use of the space above the circuit board pads 2. In terms of effectiveness, the method for manufacturing a circuit board with a switching chip in this application increases the solder capacity of the circuit board pads 2 by precisely controlling the thickness of the first solder mask layer 4 and the size of the first clearance hole 5, thus preventing solder paste overflow and short circuits during the soldering process.

[0042] In addition, the method for manufacturing a circuit board with a switching chip in this application can also improve the adhesion between the first green oil layer 4 and the circuit board body 1 by adjusting the chemical composition of the first green oil layer 4, thereby solving the delamination problem that may occur during the reflow soldering process of the circuit board.

[0043] In the method for manufacturing a circuit board with a switching chip according to this application, the steps of forming a green solder mask layer on the outside of the circuit board body 1 by a secondary green solder mask process, and opening a plurality of stepped mounting holes 9 on the green solder mask layer that correspond one-to-one with a plurality of circuit board pads 2 located in the chip soldering area 10 of the circuit board body 1, further include: brushing another layer of green solder mask on the first green solder mask layer 4 to form a second green solder mask layer 6 covering the first green solder mask layer 4; opening holes in the second green solder mask layer 6 to form a plurality of second clearance holes 7 that correspond one-to-one with a plurality of first clearance holes 5, and making the cross-sectional area of ​​the second clearance hole 7 larger than the cross-sectional area of ​​the corresponding first clearance hole 5; wherein, the plurality of first clearance holes 5 and the plurality of second clearance holes 7 correspond one-to-one to form a plurality of stepped mounting holes 9.

[0044] Technically, the method for manufacturing a circuit board with a switching chip in this application utilizes a secondary solder mask process to create stepped mounting holes 9, providing additional solder space for the circuit board pads 2. In principle, the second clearance hole 7 at the second solder mask layer 6 is larger than the first clearance hole 5 at the first solder mask layer 4, ensuring sufficient effective solder space above the circuit board pads 2 to accommodate solder paste, while also providing accurate positioning for the support pillars 8. In terms of effectiveness, the method for manufacturing a circuit board with a switching chip in this application effectively avoids soldering defects such as short circuits and pillow effects caused by thermal deformation of the switching chip 3 and the circuit board body 1 during reflow soldering, significantly improving the soldering quality and reliability of the circuit board.

[0045] In addition, the method for manufacturing a circuit board with a switching chip in this application can also improve the adhesion between the second green solder mask layer 6 and the first green solder mask layer 4 by adjusting the chemical composition of the second green solder mask layer 6, thereby solving the delamination problem that may occur during the reflow soldering process of the circuit board.

[0046] In the method for manufacturing a circuit board with a switching chip according to this application, the step of placing solder paste in each stepped mounting hole 9 includes: placing a stencil 11 outside the solder mask layer, such that the plurality of connecting holes 12 on the stencil 11 are set one-to-one with the plurality of stepped mounting holes 9, and placing solder paste on the stencil 11 so that the solder paste flows into the plurality of stepped mounting holes 9 one-to-one through the plurality of connecting holes 12.

[0047] Technically, the method for manufacturing a circuit board with a switching chip in this application achieves precise control over the amount and position of solder paste by using a stencil 11 with multiple precise connecting holes 12. In principle, the multiple connecting holes 12 of the stencil 11 correspond one-to-one with multiple stepped mounting holes 9, ensuring that the solder paste is accurately filled above each circuit board pad 2, while avoiding excessive or insufficient solder paste. Effectively, the method for manufacturing a circuit board with a switching chip in this application improves the quality and consistency of the solder joints between the switching chip 3 and the circuit board body 1, and reduces soldering defects such as cold solder joints and insufficient solder.

[0048] In addition, the method for manufacturing a circuit board with a switching chip in this application can also improve the durability and precision of the stencil 11 by optimizing the material and thickness of the stencil 11 and the position and size of the connecting hole 12, such as by using nanoscale materials to make the stencil 11, thereby solving problems such as wear and deformation that may occur in the stencil 11 under long-term use or high-density welding conditions.

[0049] In the method for manufacturing a circuit board with a switching chip according to this application, the step of inserting a support post 8 into at least one of a plurality of stepped mounting holes 9 includes: inserting four support posts 8 into four stepped mounting holes 9 respectively, which are respectively provided in a one-to-one correspondence with the four corners of the chip soldering area 10.

[0050] Technically, the method for manufacturing a circuit board with a switching chip in this application provides stable physical support for the switching chip 3 by installing support pillars 8 at specific locations in the chip soldering area 10 of the circuit board body 1. In principle, the addition of the support pillars 8 prevents the switching chip 3 from sinking and deforming during reflow soldering, ensuring a good connection between the switching chip 3 and the circuit board body 1. Effectively, the method for manufacturing a circuit board with a switching chip in this application significantly reduces soldering defects caused by the weight of the switching chip 3, such as short circuits and uneven solder joints, thereby improving product yield and reliability.

[0051] In addition, the method for manufacturing a circuit board with a switching chip in this application can also be improved by increasing the number of support posts 8 or adjusting their positions, for example, by inserting support posts 8 into the stepped mounting holes 9 in the middle of the chip soldering area 10, in order to accommodate the soldering of heavier or larger switching chips 3 and solve the soldering problems caused by the increase in the size and weight of the switching chips.

[0052] Specifically, the interior of a reflow oven is typically divided into 14 zones along the soldering direction of the circuit board, each with its own upper and lower heaters. Zones 1 to 7 are preheating zones, where the temperature gradually increases; zones 8 to 12 are reflow zones (also called peak temperature zones), where the highest temperature reaches 295°C; and zones 13 to 14 are cooling zones, where the temperature drops rapidly.

[0053] In the reflow soldering process, the switching chip 3 and the circuit board body 1 need to be placed in the reflow soldering oven for soldering; wherein, the temperature rise slope of the soldering is 0.5℃ / s to 1.5℃ / s; and / or, the duration of the soldering temperature between 150℃ and 200℃ is 90s to 130s; and / or, the duration of the soldering temperature above 217℃ is 90s to 140s; and / or, the temperature drop slope of the soldering is -1.5℃ / s to -0.5℃ / s; and / or, the exit temperature of the circuit board is less than or equal to 150℃.

[0054] Technically, the method for manufacturing a circuit board with a switching chip in this application ensures the stability and quality of the soldering process between the switching chip 3 and the circuit board body 1 by precisely controlling the temperature change over time during the reflow soldering process. In principle, precise temperature control affects the melting and solidification process of the solder, thereby influencing the formation of the solder joint. Effectively, the method for manufacturing a circuit board with a switching chip in this application effectively avoids soldering defects such as cold solder joints and pillow effects caused by excessively rapid temperature changes during the soldering process between the switching chip 3 and the circuit board body 1, thus improving the soldering yield and reliability of the circuit board.

[0055] like Figures 1 to 7 As shown, this application provides a circuit board with a switching chip, manufactured using the above-described method for manufacturing a circuit board with a switching chip. The circuit board with a switching chip includes: a circuit board body 1 and a plurality of circuit board pads 2 disposed on a chip soldering area 10 on the circuit board body 1; a solder mask layer covering the circuit board body 1, wherein a plurality of stepped mounting holes 9 are provided on the solder mask layer to avoid the plurality of circuit board pads 2 in a one-to-one correspondence; a switching chip 3 located on the side of the solder mask layer away from the circuit board body 1; and a support post 8 located in at least one of the plurality of stepped mounting holes 9, wherein one end of the support post 8 is connected to the circuit board pad 2 and the other end of the support post 8 is connected to the switching chip 3.

[0056] Technically, the circuit board with a switching chip in this application solves the problem of soldering a large-sized switching chip 3 to the circuit board body 1 by setting a solder mask layer and stepped mounting holes 9 on the circuit board body 1, and setting support pillars 8 at specific positions. In principle, the design of the solder mask layer and stepped mounting holes 9 increases the solder capacity of the circuit board pads 2, while the support pillars 8 prevent deformation of the switching chip 3 during the soldering process. In terms of effectiveness, the circuit board with a switching chip in this application significantly improves the soldering yield between the large-sized switching chip 3 and the circuit board body 1, reduces the production cost of the circuit board, and enhances the market competitiveness of the circuit board.

[0057] like Figure 4 and Figure 5 As shown, the sprue layer includes a first sprue layer 4 covering the circuit board body 1, and each stepped mounting hole 9 includes a first clearance hole 5 formed on the first sprue layer 4; the sprue layer also includes a second sprue layer 6 covering the first sprue layer 4, and each stepped mounting hole 9 also includes a second clearance hole 7 formed on the second sprue layer 6 and communicating with the corresponding first clearance hole 5; wherein, the cross-sectional area of ​​the second clearance hole 7 is larger than the cross-sectional area of ​​the corresponding first clearance hole 5.

[0058] Technically, the circuit board with the switching chip in this application forms stepped mounting holes 9 with varying apertures through a secondary solder mask process and hole-opening operation. In principle, the design of the first clearance hole 5 and the second clearance hole 7 ensures efficient use of the space above the circuit board pads 2, while providing accurate positioning for the support pillars 8. Functionally, the circuit board with the switching chip in this application effectively avoids solder paste overflow and short circuits during the soldering process, improving soldering quality and reliability.

[0059] In addition, the circuit board with the switching chip of this application can also be adapted to switching chips 3 of different sizes and weights by adjusting the shape and size of the first clearance hole 5 and the second clearance hole 7, thus solving the soldering problem caused by the change in size and weight of the switching chip 3.

[0060] In the circuit board with a switching chip of this application, the first clearance hole 5 and the second clearance hole 7 are flexibly designed so that their shape and size can be adjusted according to the specific specifications of the switching chip 3. This directly addresses the diversity of the size and weight of the switching chip 3, thereby effectively solving the soldering challenges caused by the variation in the specifications of the switching chip 3. By precisely matching the geometric parameters of the first clearance hole 5 and the second clearance hole 7 with the physical characteristics of the switching chip 3, it is possible to prevent uneven solder distribution or poor soldering phenomena such as short circuits, cold solder joints, or pillow effects during reflow soldering. This not only improves the compatibility of the circuit board body 1 with different switching chips 3, but also further enhances the stability and reliability of the soldering process. It ensures that even when facing larger and heavier high-performance switching chips 3, the circuit board can maintain a high level of soldering quality, meeting the stringent process requirements of electronic equipment for switching chip soldering, thereby reducing production costs and enhancing product competitiveness.

[0061] like Figures 3 to 6 As shown, the chip bonding area 10 is a rectangular area. The first clearance hole 5 is a circular hole with a height of a and a diameter of d1. The second clearance hole 7 is a circular hole with a height of c and a diameter of d2. The support post 8 is a cylinder with a height of h and a diameter of d0. The distance between the center line of the support post 8 and the edge of the chip bonding area 10 is L. Wherein, a≤c; and / or, a+c≥25μm; and / or, 10μm≤a≤(a+c) / 2; and / or, d2-d1≥100μm; and / or, d1>d0; and / or, 0.23mm≤h≤0.27mm; and / or, 0.08mm≤d0≤0.12mm; and / or, 4.98mm≤L≤5.02mm.

[0062] Technically, the circuit board with the switching chip in this application ensures precise matching of the stepped mounting holes 9 and the support pillars 8, as well as sufficient capacity for solder paste, through specific dimensional parameter control. In principle, the dimensional parameters of the first clearance hole 5 and the second clearance hole 7, along with the dimensional parameters of the support pillars 8, jointly determine the solder capacity of the space above the circuit board pads 2 and the physical stability of the shape of the switching chip 3. In terms of effectiveness, the circuit board with the switching chip in this application, by precisely controlling the dimensions of each part, improves the stability and quality of the soldering process, reduces production costs, and enhances the market competitiveness of the circuit board.

[0063] like Figure 8 and Figure 9 As shown, this application also provides a stencil 11, applicable to the above-described method for manufacturing a circuit board with a switching chip. The stencil includes a stencil body 13 and a switching chip region 14 located on the stencil body 13. The switching chip region 14 includes a plurality of interconnecting holes 12 spaced apart. The plurality of interconnecting holes 12 are arranged one-to-one with a plurality of circuit board pads 2 for allowing solder paste to pass through. The thickness of the switching chip region 14 is 0.13 mm to 0.17 mm; and / or the diameter of the interconnecting holes 12 is 17 mil to 20 mil.

[0064] Technically, the stencil 11 of this application achieves precise control over the amount of solder paste by precisely controlling the thickness of the stencil body 13 and the diameter of the connecting holes 12. In principle, the multiple connecting holes 12 of the stencil 11 correspond one-to-one with the multiple circuit board pads 2 on the circuit board body 1, ensuring that the solder paste is accurately filled onto each circuit board pad 2, while avoiding excessive or insufficient solder paste. In terms of effectiveness, the stencil 11 of this application improves the quality and consistency of soldering, reduces soldering defects such as cold solder joints and insufficient solder, thereby improving soldering yield and product reliability.

[0065] Furthermore, the thickness of the switching chip area 14 is 0.15 mm, and the diameter of the via 12 is 18 mil.

[0066] In addition, the steel mesh 11 of this application can also improve its durability and precision by optimizing its own material and surface treatment process, such as using nano-level materials and special coatings, thus solving the problem of wear and deformation that may occur in the steel mesh 11 under long-term use.

[0067] Specifically, the stencil 11 is manufactured using nanoscale materials, which are renowned for their superior hardness and stability, significantly resisting wear and deformation that may occur under prolonged and frequent use. Furthermore, special surface treatment processes, such as the application of a nano-coating with low surface energy and excellent wear resistance, further enhance its corrosion resistance, extend its service life, and improve the accuracy and consistency of solder paste transfer. These combined technologies not only ensure more precise control of the solder amount during each soldering process, reducing soldering defects such as cold solder joints or excess solder buildup, but also significantly reduce the cost of frequent replacements due to stencil 11 wear, greatly improving production efficiency and economic benefits, and providing a solid technical guarantee for large-scale, high-frequency reflow soldering operations.

[0068] The specific method for manufacturing the circuit board with the switching chip in this application is as follows:

[0069] When designing the circuit board with the switching chip, the engineering drawings should specify that a secondary solder mask process is required in the chip soldering area 10, and four support pillars 8 should be set at the four corners of the chip soldering area 10.

[0070] In the fabrication process of a circuit board with a switching chip, firstly, solder paste is printed onto the circuit board body 1, followed by short-time baking, exposure, and development to form a first solder paste layer 4, and multiple first clearance holes 5 are formed on the first solder paste layer 4; secondly, solder paste is printed onto the first solder paste layer 4, followed by short-time baking, exposure, and development to form a second solder paste layer 6, and multiple second clearance holes 7 are formed on the second solder paste layer 6; thirdly, solder paste is precisely placed into multiple stepped mounting holes 9 using a stencil 11 to ensure that the volume accuracy of the solder paste in each stepped mounting hole 9 is controlled within ±3%, thus solving the problem of micro solder balls. (Diameter < 0.3mm) Solder bridging problem; Next, the four support pillars 8 are precisely mounted into the four stepped mounting holes 9 at the four corners of the chip soldering area 10 on the circuit board body 1 using a placement machine; Subsequently, the switching chip 3 is placed in the chip soldering area 10; Finally, through a refined reflow soldering process, the heating slope, preheating temperature duration, soldering temperature duration, cooling slope, and circuit board exit temperature are controlled to minimize the deformation of the switching chip and circuit board in the high-temperature environment, avoid short circuits, cold solder joints, and pillow effect, and ensure the stability of the soldering process and the quality of the solder joints to form a circuit board with switching chips.

[0071] This resulted in a breakthrough improvement in the soldering yield of the circuit boards with switching chips, increasing the effective solder space above the circuit board pad 2 by more than 15%, thereby achieving a solder paste coverage of over 99% above the pad 2 (compared to only 80% in traditional processes). The volume control precision of the solder paste was improved to ±3%, resolving the bridging issue of micro-solder balls (diameter <0.3mm). This reduced the cold solder joint rate of the switching chip 3 by 99%, and the support pillars 8 prevented short circuits caused by the heavy switching chip 3 collapsing the solder paste. Furthermore, the temperature control of the reflow soldering process stabilized the IMC (Cu6Sn5) layer thickness at 2.8±0.3μm (compared to fluctuations of 1.5μm to 4.2μm in traditional processes), improving the interface bonding strength by 45%.

[0072] The foregoing has provided a detailed description of the manufacturing method, circuit board, and stencil of a circuit board with a switching chip provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A method for manufacturing a circuit board with a switching chip, characterized in that, include: A green solder mask layer is formed on the outside of the circuit board body (1) by a secondary green solder mask process, and multiple stepped mounting holes (9) are opened on the green solder mask layer, which correspond one-to-one with multiple circuit board pads (2) located in the chip soldering area (10) of the circuit board body (1). Solder paste is placed in each of the stepped mounting holes (9); Insert a support post (8) into at least one of the plurality of stepped mounting holes (9); The switching chip (3) is attached to the outside of the green oil composite layer and is positioned corresponding to the chip soldering area (10); The solder paste is melted and then cooled by reflow soldering to solder the switching chip (3) to the circuit board body (1) to form a circuit board.

2. The method for manufacturing a circuit board with a switching chip according to claim 1, characterized in that, The steps of forming a green solder mask layer on the outside of the circuit board body (1) by a secondary green solder mask process, and opening multiple stepped mounting holes (9) on the green solder mask layer that correspond one-to-one with the multiple circuit board pads (2) of the chip soldering area (10) located on the circuit board body (1) include: A layer of green oil is brushed on the outside of the circuit board body (1) to form a first green oil layer (4) covering the circuit board body (1) and the plurality of circuit board pads (2) located on the circuit board body (1). Holes are made in the first green oil layer (4) to form a plurality of first clearance holes (5) that correspond one-to-one with the plurality of circuit board pads (2).

3. The method for manufacturing a circuit board with a switching chip according to claim 2, characterized in that, The step of forming a green solder mask layer on the outside of the circuit board body (1) by a secondary green solder mask process, and opening multiple stepped mounting holes (9) on the green solder mask layer that correspond one-to-one with the multiple circuit board pads (2) of the chip soldering area (10) located on the circuit board body (1), further includes: Apply another layer of green oil on the first green oil layer (4) to form a second green oil layer (6) covering the first green oil layer (4). A hole is made in the second green oil layer (6) to form a plurality of second clearance holes (7) that are connected to the plurality of first clearance holes (5) in a one-to-one correspondence, and the area of ​​the cross-section of the second clearance hole (7) is greater than the area of ​​the cross-section of the corresponding first clearance hole (5); The plurality of first clearance holes (5) and the plurality of second clearance holes (7) are respectively formed by the plurality of stepped mounting holes (9).

4. The method for manufacturing a circuit board with a switching chip according to claim 1, characterized in that, The step of placing solder paste into each of the stepped mounting holes (9) includes: Place the stencil (11) outside the green oil composite layer, so that the multiple connecting holes (12) on the stencil (11) correspond one-to-one with the multiple stepped mounting holes (9), and place solder paste on the stencil (11) so that the solder paste flows into the multiple stepped mounting holes (9) one-to-one through the multiple connecting holes (12).

5. The method for manufacturing a circuit board with a switching chip according to claim 1, characterized in that, The step of inserting the support post (8) into at least one of the plurality of stepped mounting holes (9) includes: Four support posts (8) are inserted into the four stepped mounting holes (9) that are respectively provided in the plurality of stepped mounting holes (9) corresponding to the four corners of the chip welding area (10).

6. The method for manufacturing a circuit board with a switching chip according to claim 1, characterized in that, In the reflow soldering process, The welding temperature rise slope is from 0.5℃ / s to 1.5℃ / s; and / or, The welding temperature is between 150°C and 200°C for a duration of 90 to 130 seconds; and / or, The welding temperature is above 217°C for a duration of 90 to 140 seconds; and / or, The welding temperature decreases at a rate of -1.5℃ / s to -0.5℃ / s; and / or, The circuit board exits the oven at a temperature less than or equal to 150°C.

7. A circuit board with a switching chip, characterized in that, The circuit board with a switching chip is manufactured using the method described in any one of claims 1 to 6, wherein the circuit board with the switching chip comprises: The circuit board body (1) and a plurality of circuit board pads (2) disposed on the chip soldering area (10) on the circuit board body (1). A green solder mask layer covers the outside of the circuit board body (1), and the green solder mask layer has multiple stepped mounting holes (9) for correspondingly avoiding the multiple circuit board pads (2). The switching chip (3) is located on the side of the green solder mask layer away from the circuit board body (1); A support post (8) is located in at least one of the plurality of stepped mounting holes (9), one end of the support post (8) is connected to the circuit board pad (2), and the other end of the support post (8) is connected to the switching chip (3).

8. The circuit board with a switching chip according to claim 7, characterized in that, The green oil composite layer includes a first green oil layer (4) covering the circuit board body (1), and each of the stepped mounting holes (9) includes a first clearance hole (5) opened on the first green oil layer (4). The green oil composite layer also includes a second green oil layer (6) covering the first green oil layer (4), and each of the stepped mounting holes (9) also includes a second clearance hole (7) opened on the second green oil layer (6) and connected to the corresponding first clearance hole (5). The area of ​​the cross-section of the second clearance hole (7) is greater than the area of ​​the cross-section of the corresponding first clearance hole (5).

9. The circuit board with a switching chip according to claim 8, characterized in that, The chip bonding area (10) is a rectangular area. The first clearance hole (5) is a circular hole with a height of a and a diameter of d1. The second clearance hole (7) is a circular hole with a height of c and a diameter of d2. The support pillar (8) is a cylinder with a height of h and a diameter of d0. The distance between the centerline of the support pillar (8) and the edge of the chip bonding area (10) is L. a≤c; and / or, a+c≥25μm; and / or, 10μm≤a≤(a+c) / 2; and / or, d2-d1≥100μm; and / or, d1 > d0; and / or, 0.23mm≤h≤0.27mm; and / or, 0.08mm≤d0≤0.12mm; and / or, 4.98mm≤L≤5.02mm.

10. A steel mesh, characterized in that, A method for manufacturing a circuit board with a switching chip according to any one of claims 1 to 6, wherein the stencil includes a stencil body (13) and a switching chip area (14) located on the stencil body (13), the switching chip area (14) including a plurality of spaced-apart through holes (12), the plurality of through holes (12) being arranged one-to-one with the plurality of circuit board pads (2) for allowing solder paste to pass through; wherein, The thickness of the switching chip region (14) is 0.13 mm to 0.17 mm; and / or, The diameter of the connecting hole (12) is 17 mil to 20 mil.

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