Wave soldering wiring method and printed circuit board

Abstract

The invention discloses a wave-soldering wiring method and a printed circuit board, and relates to the technical field of circuit boards. The wave-soldering wiring method comprises the following steps: determining a target wiring which needs to increase the through-current capability on a circuit board; an annular supporting frame is arranged at the position of the target wire, and the annular supporting frame corresponds to the target wire; when the circuit board is welded, the annular support frame is contacted with the liquid solder. Through the wave-soldering wiring method, the problems that in the prior art, a tin paste printing method is affected by the thickness of a tin printing steel mesh and cannot be coated with thick tin, and a wave-soldering method is affected by tin wave mobility and cannot be coated with the thick tin at a welding position can be solved, the through-current capacity of target wiring on the printed circuit board is improved, and the wiring quality of the printed circuit board is improved. And the design requirements of large-current products are met.

Description

Technical Field

[0001] The invention relates to the technical field of circuit boards, and in particular to a wave soldering routing method and a printed circuit board. Background Art

[0002] Energy storage products, such as BMS (Battery Management System) and inverters, generally have high requirements on the current carrying capacity of printed circuit boards.

[0003] In order to make the printed circuit board meet the current requirements, three methods are usually used in the prior art. One is to use the printing solder paste method to coat the copper surface with another layer of tin, the second is to use the wave soldering method to coat the copper surface with another layer of tin, and the third is to adopt the method of mounting preformed solder sheets.

[0004] However, the printed solder paste method will be affected by the thickness of the printed tin steel mesh and cannot be covered with thick tin. The wave soldering method will be affected by the fluidity of the tin wave and cannot hang thick tin at the welding position. Taking 1OZ (35μm thick) base copper as an example, the base copper thickness and solder thickness after welding generally do not exceed 0.2mm. Assuming that the line width is 2.5mm, with the help of CAD current capacity calculation software, the current at this time barely reaches 15A. According to the software calculation, if the current capacity of 30A is to be achieved, at least 0.8mm of solder thickness is required. Therefore, in some cases of large current, such as 40A or 60A, the existing technology cannot meet the requirements.

[0005] Therefore, there is an urgent need to provide a wave soldering routing method and a printed circuit board to solve the above technical problems. Summary of the invention

[0006] The object of the present invention is to provide a wave soldering routing method and a printed circuit board, so as to improve the current carrying capacity of a target routing on the printed circuit board and meet the requirements of product design and normalization for carrying large currents.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] A wave soldering routing method, the method comprising:

[0009] Identify the target traces on the board that need to have increased current capacity;

[0010] Setting an annular support frame at the target routing, wherein the annular support frame corresponds to the target routing;

[0011] When soldering the circuit board, the annular support frame is brought into contact with liquid solder.

[0012] As a preferred technical solution for a wave soldering routing method, the process of bringing the annular support frame into contact with the liquid solder includes: immersing the annular support frame in the liquid solder.

[0013] As a preferred technical solution of a wave soldering routing method, before the annular support frame is brought into contact with the liquid solder, the method further comprises:

[0014] The annular support frame is pre-fixed at the target routing line so that the annular support frame corresponds to the target routing line.

[0015] As a preferred technical solution of a wave soldering routing method, before the annular support frame is brought into contact with the liquid solder, the method further comprises:

[0016] According to the length parameter of the target routing line, the length parameter of the annular support frame is adjusted so that the length of the annular support frame corresponds to the length of the target routing line.

[0017] A printed circuit board includes a circuit board substrate, wherein the circuit board substrate is provided with a welding surface, the welding surface is provided with a high-throughput flow routing, an annular support frame is provided inside the high-throughput flow routing, and the first cross-section of the high-throughput flow routing includes a plurality of support structures of the annular support frame spaced apart along a first direction thereof.

[0018] As a preferred technical solution for a printed circuit board, the annular support frame is provided with a plurality of annular members spaced apart along a first direction thereof, and the annular members form the support structure along a first cross section of the high-throughput flow routing line.

[0019] As a preferred technical solution for a printed circuit board, a plurality of the annular members are connected in sequence in a spiral shape, so that the annular support frame is retractable along its first direction.

[0020] As a preferred technical solution for a printed circuit board, the second cross-section of the annular member is configured to be rectangular.

[0021] As a preferred technical solution for a printed circuit board, the annular support frame includes a welding section and a connecting section. The welding section includes a plurality of annular members that are spaced apart and sequentially connected along a first direction of the annular support frame. The connecting section is arranged at both ends of the welding section for connecting to the circuit board substrate.

[0022] As a preferred technical solution for a printed circuit board, a positioning hole is provided on the circuit board substrate, and the connecting section is connected to the circuit board through the positioning hole.

[0023] Beneficial effects of the present invention:

[0024] On the one hand, the present invention provides a wave soldering routing method, which is based on the wave soldering process. By arranging an annular support frame at the target routing where the flow capacity needs to be increased on the circuit board, and making the annular support frame correspond to the target routing, the annular support frame is in contact with liquid solder, so that when solder is soldered on the annular support frame and the target routing by wave soldering, the annular support frame will form a barrier to the liquid solder, and the liquid solder has its own tension, so the solder in the internal space of the annular support frame cannot escape and is retained in the annular support frame, so that a large amount of solder can be welded on the annular support frame and the target routing, thereby increasing the cross-sectional area of ​​the target routing, and thereby improving the flow capacity of the target routing on the printed circuit board.

[0025] On the other hand, the present invention also provides a printed circuit board, the welding surface of the printed circuit board is provided with a high-throughput current routing, and an annular support frame is provided inside the high-throughput current routing, and the setting of the annular support frame can increase the welding amount of solder during wave soldering, and then improve the current capacity of the high-throughput current routing through the area of ​​the second cross section of the high-throughput current routing, so as to meet the product design requirements of passing large current. At the same time, a plurality of support structures spaced along the first direction of the high-throughput current routing can be seen in the first cross section of the high-throughput current routing, which is different from the prior art, not only can the solder along the first direction of the high-throughput current routing be supported by the support structure, but also can improve the connection strength between the solder and the circuit board substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of the main steps of the wave soldering routing method provided in the first embodiment of the present invention;

[0027] Figure 2 is a structural schematic diagram of a target routing processed by the wave soldering routing method provided in the first embodiment of the present invention;

[0028] Figure 3 Schematic diagram of the annular support frame provided in the first embodiment of the present invention.

[0029] In the figure:

[0030] 1. Target routing; 11. Positioning holes;

[0031] 2. Opening window for solder mask;

[0032] 3. Annular support frame; 31. Welding section; 32. Connecting section. DETAILED DESCRIPTION

[0033] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0037] Embodiment 1

[0038] like Figure 1 and Figure 2 As shown, the main steps of the wave soldering routing method of this embodiment include: determining the target routing 1 on the circuit board that needs to increase the flow capacity, setting the annular support frame 3 at the target routing 1, and the annular support frame 3 corresponds to the target routing 1; when soldering the circuit board, making the annular support frame 3 contact with the liquid solder.

[0039] The wave soldering routing method is based on the wave soldering process. An annular support frame 3 is set at the target routing line 1 on the circuit board where the flow capacity needs to be increased, and the annular support frame 3 is made to correspond to the target routing line 1. When the circuit board is soldered, the annular support frame 3 is made to contact with the liquid solder, so that when the solder is soldered on the annular support frame 3 and the target routing line 1 by wave soldering, the annular support frame 3 will form a barrier to the liquid solder, and the liquid solder itself Due to the tension of the solder, the solder in the internal space of the annular support frame 3 cannot escape and is retained in the annular support frame 3, so that a large amount of solder can be soldered on the annular support frame 3 and the target routing line 1, thereby increasing the cross-sectional area of ​​the target routing line 1, and thereby improving the flow capacity of the target routing line 1 on the printed circuit board.

[0040] It is understandable that the target trace 1 on the circuit board that needs to increase the flow capacity can be determined according to actual use requirements, such as the traces in the area where the traces are densely packed on the circuit board. In addition, since the annular support frame 3 is mainly used to contain the flow of liquid solder, no requirements are made on the flow capacity of the annular support frame 3. Exemplarily, the solder is tin.

[0041] In this embodiment, in order to make the annular support frame 3 fully contact with the liquid solder, a wave soldering process is adopted. The process of making the annular support frame 3 contact with the liquid solder includes: immersing the annular support frame 3 in the liquid solder.

[0042] In this embodiment, before the annular support frame 3 is brought into contact with the liquid solder, the wave soldering routing method further includes: pre-fixing the annular support frame 3 at the target routing line 1 so that the annular support frame 3 corresponds to the target routing line 1 .

[0043] like Figure 2 and Figure 3 As shown, exemplarily, in order to achieve the connection between the annular support frame 3 and the circuit board substrate, the annular support frame 3 is pre-fixed at the target wiring 1 so that the annular support frame 3 corresponds to the target wiring 1, which specifically includes: opening positioning holes 11 at both ends of the target wiring 1, placing both ends of the annular support frame 3 in the positioning holes 11, and connecting with the positioning holes 11.

[0044] In this embodiment, before the annular support frame 3 is brought into contact with the liquid solder, the wave soldering routing method further includes: adjusting the length parameter of the annular support frame 3 according to the length parameter of the target routing line 1 so that the length of the annular support frame 3 corresponds to the length of the target routing line 1.

[0045] Specifically, according to the length parameter of the target wiring 1, the length parameter of the annular support frame 3 is adjusted so that the length of the annular support frame 3 corresponds to the length of the target wiring 1. The specific method includes: putting the annular support frame 3 in a stretched state. On the one hand, the stretched annular support frame 3 can adapt to target wirings 1 of different lengths, thereby improving the adaptability of the annular support frame 3; on the other hand, the stretched annular support frame 3 can make the side close to the printed circuit board fit with the target wiring 1, avoiding the occurrence of a gap between the annular support frame 3 and the target wiring 1, thereby ensuring that the reliability of the connection between the welding and the target wiring 1 is improved when the solder is welded on the annular support frame 3.

[0046] It is worth noting that, due to the different lengths of the target traces 1, the annular support frame 3 is stretched to different degrees, which will cause the turn spacing of the annular support frame 3 to change, and the surface of the tin column may have wavy undulations, but the slight curvature of the tin surface does not affect the flow capacity.

[0047] It is understandable that in the wave soldering process of the prior art, the electronic components to be soldered are arranged relatively above the circuit board, and the pins or tube pins of the electronic components will pass through the circuit board and contact the liquid solder. After the solder and the tube pins are fully in contact and cooled, the electronic components are soldered and fixed to the circuit board. In the present application, the setting direction of the annular support frame 3 is opposite to the setting direction of general electronic components, that is, when soldering, the annular support frame 3 is arranged relatively below the circuit board so that it can contact the liquid solder.

[0048] It can be understood that the connecting section 32 is pre-fixed to the circuit board through the positioning hole 11. When soldering is performed, since the liquid solder has tension and capillary force, and since the diameter of the positioning hole 11 is relatively small, the liquid solder will infiltrate the positioning hole 11, so that the solder will not only infiltrate the annular support frame 3, but also connect the connecting section 32 and the positioning hole 11 together.

[0049] In this embodiment, before soldering the annular support frame 3 and the target trace 1, it is also necessary to plate tin or flash gold on the surface of the annular support frame 3 to make it solderable.

[0050] The specific operation steps of the above wave soldering routing method are as follows: before the actual wave soldering of the circuit board, the solder mask opening 2, the positioning hole 11 and the wave soldering tray have been completed according to the position of the target routing 1 on the circuit board, and then the annular support frame 3 is inserted into the positioning hole 11 from the soldering surface of the circuit board, and then the circuit board is placed in the wave soldering tray. The wave soldering tray is provided with a window at the position corresponding to the annular support frame 3, and there is no need to support the wave soldering tray when printing tin like the copper sheet in the prior art, so the process is relatively simple. Next, plug the plug-in material (such as peripherals such as LEDs) on the mounting surface of the circuit board substrate; after the plug-in is completed, the wave soldering tray is sent to the wave soldering furnace. When the wave soldering tray passes through the tin wave in the tin bath, because the wave soldering tray has been windowed at the position of the target wiring 1, the annular support frame 3 is immersed in the tin, and the tin wave can wet the target wiring 1. The annular support frame 3 is now attached to the target wiring 1, and the annular support frame 3 has solderability, so it forms a barrier to the flow of the tin wave. In addition, due to the tension and capillary action of the molten tin itself, the solder in the internal space of the annular support frame 3 cannot escape and is retained in the annular support frame 3. The tin wave wets the entire annular support frame 3 to form a tin column, and the welding is completed.

[0051] Embodiment 2

[0052] like Figure 2 and Figure 3 As shown, this embodiment further provides a printed circuit board, including a circuit board substrate, the circuit board substrate is provided with a welding surface, the welding surface is provided with a high-throughput flow routing, an annular support frame 3 is provided inside the high-throughput flow routing, and a first cross-section of the high-throughput flow routing includes a plurality of support structures of the annular support frame 3 arranged at intervals along a first direction thereof. In this embodiment, the first direction is the x direction.

[0053] The soldering surface of the printed circuit board is provided with a high-throughflow routing, and an annular support frame 3 is provided inside the high-throughflow routing. The provision of the annular support frame 3 can increase the soldering amount of the solder during wave soldering, and then improve the current carrying capacity of the high-throughflow routing through the cross-sectional area of ​​the high-throughflow routing to meet the product design requirements of passing large currents. At the same time, the axial section of the high-throughflow routing can see multiple support structures spaced along the first direction thereof, which is different from the prior art, not only can the solder along the first direction of the high-throughflow routing be supported by the support structure, but also can improve the connection strength between the solder and the soldering surface of the circuit board substrate.

[0054] Furthermore, the material of the annular support frame 3 is a metal that is elastic and resistant to high temperatures (no deformation at 280° C.) such as copper or stainless steel, so as to ensure that the annular support frame 3 does not melt during the soldering process, thereby ensuring the fixation of the solder.

[0055] Furthermore, the annular support frame 3 is provided with a plurality of annular members spaced apart along the first direction thereof, and the annular members are used to block the liquid solder during the wave soldering process, so that the solder can form a high-throughflow routing in the shape of the second cross section of the annular member, thereby ensuring an effective increase in the flow capacity of the high-throughflow routing. Since the annular member forms a support structure along the first cross section of the high-throughflow routing, the blocking capacity of the liquid solder at all locations along the length of the high-throughflow routing is consistent, thereby not only improving the flow capacity of the high-throughflow routing, but also making the flow more stable.

[0056] Furthermore, multiple annular members are connected in sequence in a spiral shape so that the annular support frame 3 is scalable along its first direction, so that different high-throughput current routing lines can use an annular support frame 3 of the same length, and the annular support frame 3 only needs to be stretched to different lengths when in use, without the need for precise customization according to the length of the target routing line 1 as in the prior art prefabricated sheets or high-current copper wires, which is conducive to normalized design, improves the versatility of the annular support frame 3 while reducing the cost of the printed circuit board.

[0057] Furthermore, the second cross section of the annular member is set to be rectangular, and the long side of the rectangle is set to fit the target line 1, that is, the annular member is flat. This arrangement can increase the contact area between the annular member and the target line 1, thereby increasing the connection firmness between the annular support frame 3 and the target line 1.

[0058] In this embodiment, the annular support frame 3 includes a welding section 31 and a connecting section 32. The welding section 31 includes a plurality of annular members spaced and sequentially connected along the first direction of the annular support frame 3. The annular members are used to block the liquid solder during the wave soldering process, so that the liquid solder can be welded to the target wiring 1 in the shape of the second cross section of the welding section 31, ensuring that the flow capacity of the solder to the target wiring 1 is effectively increased; and a plurality of welding sections are spaced along the first direction of the target wiring 1 to cover the target wiring 1, so that the blocking capacity of the target wiring 1 at all locations along the length of the target wiring 1 is consistent, thereby not only improving the flow capacity of the target wiring 1 after wave soldering, but also making the flow more stable. The connecting section 32 is arranged at both ends of the welding section 31, and is used to connect with the circuit board substrate. While ensuring that the annular support frame 3 is stably connected to the circuit board substrate, the wave soldering effect can be further ensured.

[0059] Furthermore, a positioning hole 11 is provided on the circuit board substrate, and the connecting section 32 is connected to the circuit board substrate through the positioning hole 11. In order to realize the connection between the annular support frame 3 and the circuit board substrate, positioning holes 11 are opened at both ends of the target wiring 1, so that both ends of the annular support frame 3 can be placed in the positioning holes 11 and connected to the positioning holes 11, that is, the positioning holes 11 are opened at both ends of the circuit board substrate corresponding to the target wiring 1, and its diameter is adapted to the diameter of the connecting section 32, so as to ensure that the connecting section 32 placed in the positioning hole 11 can realize the stable connection between the annular support frame 3 and the circuit board substrate. Optionally, the connecting section 32 can be set as a straight section, connected to the positioning hole 11 by interference or welding; or the connecting section 32 can also be set as a hook, and the connection with the circuit board substrate is realized by hooking on the positioning hole 11.

[0060] It is worth noting that the printed circuit board in this embodiment can be manufactured by the wave soldering routing method provided in the first embodiment.

[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A wave soldering routing method, characterized in that: The method comprises: Determine the target traces on the circuit board that need to have increased current flow capacity (1); The annular support frame (3) is arranged at the target routing line (1), and the annular support frame (3) corresponds to the target routing line (1); When soldering the circuit board, the annular support frame (3) is brought into contact with liquid solder.

2. The wave soldering routing method according to claim 1, characterized in that: The process of bringing the annular support frame (3) into contact with liquid solder comprises: immersing the annular support frame (3) in the liquid solder.

3. The wave soldering routing method according to claim 1, characterized in that: Before bringing the annular support frame (3) into contact with the liquid solder, the method further comprises: The annular support frame (3) is pre-fixed at the target routing line (1) so that the annular support frame (3) corresponds to the target routing line (1).

4. The wave soldering routing method according to claim 1, characterized in that: Before bringing the annular support frame (3) into contact with the liquid solder, the method further comprises: According to the length parameter of the target routing line (1), the length parameter of the annular support frame (3) is adjusted so that the length of the annular support frame (3) corresponds to the length of the target routing line (1).

5. A printed circuit board, characterized in that: The invention comprises a circuit board substrate, the circuit board substrate is provided with a welding surface, the welding surface is provided with a high-throughput flow routing, an annular support frame (3) is provided at the high-throughput flow routing, and the first cross-section of the high-throughput flow routing comprises a plurality of support structures of the annular support frame (3) arranged at intervals along the first direction thereof.

6. The printed circuit board according to claim 5, characterized in that: The annular support frame (3) is provided with a plurality of annular members spaced apart along a first direction thereof, and the annular members form the support structure along a first cross section of the high-throughput flow routing line.

7. The printed circuit board according to claim 6, characterized in that: The plurality of annular members are connected in sequence in a spiral shape, so that the annular support frame (3) is retractable along its first direction.

8. The printed circuit board according to claim 6, characterized in that: The second cross section of the annular member is configured to be rectangular.

9. The printed circuit board according to claim 6, characterized in that: The annular support frame (3) comprises a welding section (31) and a connecting section (32); the welding section (31) comprises a plurality of annular members which are spaced apart and sequentially connected along a first direction of the annular support frame (3); the connecting section (32) is arranged at both ends of the welding section (31) and is used for connecting to the circuit board substrate.

10. The printed circuit board according to claim 9, characterized in that: A positioning hole (11) is provided on the circuit board substrate, and the connecting section (32) is connected to the circuit board substrate through the positioning hole (11).

Images