Solder pre-planting apparatus, pre-planting process and packaging method

Abstract

The application provides a solder pre-planting device, a pre-planting process and a packaging method. The device realizes accurate positioning and hovering control of the solder pad through the collaborative design of the T-shaped cavity structure, the height adjusting mechanism and the needle stopper. The micron-level annular gap realizes heat insulation and overflow prevention. The size is optimized to balance the installation tolerance and the alignment accuracy, and manual and automatic adjustment modes are provided to balance the operation flexibility and the automation prospect. The design significantly improves the solder forming stability and the product yield. The pre-planting process based on the device can form a standardized solder body in an independent station, and the packaging method realizes reliable connection through two reflow soldering. The overall scheme simplifies the production process, reduces the dependence on precision printing process, improves the automation level, and realizes efficiency improvement and cost optimization.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor integrated circuit manufacturing technology, and relates to a solder pre-planting device, pre-planting process and packaging method. Background Technology

[0002] Power module packaging technology is facing the dual challenges of high power density and high-efficiency production. Current mainstream inline solder paste printing processes have significant technical bottlenecks: direct printing of solder paste onto copper-clad laminates requires high-precision positioning equipment, and the printing process itself is easily affected by solder paste viscosity, stencil condition, and environmental factors, readily resulting in defects such as uneven printing thickness, pattern misalignment, bridging, or missing prints. This not only leads to fluctuations in subsequent soldering yield but also forces the production line to add optical inspection and rework stations, severely hindering production cycle time and automation continuity. Simultaneously, as power modules evolve towards multi-pin, fine-pitch, and three-dimensional stacking, the issues of thermal management and precise solder distribution in the pin area are becoming increasingly prominent. In traditional processes, pins and pads are prone to thermal short circuits during reflow soldering, and solder tends to climb or overflow along the pins at high temperatures, affecting electrical insulation performance and long-term reliability. While existing pre-plating solder technology can partially solve these problems, it still falls short in terms of precise solder volume control, pin thermal isolation, and flexibility to adapt to different product specifications, making it difficult to meet the stringent requirements of high-reliability power modules for solder joint consistency and process stability.

[0003] Therefore, the industry urgently needs an innovative pre-plating solution that can achieve precise quantitative distribution of solder, effectively isolate the heat-affected zone of pins, adapt to rapid switching between multiple product specifications, and be integrated into automated production lines.

[0004] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a solder pre-planting device, pre-planting process and packaging method to solve the problems of complex process, difficult solder forming control, low degree of automation and poor soldering consistency caused by traditional solder paste printing process in the packaging of existing power modules.

[0006] To achieve the above and other related objectives, the present invention provides a solder pre-implantation apparatus, a pre-implantation process, and a packaging method, comprising:

[0007] First, this application provides a solder pre-planting device, comprising:

[0008] Support base;

[0009] A pin clamp is mounted on the support base via a height adjustment mechanism, and the pin clamp has multiple through T-shaped cavities.

[0010] A pin stop is provided on the support base and located below the corresponding T-shaped cavity, and the height of the top end of the pin stop is adjustable;

[0011] The T-shaped cavity includes an upper frustum-shaped pad receiving cavity and a lower pin guide hole coaxial with the pad receiving cavity; the pad receiving cavity is used to receive the pad of the workpiece to be soldered; the inner diameter of the pin guide hole is larger than the diameter of the pin of the workpiece to form a heat-insulating and anti-overflowing annular gap between them, and the depth of the pin guide hole is smaller than the length of the pin;

[0012] The height adjustment mechanism and the ejector pin stop are configured to adjust in coordination to dynamically adjust the relative distance between the pin clamp and the ejector pin stop in the vertical direction; when the lower end of the inserted pin is blocked by the ejector pin stop, the pad is raised and suspended at a preset target height through coordinated operation.

[0013] Optionally, the preset target height can be continuously changed and set by adjusting the height adjustment mechanism and / or the ejector pin stop to adapt to workpieces of different specifications.

[0014] Optionally, the pad receiving cavity is a groove for accommodating the pad, the upper surface of the pad is lower than the opening plane of the groove, and there is a preset distance between the lower surface of the pad and the bottom plane of the groove. The space defined by the preset distance is a pre-installed solder space. The pre-installed solder space is used to accommodate the solder formation and to make the surface of the solder formation after solidification flush with the opening plane.

[0015] Optionally, the height adjustment mechanism is a manual adjustment mechanism or an automatic adjustment mechanism; wherein, the manual adjustment mechanism includes a threaded post disposed on the pin clamp and a nut cooperating with the threaded post, the threaded post being mounted on the support base, and height adjustment is achieved by rotating the nut; the automatic adjustment mechanism includes a clamp drive motor, a transmission assembly, and a clamp mounting base; the pin clamp is fixedly mounted on the clamp mounting base; the clamp drive motor drives the clamp mounting base to perform linear lifting and lowering motion relative to the support base through the transmission assembly.

[0016] Optionally, the height of the ejector pin stop can be adjusted and locked independently of the height adjustment mechanism; the height of the ejector pin stop is adjusted by a manual adjustment structure or an electric drive device; the electric drive device includes an ejector pin drive motor and an ejector pin transmission mechanism connected to the ejector pin drive motor.

[0017] Optionally, it also includes a control system; when the height adjustment mechanism is an automatic adjustment mechanism, the clamp drive motor is electrically connected to the control system; when the ejector pin stop is adjusted by an electric drive device, the ejector pin drive motor is electrically connected to the control system; the control system controls the drive motor electrically connected to it according to the configuration of the solder pre-planting device, so as to position the solder pad to the preset target height.

[0018] Optionally, the minimum inner diameter of the pad receiving cavity is greater than the diameter of the pad, and the excess is 0.5 mm to 1 mm; the depth of the pad receiving cavity is at least 2.5 times the thickness of the pad.

[0019] Optionally, the radial width of the annular gap is 0.05 mm to 0.1 mm; the depth of the pin guide hole is not greater than half the length of the pin.

[0020] This application also provides a pre-planting process using the solder pre-planting apparatus described in any of the preceding claims, comprising the following steps:

[0021] S1, Adjust the height adjustment mechanism to increase the distance between the pin clamp and the support base;

[0022] S2, insert the multiple workpieces vertically into the T-shaped cavity respectively, so that the pins extend downwards;

[0023] S3, reverse the height adjustment mechanism to reduce the distance between the pin holder and the support base until the pin stop contacts and lifts the lower end of the pin, so that the pad is lifted and stably suspended in the predetermined position in the pin holder.

[0024] S4, providing a solder application assembly and pre-planting solder on the back side of the pad of the workpiece to form a solder formation of a predetermined height;

[0025] S5, Clean the workpiece after pre-applied solder.

[0026] In addition, this application also provides a packaging method based on the aforementioned pre-implantation process, comprising the following steps:

[0027] Provide the workpiece processed by the pre-planting process, wherein the workpiece is a signal terminal having a solid solder formation on the pad;

[0028] The signal terminal is mounted to the designated position on the copper-clad laminate, so that the solid solder formation is aligned and in contact with the surface of the copper-clad laminate;

[0029] The copper-clad substrate with the signal terminals is reflow soldered.

[0030] Cooling forms solder joints.

[0031] As described above, this invention provides a solder pre-planting device, a pre-planting process, and a packaging method. The device achieves precise pad positioning and hovering control through the coordinated design of a T-shaped cavity structure, a height adjustment mechanism, and a pin stop. The micron-level annular gap provides heat insulation and spill prevention; its optimized dimensions balance installation tolerance and alignment accuracy, and it offers both manual and automatic adjustment modes, balancing operational flexibility and automation potential. This design significantly improves solder forming stability and product yield. The pre-planting process based on this device can form standardized solder bodies at independent workstations, and the packaging method uses two reflow soldering processes to achieve reliable connections. The overall solution simplifies the production process, reduces reliance on precision printing processes, and achieves efficiency improvement and cost optimization while enhancing automation levels. Attached Figure Description

[0032] Figure 1 The diagram shown is a structural schematic of the solder pre-planting device according to an embodiment of the present invention.

[0033] Figure 2 The diagram shown is a schematic representation of a solder pre-planting device with an automatic height adjustment mechanism, according to an embodiment of the present invention.

[0034] Figure 3 The illustration is shown as an embodiment of the present invention. Figure 1 or Figure 2 A schematic diagram of the structure during the pre-planting of solder in the pre-planting device.

[0035] Figure 4 The diagram shown is a schematic representation of the structure after the pre-applied solder has cooled in an embodiment of the present invention.

[0036] Figure 5 The diagram shows a flow chart of the automated packaging process according to an embodiment of the present invention.

[0037] Explanation of reference numerals in the attached figures

[0038] 100 workpiece 110 solder pads 120 pin 200 Pin clamp 210 Pad Receiving Cavity 220 Pin guide hole 230 T-shaped cavity 300 support base 310 Nut 320 Fixture mounting base 330 Transmission components 340 clamp drive motor 350 Threaded column 360 Height adjustment mechanism 400 Ejector pin stop 410 ejector pin drive motor 420 Ejector pin transmission mechanism 500 control system 600 Solder application assembly Detailed Implementation

[0039] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0040] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0041] Example 1

[0042] This embodiment provides a solder pre-implantation device, which will be described below in conjunction with the appendix to the specification. Figure 1 ~Appendix Figure 4 The paper introduces and explains the relevant solder pre-planting device.

[0043] See Figures 1-2 The solder pre-planting device includes: a support base 300, a pin clamp 200, and a pin stop 400.

[0044] The pin clamp 200 is mounted on the support base 300 via the height adjustment mechanism 360, and the pin clamp 200 is provided with multiple through T-shaped cavities 230;

[0045] Ejector stop 400 is disposed on support base 300 and located below corresponding T-shaped cavity 230, and the top height of ejector stop 400 is adjustable.

[0046] The T-shaped cavity 230 includes a pad receiving cavity 210 with an upper part in the shape of a frustum cone and a pin guide hole 220 coaxial with the pad receiving cavity 210 at the lower part; the pad receiving cavity 210 is used to receive the pad 110 of the workpiece 100 to be soldered; the inner diameter of the pin guide hole 220 is larger than the diameter of the pin 120 of the workpiece 100, so as to form a heat-insulating and anti-overflowing annular gap between the two, and the depth of the pin guide hole 220 is smaller than the length of the pin 120 of the workpiece 100.

[0047] The height adjustment mechanism 360 and the ejector pin stop 400 are configured to adjust in coordination to dynamically adjust the relative distance between the pin clamp 200 and the ejector pin stop 400 in the vertical direction. When the lower end of the pin 120 of the inserted workpiece 100 is blocked by the ejector pin stop 400, the pad 110 of the workpiece 100 is raised and suspended at a preset target height through coordinated operation.

[0048] Specifically, in this embodiment, tin is used as the solder. The support base 300 is made of aluminum alloy with a thickness ranging from 0.5 to 2 mm. The support base 300 can be equipped with moving parts to accommodate the needs of moving pins or pre-installing solder. This device achieves precise adjustment of the height of the pad 110 through the synergistic action between the height-adjustable pin clamp 200 and the ejector pin stop 400 on the support base 300. In addition, the special design of the T-shaped cavity 230 not only provides physical isolation but also achieves precise guidance and shaping control of the solder. When the workpiece 100 is loaded, the pin 120 passes through the lower pin guide hole 220, while the pad 110 is accommodated in the upper pad receiving cavity 210. The root of the connection between the two is precisely located at the annular throat where the bottom of the pad receiving cavity 210 intersects with the top of the pin guide hole 220. This annular throat is a key area for solder filling and shaping. During the soldering process, molten solder is injected into the pre-pile solder space around the pad 110 and, driven by capillary action and pressure, is actively guided and fills the entire circumferential interface where the pad 110 root connects to the pin 120. Simultaneously, the extremely small annular gap between the pin guide hole 220 at the bottom of the cavity and the pin 120 physically constitutes a reliable barrier, effectively preventing solder from overflowing further down the pin 120. Furthermore, since most of the pin 120 is suspended or in contact with the low-temperature pin holder 200 hole wall, its temperature is significantly lower than that of the pad 110 area. Molten solder does not easily wet the lower-temperature surface of the pin 120, which may be surrounded by the hole wall. At the same time, the inner wall of the pin guide hole 220 (usually made of a non-wetting material such as stainless steel) also inhibits solder adhesion. Therefore, the solder is precisely confined within the pre-defined cavity, forming a full and consistent solder mass on the back and root of the pad 110, without overflowing downwards along the pin 120, ensuring a high degree of controllability and forming quality in the soldering process. Of course, the T-shaped cavity 230 design has various variations, such as multi-stage steps, asymmetric structures, or integrated venting channels. Furthermore, the choice of solder is not limited to tin-based materials, and the support base 300 can be flexibly designed in terms of specific materials and thickness parameters according to application requirements, offering wide applicability.

[0049] In one specific embodiment, the ejector pin stop 400 is provided with a positioning structure, which is a conical or V-shaped groove formed at the top of the ejector pin stop 400. In another embodiment, the positioning structure is a guide sleeve fixed to the top of the ejector pin stop 400. The guide sleeve has a centering hole coaxial with the pin guide hole 220, and the inner diameter of the centering hole is slightly larger than the diameter d1 of the pin 120.

[0050] As an example, the preset target height can be continuously changed and set by adjusting the height adjustment mechanism 360 and / or the ejector pin stop 400 to adapt to workpieces 100 of different specifications.

[0051] Specifically, the preset target height is not a fixed value, but can be steplessly and precisely set and locked through independent or coordinated operation of two adjustment methods, depending on the size of different workpieces 100, the length of pins 120, or welding process requirements. In one specific embodiment, the pin clamp 200 can be provided with multiple T-shaped cavities 230, each corresponding to its respective ejector pin stop 400. Multiple T-shaped cavities 230 can be set independently to simultaneously meet the needs of workpieces 100 of different sizes. This design allows the device to flexibly handle various types of workpieces 100 without the need to replace or customize dedicated positioning components, thereby significantly improving the equipment's versatility, adaptability, and production flexibility, and reducing the time and cost of switching between different products.

[0052] As an example, the pad receiving cavity 210 is a groove for accommodating the pad 110. The upper surface of the pad 110 is lower than the opening plane of the groove, and there is a preset distance between the lower surface of the pad 110 and the bottom plane of the groove. The space defined by the preset distance is the pre-installed solder space. The pre-installed solder space is used to accommodate the solder formation.

[0053] Specifically, in this device, the pre-padded solder space is the core for achieving standardized solder forming. The function of the pre-padded solder space is to accommodate a quantitative amount of molten solder and, after cooling and solidification, form a regular and uniform solder body (such as pre-padded solder balls). The entire process relies on the coordinated adjustment of the height adjustment mechanism 360 and the ejector pin stop 400. First, by operating the height adjustment mechanism 360 to coarsely adjust the overall height of the insert clamp 200, and combined with the fine setting of the ejector pin stop 400, the solder pad 110 of the workpiece 100 inserted into the T-shaped cavity 230 is precisely raised and stably suspended at a preset target height within the solder pad receiving cavity 210. In this suspended state, a pre-padded solder space with a controllable preset spacing is formed between the lower surface of the solder pad 110 and the bottom plane of the groove. The height of this space is directly determined by the coordinated adjustment. Therefore, the final shape of the solder body after a quantitative amount of solder is injected into this space and solidified is determined by this space. By precisely matching the groove depth, preset spacing, and solder amount, it can be ensured that the upper surface of the solidified solder body is ultimately flush with the opening plane of the groove, thus forming a welding interface at a preset height. This not only achieves consistency in solder joint shape and height but also allows the same device to flexibly form standardized solder joints of different volumes, all with their upper surfaces flush with the same reference plane (opening plane), by setting different hovering heights. This provides a precise and reliable reference for subsequent automated mounting and welding.

[0054] As an example, the height adjustment mechanism 360 can be a manual adjustment mechanism or an automatic adjustment mechanism; wherein, the manual adjustment mechanism includes a threaded post 350 disposed on the pin clamp 200 and a nut 310 that mates with the threaded post 350, the threaded post 350 is mounted on the support base 300, and the height is adjusted by rotating the corresponding nut 310; the automatic adjustment mechanism includes a clamp drive motor 340, a transmission assembly 330 and a clamp mounting base 320; the pin clamp 200 is fixedly mounted on the clamp mounting base 320; the clamp drive motor 340 drives the clamp mounting base 320 to perform linear lifting and lowering motion relative to the support base 300 through the transmission assembly 330.

[0055] Specifically, as one implementation of the manual adjustment scheme, by rotating the corresponding nut 310, the pin clamp 200 can be driven to move up and down relative to the support base 300, thereby achieving fine adjustment and locking of the height.

[0056] Furthermore, as a specific implementation of the automatic adjustment scheme, the pin clamp 200 is fixedly mounted on the clamp mounting base 320, and the clamp drive motor 340 drives the clamp mounting base 320 through the transmission component 330 (e.g., gear rack or synchronous belt pulley mechanism), thereby causing the pin clamp 200 to make precise linear lifting and lowering movements relative to the support base 300.

[0057] As an example, the height of the ejector stop 400 can be adjusted and locked independently of the height adjustment mechanism 360; the height of the ejector stop 400 can be adjusted by a manual adjustment structure or an electric drive device; the electric drive device includes an ejector drive motor 410 and an ejector transmission mechanism 420 connected to the ejector drive motor 410.

[0058] Specifically, the height of the ejector pin stop 400 can be independently adjusted and locked to set the blocking position of the lower end of the pin 120 of the workpiece 100, and coordinate with the height of the pin clamp 200 to form dynamic hovering control of the pad 110. Depending on operational requirements, the height of the ejector pin stop 400 can be adjusted manually or electrically.

[0059] In the manual adjustment scheme, in this embodiment, the pin stop 400 can be designed as a fine-tuning screw structure with scale markings, or it can be connected to the slide rail by a locking screw, so that the operator can conveniently and intuitively set the height and mechanically fix it according to the length of the pin 120.

[0060] In the electrically driven solution, the ejector pin stop 400 is connected to an independent electric drive unit. This unit mainly includes an ejector pin drive motor 410 (such as a stepper motor or servo motor) and an ejector pin transmission mechanism 420 (such as a lead screw and nut pair or a precision linear module) connected to the motor output. By driving the ejector pin stop 400 to make precise linear movements in the vertical direction through the transmission mechanism, not only can the height be quickly and programmably adjusted, but it can also be linked with the height adjustment mechanism 360 of the pin clamp 200 for linkage control, thereby completing the precise positioning of the pad 110 in the automated production process.

[0061] As an example, a control system 500 is also included; when the height adjustment mechanism 360 is an automatic adjustment mechanism, the clamp drive motor 340 is electrically connected to the control system 500; when the ejector pin stop 400 is adjusted by an electric drive device, the ejector pin drive motor 410 is electrically connected to the control system 500; the control system 500 is configured to position the solder pad 110 to a preset target height by coordinating the clamp drive motor 340 and the ejector pin drive motor 410. Depending on the configuration of the solder pre-planting device, the drive motor electrically connected thereto is controlled to position the solder pad 110 to the preset target height.

[0062] Specifically, the fixture drive motor 340 (for controlling the height of the pin clamp 200) and the ejector drive motor 410 (for controlling the height of the ejector stop 400) are both electrically connected to the control system 500 via their respective drivers, receiving motion commands from the corresponding control system 500. The control system 500 is configured to have a coordinated motion control function, and it has pre-stored or can input in real time process parameters such as the pin length 120 of the workpiece 100 and the height of the target pad 110. Through a specific control algorithm, it synchronously or sequentially sends precise pulse or analog signals to the two motors to drive them to coordinate their movements. Furthermore, firstly, the control system 500 instructs the ejector drive motor 410 to raise the ejector stop 400 to a predetermined reference position matching the length of the pin 120 of the workpiece 100. Then, the control system 500 instructs the fixture drive motor 340 to move the pin clamp 200 downwards until the lower end of the pin 120 of the workpiece 100 contacts the ejector stop 400 and is obstructed. At this point, through feedback from a force sensor or position encoder, the control system 500 can accurately identify the contact point and continue to control the fixture drive motor 340 to descend slightly according to a preset program, thereby precisely lifting the pad 110 and stabilizing it at a preset target height. The entire process is automated and repeatable, ensuring high consistency, high efficiency, and high precision in the positioning of the pad 110 during mass production. In another specific embodiment, the device also includes a height feedback device to receive and process information from the control system and output instructions in a timely manner. Of course, in one specific embodiment, the height adjustment mechanism 360 is a manual adjustment mechanism, while the ejector pin stop 400 is adjusted by an electric drive device. In this case, the control system 500 is connected to the ejector pin stop 400 to achieve electric control of the ejector pin stop 400. In another embodiment, the height adjustment mechanism 360 is an electric adjustment mechanism, while the ejector pin stop 400 is adjusted by a manual adjustment device. In this case, the control system 500 is connected to the height adjustment mechanism 360 to achieve electric control of the height adjustment mechanism 360.

[0063] As an example, the minimum inner diameter of the pad receiving cavity 210 is D2, and the diameter of the pad 110 is d2, where D2 and d2 satisfy 0.5mm≤D2-d2≤1mm; the depth of the pad receiving cavity 210 is H2, and the thickness of the pad 110 is t; H2 and t satisfy H2≥2.5t.

[0064] See Figure 1Specifically, the key dimensions of the pad receiving cavity 210 are designed to ensure stable positioning of the workpiece 100 and facilitate high-quality pre-poured solder. The range of D2-d2 is designed to be 0.5~1mm, such as any value within this range, like 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, etc. This design aims to provide sufficient assembly tolerance to ensure that the workpiece 100 can be smoothly and without jamming during loading and unloading, ensuring production cycle time and operational reliability. At the same time, since the pad receiving cavity 210 is typically a truncated cone-shaped structure with a larger top and a smaller bottom, this gap range gives the pad 110 a certain self-aligning capability, allowing it to naturally adjust to a position close to the center of the pad receiving cavity 210 under the action of gravity, thus laying the foundation for the subsequent formation of a solder body with uniform circumferential thickness. Thirdly, this gap also provides a safety space for material thermal expansion, preventing damage to the workpiece 100 or the fixture due to differences in the coefficient of thermal expansion at the high temperature of soldering.

[0065] Furthermore, the depth design between the depth H2 of the pad receiving cavity 210 and the thickness t of the pad 110 ensures that the upper surface of the pad 110 is lower than the opening plane of the groove. The height difference between the two (i.e., H2-t) directly constitutes the axial height of the "pre-pile solder space" used to accommodate the solder. The setting of H2≥2.5t means that the axial space height reserved for the solder is at least 1.5 times the thickness of the pad 110. This ensures sufficient and consistent volume to form a mechanically reliable and well-shaped solder mass (such as a solder ball), while avoiding poor solder formation or appearance defects due to insufficient space.

[0066] As an example, the radial width of the annular gap is 0.05~0.1mm; the depth of the pin guide hole 220 is H1, and the length of the pin 120 is L, where H1 and L satisfy H1≤L / 2.

[0067] Specifically, the mating dimensions between the lead guide hole 220 and the lead 120 of the workpiece 100 are precisely designed to ensure effective thermal isolation, reliable solder spill prevention, and sufficient travel space for the lifting action. The difference between the inner diameter D1 of the lead guide hole 220 and the diameter d1 of the lead 120 of the workpiece 100 forms an annular gap with a radial width controlled within the range of 0.05~0.1mm. This micron-level gap design reduces the contact area between the lead 120 and the metal hole wall, forming an effective thermal barrier that prevents heat from being conducted downwards along the lead 120 during soldering, avoiding unnecessary thermal impact on the distal end of the lead 120 or the soldered area. Secondly, this extremely narrow gap generates a strong capillary flow resistance effect under the surface tension of the molten solder, thereby forming a reliable physical seal that actively prevents solder from seeping downwards along the lead 120, ensuring that the solder is precisely confined to the back and root area of ​​the pad 110.

[0068] Furthermore, the depth restriction of H1 ≤ L / 2 ensures that after the workpiece 100 is inserted, more than half of the pin 120 length (≥ L / 2) hangs below the pin guide hole 220, where L refers to the total length of the pin 120. By reserving a sufficiently long pin segment below the pin 120, a clear contact and action area is provided for the ejector pin stop 400, ensuring the stability and precision of the lifting action. This prevents problems such as unstable contact, poor lifting force transmission, or ineffective lifting caused by an excessively deep pin guide hole 220 (excessively large H1), thus preventing precise control of the pad 110's hovering height. Simultaneously, this depth ratio affects the volume and shape of the solder forming space. This design ensures precise and stable positioning of the pad 110 both radially and axially, providing crucial geometric constraints for the subsequent formation of high-quality, consistent solder joints. At the same time, the solder is precisely guided and filled to the entire circumferential interface between the pad 110 and the pin 120, forming a full weld seam, effectively increasing the connection area and mechanical strength.

[0069] It should be noted that the specific dimensions mentioned above (0.5mm≤D2-d2≤1mm and H2≥2.5t; gap of 0.05~0.1mm and depth relationship of H1≤L / 2) are a typical design example. In practical applications, adaptive adjustments can be made based on this design principle according to different workpiece sizes, solder characteristics and process requirements, which does not constitute a limitation on the scope of the present invention.

[0070] In summary, this pre-applied solder device, through the collaborative design of its T-shaped cavity structure, height adjustment mechanism, and ejector pin stop, demonstrates significant technical advantages in terms of ease of operation, process controllability, and repeatability. Specifically: its collaborative adjustment mechanism enables precise programmable positioning of the solder pad height; the T-shaped cavity and micron-level annular gap effectively ensure thermal isolation and solder overflow prevention; the optimized key dimensions of the solder pad receiving cavity and pin guide holes balance assembly tolerance, alignment capability, and thermal expansion margin; and the coexistence of manual and automatic adjustment modes provides operational flexibility and potential for automation expansion. The overall design, through precise control of solder morphology and volume, not only ensures the stability of the heating process and solder formation but also lays a solid foundation for achieving standardized and highly consistent welding processes, significantly improving product yield and process reliability.

[0071] Example 2

[0072] This embodiment proposes a pre-planting process, employing any of the solder pre-planting devices described in Embodiment 1 above. The following is a detailed description in conjunction with the appendix. Figure 1 ~Appendix Figure 2 The process for pre-applying solder includes the following steps:

[0073] First, refer to Figure 1 and Figure 2Adjust the height adjustment mechanism 360° to increase the distance between the pin clamp 200 and the support base 300.

[0074] Specifically, the height adjustment mechanism 360 is adjusted to increase the vertical distance between the pin clamp 200 and the support 300. This step aims to provide operating space for subsequent loading and positioning adjustment of the workpiece 100. By operating the height adjustment mechanism 360 (manually rotating the corresponding nut 310 or setting the clamp drive motor 340), the pin clamp 200 is driven upward, creating sufficient space between it and the support 300, thereby providing passage space for the pin 120 and ensuring that the pin 120 of the workpiece 100 can pass smoothly and without interference through the pin guide hole 220. Simultaneously, it also allows for the travel of the ejector pin stop 400, providing movement space for the ejector pin stop 400 to move upward and lift the lower end of the pin 120. Furthermore, by adjusting the initial distance, the device can be adapted to workpieces 100 with different pin lengths, improving versatility.

[0075] Next, multiple workpieces 100 are vertically inserted into the corresponding T-shaped cavities 230 of the pin clamp 200, so that the pins 120 of the workpieces 100 extend downwards.

[0076] Specifically, in this embodiment, the pre-soldering device is connected to an automated feeding mechanism, which picks up the workpiece 100, aligns the pad 110 end of the workpiece 100 with it, and places it into the pad receiving cavity 210 at the top of the T-shaped cavity 230. Then, a light force is applied vertically (depending on the actual situation) to allow the pins 120 of the workpiece 100 to smoothly pass through the lower pin guide hole 220 until the pins 120 extend a certain length from the bottom of the pin holder 200. During this process, the pad receiving cavity 210 provides radial positioning and circumferential constraint for the pads 110 of the workpiece 100, while the pin guide hole 220 ensures that the pins 120 maintain a vertical orientation, preventing skewing. After all workpieces 100 are loaded, they are arranged in an array with their pins 120 hanging downwards, ensuring that the initial orientation of each workpiece 100 is consistent before soldering.

[0077] Next, the height adjustment mechanism 360 is adjusted in the opposite direction to reduce the distance between the pin holder 200 and the support base 300 until the pin stop 400 contacts and lifts the lower end of the pin 120, so that the pad 110 is lifted and stably suspended in the predetermined position in the pin holder 200.

[0078] Specifically, after the workpiece 100 is loaded, the height adjustment mechanism 360 is operated in the opposite direction to step S1 (the nut 310 corresponding to the manual reverse knob or the clamp drive motor 340 runs in reverse). As the pin clamp 200 descends, the lower ends of the downward-extending pins 120 of each workpiece 100 will gradually approach and eventually contact the pre-set height ejector pin stop 400, thus stopping the pins 120 from descending. If the pin clamp 200 continues to move downward at this time, since the pins 120 are blocked by the ejector pin stop 400, the workpiece 100 will have an upward relative displacement relative to the pin clamp 200, thereby gradually lifting the pads 110 of the workpiece 100 from the bottom of the pad receiving cavity 210. Through the coordinated control of the height adjustment mechanism 360 and the ejector pin stop 400, when the back of the pad 110 reaches the preset target height, the pad 110 is stably suspended in the pad receiving cavity 210. A precise pre-soldering space is formed between the lower surface of the pad 110 and the bottom of the pad receiving cavity 210. This enables the synchronous and precise positioning of the pads 110 of all workpieces 100, providing a uniform and consistent forming space for subsequent soldering.

[0079] Next, a solder application assembly 600 is provided, and solder is pre-planted on the back side of the pad 110 of the workpiece 100 to form a solder formation of a predetermined height.

[0080] For details, please refer to Figures 2-3 , Figure 3 In this embodiment, the solder on the surface of pad 110 before the pre-padded solder cools is shown as an example. Since the solder used is solder, the solder application component 600 can be a soldering iron, an automatic soldering mechanism, etc. During the soldering process, molten solder (such as solder wire) is quantitatively applied through this component to the pre-padded solder space enclosed by the back of pad 110 and the bottom of pad receiving cavity 210. The solder melts upon heating and fills the space, achieving good wetting and bonding at the root of pad 110. Subsequently, it cools and solidifies naturally, ultimately forming a solder formation (such as a hemispherical or columnar solder joint) with a regular shape, fixed volume, and uniform height on the back of pad 110. See also Figure 4 After cooling, the solder joint between the pad 110 and the pin 120 of the workpiece 100 becomes convex, and its solder joint strength is superior to that of conventional soldering processes. The height of this solder formation is precisely controlled by the dimensions of the pre-installed solder space, thereby ensuring that it meets the assembly and soldering requirements of subsequent packaging processes. Of course, the solder application component 600 can also be manually controlled; there is no limitation here.

[0081] Furthermore, in one specific embodiment, the solder application component 600 in this device communicates with the control system 500. The control system 500, through coordinated control of the height adjustment mechanism 360, the ejector pin stop 400, and the solder application component 600, enables the solder application component 600 to precisely align with the opening of the pad receiving cavity 210 and perform the solder placement operation, thereby achieving full-process automation and precise control. This process is based on quantitative supply and process coordinated control, with the solder volume strictly matching the pre-placed solder space volume to prevent overflow from the source; simultaneously, the solder placement process is fast and controllable, with the heat source quickly removed after the solder melts and fills, and rapid solidification under the constraint of the T-shaped cavity 230, avoiding capillary penetration. Through the coordinated drive of the control system 500, a quantitative amount of solder is precisely applied to the back of the positioned pad 110, ultimately forming a regular, consistent, and reliable solder body.

[0082] Finally, the pre-applied solder workpiece 100 is cleaned.

[0083] Specifically, in this embodiment, the workpiece 100 after tinning is placed in a cleaning device to remove residual flux, oxides, and other contaminants from the tinning process, ensuring the cleanliness of the solder joints and the surface of the workpiece 100. The workpiece 100 is then dried to meet the cleanliness and reliability standards required for subsequent packaging or storage.

[0084] As shown above, by determining the total volume of the solder body through "highly precise adjustment" and controlling the precise flow direction and final shape of the solder through "T-shaped cavity guidance and limiting," reliable solder filling at the root and effective anti-overflow of pin 120 are simultaneously achieved. This not only ensures the metallurgical bonding strength and electrical continuity of the solder, but also greatly improves process stability and product yield, demonstrating significant advantages in operational controllability and repeatability.

[0085] Example 3

[0086] This embodiment provides a packaging method based on the pre-applied solder process of Embodiment 2. The method mainly includes two stages: a substrate functional module fabrication stage and a signal terminal assembly and soldering stage. (See reference...) Figure 5 The steps are as follows:

[0087] First, the substrate functional module preparation stage is carried out, which is a conventional process stage. Specifically, it includes: providing a copper-clad substrate, mounting solder sheets and functional devices accordingly, fixing it after the first formic acid reflow soldering, and then bonding and interconnecting the functional devices as needed to obtain a substrate semi-finished product with integrated internal functional modules.

[0088] Next, the signal terminal assembly and soldering stage of the present invention is carried out, specifically including the following steps:

[0089] First, step S3-1 is performed to provide a workpiece 100 that has been pre-processed in Embodiment 2. The workpiece 100 is a signal terminal with a solid solder formation on the pad 110.

[0090] Next, perform step S3-2 to mount the signal terminals to the designated positions on the copper-clad laminate, so that the solid solder morphs are aligned and in contact with the surface of the copper-clad laminate.

[0091] Next, step S3-3 is performed to reflow solder the copper-clad substrate equipped with signal terminals. The solid solder remelts and wets the signal terminal pads 110 and the designated positions on the copper-clad substrate to form a connection.

[0092] Next, steps S3-4 are performed. After cooling, solder joints are formed between the signal terminals and the copper-clad substrate to complete the encapsulation.

[0093] In a preferred automated embodiment, steps S3-1 and S3-2 are completed automatically: multiple signal terminals are inserted into a special fixture by an automatic pin insertion machine; after being inspected by a vision system, a robotic arm picks up the fixture and flips it to align it with the copper-clad substrate; then the signal terminals are released so that they fall precisely into the designated position.

[0094] Preferably, to ensure accurate alignment of the signal terminals with the solder joints on the copper-clad laminate, this embodiment forms localized grooves on the copper-clad laminate to achieve stable positioning of the signal terminals. Alternatively, a temporary support layer that melts or evaporates at reflow soldering temperature can be placed on the copper-clad laminate to provide stable initial contact during the mounting stage. Of course, this embodiment also includes processes such as encapsulation, potting, degassing, and curing after reflow soldering to achieve the encapsulated finished product, which will not be detailed here.

[0095] The packaging method in this embodiment moves the solder pre-planting process to an independent station, pre-forming standardized solder forms on the signal terminals, thus replacing the complex process of printing solder paste point by point on the substrate. This directly simplifies the process; since the pre-planted signal terminals are standard components, subsequent mounting eliminates the need for online printing, soldering, and flux cleaning. Automated assembly only requires visual positioning, alignment, and placement, reducing reliance on high-precision printing processes and fundamentally avoiding defects such as printing errors, misalignment, and bridging. This method significantly shortens the production cycle and reduces equipment and operating costs while ensuring consistent soldering quality.

[0096] In summary, this invention provides a solder pre-planting device, a pre-planting process, and a packaging method. The device achieves precise positioning and hovering control of the solder pads through the synergistic design of a unique T-shaped cavity structure, a height adjustment mechanism, and a pin stop. The micron-level annular gap serves multiple functions, including heat insulation, spill prevention, and installation guidance. The device offers both manual and automatic adjustment modes, combining operational flexibility with automation potential, fundamentally ensuring the consistency and stability of solder formation.

[0097] Based on the pre-forming process of this device, standardized solder morphologies with precise and controllable shape and volume can be pre-formed on the workpiece pads at an independent workstation. The corresponding packaging method utilizes these standardized workpieces, achieving highly reliable connections through automated placement and reflow soldering. This invention, through the systematic synergy of the device, process, and method, shifts the quality control point of the key factor determining solder quality—the "solder morphology"—from the production line assembly station to an independent pre-forming workstation. It effectively solves the core problems of complex processes, poor consistency, and high automation difficulty in traditional power module packaging, significantly improving solder placement accuracy and product yield while simplifying production line configuration and reducing overall costs, demonstrating outstanding industrial application value.

[0098] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A solder preplanting device characterized by, include: Support base; A pin clamp is mounted on the support base via a height adjustment mechanism, and the pin clamp has multiple through T-shaped cavities. A pin stop is provided on the support base and located below the corresponding T-shaped cavity, and the height of the top end of the pin stop is adjustable; The T-shaped cavity includes an upper frustum-shaped pad receiving cavity and a lower pin guide hole coaxial with the pad receiving cavity; the pad receiving cavity is used to receive the pad of the workpiece to be soldered; the inner diameter of the pin guide hole is larger than the diameter of the pin of the workpiece to form a heat-insulating and anti-overflowing annular gap between them, and the depth of the pin guide hole is smaller than the length of the pin; The height adjustment mechanism and the ejector pin stop are configured to adjust in coordination to dynamically adjust the relative distance between the pin clamp and the ejector pin stop in the vertical direction; when the lower end of the inserted pin is blocked by the ejector pin stop, the pad is raised and suspended at a preset target height through coordinated operation.

2. The solder pre-implantation device according to claim 1, characterized in that: The preset target height can be continuously changed and set by adjusting the height adjustment mechanism and / or the ejector pin stop to adapt to workpieces of different specifications.

3. The solder pre-implantation device according to claim 1, characterized in that: The pad receiving cavity is a groove for accommodating the pad. The upper surface of the pad is lower than the opening plane of the groove, and there is a preset distance between the lower surface of the pad and the bottom plane of the groove. The space defined by the preset distance is the pre-installed solder space. The pre-installed solder space is used to accommodate the solder formation.

4. The solder pre-implantation device according to claim 1, characterized in that: The height adjustment mechanism can be a manual or automatic adjustment mechanism. The manual adjustment mechanism includes a threaded post on the pin clamp and a nut that mates with the threaded post. The threaded post is mounted on the support base, and height adjustment is achieved by rotating the nut. The automatic adjustment mechanism includes a clamp drive motor, a transmission assembly, and a clamp mounting base. The pin clamp is fixedly mounted on the clamp mounting base. The clamp drive motor drives the clamp mounting base to perform linear lifting and lowering motion relative to the support base via the transmission assembly.

5. The solder pre-implantation device according to claim 1, characterized in that: The height of the ejector pin stop can be adjusted and locked independently of the height adjustment mechanism; the height of the ejector pin stop can be adjusted by a manual adjustment structure or an electric drive device; the electric drive device includes an ejector pin drive motor and an ejector pin transmission mechanism connected to the ejector pin drive motor.

6. The solder pre-implantation device according to claim 4 or 5, characterized in that: It also includes a control system; when the height adjustment mechanism is an automatic adjustment mechanism, the clamp drive motor is electrically connected to the control system; when the ejector pin stop is adjusted by an electric drive device, the ejector pin drive motor is electrically connected to the control system; the control system controls the drive motor electrically connected to it according to the configuration of the solder pre-planting device, so as to position the solder pad to the preset target height.

7. The solder pre-implantation device according to claim 1, characterized in that: The minimum inner diameter of the pad receiving cavity is greater than the diameter of the pad, and the excess is 0.5 mm to 1 mm; the depth of the pad receiving cavity is at least 2.5 times the thickness of the pad.

8. The solder pre-implantation device according to claim 1, characterized in that: The radial width of the annular gap is 0.05 mm to 0.1 mm; the depth of the pin guide hole is not greater than half the length of the pin.

9. A pre-planting process, characterized in that, Using the solder pre-implantation apparatus according to any one of claims 1 to 8 includes the following steps: S1, Adjust the height adjustment mechanism to increase the distance between the pin clamp and the support base; S2, insert the multiple workpieces vertically into the corresponding T-shaped cavities respectively, so that the pins extend downwards; S3, reverse the height adjustment mechanism to reduce the distance between the pin holder and the support base until the pin stop contacts and lifts the lower end of the pin, so that the pad is lifted and stably suspended in the predetermined position in the pin holder. S4, providing a solder application assembly and pre-planting solder on the back side of the pad of the workpiece to form a solder formation of a predetermined height; S5, Clean the workpiece after pre-applied solder.

10. A packaging method, based on the pre-implantation process of claim 9, characterized in that, Includes the following steps: Provide the workpiece processed by the pre-planting process of claim 9, wherein the workpiece is a signal terminal having a solid solder formation on the pad; The signal terminal is mounted to the designated position on the copper-clad laminate, so that the solid solder formation is aligned and in contact with the surface of the copper-clad laminate; The copper-clad substrate with the signal terminals is reflow soldered. Cooling forms solder joints.

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