Apparatus and method for trapezoidal deoxidation of coga device solder posts

Abstract

This invention discloses an apparatus and method for trapezoidal deoxidation of CCGA device solder pillars. The apparatus comprises a stainless steel mesh, a base, gaskets, pads, a cover plate, fastening screws, and an anti-static stainless steel brush. The method involves fixing the stainless steel mesh to the base with countersunk screws, then sequentially placing the gaskets, CCGA devices, and pads, securing the pads with fasteners, and finally fixing the cover plate. The length of the solder pillar extending beyond the stainless steel mesh is controlled by adjusting the gasket thickness. Deoxidation is performed in two steps: first, the solder pillar extends 0.2 mm beyond the stainless steel mesh by adjusting the gasket thickness, and then is sanded smooth with 400-grit sandpaper; second, the solder pillar extends 0.5 mm beyond the stainless steel mesh by adjusting the gasket thickness again, and then the sides of the solder pillar are deoxidized using an anti-static stainless steel brush. This invention's apparatus and method can remove oxides from the welding surface of CCGA device solder pillars, improving the welding pass rate and solder joint quality of CCGA devices.

Description

Technical Field

[0001] This invention belongs to the technical field of electronic packaging, and particularly relates to an apparatus and method for deoxidizing the bond pillars of CCGA devices by trapezoidal shaping. Background Technology

[0002] Since CCGA devices are mainly used in the aerospace electronics field, their reliability requirements are high. CCGA device solder pillars are composed of high-lead solder. Existing devices do not deoxidize the CCGA device solder pillars during assembly. The soldering process can easily lead to solder segregation, solder pillar misalignment, non-wetting of solder joints, cold solder joints, and other soldering defects, which reduce the reliability of CCGA devices and may even cause CCGA device failure. Summary of the Invention

[0003] In view of this, the apparatus for trapezoidal deoxidation of CCGA device solder pillars of the present invention improves the soldering pass rate and soldering quality of CCGA devices.

[0004] A device for trapezoidal deoxidation of CCGA device solder pillars includes a stainless steel mesh, a base, a gasket, a pad, and a cover plate, wherein...

[0005] The stainless steel mesh includes a base plate and a first protrusion disposed in the central region of the top surface of the base plate, wherein the central region of the first protrusion is provided with a hole array structure.

[0006] The base has a first through hole in the central area that matches the shape of the first boss, and the base is mounted on the top surface of the base plate by screws.

[0007] The shape of the gasket is adapted to the shape of the first through hole, and a second through hole adapted to the shape of the CCGA device is opened in the central area. The gasket is placed in the first through hole and the CCGA device is placed on top of the gasket. The solder post part of the CCGA device protrudes from the hole array structure and leaves an extension section.

[0008] The shape of the pad is adapted to the shape of the gasket. The bottom center area of ​​the pad is provided with a first groove whose shape is adapted to the top cover plate of the CCGA device. Vent holes are provided at intervals on the first groove. The vent holes extend to the top surface of the pad. The pad is placed on top of the CCGA device, and the bottom surface of the pad does not contact the top cover plate of the CCGA device.

[0009] The cover plate is designed with a cross-shaped stepped structure and its cross-sectional dimensions are larger than those of the base. The cover plate is attached to the base by a button screw. A clamping screw is provided in the central area of ​​the cover plate. One end of the clamping screw passes through the cover plate. Rotating the clamping screw can press down the pad to prevent the CCGA device from shaking in the first through hole.

[0010] The beneficial effects of the present invention are as follows:

[0011] The structure of this invention can prevent CCGA devices from shaking in the first through hole, enabling rapid CCGA device assembly. The structure is simple and low-cost. Oxidation is removed by polishing with 400-grit sandpaper until the end face of the solder column is flat and uniformly presents a silvery-white metallic luster. This removes oxides from the soldering surface of the CCGA device solder column, improving the welding qualification rate and solder joint quality of the CCGA device. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is an exploded view of the overall structure;

[0014] Figure 2 This is a schematic diagram of the overall structure;

[0015] Figure 3 This is the main sectional view of the overall structure, where,

[0016] 1. Stainless steel mesh; 2. Base; 3. Gasket; 4. Pad; 5. Cover plate; 6. Antistatic stainless steel brush; 11. Base plate; 12. First boss; 21. First through hole; 31. Second through hole; 41. First groove; 42. Vent hole; 51. Clamping screw. Detailed Implementation

[0017] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0018] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0019] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0020] like Figures 1 to 3 The apparatus shown for trapezoidal deoxidation of CCGA device solder pillars includes a stainless steel mesh 1, a base 2, a gasket 3, a pad 4, and a cover plate 5.

[0021] The stainless steel mesh includes a base plate 11 and a first boss 12 disposed in the central region of the top surface of the base plate 11, wherein the central region of the first boss 12 is provided with a hole array structure.

[0022] The base 2 has a first through hole 21 in the central area that matches the shape of the first boss 12. The base 2 is mounted on the top surface of the base plate 11 by screws.

[0023] The shape of the pad 3 is adapted to the shape of the first through hole 21, and a second through hole 31 adapted to the shape of the CCGA device is opened in the central area. The pad 3 is placed in the first through hole 21, and the CCGA device is placed on top of the pad 3, with the solder post part of the CCGA device protruding from the hole array structure and leaving an extension section.

[0024] The shape of the pad 4 is adapted to the shape of the pad 3. The bottom center area of ​​the pad 4 is provided with a first groove 41 whose shape is adapted to the top cover plate of the CCGA device. Vent holes 42 are provided at intervals on the first groove 41. The vent holes 42 extend to the top surface of the pad 4. The pad 4 is placed above the CCGA device, and the bottom surface of the pad 4 does not contact the top cover plate of the CCGA device.

[0025] The cover plate 5 is designed with a cross-shaped stepped structure and its cross-sectional dimensions are larger than those of the base. The cover plate 5 is fitted onto the base 2 with a button screw. A clamping screw 51 is provided in the central area of ​​the cover plate 5. One end of the clamping screw 51 passes through the cover plate 5. Rotating the clamping screw 51 can press down the pad 4 to prevent the CCGA device from shaking in the first through hole 21. This allows for rapid CCGA device assembly. The structure is simple and the cost is low. Use 400-grit sandpaper to polish and remove oxidation until the end face of the solder column is flat and uniformly presents a silvery-white metallic luster. Remove the oxide from the welding surface (end face and side face) of the CCGA device solder column to improve the welding qualification rate and solder joint quality of the CCGA device.

[0026] Furthermore, the hole array structure features a 34*34 hole array. For example, the stainless steel mesh 1 has through holes with a diameter of 0.58mm, and the surface array is 34*34. Stainless steel mesh 1 comes in two types, with spacings of 1.27mm and 1.0mm. The overall thickness of stainless steel mesh 1 is 1.6mm, with a 0.5mm recessed central window to protect the CCGA device's side solder joints from damage during assembly and disassembly. The back openings of stainless steel mesh 1 feature a C0.1 chamfered edge design, facilitating the insertion of CCGA device solder posts into the corresponding holes in stainless steel mesh 1, covering 99% of CCGA device sizes on the market.

[0027] Furthermore, the height of the first through hole 21 is greater than the sum of the heights of the first boss 12, the gasket 3, the pad 4, and the CCGA device.

[0028] Secondly, a method for deoxidizing CCGA device solder pillars by trapezoidal shaping is provided, using the apparatus described above, the method comprising:

[0029] S1: Make two types of gaskets, including a first gasket and a second gasket. The thickness of the first gasket is greater than that of the second gasket. (The two gaskets are the same except for the thickness parameter).

[0030] S2: Use the first pad to support the CCGA device, so that the length of the CCGA device's solder post protrusion hole array structure is the first protrusion section, and grind the first protrusion section until it is flush with the bottom surface of the base plate 11.

[0031] S3: Replace the first shim with the second shim, and make the length of the solder post protrusion hole array structure of the CCGA device after one grinding be the second protrusion section. Use an anti-static stainless steel brush 6 to process the second protrusion section until part of the length of the second protrusion section is a trapezoidal cylindrical structure.

[0032] Furthermore, the top surface of each hole in the hole array structure is provided with a C0.1 chamfer to prevent the solder posts of the CCGA device from being rigidly damaged by the hole array structure during placement.

[0033] Working principle: The stainless steel mesh 1 and the base 2 are positioned and fastened by countersunk screws 7; then, the shim 3, the CCGA device to be deoxidized, the pad 4, and the cover plate 5 are placed in sequence, and the cover plate 5 is fixed to the base 2 by fasteners 8. The deoxidation is divided into two steps. In the first step, the thickness of the shim is adjusted so that the welding column protrudes 0.2mm from the stainless steel mesh, and then it is polished smooth with 400-grit sandpaper; in the second step, the thickness of the shim is adjusted so that the welding column protrudes 0.5mm from the stainless steel mesh, and then the side of the welding column is deoxidized using an anti-static stainless steel brush.

[0034] Preferably, the stainless steel mesh 1 has through holes with a diameter of 0.58mm and a face array of 34*34. There are two types of stainless steel mesh 1, with spacings of 1.27mm and 1.0mm respectively. The overall thickness of stainless steel mesh 1 is 1.6mm, with a 0.5mm recessed central window to protect the CCGA device side solder joints from damage during assembly and disassembly. The back openings of stainless steel mesh 1 feature a C0.1 chamfered edge design, facilitating the insertion of CCGA device solder posts into the corresponding holes in stainless steel mesh 1, covering 99% of CCGA device sizes on the market.

[0035] The specific application of the operation method is as follows:

[0036] Secure the stainless steel mesh 1 to the base 2 using countersunk screws 7;

[0037] Place the 0.9mm pad 3, the CCGA device to be deoxidized, and the pad block 4 into the base in sequence, so that the welding column extends 0.2mm beyond the upper surface of the stainless steel mesh 1;

[0038] Secure the cover plate 5 to the base 2 with fasteners 8;

[0039] Fastener 6 is used to fix pad 4 to prevent relative displacement of internal components.

[0040] Polish the protruding end of the welding column with 400-grit sandpaper to remove oxidation until the end face of the welding column is flat and uniformly presents a silvery-white metallic luster.

[0041] Disassemble the device and replace the gasket 3. Note that it is not necessary to disassemble the stainless steel mesh 1 from the base 2.

[0042] Place the 0.4mm pad 3, the CCGA device to be deoxidized, and the pad block 4 into the base in sequence, so that the welding column extends 0.5mm beyond the upper surface of the stainless steel mesh 1;

[0043] Secure the cover plate 5 to the base 2 with fasteners 8;

[0044] Fasteners 6 are used to fix pads 4 to prevent relative displacement of internal components.

[0045] Using an anti-static stainless steel brush, move it along the X and Y directions respectively, then rotate the device 45° and repeat the above operation, the same number of times in each direction, at least 5 times;

[0046] Disassemble the device, remove the CCGA device, and complete the trapezoidal deoxidation of the CCGA device's solder joint ends.

[0047] Stainless steel mesh 1 has 0.58mm diameter through holes in a 34*34 array. It comes in two types with spacings of 1.27mm and 1.0mm. The overall thickness of stainless steel mesh 1 is 1.6mm, with a 0.5mm recessed central window to protect the CCGA device solder joints from damage during assembly and disassembly. The back openings of stainless steel mesh 1 feature a C0.1 chamfered edge design to facilitate insertion of CCGA device solder posts into the corresponding holes.

[0048] The inner frame of base 2 measures 44.1*44.1mm and has an inner depth of 8.0mm, which can cover 99% of the CCGA device sizes on the market.

[0049] The outer frame of spacer 3 is 44*44mm, and the inner frame size is related to the size of the CCGA device. Spacer 3 has two thicknesses: a 0.9mm spacer is used when deoxidizing the end face of the solder post to ensure a solder post protrusion length of 0.2mm; a 0.4mm spacer is used when deoxidizing the side face of the solder post to ensure a solder post protrusion length of 0.5mm.

[0050] The outer dimensions of pad 4 are 44*44mm, and the inner dimensions are related to the dimensions of the CCGA device body. Pad 4 is designed with two 5mm diameter vent holes to prevent negative pressure from being generated due to close contact between the device body and pad 4.

[0051] The method for removing oxidation from the side of the weld column involves using an anti-static stainless steel brush, moving it along the X and Y directions respectively, and then rotating the device 45° and repeating the above operation. The number of repetitions in each direction should be the same, at least 5 times. This method can correct the shape of the welded end of the weld column to a trapezoidal shape.

[0052] After the CCGA device's solder joint end is deoxidized by trapezoidal shaping using the above-mentioned deoxidation device and method, the CCGA device is soldered to the corresponding position on the printed circuit board, forming a side solder joint on the printed circuit board.

[0053] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for deoxidizing the bond pillars of a CCGA device by trapezoidal shaping, characterized in that... The system includes a stainless steel mesh, a base, a gasket, a pad, and a cover plate. The stainless steel mesh includes a base plate and a first boss located in the central region of the top surface of the base plate. The central region of the first boss has a hole array structure. The base has a first through hole in its central region that matches the shape of the first boss. The base is mounted on the top surface of the base plate by screws. The gasket's shape matches the shape of the first through hole, and its central region has a second through hole that matches the shape of a CCGA device. The gasket is placed in the first through hole, and the CCGA device is placed above the gasket, with the solder post portion of the CCGA device extending out of the hole array structure and leaving an extended section. The shape of the pad matches the shape of the gasket, and the bottom of the pad... A first groove, shaped to match the top cover plate of the CCGA device, is provided in the central area of ​​the surface. Vent holes are spaced apart in the first groove, extending to the top surface of the pad. The pad is placed above the CCGA device, with its bottom surface not in contact with the top cover plate. The cover plate has a cross-step structure and a cross-sectional dimension larger than that of the base. It is secured to the base with a button screw. A clamping screw is located in the central area of ​​the cover plate, with one end passing through the cover plate. Rotating the clamping screw presses down on the pad, preventing the CCGA device from wobbling in the first through-hole. The height of the first through-hole is greater than the sum of the heights of the first boss, the pad, the pad, and the CCGA device. The method includes... S1: Make two types of gaskets, including a first gasket and a second gasket, wherein the thickness of the first gasket is greater than the thickness of the second gasket; S2: Use the first pad to support the CCGA device, so that the length of the CCGA device's solder post protrusion hole array structure is the first protrusion section, and grind the first protrusion section until it is flush with the bottom surface of the base plate. S3: Replace the first shim with the second shim, and make the length of the solder post protrusion hole array structure of the CCGA device after one grinding be the second protrusion section. Use an anti-static stainless steel brush to process the second protrusion section until part of the length of the second protrusion section is a trapezoidal cylindrical structure.

2. The method according to claim 1, characterized in that, Each hole in the hole array structure has a beveled edge C0.1 on its top surface to prevent the solder posts of the CCGA device from being rigidly damaged by the hole array structure during placement.

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