A tool and method for CCGA package device post planting

Abstract

The application relates to a tool and method for a CCGA packaged device column planting, which is based on the column grid array packaged device column planting process technology, improves a welding column (6) device, the device is a machining integrated tool, the application reduces assembly errors, can improve the welding precision of the welding column (6) and the device, the design scheme can make the CCGA device more uniform in overall heating, and the solder can be more fully melted, so that the reliability of the device in the production and manufacturing, reliability experiment and formal use process can be ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to a tool and method for CCGA package device post. BACKGROUND

[0002] In aerospace electronics manufacturing, CCGA package devices are widely used in SMT industry soldering.

[0003] In the device soldering process, due to abnormal soldering, such as pin hole, device collapse and other defects, the device needs to be re-posted for repair.

[0004] The traditional post method uses polyimide base and graphene support to fix the soldering column to ensure the alignment accuracy, which needs multiple tool assembly and has the disadvantage of cumulative tolerance. And the polyimide base is larger than the integrated machining tool, the thermal conductivity of polyimide is 0.1-0.6 (W / m*k), which is not as good as the thermal conductivity of aluminum alloy tool of 230-236 (W / m*k), which is easy to cause the soldering column to be skewed due to uneven temperature, affecting the reliability of the soldering column. This is the disadvantage of the existing traditional reflow soldering post method.

[0005] The traditional post tool uses graphite tool, its thermal expansion coefficient parallel to the base surface is about 1~3*10 -6 / ℃, the thermal expansion coefficient perpendicular to the base surface is about 15~30*10 -6 / ℃, and the thermal expansion coefficient of high-lead soldering column is about 25~30*10 -6 / ℃, which is quite different from the graphite tool in the parallel direction to the base surface, resulting in deformation constraint and the risk of soldering column damage.

[0006] The traditional split tool structure is complex and has reduced precision. SUMMARY

[0007] The purpose of the present application is to provide a tool and method for CCGA package device post, which can reduce assembly error, improve soldering accuracy of soldering column and device, and ensure the reliability of device in production, manufacturing, reliability test and formal use.

[0008] The purpose of the present application is achieved by a tool for CCGA package device post, characterized by:

[0009] ① An aluminum alloy integrated main tool with a 0.02mm anti-static oxide layer plated on the surface;

[0010] ② The tool has L-shaped blocks at four corners for positioning components and materials, and the L-shaped blocks play a guiding role when placing components;

[0011] ③The four corners of the tool have one corner with a chamfered corner and the other three corners with a rounded corner, which is a mistake-proof design. The components are placed in the chamfered corner corresponding to the straight corner of the tool;

[0012] ④The tool surface of the component placement position is designed with a boss to raise the component, and the hot air melts the solder more fully during reflow soldering;

[0013] ⑤The tool back is made with a sink groove and chamfered around, absorbing heat during reflow soldering;

[0014] ⑥The tool has a through hole punched from the back, which is consistent with the layout of the CCGA pad and has double chamfered for easy installation of the solder column;

[0015] ⑦The integral tool mounting hole is larger than the solder column;

[0016] ⑧The ratio of the distance between the through holes of the integral tool and the pads is 1.1, ensuring compatibility.

[0017] The resistivity of the main surface anti-static oxide layer is 10 6 ~ 10 9 Ω to prevent components from being damaged by static electricity.

[0018] There is a space between the side of the component and the tool, so that the hot air melts the solder fully during reflow soldering.

[0019] The tool back is made with a sink groove and chamfered around, absorbing heat during reflow soldering, and the heat absorption rate is increased by 15%.

[0020] The tool mounting hole is 0.03mm larger than the solder column, the effective fixing length of the solder column is 1.3mm, and the solder column positioning is guaranteed.

[0021] A method for using a tool for CCGA packaged device column planting, characterized in that,

[0022] at least includes the following steps:

[0023] ① Select components that meet the column planting requirements, including tin printing steel mesh, column planting tool, polyimide tape, tin paste, device, solder column;

[0024] ② Attach the polyimide tape to the non-welding surface of the component;

[0025] ③ Use the steel mesh to print solder on the component pad;

[0026] ④ Fix the component through the L-shaped block of the tool, the L-shaped block of the tool is used for rough positioning, and the chamfer of the L-shaped block is used for fine guiding to improve the assembly efficiency of the component;

[0027] ⑤ Place the solder column in the solder column hole of the tool;

[0028] ⑥ After the components and solder pillars are installed, the through-hole layout and pad position matching accuracy is ±0.15mm;

[0029] ⑦ Use reflow soldering method, combined with temperature profile, to melt the solder. There is a 0.5mm gap between the component and the tooling to facilitate the flow of hot air and ensure that the solder joint is heated evenly. The measured temperature difference of the component during reflow soldering is 3℃. After reflow soldering, the solder pillar and the component are soldered together. After the soldering is completed, the component is removed from the solder pillar hole and the polyimide tape wrapped around the component is removed.

[0030] ⑧ Components should be mounted vertically and inspected with a 20-45x microscope. The center of the component pin should be aligned with the center of the pad, and the component's solder post should fall completely on the pad. A solder post offset of ≤10% of the solder joint diameter is considered acceptable.

[0031] ⑨ Welding quality inspection: Use a 20-45x microscope to inspect the solder joints. The solder should continuously wet the solder column, with the solder wetting the solder column at an angle of not less than 270°. The solder joints should be bright and free from cold soldering. There should be no bridging, foreign matter, or pinholes in the solder joints. X-ray equipment should be used to detect the void rate of the solder joints. The void rate should be ≤10% of the diameter of the solder column.

[0032] ⑩ Take photos and archive them after the inspection is passed.

[0033] In this invention, the placement slot for the component is 0.1 mm larger than the component itself, and the component body is wrapped with a 0.06 mm thick polyimide tape to ensure an interference fit between the component and the tooling, thereby improving the positioning accuracy of the component.

[0034] In this invention, the welding post hole is 0.03 mm larger than the welding post, and the effective fixed welding post length is 1.3 mm; the spacing of the welding post hole is the same as the spacing of the pads on the component, and the number of welding posts is consistent with the number of pads on the component.

[0035] This invention has the following advantages compared to traditional methods:

[0036] 1. Traditional reflow soldering method uses a polyimide base and graphene bracket to fix the weld column and ensure alignment accuracy. It requires multiple tooling for assembly, which can lead to insufficient cumulative tolerance. In addition, the polyimide base is larger than the tooling of a one-piece machine. The thermal conductivity of polyimide (0.1-0.6 W / m*k) is not as good as that of aluminum alloy tooling (230-236 W / m*k). It is easy for uneven temperature to cause the weld column to be skewed at the corners, affecting the reliability of the weld column. This is the shortcoming of the existing traditional reflow soldering method for weld column installation.

[0037] 2. Traditional column planting fixtures use graphite fixtures, whose coefficient of thermal expansion parallel to the base surface is approximately 1 to 3 × 10⁻⁶. -6 / ℃, the coefficient of thermal expansion perpendicular to the base plane is approximately 15~30*10. -6 / ℃, while the coefficient of thermal expansion of high-lead solder pillars is approximately 25-30*10.-6 The temperature difference between the aluminum alloy and the graphite tooling in the direction parallel to the base surface is significant, resulting in constrained deformation and a risk of weld damage. The aluminum alloy used in this invention has a thermal expansion coefficient of approximately 23*10⁻⁶. -6 / ℃, matching the thermal expansion coefficient of high-lead weld pillars, with similar deformation amounts, thus solving the problem of weld pillar damage.

[0038] 3. Traditional split tooling structures are complex to assemble and have reduced precision. The main body of this invention is made of aluminum alloy in one piece, with a simple structure and high precision. Moreover, the surface is coated with a 0.02mm antistatic oxide layer, which improves the durability of the tooling.

[0039] 4. This invention utilizes an L-shaped stop and chamfered corner design to synergistically improve assembly efficiency. L-shaped stops are machined at the four corners of the tooling to position materials, and the angles of the stops are designed to guide material placement. One corner of the tooling is chamfered, while the other triangles are rounded for error prevention. When placing components, the corner of the component corresponds to the chamfered right angle position of the tooling.

[0040] 5. This invention uses a sink + boss to optimize hot air flow. The back of the tooling is made with a sink and the edges are chamfered to absorb heat during reflow soldering. The device placement position is provided with a boss to raise the device. There is a certain space between the device side pad and the tooling. During reflow soldering, the hot air allows the solder to melt more fully.

[0041] The present invention will be further described below with reference to the accompanying drawings of the embodiments. Attached Figure Description

[0042] Figure 1 This is a structural diagram of an embodiment of the invention;

[0043] Figure 2 yes Figure 1 Side view;

[0044] Figure 3 This is a top-view diagram of the tooling.

[0045] In the diagram, 1 is tooling; 2 is components; 3 is an L-shaped stop; 4 is a chamfer; 5 is a placement groove; 6 is a welding post; 7 is a welding post hole; 8 is a boss; and 9 is a settling tank. Detailed Implementation

[0046] To clearly illustrate the technical features of this solution, the following detailed implementation method, in conjunction with its accompanying drawings, will be used to describe the solution.

[0047] Material selection: Tooling 1 is made of aluminum alloy with surface oxidation treatment to provide antistatic properties.

[0048] like Figure 1 and Figure 2 As shown, this invention relates to a tooling for pillar mounting of CCGA packaged devices, characterized in that:

[0049] ① An integrated aluminum alloy fixture with a 0.02mm antistatic oxide layer on the machined surface;

[0050] ② The tooling is designed with L-shaped blocks 3 at the four corners for positioning components and materials. The L-shaped blocks 3 serve as guides when placing components 2.

[0051] ③ One of the four corners of fixture 1 is a chamfered corner, and the other three corners are rounded corners. This is a mistake-proof design. The components are placed at the positions corresponding to the chamfered corner and the right angle of fixture 1.

[0052] ④ The tooling surface where component 2 is placed is designed with a boss 8 to elevate component 2, so that the hot air during reflow soldering can melt the solder more fully;

[0053] ⑤ The back of tooling 1 is made with a sink 9 and chamfered around the edges 4 to absorb heat during reflow soldering;

[0054] ⑥ Fixture 1 has through holes drilled from the back, the layout of which is consistent with the CCGA pad layout, and double-sided chamfer 4 to facilitate the installation of solder pillars 6;

[0055] ⑦ The mounting hole of the integrated tooling 1 is 0.03mm larger than that of the welding column 6, effectively fixing the length of the welding column 6 by 1.3mm and ensuring the positioning of the welding column 6;

[0056] ⑧ The ratio of through-hole spacing to pad spacing in the integrated fixture is 1.1 to ensure compatibility.

[0057] The resistivity of the antistatic oxide layer on the main body surface is 10. 6 ~10 9 Ω is provided to prevent damage to components due to static electricity. There is space between the side of component 2 and tooling 1 to allow the hot air to fully melt the solder during reflow soldering.

[0058] like Figure 3 As shown, in this invention, the back of the fixture 1 is made with a recessed groove 9 and beveled around the edges 4, which absorbs heat during reflow soldering, increasing the heat absorption rate by 15%. The mounting hole of the fixture 1 is 0.03mm larger than the welding post, effectively fixing the welding post 6 by 1.3mm in length, ensuring the positioning of the welding post 6. The ratio of the through hole spacing to the pad spacing of the fixture 1 is 1.1 to ensure compatibility.

[0059] like Figure 1 , Figure 2 , Figure 3 As shown, this invention relates to a method of using a tooling for pillar mounting of CCGA packaged devices, the specific steps of which are as follows:

[0060] ① Select components that meet the requirements for column mounting, including solder stencil, column mounting fixture, polyimide tape, solder paste, components, and solder posts 6;

[0061] ② Apply polyimide tape to the non-soldering surface of component 2;

[0062] ③ Use a stencil to print solder on the pads of component 2;

[0063] ④ Fix component 2 with the four corner L-shaped blocks 3 of tooling 1. The four corner L-shaped blocks 3 are used for coarse positioning, and the chamfer 4 of the L-shaped blocks 3 is used for fine guidance, thereby improving the assembly efficiency of component 2.

[0064] The placement slot 5 of component 2 is 0.1mm larger than component 2. A 0.06mm thick polyimide tape is wrapped around the body of component 2 to make component 2 and tooling 1 have an interference fit, so as to improve the positioning accuracy of component 2.

[0065] ⑤ Place the welding post 6 in the welding post hole 7. The welding post hole 7 is 0.03mm larger than the welding post 6, effectively fixing the length of the welding post 6 by 1.3mm. The spacing of the welding post holes 7 is the same as the spacing of the pads on the component. The number of holes is the same as the number of pads on component 2.

[0066] ⑥ After component 2 and solder post 6 are installed, the through hole layout and pad position matching accuracy is ±0.15mm;

[0067] ⑦ Using reflow soldering and in conjunction with the temperature profile, the solder is melted. A 0.5mm gap exists between component 2 and fixture 1 to facilitate hot air flow, ensuring uniform heating of the solder joints. The measured reflow soldering temperature difference is 3℃. See the attached diagram for a detailed hot air flow diagram. Figure 2 As shown, after reflow soldering, the solder post 6 and component 2 are soldered together. After soldering, component 2 is removed from the solder post fixture, and the polyimide tape wrapped around the component is removed.

[0068] ⑧ Component 2 is mounted vertically. When inspected with a 20-45x microscope, the center of the pin of component 2 should be aligned with the center of the pad. The solder post 6 of component 2 should fall completely on the pad. An offset of solder post 6 ≤ 10% of the solder joint diameter is considered acceptable.

[0069] ⑨ Welding quality inspection: Use a 20-45x microscope to inspect the solder joints. The solder should continuously wet the solder pillar 6, with a solder wetting angle of not less than 270°. The solder joints should be bright, without cold soldering, bridging, foreign matter, or pinholes. X-ray equipment should be used to detect the void rate of the solder joints. The void rate should be ≤10% of the diameter of the solder pillar 6.

[0070] ⑩ Take photos and archive them after the inspection is passed.

[0071] Based on the pillar-mounting technology of pillar-gate array (CCGA) devices, the pillar 6 bonding device is improved. This device is a machined integrated fixture, reducing assembly errors and improving the bonding accuracy of pillar 6 and the device. This design allows for more uniform heating of the CCGA device and more complete solder melting, ensuring the reliability of the device during manufacturing, reliability testing, and formal use.

Claims

1. A fixture for pillar mounting in CCGA packaged devices, characterized in that: The machined surface is coated with a 0.02mm antistatic oxide layer. The machined fixture (1) has L-shaped blocks (3) at the four corners for positioning components. The L-shaped blocks (3) serve as guides when placing components (2). One corner of the four corners of the machined fixture (1) is chamfered, and the other three corners are rounded. The component (2) is placed at the position corresponding to the chamfered corner and the right angle of the machined fixture (1). The machined fixture (1) is positioned at the position of the component (2). 1) The surface is designed with a boss (8) to raise the component (2) so that the hot air can melt the solder more fully during reflow soldering; the back of the fixture (1) is made with a groove (9) and chamfered around the edges to absorb heat during reflow soldering; the fixture (1) has through holes drilled from the back, the through hole layout is consistent with the CCGA pad layout, and the double-sided chamfering facilitates the installation of the solder pillars (6); the mounting holes of the integrated fixture (1) are larger than those of the solder pillars (6); the ratio of the through hole spacing to the pad spacing of the integrated fixture (1) is 1.1 to ensure compatibility.

2. The fixture for pillar mounting of CCGA packaged devices according to claim 1, characterized in that: The resistivity of the antistatic oxide layer on the main body surface is 10. 6 ~10 9 Ω, to prevent components (2) from being damaged by static electricity.

3. The fixture for pillar mounting of CCGA packaged devices according to claim 1, characterized in that: There is space between the side of the component (2) and the tooling (1) so that the hot air can fully melt the solder during reflow soldering.

4. The fixture for pillar mounting of CCGA packaged devices according to claim 1, characterized in that: The tooling (1) has a sink on the back and chamfers around the edges to absorb heat during reflow soldering, increasing the heat absorption rate by 15%.

5. The fixture for pillar mounting of CCGA packaged devices according to claim 1, characterized in that: The mounting hole of the tooling (1) is 0.03mm larger than that of the welding column (6), effectively fixing the length of the welding column (6) to 1.3mm, thus ensuring the positioning of the welding column (6).

6. A method for inserting columns using the tooling as described in claim 1, characterized in that, It should include at least the following steps: (1) Select components that meet the requirements of the soldering column (6), including tin-printed stencil, soldering column tooling, polyimide tape, solder paste, components, and soldering column (6); (2) Apply polyimide tape to the non-soldering surface of component (2); (3) Use a stencil to print solder on the pads of component (2); (4) Fix the component (2) by the four corner L-shaped blocks (3) of the tooling (1), perform coarse positioning by the four corner L-shaped blocks (3), and perform fine guidance by the chamfer of the L-shaped blocks (3), thereby improving the assembly efficiency of the component (2). (5) Place the welding column (6) in the welding column hole (7) of the tooling (1); (6) After the components (2) and the solder pillars (6) are installed, the through hole layout and the pad position matching accuracy is ±0.15mm; (7) Using reflow soldering, combined with the temperature profile, the solder is melted. There is a 0.5mm gap between the component (2) and the fixture (1) to facilitate the flow of hot air. The solder joint is heated evenly. The measured reflow soldering temperature difference of the component (2) is 3℃. After reflow soldering, the solder column (6) and the component (2) are soldered together. After the soldering is completed, the component (2) is taken out from the solder column hole (7) and the polyimide tape wrapped around the component is removed. (8) Component (2) shall be mounted vertically and inspected with a 20-45x microscope. The center of the pin of component (2) shall be aligned with the center of the pad. The solder post (6) of component (2) shall fall completely on the pad. The offset of the solder post (6) ≤ 10% of the solder joint diameter shall be considered acceptable. (9) Welding quality inspection: Use a 20-45x microscope to inspect the solder and the solder column (6) continuously wet the solder, the solder wets the solder column at a degree of not less than 270°, the solder joint is bright, there is no cold soldering phenomenon, the solder joint has no bridging, no foreign matter, no pinholes, and use X-ray equipment to detect the void rate of the solder joint. The void rate is ≤ 10% of the diameter of the solder column (6); (10) Take photos and archive them after the inspection is passed; The placement slot (5) of component (2) is 0.1 mm larger than component (2). A 0.06 mm thick polyimide tape is wrapped around the body of component (2) to make component (2) and tooling (1) interference fit, so as to improve the positioning accuracy of component (2).

7. A method for inserting columns using the tooling described in claim 1 according to claim 6, characterized in that, The welding post hole (7) is 0.03mm larger than the welding post (6), and the effective fixed welding post (6) length is 1.3mm; the spacing of the welding post hole (7) is the same as the spacing of the pads on the component (2), and the number of welding posts (6) is the same as the number of pads on the component (2).

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