PGA device gold-free plating tooling

Abstract

The application provides a PGA device gold removal tin plating tool, a device bonding layer is located on the upper surface of a gold removal tin plating handle, a through hole is arranged at the center of the device bonding layer, the array shape, the number and the hole distance of the through hole are equal to the array shape, the number and the spacing of the device pin respectively, the diameter of the through hole is greater than the diameter of the device pin, all the through holes form a through hole array, and PGA device alignment loading and fixing are realized. The application solves the problem that the root tin plating distance caused by the device hand holding or the forceps holding does not meet the standard requirements, avoids the problem of personnel operation scalding, realizes gold removal tin plating of gold plated pin PGA and other through hole packaging devices, and guarantees the reliability of the welding point. Through handheld operation, the heat source is far away, and the more than 2mm non-tin plating distance required by the national military standard can be accurately realized, the operation is convenient, and the cost is low.

Description

Technical Field

[0001] This invention relates to the field of electronic assembly technology, and more particularly to tooling for removing gold and tin plating from devices. Background Technology

[0002] In current military products, especially connectors, gold plating of the leads is common, primarily to improve their corrosion and chemical resistance. However, according to relevant national military standards, direct soldering on gold-plated component leads is prohibited; a gold removal and tinning process is required. Otherwise, a brittle gold-tin compound, AuSn4, will form, reducing the solder joint strength.

[0003] Pin Grid Array (PGA) packaged devices have pins arranged in an array on the bottom surface. They are ceramic-encapsulated with gold-plated pins, which are needle-shaped, typically 1.5-7mm long, and with a pin pitch of 1.27mm or 2.54mm. According to relevant national military standards, gold-plated pin devices must undergo a gold-removal and tinning process before soldering to prevent the formation of the gold-tin compound AuSn4, known as gold brittleness, which reduces solder joint strength. To address the post-soldering gold brittleness issue and improve solder joint reliability, PGA packaged devices must undergo a gold-removal and tinning process.

[0004] For removing gold plating from PGA packaged devices, the industry typically employs manual handling or tweezers to immerse the device in a solder pot. However, this method has several drawbacks: firstly, it cannot precisely control the 2mm unplated distance required by GJB 1150A-2017 "General Requirements for Electrical Assembly of Electronic Countermeasures Equipment"; secondly, the high temperatures during soldering may cause the device to become unstable and fall out of the pot, rendering it unusable; and thirdly, the solder pot's temperature of around 250°C poses a significant risk of burns to operators during manual handling. Due to the numerous pins and large size of PGA packaged devices, manual handling or immersion is difficult, and maintaining the 2mm unplated distance is challenging. While some industries use equipment to handle PGA devices, this method is costly and inefficient. To address these three shortcomings of existing technologies, this invention designs a gold plating fixture that can secure PGA devices in solder pots with the largest diameter (250mm×250mm), precisely control the soldering distance, and ensure safe operation. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a gold removal and tinning fixture for PGA devices, which is a gold removal and tinning device that can fix PGA devices, accurately control the tinning distance, and operate safely.

[0006] This invention provides a gold-plating and tin-removing fixture for PGA devices, enabling the removal of gold plating and tin-removing from gold-plated PGA packages while maintaining a 2mm untinned distance from the package body. The process is simple and highly operable. This invention proposes a handheld fixture for removing gold plating and tin-removing from PGA packages, which is convenient to operate, keeps away from heat sources, and accurately achieves the 2mm untinned distance required by national military standards.

[0007] The technical solution adopted by this invention to solve its technical problem is:

[0008] A PGA device gold removal and tinning fixture includes a device bonding layer 1 and a gold removal and tinning handle 3. The device bonding layer 1 is located on the upper surface of the gold removal and tinning handle 3. At the center of the device bonding layer 1, through holes are set in the device bonding layer 1 according to the PGA device array structure. The array shape, number, and hole spacing of the through holes are equal to the array shape, number, and spacing of the device pins, respectively. The diameter of the through holes is larger than the diameter of the device pins. All through holes form a through hole array 2 to realize the alignment, insertion, and fixation of the PGA device.

[0009] The gold-plated handle 3 includes an operating area 4 and a handle 5. The operating area 4 is rectangular, and the handle 5 is connected to one of the short sides of the operating area 4. A square hole is opened in the center of the operating area 4 according to the shape of the PGA device. The position of the square hole corresponds to the position of the through-hole array 2. The size of the square hole is larger than the outer size of the device, so as to realize the smooth insertion and removal of the PGA device.

[0010] Except for the fact that the length of the gold-plated tin handle 3 is greater than the length of the tin pot, the far end of the handle 5 and the connection between the handle 5 and the operating area 4 are rounded to ensure safe operation away from heat sources. Safe operation can be achieved through the handle 5.

[0011] The device adhesive layer 1 and the gold removal and tinning handle 3 are bonded together in a double-layer overlap to form a PGA gold removal and tinning fixture. The fixture fixes the device through the through-hole array 2. The thickness of the device adhesive layer 1 and the gold removal and tinning handle 3 after bonding is greater than the distance without tinning.

[0012] In the aforementioned PGA device gold removal and tinning tooling, the device bonding layer 1 and the gold removal and tinning handle 3 are made of the same material, which is a material incompatible with tin and lead, with a deformation greater than 0.1 mm and resistance to high temperature of 200℃.

[0013] In the PGA device gold removal and tinning fixture, the thickness of the gold removal and tinning handle 3 is 2mm to 2.5mm, and the square hole in its center is made according to the shape of the PGA device. The perimeter of the square hole is 0.4mm to 0.6mm larger than the shape of the device. The length of the handle 5 is greater than 70mm, and the rounded corners of the handle 5 are R5mm to R8mm.

[0014] In the PGA device gold-plating tooling, the thickness of the device bonding layer 1 is 0.3mm to 0.5mm, the size of the device bonding layer 1 is the same as the width and length of the operating area 4, all through holes have the same diameter, and the diameter of the through holes is 0.1mm to 0.2mm larger than the diameter of the device pins.

[0015] In the PGA device gold-plating tooling, the device bonding layer 1 overlaps with the operating area 4, and the two layers are bonded together by adhesive.

[0016] The beneficial effects of this invention are that the provided PGA device gold removal and tinning fixture and method are lightweight and convenient, solving the problem that the root tinning distance does not meet the standard requirements due to hand-holding or tweezers, and also avoiding the problem of burns to personnel during operation. Simultaneously, a series of gold removal and tinning fixtures can be designed according to PGA packaged devices of different package sizes and lead sizes, as well as other through-hole packaged devices, to achieve gold removal and tinning of gold-plated PGA leads and other through-hole packaged devices, ensuring solder joint reliability. This invention proposes a gold removal and tinning fixture for PGA packaged devices, which can be operated by hand, away from heat sources, and can accurately achieve the non-tinning distance of more than 2mm required by national military standards, making it convenient to operate and low in cost. Attached Figure Description

[0017] Figure 1 This is a top view of the gold-plating removal fixture for the PGA device of the present invention;

[0018] Figure 2 for Figure 1 Side view;

[0019] Figure 3 This is a flowchart of the gold removal and tinning process for the PGA packaged device of the present invention;

[0020] In the figure, 1-device bonding layer, 2-through-hole array, 3-gold removal and tinning handle, 4-operation area, 5-handle. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] A tooling for removing gold plating from PGA devices, such as Figure 1 and Figure 2 As shown, it includes a device bonding layer 1 and a gold removal and tinning handle 3. The device bonding layer 1 is located on the upper surface of the gold removal and tinning handle 3. At the center of the device bonding layer 1, through holes are set in the device bonding layer 1 according to the PGA device array structure. The array shape, number, and hole spacing of the through holes are equal to the array shape, number, and spacing of the device pins, respectively. The diameter of the through holes is larger than the diameter of the device pins. All through holes form a through hole array 2 to realize the alignment, loading, and fixation of the PGA device.

[0023] The gold-plated handle 3 includes an operating area 4 and a handle 5. The operating area 4 is rectangular, and the handle 5 is connected to one of the short sides of the operating area 4. A square hole is opened in the center of the operating area 4 according to the shape of the PGA device. The position of the square hole corresponds to the position of the through-hole array 2. The size of the square hole is larger than the outer size of the device, so as to realize the smooth insertion and removal of the PGA device.

[0024] Except for the fact that the length of the gold-plated tin handle 3 is greater than the length of the tin pot, the far end of the handle 5 and the connection between the handle 5 and the operating area 4 are rounded to ensure safe operation away from heat sources. Safe operation can be achieved through the handle 5.

[0025] The device adhesive layer 1 and the gold removal and tinning handle 3 are bonded together in a double-layer overlap to form a PGA gold removal and tinning fixture. The fixture fixes the device through the through-hole array 2. The thickness of the device adhesive layer 1 and the gold removal and tinning handle 3 after bonding is greater than the distance without tinning.

[0026] In the aforementioned PGA device gold removal and tinning tooling, the device bonding layer 1 and the gold removal and tinning handle 3 are made of the same material, which is a material incompatible with tin and lead, with a deformation greater than 0.1 mm and resistance to high temperature of 200℃.

[0027] In the PGA device gold removal and tinning fixture, the thickness of the gold removal and tinning handle 3 is 2mm to 2.5mm, and the square hole in its center is made according to the shape of the PGA device. The perimeter of the square hole is 0.4mm to 0.6mm larger than the shape of the device. The length of the handle 5 is greater than 70mm, and the rounded corners of the handle 5 are R5mm to R8mm.

[0028] The PGA device gold-plating tooling has a device bonding layer 1 with a thickness of 0.3mm to 0.5mm. The dimensions of the device bonding layer 1 are the same as the operating area 4 in width and length. All through holes have the same diameter, and the diameter of the through holes is 0.1mm to 0.2mm larger than the diameter of the device leads.

[0029] The PGA device gold-plating tooling has a device bonding layer 1 that overlaps with the operating area 4, and the two layers are bonded together with adhesive.

[0030] In this embodiment, a PGA packaged device with a lead diameter of 0.9 mm and 109 leads is used as an example for gold removal and soldering. The PGA device gold removal and soldering fixture is as follows: Figure 1 , Figure 2As shown, polytetrafluoroethylene (PTFE) material is used. The device bonding layer 1 is 220mm long, 70mm wide, and 0.3mm thick. The device placement slot 2 has a center array of 109 Φ1.1mm through holes, symmetrically spaced at 2.54mm intervals. The gold removal and tinning handle 3 is 290mm long and 2mm thick, with the operating area 4 being 220mm long and 70mm wide, featuring a 31mm x 31mm square hole in the center. The handle 5 is 70mm long and 30mm wide, with a rounded corner radius of R5mm. The device bonding layer 1 and the gold removal and tinning handle 3 are bonded together using epoxy adhesive DG-3 in a double-layer overlapping manner and left to stand for 24 hours.

[0031] The method for removing gold plating from PGA packaged devices using the above-mentioned tooling is as follows: Figure 3 As shown, the feature is that it includes the following steps:

[0032] Step 1: Turn on the power switch of the gold and tin removal pot, and set the temperature to 250 ℃~280 ℃. In this embodiment, 250 ℃ is used.

[0033] Step 2: Once the solder has melted, use a scraper to remove any remaining solder from the surface of the solder pot, ensuring that there is no excess solder on the surface.

[0034] Step 3: Use anti-static tweezers to place the PGA device into the through-hole array in device placement slot 2 of the gold removal and tinning fixture, press the upper surface of the PGA device to make the device fit tightly against the fixture, and expose the PGA device pins;

[0035] Step 4: The PGA device is exposed on the pins of the device placement slot 2. Apply flux evenly using an anti-static brush.

[0036] Step 5: Hold the gold removal and tinning fixture and tilt it downwards at a 30° angle into the gold removal and tinning pot with the exposed PGA pin surface of the fixture. Then gradually make the pin surface of the fixture horizontal. Place the two ends of the operating area 4 in the gold removal and tinning handle 3 on the edge of the gold removal and tinning pot so that all the exposed PGA device pins are immersed in the gold removal and tinning pot. The immersion time is 1 s to 2 s.

[0037] Step 6: Lift the gold-removing and tinning fixture vertically upwards and remove it from the gold-removing and tinning pot;

[0038] Step 7: Turn on the power switch of the tinning pot, and set the temperature to 240 ℃~260 ℃. In this embodiment, 240 ℃ is used.

[0039] Step 8: Once the solder has melted, use a scraper to remove any residual solder from the surface of the solder pot, ensuring that there is no excess solder on the surface.

[0040] Step 9: Apply flux evenly to the exposed pins of the PGA device in device placement slot 2 using an anti-static brush;

[0041] Step 10: Hold the gold removal and tinning tool and tilt it downwards at an angle of 30° to 45° to place it into the tinning pot. In this embodiment, 30° is used. Then gradually make the pin surface of the tool horizontal. Place the two ends of the operating area 4 in the gold removal and tinning handle 3 on the edge of the tinning pot so that all the exposed PGA device pins are immersed in the tinning pot. The immersion time is 1 s to 2 s.

[0042] Step 11: Lift the tinning fixture vertically upwards and remove it from the tinning pot;

[0043] Step 12: Use anti-static tweezers to remove the PGA device from the fixture, and turn off the gold removal pot and the tinning pot.

Claims

1. A gold-plating removal and soldering tooling for PGA devices, comprising a device adhesive layer (1) and a gold-plating removal and soldering handle (3), characterized in that: The PGA device gold removal and tinning fixture has a device bonding layer (1) located on the upper surface of the gold removal and tinning handle (3). At the center of the device bonding layer (1), through holes are set in the device bonding layer (1) according to the PGA device array structure. The array shape, number, and hole spacing of the through holes are equal to the array shape, number, and spacing of the device pins, respectively. The diameter of the through holes is larger than the diameter of the device pins. All through holes form a through hole array (2) to realize the alignment, installation, and fixation of the PGA device.

2. The PGA device gold plating removal fixture according to claim 1, characterized in that: The gold-plated tin handle (3) includes an operating area (4) and a handle (5). The operating area (4) is rectangular, and the handle (5) is connected to a short side of the operating area (4). A square hole is opened in the center of the operating area (4) according to the shape of the PGA device. The position of the square hole corresponds to the position of the through-hole array (2). The size of the square hole is larger than the size of the device, so that the PGA device can be smoothly installed and removed.

3. The PGA device gold-plating removal fixture according to claim 2, characterized in that: Except for the length of the gold-plated tin handle (3) which is longer than the length of the tin pot, the far end of the handle (5) and the connection between the handle (5) and the operating area (4) are rounded to achieve safe operation away from the heat source. Safe operation can be achieved through the handle (5).

4. The PGA device gold-plating removal fixture according to claim 1, characterized in that: The device adhesive layer (1) and the gold removal and tinning handle (3) are bonded together in a double layer to form a PGA gold removal and tinning fixture. The fixture fixes the device through the through hole array (2). The thickness of the device adhesive layer (1) after bonding with the gold removal and tinning handle (3) is greater than the distance without tinning.

5. The PGA device gold removal and tinning fixture according to claim 1, characterized in that: In the gold removal and tinning tooling of the PGA device, the device bonding layer (1) and the gold removal and tinning handle (3) are made of the same material, which is a material incompatible with tin and lead, with a deformation greater than 0.1 mm and a high temperature resistance of 200℃.

6. The PGA device gold-plating removal fixture according to claim 2, characterized in that: In the gold removal and tinning tooling for the PGA device, the thickness of the gold removal and tinning handle (3) is 2mm to 2.5mm, and the square hole in the center of it is made according to the shape of the PGA device. The perimeter of the square hole is 0.4mm to 0.6mm larger than the shape of the device. The length of the handle (5) is greater than 70mm, and the rounded corner of the handle (5) is R5mm to R8mm.

7. The PGA device gold plating removal fixture according to claim 2, characterized in that: The gold-removing and tinning tooling for the PGA device has a device bonding layer (1) with a thickness of 0.3mm to 0.5mm. The dimensions of the device bonding layer (1) are the same as the operating area (4) in width and length. All through holes have the same diameter, and the diameter of the through holes is 0.1mm to 0.2mm larger than the diameter of the device pins.

8. The PGA device gold plating removal fixture according to claim 2, characterized in that: The gold-removing and tinning tooling for the PGA device has the device adhesive layer (1) overlapping with the operating area (4) and is double-layered bonded by adhesive.

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