BGA device adhesive dispensing protection device to prevent solder joint contamination

Abstract

This utility model discloses a BGA device adhesive dispensing protection device to prevent solder joint contamination, belonging to the field of electronic assembly technology. It solves the problem in existing technologies where epoxy adhesive easily flows and contaminates BGA solder joints during the corner dispensing and reinforcement process. The device includes four L-shaped peripheral limiting structures positioned around the four corners of the BGA device. Each peripheral limiting structure has protrusions at both ends that are detachably connected to side baffles. This utility model uses detachably connected peripheral limiting structures and side baffles to form L-shaped grooves for accommodating adhesive, effectively protecting the BGA device solder joints and preventing adhesive from flowing into the bottom of the BGA device and contaminating the solder joints. This avoids thermal fatigue failure of BGA device solder joints under temperature cycling conditions due to the mismatch of thermal expansion coefficients of different materials.

Description

Technical Field

[0001] This utility model relates to the field of electronic assembly technology, specifically to a BGA device adhesive dispensing protection device to prevent solder joint contamination. Background Technology

[0002] In high-reliability avionics products, to address the issue of solder joint fracture failure caused by the poor vibration resistance of heavy BGA devices in high-vibration environments, high-strength epoxy adhesive is often used to reinforce the four corners of the BGA devices with L-shaped adhesive dots. This improves the board-level application reliability of the BGA device solder joints. Figure 13 As shown.

[0003] Because all types of epoxy adhesives have a certain degree of flowability, regardless of whether manual or automated dispensing methods are used, epoxy adhesive may flow outwards to unwanted areas around the BGA, or flow inwards to the BGA solder joints at the bottom of the device. Furthermore, epoxy adhesive flowing into the bottom of the BGA device and contaminating the solder joints is difficult to detect. For high-reliability electronic products, epoxy adhesive contamination of solder joints is a restricted process. Epoxy adhesive flowing onto component solder joints can cause solder joint cracking and failure due to differences in the thermal expansion coefficients of different materials. Therefore, the dispensing process should prevent adhesive from flowing onto the solder joints. However, current process designs lack effective methods to prevent epoxy adhesive from flowing and contaminating the BGA solder joints after dispensing at the four corners of the BGA. Utility Model Content

[0004] To address the aforementioned problems in the prior art, this utility model provides a BGA device adhesive dispensing protection device to prevent solder joint contamination, solving the problem that the epoxy adhesive easily flows and contaminates the BGA solder joints during the adhesive dispensing and reinforcement process at the four corners of the BGA device in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A BGA device adhesive dispensing protection device for preventing solder joint contamination is provided, comprising four L-shaped peripheral limiting structures respectively surrounding the four corners of the BGA device. Each peripheral limiting structure has a boss at both ends that can be detachably connected to a side baffle. The two side baffles located on each peripheral limiting structure pass through the two bosses and abut against each other, and the outer wall surfaces of the two side baffles and the inner wall surfaces of the peripheral limiting structures form an L-shaped groove for accommodating adhesive.

[0007] In this solution, a detachable peripheral limiting structure and side baffle are used to form an L-shaped groove for accommodating adhesive. This can help protect the solder joints of BGA devices, prevent adhesive from flowing into the bottom of the BGA devices and contaminating the solder joints, and avoid thermal fatigue failure of the solder joints of BGA devices in electronic products due to the mismatch of thermal expansion coefficients of different materials under temperature cycling conditions. Moreover, it can be easily removed after the adhesive has cured, and will not stick to the adhesive and become impossible to remove, thus playing a role in protecting the solder joints of BGA devices.

[0008] Furthermore, two protrusions on each peripheral limiting structure are respectively vertically disposed on the inner wall surfaces at both ends of the peripheral limiting structure; the outer wall of each protrusion is provided with a through groove for the side baffle to pass through. The through groove is provided to ensure that the side baffle is flush with the peripheral edge of the BGA device and consistent with the height of the bottom solder ball of the BGA, so as to restrict the adhesive from flowing into the bottom of the solder ball of the BGA device.

[0009] Furthermore, each boss has a blind hole on its outer end face, and each side panel has a tail baffle at its end, with a pin on each tail baffle for insertion into the blind hole. The engagement of the pin and the blind hole facilitates the fixation of the outer limiting structure and the side panels.

[0010] Furthermore, each side panel has a slot at its bottom end near the rear panel for engaging with the corresponding through slot on the boss. The slot facilitates the limiting of the side panel's position.

[0011] Furthermore, each side panel has a pointed tip at its end near the rear panel, which appears as an isosceles right triangle when viewed from above. The two pointed tips facilitate a tight fit between the contact ends of the two side panels.

[0012] Furthermore, the height of each peripheral limiting structure is 1 / 2 to 2 / 3 of the height of the BGA device.

[0013] Furthermore, the height of each side baffle is the same as the diameter height of the solder balls in the BGA device.

[0014] Furthermore, each side panel and each peripheral limiting structure has a Teflon coating on its outer surface. The Teflon coating ensures that the side panels and peripheral limiting structures can be easily removed after the L-shaped adhesive at the four corners of the BGA device has cured, preventing them from bonding together after the adhesive has cured and becoming impossible to remove.

[0015] This utility model discloses a BGA device adhesive dispensing protection device to prevent solder joint contamination, the beneficial effects of which are:

[0016] 1. This utility model adopts a detachable external limiting structure and a side baffle to form an L-shaped groove for accommodating adhesive, which can protect the solder joints of BGA devices, prevent adhesive from flowing into the bottom of the BGA devices and contaminating the solder joints, avoid thermal fatigue failure of BGA device solder joints in electronic products due to the mismatch of thermal expansion coefficients of different materials under temperature cycling conditions, and can be easily removed after the adhesive has cured, without sticking to the adhesive and being unable to be removed, thus playing a role in protecting the solder joints of BGA devices.

[0017] 2. The Teflon coating of this utility model ensures that the side baffles and peripheral limiting structures can be easily removed after the L-shaped adhesive at the four corners of the BGA device has cured, avoiding the situation where the adhesive becomes bonded together after curing and cannot be removed. Attached Figure Description

[0018] Figure 1 A schematic diagram of a dispensing protection device for BGA devices to prevent solder joint contamination;

[0019] Figure 2 This is a top view of the outer limiting structure;

[0020] Figure 3 This is a front view of the outer limiting structure;

[0021] Figure 4 This is a top view of the side panel;

[0022] Figure 5 This is a front view of the side panel;

[0023] Figure 6 This is a left view of the side panel;

[0024] Figure 7 This is a top view of the outer limiting structure;

[0025] Figure 8 This is a front view of the outer limiting structure;

[0026] Figure 9 This is a top view of the side panel;

[0027] Figure 10 This is a front view of the side panel;

[0028] Figure 11 This is a front view of the connection between the BGA device and the PCBA.

[0029] Figure 12 A schematic diagram of the bottom solder balls of a BGA device;

[0030] Figure 13 This is a schematic diagram of adhesive dispensing around an existing BGA device.

[0031] The components include: 1. peripheral limiting structure; 11. boss; 12. through slot; 13. blind hole; 2. side baffle; 21. tail baffle; 22. pin; 23. tip; 24. slot; 3. BGA device; 4. adhesive. Detailed Implementation

[0032] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0033] This embodiment provides a BGA device adhesive dispensing protection device to prevent solder joint contamination. It is used to solve the problem that the epoxy adhesive is easy to flow and thus contaminates the BGA solder joints during the adhesive dispensing and reinforcement process at the four corners of the BGA device in the prior art. It is shown in detail below.

[0034] refer to Figure 1 A BGA device adhesive dispensing protection device for preventing solder joint contamination includes four peripheral limiting structures 1, each of which is L-shaped and is respectively arranged around the four corners of the BGA device 3. Each peripheral limiting structure 1 has a boss 11 at both ends that can be detachably connected to a side baffle 2.

[0035] In this structure, one end of each of the two side baffles 2 located on each peripheral limiting structure 1 passes through two protrusions 11 and abuts against each other, and the outer wall surface of the two side baffles 2 and the inner wall surface of the peripheral limiting structure 1 surround each other to form an L-shaped groove for accommodating the adhesive 4.

[0036] For details, please refer to Figure 2 and Figure 3 Each peripheral limiting structure 1 has two protrusions 11 vertically mounted on the inner walls at both ends. Each protrusion 11 has a blind hole 13 on its outer end face. Each side baffle 2 has a tail baffle 21 at its end, and each tail baffle 21 has a pin 22 for insertion into the blind hole 13. The engagement of the pin 22 and the blind hole 13 facilitates the fixation of the peripheral limiting structure 1 and the side baffle 2.

[0037] As a further embodiment, each boss 11 has a through groove 12 on its outer wall for the side baffle 2 to pass through. The through groove 12 ensures that the side baffle 2 is flush with the outer edge of the BGA device 3 and has the same height as the bottom solder balls of the BGA, thereby limiting the flow of adhesive 4 into the bottom of the solder balls of the BGA device 3. Furthermore, each side baffle 2 has a slot 24 on its bottom end near the tail baffle 21 for engaging with the through groove 12 on the corresponding boss 11. The slot 24 facilitates the limiting of the side baffle 2.

[0038] For better sealing of the L-groove, refer to adhesive 4. Figures 3-5 Each side panel 2 has a pointed tip 23 at the end near the tail panel 21, which is an isosceles right triangle in plan view. The two pointed tips 23 are provided to ensure that the contact ends of the two side panels 2 are tightly attached.

[0039] To facilitate the removal of the side baffles 2 and the peripheral limiting structures 1, a Teflon coating is provided on the outer surface of each peripheral limiting structure 1 and each side baffle 2. The Teflon coating ensures that the side baffles 2 and the peripheral limiting structures 1 can be easily removed after the L-shaped adhesive 4 at the four corners of the BGA device 3 has cured, avoiding the situation where the adhesive 4 becomes bonded together after curing and cannot be removed.

[0040] In this embodiment, reference Figures 6-12 Where L is the side length of BGA device 3; L1 is the length of each side of the peripheral limiting structure 1; d is the diameter of the bottom solder ball of BGA device 3; a is the distance from the outermost solder ball to the edge of BGA device 3; H is the total height of BGA device 3; h1 is the height of peripheral limiting structure 1, and is 1 / 2 to 2 / 3 of H; h2 is the total height of through slot 12 or the total height of side baffle 2, and h2=d; h3 is the slot depth of through slot 12; W is the width of each side of peripheral limiting structure 1; W1 is the distance from the outer wall of boss 11 to one side of peripheral limiting structure 1; W2 is the length of through slot 12 or slot 24; W3 is the slot width of through slot 12 or the width of the tip 23 on side baffle 2.

[0041] In summary, the usage method of this solution is as follows:

[0042] S1. Apply double-sided adhesive to the surface where the peripheral limiting structure 1 contacts the PCBA surface to fix the relative position of the peripheral limiting structure 1 and the BGA device 3.

[0043] S2. The outer limiting structure 1 is fixed to the adhesive application area on the PCBA surface using the double-sided adhesive in step S1, and the two protrusions 11 in the outer limiting structure 1 extend into the bottom of the BGA device 3.

[0044] S3. Insert the two side baffles 2 into the two through slots 12 of the outer limiting structure 1 respectively, and complete the positioning of the side baffle 2 device and the outer limiting device by the cooperation of the pin 22 and the blind hole 13.

[0045] S4. Repeat steps S1 to S3 until all four peripheral limiting structures 1 are installed around the BGA device 3.

[0046] S5. Apply L-shaped adhesive to the four corners of the BGA device 3 with the adhesive protection device installed, and then cure the adhesive.

[0047] S6. Remove all side panels 2 and peripheral limiting structures 1 in sequence. Specifically, before removing the peripheral limiting structure, spray a ring of cleaning alcohol between the outer perimeter of the PCBA and the contact surface of the peripheral limiting structure 1 to make the double-sided adhesive ineffective.

[0048] Although the specific embodiments of the utility model have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this patent.

Claims

1. A BGA device adhesive dispensing protection device to prevent solder joint contamination, characterized in that, It includes four L-shaped peripheral limiting structures (1) that surround the four corners of the BGA device (3). Each peripheral limiting structure (1) has a boss (11) that can be detachably connected to the side baffle (2) at both ends. In this case, one end of each of the two side baffles (2) located on each of the peripheral limiting structures (1) passes through the two bosses (11) and abuts against each other, and the outer wall surface of the two side baffles (2) and the inner wall surface of the peripheral limiting structure (1) surround each other to form an L-shaped groove for accommodating the adhesive (4).

2. The BGA device dispensing protection device for preventing solder joint contamination according to claim 1, characterized in that, Two protrusions (11) on each of the peripheral limiting structures (1) are respectively vertically arranged on the inner wall surfaces at both ends of the peripheral limiting structure (1); the outer wall of each protrusion (11) is provided with a through groove (12) for the side baffle (2) to pass through.

3. The BGA device dispensing protection device for preventing solder joint contamination according to claim 2, characterized in that, Each of the bosses (11) has a blind hole (13) on its outer end face, and each of the side baffles (2) has a tail baffle (21) at its end. Each tail baffle (21) has a pin (22) for inserting into the blind hole (13).

4. The BGA device dispensing protection device for preventing solder joint contamination according to claim 3, characterized in that, Each of the side baffles (2) has a slot (24) on its bottom end near the tail baffle (21) for engaging with the through slot (12) on the corresponding boss (11).

5. The BGA device dispensing protection device for preventing solder joint contamination according to claim 3, characterized in that, Each of the side panels (2) has a pointed tip (23) that is an isosceles right triangle in plan view at the end near the tail panel (21).

6. The BGA device dispensing protection device for preventing solder joint contamination according to claim 1, characterized in that, The height of each of the peripheral limiting structures (1) is 1 / 2 to 2 / 3 of the height of the BGA device (3).

7. The BGA device dispensing protection device for preventing solder joint contamination according to claim 1, characterized in that, The height of each of the side baffles (2) is the same as the diameter height of the solder ball at the bottom of the BGA device (3).

8. The BGA device dispensing protection device for preventing solder joint contamination according to claim 1, characterized in that, Each of the side baffles (2) and each of the peripheral limiting structures (1) has a Teflon coating on its outer surface.

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