Repair method of BGA (Ball Grid Array) packaging surface-mounted connector and ball mounting tool

Abstract

The invention belongs to the technical field of electronic assembly repair of electronic and electrical products, and particularly relates to a repair method and a ball mounting tool for a BGA (ball grid array) packaging surface-mounted connector, and the repair method comprises the steps: removing residual soldering tin on a bonding pad of the BGA packaging surface-mounted connector in a tin pot tinning and heating detinning combined mode; the problem of cleaning the BGA packaging surface-mounted connector bonding pad is solved, the BGA packaging surface-mounted connector bonding pad with residual soldering tin removed and the solder balls are installed on the ball mounting tool, the solder balls are fused through reflow soldering, and the repair work of the BGA packaging surface-mounted connector is completed. Through combination of the soldering paste and the ball mounting tool, the ball mounting problem of the BGA packaging surface-mounted connector is solved, the repair work of the BGA packaging surface-mounted connector is completed, an efficient and reliable technological method is provided for repair of the BGA packaging surface-mounted connector of the structure, and the repair capacity of the BGA packaging surface-mounted connector is established.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic assembly repair of electronic and electrical products, and particularly relates to a repair method for a BGA package surface mount connector and a ball planting tooling. Background Art

[0002] With the development of aerospace electronic products towards miniaturization and high density, the selection of BGA package surface mount connectors and their reflow soldering processes is becoming more and more widespread.

[0003] To ensure that the solder balls are not disturbed by the outside world and shift during the ball planting and soldering process, the welding surface of the BGA package surface mount connector is generally designed as a plastic "concave" groove shape. During the ball planting process, the solder balls are placed at the center of the "concave" groove, and the ball planting work of the BGA package surface mount connector is completed through the reflow soldering technology. During the welding process of the printed parts, the BGA package surface mount connector often has abnormal solder balls (such as: too large solder ball bubbles, poor solder ball collapse, connector offset, etc.) after welding due to reasons such as unreasonable printed part pad design, pad contamination, solder ball oxidation, and unreasonable temperature curve design. For BGA package surface mount connectors with welding defects, repair is required. However, due to its special structure, the BGA package surface mount connector cannot be cleaned and ball planted after disassembly. Therefore, for such BGA package surface mount connectors during the repair process, a new connector needs to be replaced, resulting in increased repair costs, extended production cycles, and low production efficiency.

[0004] Therefore, in order to reduce the repair cost, improve the production efficiency, and solve the problem that the BGA package surface mount connector cannot be cleaned and ball planted after disassembly, a new process method needs to be proposed to achieve the high-reliability repair work of the BGA package surface mount connector. Summary of the Invention

[0005] The purpose of the present invention is to provide a repair method for a BGA package surface mount connector to solve the technical problems in the prior art that the BGA package surface mount connector cannot be cleaned and ball planted after disassembly, so for such BGA package surface mount connectors during the repair process, a new connector needs to be replaced, resulting in increased repair costs, extended production cycles, and low production efficiency.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: In the first aspect, the present application discloses a repair method for a BGA package surface mount connector, including: Removing the residual solder on the pads of the BGA package surface mount connector by combining the method of tinning with a tin pot and heating to remove tin; Install the pads and solder balls of the BGA package surface mount connector with residual solder removed onto the ball mounting tooling respectively, melt the solder balls through reflow soldering, and complete the repair of the BGA package surface mount connector.

[0007] Preferably, the method combining tinning in a tin pot and heating to remove tin includes the following steps: S101: Apply flux on the pads of the BGA package surface mount connector. S102: Melt and remove the residual solder balls on the pads of the BGA package surface mount connector through the tin pot for tinning. S103: For the residual solder in the bottom groove of the BGA package surface mount connector, place solder balls in the bottom groove, heat and melt them, apply flux paste on the surface of the solidified solder balls after melting, melt the residual solder and remove it.

[0008] Preferably, when tinning in the tin pot, the liquid level of the solder in the tin pot covers the pads of the BGA package surface mount connector; the temperature of the tin pot is 255 - 270 °C; the tinning process lasts for 2 s - 3 s; after tinning is completed, move the BGA package surface mount connector vertically upward out of the liquid level of the solder in the tin pot.

[0009] Preferably, in S103, the diameter of the solder balls placed in the bottom groove is equal to the diameter of the bottom groove; after applying flux paste on the surface of the solidified solder balls after melting, use solder wire on the surface of the soldering iron for melting and stacking to obtain a soldering iron with stacked solder, use the soldering iron with stacked solder to melt the solder balls in the bottom groove, and remove the residual solder by the siphon action of the solder.

[0010] Preferably, after applying flux paste on the pads of the BGA package surface mount connector with residual solder removed, install it onto the ball mounting tooling.

[0011] Preferably, after melting the solder balls through reflow soldering, cool to room temperature, soak the BGA package surface mount connector in absolute ethanol for 3 min - 5 min, and brush off the residues on the surface and end face of the solder balls.

[0012] In a second aspect, the present application discloses a ball mounting tooling, which is applied to the repair method of the BGA package surface mount connector described in any one of the above, and includes a base and a ball leakage upper die; a placement groove adapted to the BGA package surface mount connector is opened at the center of the base, and a plurality of guiding grooves are opened at the edge of the base; a ball leakage steel sheet is arranged on the lower surface of the ball leakage upper die, and a plurality of ball leakage holes are opened on the ball leakage steel sheet, and the ball leakage holes are adapted to the bottom grooves of the BGA package surface mount connector; guiding columns adapted to the guiding grooves are arranged at the edge of the ball leakage upper die.

[0013] Preferably, after placing the BGA package surface mount connector in the placement groove, the pads of the BGA package surface mount connector are flush with the upper surface of the base.

[0014] Preferably, the aperture of the ball leakage hole is 0.03 mm to 0.05 mm larger than the diameter of the solder ball.

[0015] Preferably, the arrangement and quantity of the ball leakage holes correspond to the pads of the BGA package surface mount connector.

[0016] Compared with the prior art, the present invention has the following beneficial effects: For the disassembled BGA package surface mount connector, by combining the method of dipping in a solder pot with manual soldering iron desoldering, the problem of cleaning the pads of the BGA package surface mount connector is solved. By combining the soldering paste with the ball planting tooling, the problem of ball planting for the BGA package surface mount connector is overcome, and the repair work of the BGA package surface mount connector is completed. This provides an efficient and reliable process method for the repair of BGA package surface mount connectors of such structures and establishes the ability to repair BGA package surface mount connectors.

[0017] By repairing the disassembled BGA package surface mount connector, the repair work of the BGA package surface mount connector on single-sided, double-sided, and multi-layer printed circuit board assemblies in electronic and electrical products can be completed. On the premise of ensuring reliability, it does not affect the normal progress of each process in subsequent SMT production, improves the production efficiency of the product. At the same time, due to the repair and use of the BGA package surface mount connector, the waste of time and resources in the production process caused by replacing new materials is avoided, and the repair cost in the production process is reduced. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0019] Figure 1 It is the process flow chart of the repair process of the BGA package surface mount connector according to the embodiment of the present invention; Figure 2 It is the schematic diagram of the position of the bottom solder balls of the BGA package surface mount connector according to the embodiment of the present invention; Figure 3 It is the schematic diagram of dipping the BGA package surface mount connector in a solder pot according to the embodiment of the present invention; Figure 4 It is the schematic diagram of the ball planting tooling of the BGA package surface mount connector according to the embodiment of the present invention.

[0020] Among them: 1 - solder ball; 2 - bottom groove; 3 - base of the ball planting tooling; 4 - placement groove; 5 - upper die of the ball leakage; 6 - guiding column of the ball planting tooling; 7 - steel sheet of the ball leakage; 8 - ball leakage hole. Detailed implementation manners

[0021] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0024] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships in which the inventive product is customarily placed during use, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, terms such as "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0025] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0026] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0027] The present invention will be further described in detail below with reference to the accompanying drawings: The object of the present invention is to provide a repair method for BGA package surface mount connectors. By adopting a process method combining tin pot tinning and soldering iron tinning to remove tin, the problem of cleaning the pads of such BGA package surface mount connectors is solved. At the same time, a method combining soldering paste and ball mounting tooling is used to solve the ball mounting problem, thereby realizing the repair work of BGA package surface mount connectors. The specific steps are as follows: Use a combination of tin pot tinning and heating tin removal treatment to remove the residual solder on the pads of the BGA package surface mount connector; Install the pads and solder balls of the BGA package surface mount connector with the residual solder removed onto the ball mounting tooling respectively, and melt the solder balls through reflow soldering to complete the repair work of the BGA package surface mount connector.

[0028] Since the solder balls on the welding surface of the BGA package surface mount connector are all located in the restricted "concave" grooves and cannot be cleaned with a solder sucker after disassembly, the present application melts and removes the residual solder of the device by using molten solder to achieve the purpose of cleaning the pads. At the same time, solder paste and ball mounting tooling are used for ball mounting of the BGA package surface mount connector to achieve the purpose of repairing the BGA package surface mount connector. By repairing the disassembled BGA package surface mount connector, the repair work of BGA package surface mount connectors on single-sided, double-sided and multi-layer printed circuit board assemblies in electronic and electrical products can be completed. Without affecting the normal progress of subsequent SMT production processes, the production efficiency of the product is improved. At the same time, due to the repair and use of BGA package surface mount connectors, the waste of time and resources in the production process caused by replacing new materials is avoided, and the repair cost in the production process is reduced.

[0029] In some embodiments, the combination of tin pot tinning and heating tin removal treatment includes the following steps: S101: Apply flux on the pads of the BGA package surface mount connector; S102: Melt and remove the residual solder balls on the pads of the BGA package surface mount connector through a tin pot for tinning; S103: For the residual solder in the bottom groove 2 of the BGA package surface mount connector, place a solder ball in the bottom groove 2, heat and melt it, apply flux on the surface of the solidified solder ball after melting, and melt and remove the residual solder.

[0030] In some embodiments, when tinning with a tin pot, the solder level in the tin pot covers the pads of the BGA package surface mount connector; the temperature of the tin pot is 270°C; the tinning process lasts for 2s - 3s; after tinning is completed, the BGA package surface mount connector is vertically removed upward from the solder level in the tin pot.

[0031] In some embodiments, in S103, the diameter of the solder balls placed in the bottom groove 2 is equal to the diameter of the bottom groove 2; after applying flux on the surface of the solidified solder balls after melting, molten stacking is performed on the surface of the soldering iron using solder wire to obtain a soldering iron with a solder heap, and the solder balls in the bottom groove 2 are melted using the soldering iron with a solder heap, and the residual solder is removed by the siphon action of the solder.

[0032] In some embodiments, a method for repairing a BGA package surface mount connector includes: Removing the residual solder on the pads of the BGA package surface mount connector by combining tinning with a tin pot and heating to remove tin; S101: Apply flux on the pads of the BGA package surface mount connector; S102: Melt and remove the residual solder balls on the pads of the BGA package surface mount connector through a tinning tin pot; S103: For the residual solder in the bottom groove 2 of the BGA package surface mount connector, place solder balls in the bottom groove 2, heat and melt them, apply flux on the surface of the solidified solder balls after melting, and melt and remove the residual solder.

[0033] Apply flux on the pads of the BGA package surface mount connector from which the residual solder has been removed, respectively install the pads of the BGA package surface mount connector from which the residual solder has been removed and the solder balls onto a ball mounting tooling, and melt the solder balls through reflow soldering to complete the repair work of the BGA package surface mount connector.

[0034] The present application aims to solve the problem that the BGA package surface mount connector cannot be repaired after disassembly, reduce the cost of material replacement brought by the repair, and also propose a method for cleaning the BGA pads, which can be applied and extended to other similar-structured devices. In view of the welding defects such as excessive solder ball bubbles, solder ball collapse, and overall offset of the BGA package surface mount connector that are likely to occur after reflow soldering, the original repair process requires disassembling the BGA package surface mount connector and replacing it with a new device. The present application provides a simple and efficient process method for repairing the BGA package surface mount connector. That is, by applying flux (flux paste) to the bottom of the disassembled BGA package surface mount connector, combining the method of tinning with a tin pot and tinning with a soldering iron, melting and removing the bottom solder of the BGA package surface mount connector through the molten solder, and at the same time completing the ball placement of the BGA package surface mount connector through the flux paste and the ball mounting tooling, and completing the ball mounting work of the BGA package surface mount connector in the way of reflow soldering, thereby completing the repair work of the BGA package surface mount connector, and thus solving the problem that the production process defects can be repaired.

[0035] In some embodiments, a method for repairing a BGA package surface mount connector is carried out according to the Figure 1 shown process, and the specific steps are as follows: Step 1: According to the product repair process, for the printed circuit board assembly that needs to be repaired, the BGA-packaged surface-mount connector with soldering defects needs to be disassembled using a rework workstation, and flux is applied to the bottom of the disassembled BGA-packaged surface-mount connector.

[0036] Step 2: Perform tinning treatment using a tinning pot. The residual solder at the bottom of the BGA-packaged surface-mount connector is melted by the high-temperature molten solder solution in the tinning pot, and the solder at the bottom of the BGA-packaged surface-mount connector is initially removed through the siphon action of the solder. When tinning, the position of the BGA-packaged surface-mount connector relative to the solder level in the tinning pot is as Figure 3 shown. During the tinning process, the temperature of the tinning pot is set to 260 °C, and the tinning process is maintained for 2 s to 3 s. After completing the tinning work, the surface-mount connector is lifted vertically with respect to the liquid level position.

[0037] Step 3: For the small amount of residual solder that still remains in the bottom groove 2 after the tinning of the tinning pot is completed, solder balls with the same diameter as the solder balls of the BGA-packaged surface-mount connector are selected and placed in the bottom groove 2, and an electric soldering iron is used to melt them.

[0038] Step 4: To facilitate the evacuation of the solder during the de-soldering process of the electric soldering iron, a small amount of soldering paste is brushed on the surface of the solder ball after melting and solidifying.

[0039] Step 5: Melt and stack solder wire on the surface of the electric soldering iron, and then use the soldering iron with stacked solder to melt the solder balls in the bottom groove 2. Utilize the siphon action of the solder and, with the assistance of the soldering paste, complete the evacuation of the solder.

[0040] Step 6: Apply a small amount of soldering paste to the bottom groove 2 of the BGA-packaged surface-mount connector with the residual solder cleaned. On the one hand, it is convenient to place the solder balls therein and use the viscosity of the soldering paste to assist in fixing the solder balls. On the other hand, during the melting process of the solder balls, the oxide layer on the surface of the solder balls is removed, reducing the surface tension of the solder and ensuring good wetting of the solder joints.

[0041] Step 7: Place the solder balls through a ball placement tooling. After completion, the quality of the placed balls needs to be inspected. The arrangement and quantity of the solder balls correspond one by one to the pads of the BGA-packaged surface-mount connector, and the diameter consistency of the solder balls is good.

[0042] Step 8: For the BGA-packaged surface-mount connector with ball placement completed, perform reflow soldering using a reflow soldering furnace to complete the melting and wetting of the solder balls. After reflow soldering, wait for the BGA-packaged surface-mount connector to cool to room temperature. Then, immerse the BGA-packaged surface-mount connector in a container filled with anhydrous ethanol for 3 to 5 minutes. Gently pick up the BGA-packaged surface-mount connector with one hand (note: do not touch the solder balls), and with the other hand, use an anti-static brush dipped in anhydrous ethanol to brush along the solder balls and the end faces of the solder balls to remove the residues on the surfaces and end faces of the solder balls. When brushing, apply light force to prevent the solder balls from being scratched and deformed or the BGA-packaged surface-mount connector from being damaged.

[0043] As Figure 4 shown, the ball placement tooling used in the repair process of the BGA-packaged surface-mount connector is used to achieve the ball placement work of the BGA-packaged surface-mount connector. It includes a base 3 and a ball leakage upper die 5; a placement groove 4 adapted to the BGA-packaged surface-mount connector is provided at the center of the base 3, and a plurality of guide grooves are provided at the edge of the base 3; a ball leakage steel sheet 7 is provided on the lower surface of the ball leakage upper die 5, and a plurality of ball leakage holes 8 are provided on the ball leakage steel sheet 7, and the ball leakage holes 8 are adapted to the bottom grooves 2 of the BGA-packaged surface-mount connector; guide posts 6 adapted to the guide grooves are provided at the edge of the ball leakage upper die 5.

[0044] The working principle of the ball placement tooling is as follows: Place the BGA-packaged surface-mount connector with the pads cleaned in the placement groove 4. The ball leakage upper die 5 fits tightly with the base 3 of the ball placement tooling without gaps. Place solder balls with the same diameter as the BGA-packaged surface-mount connector on the ball leakage steel sheet 7. Use the guide posts 6 of the ball placement tooling to align the ball leakage holes 8 completely with the bottom grooves 2 of the BGA-packaged surface-mount connector. Gently shake the ball placement tooling to make the solder balls enter the bottom grooves 2 through the ball leakage holes 8, ensuring that there are solder balls in all the leakage holes to complete the ball placement work of the BGA-packaged surface-mount connector.

[0045] In some embodiments, the placement groove 4 is a placement groove 4 milled by machining in the base 3 of the ball placement tooling to match the outer dimensions of the BGA-packaged surface-mount connector. The depth of the placement groove 4 should meet the requirement that after the BGA-packaged surface-mount connector is placed therein, the ball placement surface (pad) of the BGA-packaged surface-mount connector should be flush with the upper surface of the base 3 of the ball placement tooling.

[0046] In some embodiments, the ball leakage steel sheet 7 is located on the lower surface of the ball leakage upper die 5. The designed opening size on the ball leakage steel sheet should be 0.03 mm to 0.05 mm larger than the diameter of the solder ball, and the center positions should correspond one by one to the center positions of the grooves of the BGA-packaged surface-mount connector.

[0047] The present invention can achieve the repair work of BGA-packaged surface mount connectors, and can meet the repair work of products after defects occur in the reflow soldering of BGA-packaged surface mount connectors. This process method is stable and reliable, avoiding the waste of time and resources caused by replacing new devices during repair, and also reducing the repair cost.

[0048] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for repairing a BGA package surface mount connector, characterized in that: include: Use a combination of tinning in a tin pot and heating to remove the residual solder on the pads of the BGA package surface mount connector; The BGA package surface mount connector pads and solder balls from which the residual solder has been removed are installed on the ball planting tooling respectively, and the solder balls are melted by reflow soldering to complete the repair work of the BGA package surface mount connector.

2. A method for repairing a BGA package surface mount connector according to claim 1, characterized in that: The method of combining tin pot tinning and heating tin removal treatment comprises the following steps: S101: Apply flux to the BGA package surface mount connector pads; S102: melting and removing the residual solder balls on the solder pads of the BGA package surface mount connector by using a tinning pot; S103: For the residual solder in the bottom groove (2) of the BGA package surface mount connector, a solder ball is placed in the bottom groove (2), heated to melt, and flux paste is applied to the surface of the solder ball that has solidified after melting to melt and remove the residual solder.

3. The method for repairing a BGA package surface mount connector according to claim 1, characterized in that: When the tin pot is tinning, the solder liquid level of the tin pot is above the BGA package surface mount connector pad; the tin pot temperature is 255-270° C.; the tinning process is maintained for 2s-3s; after the tinning is completed, the BGA package surface mount connector is moved upwardly and vertically to the solder liquid level of the tin pot.

4. The method for repairing a BGA package surface mount connector according to claim 2, characterized in that: In the above S103, the diameter of the solder ball placed in the bottom groove (2) is equal to the diameter of the bottom groove (2); after the surface of the solder ball that has been melted and solidified is coated with solder paste, solder wire is used to melt and accumulate on the surface of the electric soldering iron to obtain a tin-pile electric soldering iron; the solder ball in the bottom groove (2) is melted using the tin-pile electric soldering iron, and the residual solder is removed by using the siphon effect of the solder.

5. The method for repairing a BGA package surface mount connector according to claim 1, characterized in that: After removing the residual solder, apply flux paste to the BGA package surface mount connector pads and install it on the ball placement tool.

6. The method for repairing a BGA package surface mount connector according to claim 1, characterized in that: After the solder balls are melted by reflow soldering and cooled to room temperature, the BGA package surface mount connector is immersed in anhydrous ethanol for 3min~5min, and the residues on the surface and end face of the solder balls are brushed off.

7. A bulb planting tool, characterized in that: The repair method of the BGA package surface mount connector as claimed in any one of claims 1 to 6 comprises a base (3) and a ball leakage upper mold (5); a placement groove (4) adapted to the BGA package surface mount connector is provided at the center of the base (3), and a plurality of guide grooves are provided at the edge of the base (3); a ball leakage steel sheet (7) is provided on the lower surface of the ball leakage upper mold (5), and a plurality of ball leakage holes (8) are provided on the ball leakage steel sheet (7), and the ball leakage holes (8) are adapted to the bottom groove (2) of the BGA package surface mount connector; and a guide column (6) adapted to the guide groove is provided on the edge of the ball leakage upper mold (5).

8. The bulb planting tool according to claim 7, characterized in that: After the BGA package surface mount connector is placed in the placement groove (4), the BGA package surface mount connector pad is flush with the upper surface of the base (3).

9. The bulb planting tool according to claim 7, characterized in that: The diameter of the ball leakage hole (8) is 0.03 mm to 0.05 mm larger than the diameter of the solder ball.

10. The bulb planting tool according to claim 7, characterized in that: The arrangement and number of the ball leakage holes (8) correspond to the pads of the BGA package surface mount connector.

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