Tool for locally printing solder paste on printed board during BGA reworking

Abstract

The utility model belongs to the technical field of solder paste printing, and discloses a tool for locally printing solder paste on a printed board during BGA reworking. The printing sheet is fixedly connected to the base, a printing space is formed between the printing sheet and the base, and a pattern part is arranged on the printing sheet; and the scraper blade is matched with the printing sheet for use. The technical problem of difficulty in local solder paste printing of the printed board when the BGA packaging device is reworked is solved. According to the scheme, the structure is reasonable, use and operation are simple, and the reworking efficiency and the qualified rate of the BGA packaging device are effectively improved.

Description

Technical Field

[0001] This utility model belongs to the field of solder paste printing technology, specifically relating to a device for partially printing solder paste on a printed circuit board during the rework of BGA packaged devices. Background Technology

[0002] BGA packaging utilizes the entire bottom solder ball to connect to the printed circuit board, significantly increasing the device's I / O count, shortening the signal transmission path, and providing excellent heat dissipation. Due to the short leads, the self-inductance and mutual inductance between the leads are very low, resulting in good frequency characteristics. Therefore, high-speed, highly integrated chips currently use BGA packaging. As aerospace electrical equipment increasingly moves towards miniaturization, lightweight design, and multi-functionality, more and more BGA-packaged devices are being used on their internal printed circuit board assemblies. However, BGA packaging is not without its limitations. Because the solder joints are hidden on the bottom of the device, they are difficult to repair. Compared to components with exposed leads, rework is more difficult. Even a single poor solder joint causing a fault requires the entire device to be disassembled and reworked using specialized rework equipment and following specific rework processes.

[0003] Compared to civilian products, aerospace products have much stricter quality control requirements. To avoid soldering quality issues caused by insufficient solder at the pads on the printed circuit board (PCB) after rework of BGA packaged devices, solder needs to be locally added to the corresponding pads on the PCB before mounting the new BGA packaged devices. Since other components are present around the reworked BGA devices on the PCB assembly, solder paste printing cannot be done using a stencil. Solder paste sprayers and solder paste applicators can achieve localized soldering on the PCB pads; however, these machines are expensive, and most companies do not have them in-house, as investing in new equipment would increase manufacturing costs. By designing a fixture for localized solder paste printing on the PCB during BGA packaged device rework, the operation is simple, the manufacturing cost is low, and efficient localized solder paste printing on the PCB can be achieved, improving the rework pass rate of BGA packaged devices. Utility Model Content

[0004] This invention addresses the technical problem of difficulty in partial solder paste printing on printed circuit boards during the rework of BGA packaged devices. It proposes a tooling for partial solder paste printing on printed circuit boards, which can efficiently print solder paste on specific areas of the printed circuit board, thereby improving the rework pass rate of BGA packaged devices.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A fixture for partial solder paste printing on a printed circuit board during BGA rework, comprising:

[0007] Base;

[0008] A printing sheet is fixedly connected to the base, and a printing space is formed between the printing sheet and the base. A graphic portion is provided on the printing sheet.

[0009] A doctor blade, used in conjunction with the printing sheet.

[0010] As a further technical solution of this utility model, the printed sheet is cradle-shaped with one side fully open. It includes a printing part, a connecting part, and a solder blocking part. The two connecting parts are perpendicular to the two sides of the printing part, and the solder blocking part is set at an angle to the printing part.

[0011] As a further technical solution of this utility model, the graphic part is formed on the printed part, and the shape of the graphic part is adapted to the PCB pad.

[0012] As a further technical solution of this utility model, the size of the printed part is consistent with the size of the BGA packaged device.

[0013] As a further technical solution of this utility model, the bending direction of the solder blocking part is consistent with that of the connecting part, but the bending angle is less than 90 degrees, and the length of the solder blocking part is less than the length of the connecting part.

[0014] As a further technical solution of this utility model, the width of the doctor blade is consistent with the width of the printing section.

[0015] As a further technical solution of this utility model, a handle is also included, which is fixedly connected to the base.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] 1. Enables localized soldering of PCB pads during BGA rework. The printed circuit board (PCB) pattern openings precisely match the PCB pads, allowing solder paste to be applied using a squeegee.

[0018] 2. The semi-enclosed design of the printed circuit board can prevent excess solder paste from contaminating surrounding components during printing.

[0019] 3. The handle design makes the demolding of solder paste more convenient.

[0020] 4. The tooling is not only reasonably structured, but also easy to use and operate, which effectively improves the rework efficiency and pass rate of BGA packaged devices. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a tooling for partial solder paste printing on a printed circuit board during BGA rework, according to the present invention.

[0022] Figure 2 for Figure 1 The diagram is shown in the image.

[0023] In the diagram: base 2, printing plate 1, scraper blade 4, handle 3, graphic part 1-1, connecting part 1-2, solder block part 1-3. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Please see Figure 1-2 This utility model provides an embodiment of a fixture for partial solder paste printing on a printed circuit board during BGA rework, comprising: a base 2; a printed circuit board 1 and a handle 3 connected to the base 2; and a scraper blade 4 used in conjunction with the printed circuit board 1. The handle 3 is fixed to the base 2 by means of threaded fastening or screw fastening, and the scraper blade 4 is an independent structure.

[0026] like Figure 2 As shown, the printed circuit board 1 is cradle-shaped (semi-enclosed structure), with a solder-blocking part 1-3 on one side and an open structure on the opposite side to facilitate the movement of the squeegee 4. This semi-enclosed structure can prevent excess solder paste from contaminating surrounding components during partial printing on the printed circuit board. It is fixed to the base 2 by screws, and a printing space is formed between the printed circuit board 1 and the base 2 for applying solder paste.

[0027] The printed circuit board 1 includes a printing section, connecting sections 1-2, and solder resisting sections 1-3. The two connecting sections 1-2 are perpendicular to both sides of the printing section, and the solder resisting sections 1-3 are angled to the printing section. A graphic section 1-1 is formed on the printing section, and its shape matches the PCB pads. Holes are made according to the PCB pad dimensions of the device to be reworked, ensuring that solder paste can be printed onto the PCB pads. The dimensions of the printing section are consistent with the dimensions of the BGA packaged device. The bending direction of the solder resisting section 1-3 is the same as that of the connecting sections 1-2, but the bending angle is less than 90 degrees, and the length of the solder resisting section 1-3 is less than the length of the connecting sections 1-2.

[0028] The size of the printed portion of the printed circuit board 1 depends on the size of the BGA packaged device to be reworked. In this embodiment, the printed portion of the printed circuit board 1 is square, while the solder resisting portions 1-3 and the connecting portions 1-2 are trapezoidal, forming an integral structure through equipment cutting. At the same time, holes are made on the printed portion according to the positions of the BGA device pads on the PCB to ensure that the solder paste can be printed onto the PCB pads.

[0029] Cut the intersection of the printed part of the printed sheet 1 with the solder resist part 1-3 and the connecting part 1-2 into a dotted line. Then, bend the connecting parts 1-2 on both sides at 90 degrees and bend the solder resist part 1-3 at 75 degrees to form a cradle structure. Note that the height of the solder resist part 1-3 should be lower than the height of the connecting part 1-2 to leave an observation window for easy observation of the alignment of the opening of the graphic part 1-1 with the printed circuit board pads during positioning.

[0030] like Figure 1 As shown, the doctor blade 4 is used in conjunction with the printing sheet 1. The width of the doctor blade 4 is the same as the width of the printing sheet 1, and it has a certain thickness to facilitate printing operations.

[0031] Thus, the objective of this utility model has been achieved.

[0032] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A fixture for partial solder paste printing on a printed circuit board during BGA rework, characterized in that... ,include: Base; A printing sheet is fixedly connected to the base, and a printing space is formed between the printing sheet and the base. A graphic portion is provided on the printing sheet. A doctor blade, used in conjunction with the printing sheet.

2. The fixture for partial solder paste printing on a printed circuit board during BGA rework according to claim 1, characterized in that, The printed sheet is cradle-shaped with one side fully open. It includes a printing section, a connecting section, and a solder-blocking section. The two connecting sections are perpendicular to the two sides of the printing section, and the solder-blocking section is set at an angle to the printing section.

3. A fixture for partial solder paste printing on a printed circuit board during BGA rework, as described in claim 2, is characterized in that... The graphic portion is formed on the printed portion, and the shape of the graphic portion is adapted to the PCB pad.

4. A fixture for partial solder paste printing on a printed circuit board during BGA rework, as described in claim 3, is characterized in that... The dimensions of the printed section are consistent with the dimensions of the BGA packaged device.

5. A fixture for partial solder paste printing on a printed circuit board during BGA rework, as described in claim 4, characterized in that, The tin-blocking part bends in the same direction as the connecting part, but the bending angle is less than 90 degrees, and the length of the tin-blocking part is less than the length of the connecting part.

6. A fixture for partial solder paste printing on a printed circuit board during BGA rework, as described in claim 5, characterized in that, The width of the doctor blade is the same as the width of the printing section.

7. A fixture for partial solder paste printing on a printed circuit board during BGA rework, as described in any one of claims 1-6, characterized in that, It also includes a handle, which is fixedly attached to the base.

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