JPH11121912A - Method and equipment for repairing component mounted on printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the defective soldering of a component which is an object of repair work, a warpage of a printed circuit board due to heating, and other troubles by preheating the printed wiring board and, when the preheating reaches a predetermined condition, starting a regular heating of the component of repair it. SOLUTION: A small-size screen board 2 having holes confronting to foot prints is set at a given position on a printed circuit board 1 and then cream solder 6 is disposed by a squeege 7 into the holes to print the solder on the foot prints 9 of the printed circuit board 1. Nextly, a component 3 is mounted on the printed circuit board 1 with electrodes 8 faced to the foot prints 9 and then a backside of the printed circuit board 1 is preheated by a hot plate 11. When the preheating reaches the conditions that satisfy a specified temperature and a specified period of time, hot air is jet out from a nozzle 21 to regularly heat the mounted component 3. By this method, defective melting or defective attachment of solder, a warpage of the printed circuit board due to heating, and other problems can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for repairing a component mounted on a printed circuit board.
In particular, the present invention relates to a method and apparatus for repairing a printed circuit board mounted component, which is suitable for repairing an electronic component having an electrode on the back surface of a surface mounted component.

[0002]

2. Description of the Related Art When replacing a mounted component mounted on a printed circuit board, the solder of a soldering portion connecting the mounted component to be replaced and the printed circuit board is melted, and the mounted component is removed. Then, the mounted components are attached to the printed circuit board by soldering.

Here, the following terms according to the present invention are defined and clarified.

[0004] Repairing refers to removing a mounted component and attaching the mounted component when replacing a mounted component mounted on a printed circuit board.

FIG. 7 shows an explanatory diagram (part 1) of the prior art. In the same figure, when repairing the mounted components, the solder is melted to the mounted components of the printed circuit board on which the mounted components to be repaired are mounted, and the mounted components to be replaced and the printed circuit board are connected. The solder in the soldering part is melted, the mounted component is removed, and a new mounted component is mounted on the printed circuit board by soldering.

[0006] At this time, when removing and attaching the mounted component, only the vicinity of the mounted component to be replaced is heated, so that a remarkable temperature difference occurs between the temperature near the mounted component to be repaired and the temperature of the entire printed circuit board.

FIG. 8 is an explanatory diagram (part 2) of the prior art. In the figure, when heating the vicinity of a mounted component to be repaired, a repair device for a printed circuit board mounted component configured to melt hot solder by injecting hot air from a nozzle 71 is used. Therefore, since only the vicinity of the mounted component to be replaced is heated, a temperature difference between the temperature near the mounted component to be repaired and the temperature of the entire printed circuit board occurs, which may cause the printed circuit board to warp or the like. .

FIG. 9 is an explanatory view (part 3) of the prior art. In the figure, a description will be given of the supply of solder when newly mounting components are soldered to a printed circuit board.

The solder is supplied to a newly mounted component. That is, as shown in FIG. 7A, for example, a screen plate 52 provided with holes corresponding to electrodes 58 formed on a mounting component 53 described later is placed on the ceramic plate 50, and the cream solder 56 is squeegeeed by the squeegee 57. It is arranged on the hole and printed on the ceramic plate 50. Next, as shown in FIG. 5B, the mounting component 53 is mounted with the cream solder 56 printed on the ceramic plate 50 and the electrode 58 facing each other. Next, as shown in FIG. 3C, the solder cream 60 is melted by heating and transferred to the mounted component 53 to form a solder ball 60 on the mounted component.

FIG. 10 shows an explanatory diagram (part 4) of the prior art. In the figure, a configuration for injecting hot air to a mounted component to be repaired will be described.

A nozzle is provided above the mounted component 54 so as to melt the solder by blowing out hot air, and the hot air from the nozzle 71 is blown into an enclosing plate that covers the mounted component 54. That is, it is sprayed on the upper surface of the mounting component 54.

For this reason, the heat capacity of a large mounting component 54 such as a BGA (Ball Grid Array) package or a CSP (Chip Size Package) having an electrode on the back surface side of the package also increases. Since the hot air does not efficiently flow into the soldering portion 81, the hot air is jetted for a long time.

[0013]

As described above, the prior art has the following problems.

1) When replacing a mounted component, the substrate expands beyond the glass transition point by heating the printed circuit board. However, when removing or attaching a large-sized mounted component having a large heat capacity, unsoldering is not performed. Melting or unattached solder occurs, or the printed circuit board warps due to heating.

2) When supplying solder to a mounted component,
It takes a lot of man-hours for the solder transfer work, resulting in poor efficiency.

3) Since hot air is supplied to the upper surface of the mounted component when replacing the mounted component, the mounted component may be destructed by a rise in temperature due to the hot air. Also, it takes time for the hot air to reach the vicinity of the electrode portion of the component. Therefore, the repair operation is complicated and the reliability of the repair operation is reduced.

[0017]

In order to solve the above problems, the present invention takes the following measures.

At the time of repairing the mounted components, the printed circuit board is preheated in advance, and when the preheating reaches a predetermined condition, the mounted components are fully heated, and the mounted components are repaired.

By taking the above measures, the entire printed circuit board is uniformly heated beforehand, so that no solder is attached to the mounted component to be repaired and the printed circuit board is not warped due to heating.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention adopts the following embodiments.

As shown in FIG. 1, when the mounted components are repaired, the back surface of the printed circuit board on which the mounted components are mounted is preliminarily pre-heated. This heating is performed on the mounted component to be removed, and / or the mounted component is removed and / or attached.

By adopting the above-described embodiment, when replacing a mounted component, the substrate expands beyond the glass transition point by heating the printed circuit board, but the entire printed circuit board is uniformly heated. This heats the local area after the printed circuit board is expanded to some extent, so that when removing or attaching a mounted component with a large heat capacity, solder unmelting or solder non-adhesion does not occur, or the printed circuit board warpage due to heating does not occur. .

As shown in FIGS. 2 (a) and 2 (b), when repairing the mounted components, the small screen plate 2 is placed at the mounting position of the mounted components 3 to be mounted on the printed circuit board 1, and the solder paste is applied. 6 is printed facing the footprint 9 of the printed circuit board 1.

By adopting the above-described embodiment, when mounting a mounted component on a printed circuit board, it is not necessary to supply the solder to the mounted component side by printing solder directly on a local portion of the printed circuit board. The aim is to reduce the number of solder supply steps and improve workability in the work.

Further, as shown in FIGS. 2A to 2D, at the time of repairing the mounted components, the small screen plate 2 is set at the mounting position of the mounted components 3 to be mounted on the printed circuit board 1, and the cream is removed. The solder 6 is printed so as to face the footprint 9 of the printed circuit board 1, the mounted component 3 is mounted so as to face the footprint 9 of the printed circuit board 1, and the back surface of the printed circuit board 1 is preheated in advance, When the heating reaches a condition that satisfies the predetermined temperature and time, the heating is performed on the mounted component 3 to be repaired.
Is preferably attached to the printed circuit board 1 by soldering.

By adopting the above-described embodiment, when mounting the mounted parts in the repair work, it is not necessary to supply the solder to the mounted parts by directly printing the solder locally on the printed circuit board. Reduce the number of steps and improve workability. Also, since the entire printed circuit board is heated uniformly, the printed circuit board is expanded to some extent and then the local area is heated. Does not cause warpage. Therefore, the mounting operation of the mounted parts in the repair operation is facilitated, and the reliability of the repair operation is improved.

As shown in FIG. 3, when the mounted components are repaired, the back surface of the printed circuit board 1 on which the mounted components to be repaired are mounted is opposed to the back surface of the printed circuit board 1 to be preheated in advance. A hot plate 11 is provided.

According to the above-described embodiment, the base material expands beyond the glass transition point when the mounted component is replaced, but the entire printed circuit board is uniformly heated to some extent by the hot plate. The printed circuit board does not warp due to melting, no solder, or heating. Therefore, the repair operation is facilitated even for a mounted component having a large heat capacity, and the reliability of the repair operation is improved.

Further, as shown in FIG. 4, in a double-sided mounting type repair device for a printed circuit board mounted component in which the mounted components are mounted on the front surface and the back surface of the printed circuit board, the device is mounted on the back surface of the printed circuit board 1. It is preferable that a heat transfer plate 15 having a concave portion 16 formed opposite to the mounted component 5 and made of a member having thermal conductivity is provided between the printed circuit board 1 and the hot plate 11.

By adopting the above embodiment, in the repair of a printed circuit board mounted part of a double-sided mounting type,
By providing a heat transfer plate, the heat of the hot plate improves the adhesion to the printed circuit board and improves the thermal conductivity to the printed circuit board.

Further, as shown in FIG. 6, in a repair device for a printed circuit board mounted part configured to have a nozzle above the mounted part and blow hot air to melt the solder, a hot air from the nozzle is used. Is preferably provided near the electrode part of the mounted component.

By adopting the above-described embodiment, when replacing a mounted component, repair can be performed at a low temperature by supplying hot air directly to the electrodes and the soldered portions of the mounted component. For this reason, the occurrence of temperature destruction of the mounted component due to the temperature rise due to the hot air is eliminated. In addition, the time required for hot air to reach the vicinity of the electrode portion of the component is reduced. Therefore, the repair work is facilitated and the reliability of the repair work is improved. In particular, BG having an electrode on the back side of the package
This is effective for mounting components such as A package and CSP.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical embodiment according to the present invention will be described with reference to FIGS. In the following, the same portions are denoted by the same reference numerals, and detailed description may be omitted.

FIG. 1 is a diagram illustrating the principle of the present invention.

In FIG. 3, when the mounted component is repaired, first, the back surface of the printed circuit board on which the mounted component to be repaired is mounted is preheated. Next, when preheating reaches a condition that satisfies the predetermined temperature and time, the mounted component to be repaired is fully heated, and the mounted component is removed or replaced to replace the mounted component.

The preheating is preferably performed so that the base material expands beyond the glass transition point, and the entire printed circuit board is preferably heated uniformly. The heating temperature and the heating time are determined depending on the shape and size of the printed circuit board. Set in a timely manner. This prevents a significant temperature difference between the temperature near the mounted component to be repaired and the temperature of the entire printed circuit board when removing and mounting the mounted component.

FIG. 2 is an explanatory view of an embodiment of the present invention (part 1).
Is shown.

Referring to FIG. 5, a process for attaching the mounted component to the printed circuit board will be described. The supply of solder is to print cream solder directly on the local area of the printed circuit board. That is, as shown in FIG. 5A, for example, a small screen plate 2 provided with a hole 2a opposed to the footprint shown in FIG. And printed on the footprint 9 of the printed circuit board 1 by arranging the holes 2a.
When the small screen plate 2 is fixed to the printed circuit board 1, a masking tape or the like can be used.

Next, as shown in FIG. 2B, the mounting component 3 is mounted with the electrode 8 facing the footprint 9 of the printed circuit board 1. Next, as shown in FIG. 3C, the back surface of the printed circuit board 1 is preheated by a hot plate 11 in advance, and after the preheating reaches a condition satisfying a predetermined temperature and time, hot air is applied to the nozzle 21. To fully heat the mounted component 3. Next, as shown in FIG. 4D, the soldering portion 31 is formed between the electrode 8 and the footprint 9 by the main heating, and the mounting is completed.

In the preheating, when the components 4 and 5 are mounted on the front and back surfaces of the printed circuit board 1, the heat transfer plate 15 is placed between the hot plate 11 and the back surface of the printed circuit board 1. It is preferable to dispose and transfer the heat of the hot plate 11 to the back surface of the printed circuit board 1.

FIG. 3 is an explanatory view of an embodiment of the present invention (part 2).
Is shown.

Referring to FIG. 5, a configuration for preheating the back surface of the printed circuit board will be described. When repairing the mounted components, a hot plate 11 formed of a heat conductive member that is transferred from the heating device 12 is installed on the entire back surface of the printed circuit board 1 on which the mounted components to be repaired are mounted. The preheating condition is, for example, a high temperature of 200 ° C.
Heat for about a minute. After that, while preheating is continued, main heating is performed by, for example, blowing hot air from the nozzle 21a to the printed circuit board 1.

FIG. 4 is an explanatory view of an embodiment of the present invention (part 3).
Is shown.

Referring to FIG. 3, a configuration for preheating a double-sided printed circuit board will be described. The printed circuit board has a mounting component 4 including a component to be repaired mounted on a front surface, and a mounting component 5 mounted on a back surface. The concave portion 1 faces the mounting component 5 mounted on the back surface of the printed circuit board 1.
6 and a heat transfer plate 15 made of a heat conductive member is placed between the printed circuit board 1 and the hot plate 11.

FIG. 6 is a view for explaining an embodiment of the present invention (part 5).
Is shown.

Referring to FIG. 5, the structure of a nozzle for blowing hot air in the main heating will be described. As shown in FIG. 1A, the nozzle 21 is provided above the mounted component, and is configured to blow the hot air to melt the solder. Further, a pipe portion 22 is provided to guide hot air from the nozzle 21 to the vicinity of the electrode portion of the mounted component.

Further, as shown in FIG. 2B, the pipe portion 22 is disposed so as to surround the outer periphery of the mounted component. This example shows an example suitable for main heating of a large-sized mounted component such as a BGA package or a CSP having electrodes on the back surface side of the package. That is, hot air is directly blown to the vicinity of the electrode portion of the mounted component.

[0048]

As described above, according to the present invention, the following effects can be obtained.

When the mounted components are repaired, the back surface of the printed circuit board on which the mounted components are mounted is preliminarily heated, and when the preheating reaches a predetermined condition, the mounted components to be repaired are fully heated, and the mounted components are removed. Or / and mounting.

By taking the above measures, when replacing the mounted components, the substrate expands beyond the glass transition point by heating the printed circuit board, but the entire printed circuit board is heated uniformly. Since the local area is heated after the printed circuit board is expanded to a certain extent, it is possible to prevent the occurrence of solder unmelting or solder non-adhesion or warpage of the printed circuit board due to heating when removing or attaching mounted components with a large heat capacity. it can.

In repairing the mounted component, a small screen plate is placed at the mounting position of the mounted component to be mounted on the printed circuit board, and the cream solder is printed facing the footprint of the printed circuit board.

By taking the above measures, when mounting the mounted component to the printed circuit board, the solder can be directly printed on a local portion of the printed circuit board. Therefore, it is not necessary to supply the solder to the mounted component side, and it is possible to reduce the man-hour for supplying the solder in the repair work and improve the workability.

Further, at the time of repairing the mounted parts, a small screen plate is set at the mounting position of the mounted parts to be mounted on the printed circuit board, and cream solder is printed so as to face the footprint of the printed circuit board, and the mounted parts are printed. The printed circuit board is mounted facing the footprint of the circuit board, the back surface of the printed circuit board is pre-heated in advance, and when the pre-heating reaches a predetermined condition, the pre-heating is performed on the mounted component to be repaired, and the mounted component is printed. Solder and attach to the board.

By taking the above measures, it is not necessary to supply the solder to the mounting component side by directly printing the solder on the local portion of the printed circuit board when mounting the mounting component in the repair work, and the man-hour for supplying the solder is reduced. Reduction and improvement in workability can be achieved. Furthermore, by heating the entire printed circuit board evenly, the printed circuit board is expanded to some extent, and then the local area is heated. Warpage and the like can be prevented. Therefore, it is possible to facilitate the work of mounting the mounted components in the repair work and improve the reliability of the repair work.

Further, a hot plate is provided opposite to the back surface of the printed circuit board for pre-heating the back surface of the printed circuit board on which the mounted component to be repaired is mounted when the mounted component is repaired.

By taking the above measures, the base material expands beyond the glass transition point when the mounted component is replaced, but the entire printed circuit board is uniformly heated to some extent by the hot plate. The printed circuit board does not warp due to no solder or heating. Therefore, the repair operation can be facilitated even for a mounted component having a large heat capacity, and the reliability of the repair operation can be improved.

Further, in a double-sided mounting type printed circuit board mounted component repair apparatus in which the mounted components are mounted on the front and back surfaces of the printed circuit board, a concave portion is formed opposite to the mounted component mounted on the back surface of the printed circuit board. A heat transfer plate formed and made of a member having thermal conductivity is placed between the printed circuit board and the hot plate.

By taking the above measures, in repairing a component mounted on a double-sided printed circuit board, the heat of the hot plate is improved by providing a heat transfer plate to improve the adhesion to the printed circuit board. Heat conductivity can be improved. Therefore, even in the case of repairing a component mounted on a double-sided printed circuit board, warpage of the printed circuit board due to unmelted solder, unsoldered solder, or heating does not occur. Therefore, the repair operation can be facilitated even for a mounted component having a large heat capacity, and the reliability of the repair operation can be improved.

Furthermore, in a repair device for a printed circuit board mounted component, a nozzle is provided above the mounted component and hot air is blown out to melt the solder.
A pipe section is provided for guiding hot air from the nozzle to the vicinity of the electrode section of the mounted component.

By taking the above-mentioned means, it is possible to perform repair at a low temperature by directly supplying hot air to the electrodes and the soldered portions of the mounted component when replacing the mounted component. For this reason, temperature destruction of the mounted components can be prevented. Further, it is possible to reduce the time required for hot air to reach the vicinity of the electrode portion of the component. Therefore, the repair work can be facilitated and the reliability of the repair work can be improved. It is particularly effective for a mounted component such as a BGA package or a CSP having an electrode on the back surface side of the package.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory view (No. 1) of the embodiment of the present invention.

FIG. 3 is an explanatory view (part 2) of the embodiment of the present invention.

FIG. 4 is an explanatory diagram (No. 3) of the embodiment of the present invention.

FIG. 5 is an explanatory diagram (No. 4) of the embodiment of the present invention.

FIG. 6 is an explanatory view (No. 5) of the embodiment of the present invention.

FIG. 7 is an explanatory diagram (part 1) of a conventional technique.

FIG. 8 is an explanatory diagram (part 2) of a conventional technique.

FIG. 9 is an explanatory diagram (part 3) of a conventional technique.

FIG. 10 is an explanatory diagram (part 4) of a conventional technique.

[Explanation of symbols]

 1: printed circuit board 2: small screen plate 3: mounted component 6: cream solder 9: footprint 11: hot plate 15: heat transfer plate 16: concave portion 22: pipe portion

Claims (6)

[Claims] 1. A method for pre-heating a back surface of a printed circuit board on which a mounted component is mounted when the mounted component is repaired, and after the pre-heating reaches a predetermined condition, a main heating is performed on the mounted component to be repaired. Removing and / or attaching the printed circuit board. 2. A small screen plate (2) is mounted at a mounting position of a mounting component (3) to be mounted on the printed circuit board (1) when the mounting component is repaired, and a cream solder (6) is mounted on the printed circuit board (1). A printed circuit board mounted component repair method, wherein the printed circuit board is printed so as to face the footprint (9). 3. A small screen plate (2) is mounted at a mounting position of a mounting component (3) to be mounted on the printed circuit board (1) when the mounting component is repaired, and a cream solder (6) is mounted on the printed circuit board (1). ) Is printed so as to face the footprint (9), the mounting component (3) is mounted so as to face the footprint (9) of the printed circuit board (1), and the back surface of the printed circuit board (1) is reserved in advance. Heating, and when the preheating reaches a predetermined condition, main heating is performed on the mounted component (3) to be repaired, and the mounted component (3) is soldered and attached to the printed circuit board (1). The method for repairing a printed circuit board-mounted component according to claim 1 or 2, wherein 4. A hot plate (1), which is installed opposite to a back surface of a printed circuit board (1) for pre-heating the back surface of a printed circuit board (1) on which a mounted component to be repaired is mounted when the mounted component is repaired. 11) A repair device for a printed circuit board mounted part, comprising: 5. A double-sided mounting type repair device for a printed circuit board mounted component, wherein the mounted components are mounted on the front and back surfaces of the printed circuit board, wherein the mounted component (5) mounted on the back surface of the printed circuit board (1). A heat transfer plate (15) formed of a member having thermal conductivity and having a concave portion (16) formed opposite to the substrate is disposed between the printed circuit board (1) and the hot plate (11). The printed circuit board mounted part repair device according to claim 4, wherein 6. A repair device for a printed circuit board mounted component, wherein a nozzle is provided on an upper part of the mounted component and a hot air is blown out to melt the solder. The device for repairing a printed circuit board-mounted component according to claim 4, further comprising a pipe portion (22) for leading to the printed circuit board.