Method for repairing packaging device

Abstract

The invention discloses a method for repairing a packaging device, which comprises the following steps of: preparing a repairing material which comprises a light plate, a printing piece and a new component used by a packaging device; performing moisture removal treatment on the new component; the packaging device is subjected to desoldering; cleaning a bonding pad of the packaging device; the light plate and the printing piece are used for welding the new component, and the welded new component is disengaged from the light plate and the printing piece through cleaning; the cleaned new component is welded to the packaging device; and the welding spots of the new component and the packaging device are checked to ensure that the welding spots are qualified. According to the method, the stainless steel light plate with the smooth surface is used, so that the welding flux is more easily transferred to the welding end of the new component, the adhesion of the welding flux to the stainless steel light plate is less, and the soldering tin is uniformly distributed on the welding end of the new component through the welding flux transferring method. The light plate and the printing piece used in the method are easy to obtain, and the qualified rate of welding spots of the DRQFN packaging device repaired through the method is high.

Description

Technical Field

[0001] The invention belongs to the technical field of packager repair, and in particular relates to a packaged device repair method. Background Art

[0002] like Figure 2 , 3 As shown, compared with common QFN package devices, DRQFN package devices have more solder terminals and higher density. The solder terminal spacing and area of ​​a single DRQFN package device are smaller, and the solder terminals are at the bottom of the device. After soldering, the solder joints are not visible.

[0003] During the rework and repair process of packaged devices, the most important thing is to control the uniformity and consistency of solder paste coating. The existing method for rework and repair of QFN packaged devices is to directly tin the pad or soldering end with a temperature-controlled soldering iron, apply solder paste and attach the device, and then use a constant temperature hot air gun to solder the device to the printed circuit board. However, this process is difficult to ensure the uniformity of solder on each solder joint of DRQFN packaged devices, and has high technical requirements for operators. It is easy to have unstable quality problems during batch operations. A few solder joints after welding will have insufficient tin, and the welding reliability is low, resulting in quality problems such as cold solder joints when used under vibration, high and low temperature conditions, such as Figure 4 The tin deficiency phenomenon is shown in the circle.

[0004] Therefore, a process method is needed to effectively ensure the reliability of DRQFN device rework and repair, and to be suitable for reference of QFN package device rework and repair.

[0005] The patent document with the announcement number CN102151927A discloses a soldering method for soldering columns of packaged integrated circuits, including the following steps: arranging the solder columns neatly in a mold; forming a convex solder on the pad of the substrate to be implanted; placing the solder columns together with the mold on the corresponding pad of the CLGA560 circuit of the substrate to be implanted with the convex solder, and entering the reflow oven to complete the soldering; after the soldering is completed, cleaning and drying. This method requires the use of a mold for positioning during the soldering process, but is not suitable for irregularly distributed rework solder joints. At the same time, the solder paste needs to form a half-moon spherical crown on each pad, which has certain requirements for soldering technology, and the substrate to be implanted needs to be placed on a heating table for heating, which increases the process steps. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a packaging device repair method.

[0007] The present invention is achieved through the following technical solutions.

[0008] The present invention provides a packaged device repair method, comprising the following steps:

[0009] S1: Prepare the rework materials, including bare boards, printed parts and new components used in the packager;

[0010] S2: Dehumidify new components;

[0011] S3: Desoldering the packager;

[0012] S4: Clean the pads of the packager;

[0013] S5: Solder the new components using the bare board and the printed parts, and separate the soldered new components from the bare board and the printed parts by cleaning;

[0014] S6: Solder the cleaned new components to the packager;

[0015] S7: Check the solder joints of new components and packagers to ensure they are qualified.

[0016] Preferably, the surface roughness level of the light plate is less than 6.3, and the printed part has a mesh structure.

[0017] Preferably, the light plate is made of stainless steel, and the printed part is made of steel.

[0018] Preferably, the moisture removal treatment comprises baking the new components at 120-125° C. for 2-20 hours.

[0019] Preferably, in the moisture-removal treatment, new components with outer layers coated with protective paint are baked at 120-125° C. for 10-20 hours, and new components without outer layers coated with protective paint are baked at 120-125° C. for 2-4 hours.

[0020] Preferably, during the desoldering process, the maximum temperature of the printed circuit board surface of the packager is controlled at 210-225°C.

[0021] Preferably, in the pad cleaning step, a temperature-controlled soldering iron and a tin-absorbing rope are used to clean and level the tin on the pad of the packager printed circuit board, the temperature of the temperature-controlled soldering iron is 270-320° C., and the cleaning time for the same pad does not exceed 3 seconds.

[0022] Preferably, in step S5, solder paste is printed on the bare board using a printing plate, new components are mounted at the solder paste printing position, and soldering is performed, and the new components are washed off the bare board using a cleaning agent.

[0023] Preferably, the welding peak temperature is controlled at 210-225° C., wherein the time when the temperature is above 183° C. is controlled at 60-90 seconds, and the cleaning agent is a neutral cleaning agent made of anhydrous ethanol.

[0024] Preferably, in step S6, solder paste is applied to the corresponding position of the printed circuit board of the packager that needs to be repaired, and then the new components are mounted and soldered to the position of the packager that needs to be repaired.

[0025] The beneficial effects of the present invention are:

[0026] In the method of the present invention, by using a stainless steel plate with a smooth surface, the solder is more easily transferred to the solder end of the new component, and the solder adheres less to the stainless steel plate. Through the solder transfer method of the present application, the solder is evenly distributed on the solder end of the new device. The bare plate and printed parts used in the present application are obtained in a simple manner, and the qualified rate of the solder joints of the DRQFN packaged device repaired by the method of the present application is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a process flow chart of the present invention;

[0028] Figure 2 It is a schematic diagram of the DRQFN packager;

[0029] Figure 3 It is a schematic diagram of the QFN package;

[0030] Figure 4 It is a schematic diagram of the solder joints welded using the prior art QFN package device rework method; DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0032] Embodiment 1:

[0033] like Figure 1 As shown, a packaged device repair method comprises the following steps:

[0034] S1: Prepare the rework materials, including bare boards, printed parts and new components used in the packager;

[0035] S2: Dehumidify new components;

[0036] S3: Desoldering the packager;

[0037] S4: Clean the pads of the packager;

[0038] S5: Solder the new components using the bare board and the printed parts, and separate the soldered new components from the bare board and the printed parts by cleaning;

[0039] S6: Solder the cleaned new components to the packager;

[0040] S7: Use X-ray equipment to check the solder joints of new components and packagers, check the amount of tin in the solder joints, and confirm that the tin on the solder joints covers the pads without excess material and tin bridging; use a 5x magnifying glass to check the uniformity of the gap between the new components and the printed circuit board of the package to ensure compliance.

[0041] The length and width of the light board are 100×100 mm, the thickness of the light board can be 1.5-2 mm, the surface roughness level of the light board is less than 6.3, the surface is smooth and has no obvious scratches, and the printed part has a mesh structure and is used for screen printing of solder paste for DRQFN packaging devices.

[0042] The material of the light plate is stainless steel, and the material of the printed part is steel.

[0043] The moisture removal treatment includes baking the new components at 120-125° C. for 2-20 hours.

[0044] In the dehumidification treatment, the new components with the outer layer coated with protective paint are baked at 120-125°C for 10-20 hours, and in this embodiment, they are baked at 125°C for 15 hours. The new components without the outer layer coated with protective paint are baked at 120-125°C for 2-4 hours, and in this embodiment, they are baked at 120°C for 3 hours. The protective paint is a protective paint for DRQFN packagers with moisture-proof, mildew-proof and salt-fog-proof functions. The protective paint can be a DRQFN packager protective paint prepared by existing processes. The dehumidification treatment can also be selected according to the specific model of the packager, the humidity sensitivity level of its humidity-sensitive components and the thickness of the device.

[0045] During the desoldering process, the maximum temperature of the printed circuit board surface of the packager is controlled at 210-225°C.

[0046] In the pad cleaning step, a temperature-controlled soldering iron and a tin-absorbing rope are used to clean and level the tin on the pad of the package printed circuit board. The temperature of the temperature-controlled soldering iron is 270-320° C. The cleaning time of the same pad does not exceed 3 seconds to avoid damaging the pad of the printed circuit board.

[0047] In step S5, the solder paste is printed on the middle of the board using a printing plate. Lead solder paste Sn can be used according to actual needs. 63 Pb 37 Or Aluminum-free solder paste Sn 95.5 Ag4Cu 0.5 , use the rework workstation to mount the new components on the solder paste printing position, and perform soldering. Use the cleaning agent to flush the new components off the bare board, the solder on the bare board falls off with the new components, and the solder is transferred to the soldering end of the new components.

[0048] The peak welding temperature is controlled at 210-225° C. to avoid damaging new components, wherein the time when the temperature is above 183° C. is controlled at 60-90 seconds, and the cleaning agent is a neutral cleaning agent made of anhydrous ethanol.

[0049] In step S6, a thin and uniform layer of solder paste is applied to the corresponding position of the printed circuit board of the package to be repaired, and then the new components with solder are mounted and soldered to the position of the package to be repaired using the repair workstation. The solder paste can use the solder paste used in the production process of the existing DRQFN package.

[0050] The packaged device repair method of the present application is applicable to DRQFN packagers.

[0051] Comparative Example 1:

[0052] The existing packaged device rework method is used, and the steps are as follows: the packager desoldering and packager pad cleaning steps are used in the same manner as in Example 1; then the pad is tinned with a temperature-controlled soldering iron, the pad is coated with flux paste and then attached to the new component, and then the device is soldered to the printed circuit board at 200°C with a constant temperature hot air gun, using lead solder paste Sn 63 Pb 37 .

[0053] 300 solder joints on the DRQFN package were soldered by the methods of Example 1 and Comparative Example 1, and tested after soldering. The results are shown in the following table.

[0054]

[0055]

[0056] As can be seen from the above table, the method of the present invention can achieve a pass rate of 99% through reasonable temperature control and the use of light plates and printed parts. In Example 1, the conventional technology is used to perform a constant temperature welding process, and the pass rate is only 73%, which is easy to affect the overall efficiency in large-scale processing.

Claims

1. A packaged device repair method, characterized in that: The following steps are involved: S1: Prepare the rework materials, including bare boards, printed parts and new components used in the packager; S2: Dehumidify new components; S3: Desoldering the packager; S4: Clean the pads of the packager; S5: Solder the new components using the bare board and the printed parts, and separate the soldered new components from the bare board and the printed parts by cleaning; S6: Solder the cleaned new components to the packager; S7: Check the solder joints of new components and packagers to ensure they are qualified.

2. A packaged device repair method according to claim 1, characterized in that: The surface roughness level of the light plate is less than 6.3, and the printed part has a mesh structure.

3. A packaged device repair method according to claim 1, characterized in that: The material of the light plate is stainless steel, and the material of the printed part is steel.

4. A packaged device repair method according to claim 1, characterized in that: The moisture removal treatment includes baking the new components at 120-125° C. for 2-20 hours.

5. A packaged device repair method as claimed in claim 4, characterized in that: In the dehumidification treatment, new components with outer layers coated with protective paint are baked at 120-125° C. for 10-20 hours, and new components without outer layers coated with protective paint are baked at 120-125° C. for 2-4 hours.

6. A packaged device repair method according to claim 1, characterized in that: During the desoldering process, the maximum temperature of the printed circuit board surface of the packager is controlled at 210-225°C.

7. A packaged device repair method according to claim 1, characterized in that: In the pad cleaning step, a temperature-controlled soldering iron and a tin-absorbing rope are used to clean and level the tin on the pad of the package printed circuit board. The temperature of the temperature-controlled soldering iron is 270-320° C., and the cleaning time of the same pad does not exceed 3 seconds.

8. A packaged device repair method according to claim 1, characterized in that: In step S5, solder paste is printed on the bare board using a printing plate, new components are mounted at the solder paste printing position, and soldering is performed, and the new components are washed off the bare board using a cleaning agent.

9. A packaged device repair method according to claim 8, characterized in that: The peak welding temperature is controlled at 210-225° C., wherein the time when the temperature is above 183° C. is controlled at 60-90 seconds, and the cleaning agent is a neutral cleaning agent made of anhydrous ethanol.

10. A packaged device repair method according to claim 1, characterized in that: In the step S6, solder paste is applied to the corresponding position of the printed circuit board of the packager that needs to be repaired, and then new components are mounted and soldered to the position of the packager that needs to be repaired.

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