Bonding pad soldering tin cleaning method for ball grid array packaging BGA device

Abstract

The invention provides a method for cleaning soldering tin of a bonding pad of a ball grid array packaging BGA device, and relates to the field of electronic assembly, and the method comprises the steps: judging a cleaning type corresponding to the soldering tin of the bonding pad of the ball grid array packaging BGA device; under the condition that the cleaning type is that the ball grid array packaged BGA device is repaired, the ball grid array packaged BGA device is placed on a medium-temperature heating table for preheating treatment; transferring the ball grid array packaging BGA device to a high-temperature heating table for heating treatment so as to melt the soldering tin; wiping the surface of the bonding pad by the cotton balls coated with the soldering flux along the same direction so as to clean soldering tin; and carrying out cleaning treatment on the ball grid array packaging BGA device after the soldering tin cleaning. According to the invention, the soldering tin of the bonding pad of the ball grid array packaging BGA device is cleaned in a mode of wiping by using the cotton ball coated with the soldering flux, so that the thermal shock of a high-temperature electric soldering iron on the ceramic bottom plate can be effectively avoided, the use of a soldering braid is reduced, and the soldering tin cleaning efficiency and reliability of the ball grid array packaging BGA device are effectively improved.

Description

Technical Field

[0001] This application relates to the field of electronic assembly technology, and specifically relates to a method for cleaning solder on pads of a ball grid array (BGA) device. Background Art

[0002] With the development of electronic products towards miniaturization, multi-functional integration, high performance, and high reliability, higher requirements are put forward for electrical interconnection technology and I / O pin density. Since the pins of a ball grid array (BGA) device are distributed on the bottom surface of the package, while making full use of the small substrate volume, the number of pins is greatly increased, and the problems of coplanarity and warping caused by pins in fine-pitch devices can be effectively avoided. Moreover, it is more suitable for surface mount technology (SMT) and wire bonding interconnection of wiring pins on a printed circuit board (PCB). Its advantages such as high yield and excellent electrical performance make BGA devices widely used in microelectronic products and become one of the current mainstream packaging forms.

[0003] In the production of printed circuit boards for microelectronic products, BGA devices are usually assembled onto the printed circuit board by the method of soft soldering with tin-lead solder. During the process of soldering gold-plated components, the tin-lead solder will form Au-Sn intermetallic compounds with gold elements, showing obvious brittleness, that is, the gold embrittlement phenomenon, which seriously affects the reliability of electronic assembly.

[0004] In related technologies, to prevent the occurrence of gold embrittlement, it is required that gold-plated components must undergo tinning to remove gold before soldering. In the electronic assembly industry, the methods for removing gold from BGA pads mainly include manual tinning with an electric soldering iron to remove gold and automatic tinning machine tinning to remove gold. Currently, for tinning to remove gold from BGA pads and cleaning the rework pads, a process method using an electric soldering iron in cooperation with a solder wick requires a large number of solder wicks, and the high-temperature electric soldering iron will cause a certain degree of thermal shock to the ceramic substrate. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, this application provides a method for cleaning solder on pads of a ball grid array (BGA) device, which solves the problem that using an electric soldering iron will apply high-temperature thermal shock to the ceramic substrate during the pad cleaning process of a ball grid array (BGA) device, affecting the reliability.

[0006] To achieve the above objectives, this application is realized through the following technical solutions:

[0007] An embodiment of the present application provides a method for cleaning the solder on the pads of a ball grid array (BGA) package device. The method for cleaning the solder on the pads includes: determining the cleaning type corresponding to the solder on the pads of the BGA package device; when the cleaning type is to repair the BGA package device, placing the BGA package device on a medium-temperature heating stage for preheating treatment; after the preheating treatment, transferring the BGA package device to a high-temperature heating stage for heating treatment to melt the solder; after the solder melts, wiping the surface of the pads with a cotton ball coated with flux in the same direction to clean the solder; and performing a cleaning treatment on the BGA package device after the solder is cleaned.

[0008] In the embodiment of the present application, when the aforementioned cleaning type is to tin and remove gold from the BGA package device, before placing the BGA package device on the medium-temperature heating stage for preheating treatment, the method for cleaning the solder on the pads of the BGA package device further includes: uniformly coating solder paste on the surface of the pads corresponding to the BGA package device.

[0009] In the embodiment of the present application, the coating methods of the solder paste include dot coating, screen printing, and inkjet printing; the solder paste includes leaded eutectic solder and lead-free solder.

[0010] In the embodiment of the present application, when the coating method of the aforementioned solder paste is screen printing, the step of uniformly coating the solder paste on the surface of the pads corresponding to the BGA package device may specifically include the following steps: coating the solder paste on the surface of the pads by screen printing; wherein, the thickness of the stencil is 0.15 mm; setting the pressure and speed of the squeegee to make the squeegee reach the calibrated state; wherein, the pressure of the squeegee in the calibrated state is 50 psi and the speed is 15 mm / s; moving the squeegee in the calibrated state to level the solder paste and pushing the solder paste from one end of the stencil to the other end to make the solder paste evenly cover the surface of the stencil.

[0011] In the embodiment of the present application, the package forms of the BGA package device include plastic package, ceramic package, ceramic column package, and tape carrier package.

[0012] In the embodiment of the present application, the temperature setting of the medium-temperature heating stage is less than or equal to the activation temperature of the flux, and the temperature setting of the high-temperature heating stage is 20°C - 30°C higher than the solder melting point.

[0013] In the embodiment of the present application, the temperature of the medium-temperature heating stage is 130°C, and the preheating treatment time of the BGA package device on the medium-temperature heating stage is 3 min; the temperature of the high-temperature heating stage is 205°C.

[0014] In the embodiments of the present application, the base material of the cotton ball includes one of cotton and non-woven fabric to be heat-resistant and adsorb the soldering flux; the activation temperature of the soldering flux is used in combination with the solder.

[0015] In the embodiments of the present application, the cleaning methods for the ball grid array package (BGA) device after solder cleaning include vapor phase cleaning and alcohol immersion cleaning.

[0016] In the embodiments of the present application, during the process of wiping the surface of the solder pad with the cotton ball coated with the soldering flux in the same direction, the high-temperature heating table, the ball grid array package (BGA) device, and the solder pad are arranged in layers in sequence, and the solder pad is located on the side of the ball grid array package (BGA) device facing the cotton ball.

[0017] The present application provides a method for cleaning the solder on the solder pad of a ball grid array package (BGA) device. Compared with the prior art, it has the following beneficial effects:

[0018] In order to prevent thermal stress damage to the ball grid array package (BGA) device during the solder cleaning process on the solder pad, the ball grid array package (BGA) device is first placed on a medium-temperature heating table for preheating treatment; preheating can make the ball grid array package (BGA) device heat up slowly, allowing the stress inside the structure to be gradually released. During the solder cleaning process on the solder pad, in order to avoid the thermal shock caused by the high-temperature soldering iron to the ceramic base plate and reduce the use of the solder wick; the present application uses the method of wiping with a cotton ball coated with the soldering flux to clean the solder on the solder pad of the ball grid array package (BGA) device, which can effectively avoid the thermal shock caused by the high-temperature soldering iron to the ceramic base plate and reduce the use of the solder wick. The operation is simple, the process is reliable, the cost is low, and it can replace the conventional process method of using a soldering iron in cooperation with a solder wick, effectively improving the solder cleaning efficiency and reliability of the ball grid array package (BGA) device. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 It is a schematic flowchart of a method for cleaning the solder on the solder pad of a ball grid array package (BGA) device provided by an embodiment of the present application;

[0021] Figure 2 It is a schematic structural diagram of a method for cleaning the solder on the solder pad of a ball grid array package (BGA) device provided by an embodiment of the present application;

[0022] Figure 3 is Figure 2 A side view of a partial structure.

[0023] Reference numerals: high-temperature heating stage 1; cotton ball 2; pad 3; ball grid array package BGA device 4. Detailed implementation manners

[0024] 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. Apparently, the described embodiments are some but not all of the 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.

[0025] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or sequence between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitations, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0026] By providing a method for cleaning solder on the pads of a ball grid array package BGA device, the embodiments of the present application solve the problem that when cleaning the pads of a ball grid array package BGA device, using a soldering iron will apply high-temperature thermal shock to the ceramic substrate, affecting the reliability.

[0027] The general idea of the technical solutions in the embodiments of the present application to solve the above technical problems is as follows:

[0028] With the development of electronic products towards miniaturization, multi-functional integration, high performance and high reliability, higher requirements are put forward for electrical interconnection technology and I / O pin density. Since the pins of a ball grid array package BGA device are distributed on the bottom surface of the package, while making full use of the small substrate volume, the number of pins is greatly increased, and the problems of coplanarity and warping caused by pins in fine pitch devices can be effectively avoided. Moreover, it is more suitable for wire bonding interconnection of SMT and PCB wiring pins. Its advantages such as high yield and excellent electrical performance make BGA devices widely used in microelectronic products and become one of the current mainstream packaging forms.

[0029] In the production of printed circuit boards for microelectronic products, BGA devices are usually assembled onto the printed circuit boards by the method of soft soldering with tin-lead solder. During the soldering process of gold-plated components, the tin-lead solder will form Au-Sn intermetallic compounds with gold elements, showing obvious brittleness, that is, the gold embrittlement phenomenon, which seriously affects the reliability of electronic assembly. At present, in order to prevent the occurrence of gold embrittlement, it is required that gold-plated components must be subjected to tinning and gold removal treatment before soldering. In the electronic assembly industry, the main methods for removing gold from BGA pads are manual tinning with a soldering iron and tinning with an automatic tinning machine.

[0030] In the related art, for the process of tinning and gold removal of BGA pads and cleaning of rework pads, a process method using a soldering iron in cooperation with a solder wick is adopted. A large number of solder wicks are required, and the high-temperature soldering iron will cause a certain degree of thermal shock to the ceramic substrate. In addition, when using a solder wick for solder sucking operation, the solder wick needs to be placed on the solder joint, and then heated with a soldering iron, waiting for the solder to melt and be adsorbed by the solder wick. This process is relatively cumbersome, especially for some dense solder joints, the operation time will be longer, affecting the production efficiency.

[0031] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments.

[0032] First, a method for cleaning the solder on the pads of a ball grid array package (BGA) device provided by an embodiment of the present application will be introduced below.

[0033] The flowchart of a method for cleaning the solder on the pads of a ball grid array package (BGA) device provided by an embodiment of the present application is as shown in Figure 1 As shown, the method for cleaning the solder on the pads of the ball grid array package (BGA) device may include the following steps S110-S150.

[0034] S110. Determine the cleaning type corresponding to the solder on the pads of the ball grid array package (BGA) device.

[0035] S120. When the cleaning type is to repair the ball grid array package (BGA) device, place the ball grid array package (BGA) device on a medium-temperature heating table for preheating treatment.

[0036] S130. After the preheating treatment, transfer the ball grid array package (BGA) device to a high-temperature heating table for heating treatment to melt the solder.

[0037] S140. After the solder melts, wipe the surface of the pad with a cotton ball coated with flux in the same direction to clean the solder. It can be understood that the flux has strong ability to dissolve and remove oxides, which can help loosen and remove the residual solder on the pad, and at the same time will not leave too many residues.

[0038] S150. Clean the ball grid array (BGA) device after cleaning the solder by washing.

[0039] The above is the specific implementation of a method for cleaning the solder on the pads of a ball grid array (BGA) device provided by the embodiments of the present application. It can be understood that, in order to prevent thermal stress damage to the BGA device during the cleaning of the solder on the pads, the BGA device is first placed on a medium-temperature heating table for preheating treatment; preheating can make the BGA device heat up slowly, allowing the stress inside the structure to be gradually released.

[0040] During the cleaning of the solder on the pads, to avoid the thermal shock to the ceramic base plate caused by the high-temperature soldering iron and reduce the use of solder wicking tape; the present application uses the method of wiping with a cotton ball coated with flux to clean the solder on the pads of the BGA device, which can effectively avoid the thermal shock to the ceramic base plate caused by the high-temperature soldering iron and reduce the use of solder wicking tape. The operation is simple, the process is reliable, the cost is low, and it can replace the conventional process method of using a soldering iron in cooperation with a solder wicking tape, effectively improving the efficiency and reliability of cleaning the solder on the BGA device.

[0041] In some embodiments, when the above cleaning type is tinning and gold removal for the BGA device, before placing the BGA device on a medium-temperature heating table for preheating treatment, the method for cleaning the solder on the pads of the BGA device may specifically further include the following steps:

[0042] S111. Uniformly apply solder paste on the surface of the pads corresponding to the BGA device.

[0043] In the embodiments of the present application, it can be understood that the solder joints of the BGA device are solder balls distributed in an array form. When tinning and gold removal are performed, it is necessary to consider how to uniformly heat the solder balls to melt them and separate them from the gold, while avoiding thermal damage to the device; during the process of tinning and gold removal, the activator component in the solder paste can remove the oxides on the metal surface, such as the oxide film on the gold layer surface and the oxides at the parts to be tinned. This helps to ensure good contact between the solder and the metal surface, provides a clean surface for the subsequent tinning operation, improves the wettability of the solder, enables the solder to better adhere to the metal, and forms a good soldering connection.

[0044] In addition, the solder paste can also reduce the surface tension of the liquid solder, enabling the solder to spread and wet the metal surface better after melting. This is conducive to the solder evenly covering the tinned parts, filling tiny gaps and unevenness, forming a smooth and continuous tin layer, improving the quality and reliability of tinning, and reducing defects such as solder bridges and missed soldering. During the tinning process, components such as resin in the solder paste form a protective film on the metal surface, isolating the air and preventing the metal from being oxidized again at high temperatures. This protective film can also prevent the active components in the flux from causing excessive corrosion to the metal surface, playing a role in protecting the metal.

[0045] Furthermore, the solder paste can help heat transfer better to the metal surface. During the heating process, the solder paste absorbs heat and transfers it to the metal, enabling the metal to reach the temperature required for tinning faster, promoting the alloying reaction between the solder and the metal, and improving the efficiency and quality of tinning.

[0046] In some embodiments, the application methods of the solder paste include dot application, screen printing, and inkjet printing; the solder paste includes lead-containing eutectic solder and lead-free solder. It should be noted that lead-containing eutectic solder is an alloy solder mainly composed of tin and lead. The melting point of lead-free solder is usually higher than that of lead-containing eutectic solder. For example, the melting point of SAC305 is about 30°C - 40°C higher than that of lead-containing eutectic solder. Using lead-free solder requires increasing the welding temperature during the welding process.

[0047] In the embodiments of the present application, it can be understood that dot application of solder paste is a method of precisely applying the solder paste to specific positions. An appropriate amount of solder paste is loaded into the cartridge of a dispenser or a dispensing machine, and then according to the layout of the welded parts and the welding requirements, through manual or automatic control, the solder paste is dropped point by point onto the pads on the substrate or the pins of components and other positions that need to be welded. Attention should be paid to controlling the amount of solder paste during dot application. Excessive solder paste may cause welding short circuits, while too little may result in missed soldering. Dot application of solder paste has high flexibility and precision, and can be coated individually according to different welding requirements. It can perform precise solder paste dispensing in a small space and is suitable for welded parts of various shapes and sizes. At the same time, dot application of solder paste can reduce the waste of solder paste and improve the material utilization rate.

[0048] In addition, screen printing can achieve precise application of the solder paste through high-precision screen template production and printing equipment control, meet the welding requirements of high-density and fine-pitch electronic components, and can perform solder paste printing on multiple pads at one time, significantly improving production efficiency. Inkjet printing of solder paste can achieve very high positioning accuracy and solder paste amount control accuracy, can meet the coating requirements of micro-pitch and high-density pads, and is suitable for advanced packaging and fine electronic assembly.

[0049] In some embodiments, when the above-mentioned solder paste is applied by screen printing, the above-mentioned solder paste is evenly applied to the surface of the pads corresponding to the ball grid array package (BGA) device, that is, the above-mentioned S111 may specifically include the following steps:

[0050] S210. Apply the solder paste to the surface of the pads by screen printing; wherein, the thickness of the stencil is 0.15 mm.

[0051] S220. Set the pressure and speed of the squeegee to make the squeegee reach the calibrated state; wherein, the pressure of the squeegee in the calibrated state is 50 psi and the speed is 15 mm / s.

[0052] S230. Move the squeegee in the calibrated state to level the solder paste, and push the solder paste from one end of the stencil to the other end, so that the solder paste evenly covers the surface of the stencil.

[0053] In the embodiments of the present application, it can be understood that during the process of screen printing solder paste, the selection of the stencil thickness is crucial, which will directly affect the printing amount of the solder paste and the welding quality; when facing a ball grid array package (BGA) device with multiple pins and large size components, since more solder paste is required to form reliable solder joints, a relatively thick stencil is usually suitable, such as a stencil with a thickness of 0.15 - 0.2 mm; however, an overly thick stencil will result in an excessive amount of printed solder paste. During the welding process, too much solder paste is likely to flow between adjacent pins or pads, leading to short circuits, affecting the normal function of the circuit, and increasing the defective rate of the product; based on this, the stencil thickness of the present application is preferably 0.15 mm.

[0054] Furthermore, during the process of screen printing solder paste, reasonably setting the pressure and speed of the squeegee is crucial for ensuring the solder paste printing quality; the squeegee speed should be moderate to ensure that the solder paste can fully roll and fill at the openings of the stencil, while avoiding printing quality problems caused by too fast or too slow speed. The squeegee pressure should be sufficient to make the stencil closely contact the surface of the component, while ensuring that the solder paste can fully fill the openings of the stencil and be transferred to the pads, and will not cause damage to the stencil and the component. The squeegee pressure corresponds to the thickness of the stencil; based on this, the squeegee pressure in the present application is set to 50 psi and the squeegee speed is set to 15 mm / s.

[0055] In one example, the package forms of the ball grid array package (BGA) device include plastic package, ceramic package, ceramic column package, and tape carrier package.

[0056] In some embodiments, the temperature setting of the medium-temperature heating table is less than or equal to the activation temperature of the flux, and the temperature setting of the high-temperature heating table is 20°C - 30°C higher than the melting point of the solder.

[0057] Exemplarily, the temperature of the medium-temperature heating stage is 130 °C, and the preheating time of the ball grid array (BGA) package device through the medium-temperature heating stage is 3 min; the temperature of the high-temperature heating stage is 205 °C.

[0058] In some embodiments, the substrate of the cotton ball includes one of cotton and lint-free cloth to be heat-resistant and adsorb the flux; the activation temperature of the flux is used in combination with the solder.

[0059] In the embodiments of the present application, it can be understood that the combined use of the activation temperature of the flux and the solder is crucial. Different types of solders, such as the tin-lead solder with a relatively low melting point and the lead-free solder with a relatively high melting point (such as the tin-silver-copper solder), have different requirements for the activation temperature of the flux. The lead-free solder has a high melting point and requires the flux to be fully activated at a higher temperature to effectively remove the oxide on the surface of the welded part and improve the wettability when the solder melts; while the tin-lead solder requires the flux to act at a relatively low temperature. The composition of the flux, especially the active agent, determines its activation temperature. Different active agents decompose or undergo chemical reactions at different temperatures to remove oxides and reduce the surface tension. The welding process also affects the combination of the two. The wave soldering has a high speed and requires a low activation temperature of the flux to quickly play a role in a short time; the reflow soldering temperature curve is complex, and the flux needs to start activation in the preheating stage and continuously play an effect in the reflow stage, which requires a wide activation temperature range of the flux and corresponding activation performance at different temperature stages. Therefore, when selecting the flux and the solder, it is necessary to comprehensively consider their matching degree and optimize the welding temperature curve according to the specific welding process and equipment to ensure good welding quality.

[0060] In some embodiments, the cleaning methods for the ball grid array (BGA) package device after solder cleaning include vapor phase cleaning and alcohol immersion cleaning.

[0061] In some embodiments, please refer to Figure 2 and Figure 3 , during the process of wiping the surface of the solder pad in the same direction with the cotton ball coated with the flux, the high-temperature heating stage 1, the ball grid array (BGA) package device 4, and the solder pad 3 are arranged in layers in sequence, and the solder pad 3 is located on the side of the ball grid array (BGA) package device facing the cotton ball 2. It should be noted that solder is attached to the solder pad 3; after the solder melts, the cotton ball coated with the flux can be wiped along the long side direction of the ball grid array (BGA) package device 4 to clean the molten solder.

[0062] In the embodiments of the present application, it can be understood that gently wiping the surface of the solder pad in the same direction results in a relatively uniform and gentle mechanical force on the surface of the solder pad, which helps to avoid damage to the surface of the solder pad caused by uneven wiping force or back-and-forth friction. In addition, wiping in the same direction can reduce the impurity contamination caused by the cotton ball wiping back and forth on the solder pad; if wiped back and forth, the impurities that have been adsorbed on the cotton ball may be transferred back to the solder pad again, while one-way wiping can reduce this risk and keep the surface of the solder pad relatively clean.

[0063] In summary, compared with the prior art, the present application has the following beneficial effects:

[0064] 1. The present application uses the method of wiping the solder on the solder pad of the ball grid array package (BGA) device with a cotton ball coated with flux, which can effectively avoid the thermal shock to the ceramic substrate caused by a high-temperature soldering iron and reduce the use of a solder wick. The operation is simple, the process is reliable, and the cost is low. It can replace the conventional process method of using a soldering iron in cooperation with a solder wick, effectively improving the efficiency and reliability of cleaning the solder on the BGA device.

[0065] 2. In order to prevent thermal stress damage to the BGA device during the cleaning of the solder on the solder pad, the present application first places the BGA device on a medium-temperature heating stage for preheating treatment; preheating can cause the BGA device to heat up slowly, enabling the stress inside the structure to be gradually released.

[0066] 3. The present application uses a cotton ball coated with flux to wipe the surface of the solder pad along the same direction, and the mechanical force on the surface of the solder pad is relatively uniform and gentle, which helps to avoid damage to the surface of the solder pad caused by uneven wiping force or back-and-forth friction. Wiping in the same direction can reduce the impurity contamination caused by the cotton ball wiping back and forth on the solder pad.

[0067] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for cleaning solder pads of a ball grid array package (BGA) device, characterized in that: include: Determine the cleaning type corresponding to the solder pad of the ball grid array package BGA device; When the cleaning type is to rework the ball grid array package (BGA) device, the ball grid array package (BGA) device is placed on a medium temperature heating table for preheating; After the preheating treatment, the ball grid array package BGA device is transferred to a high temperature heating stage for heating treatment to melt the solder; After the solder is melted, wipe the solder pad surface in the same direction with a cotton ball coated with flux to clean the solder; Clean the ball grid array package BGA device after solder cleaning.

2. The method for cleaning solder pads of a ball grid array package (BGA) device as claimed in claim 1, characterized in that: In the case where the cleaning type is to perform tin plating and gold removal on the BGA package device, before placing the BGA package device on a medium-temperature heating table for preheating, the solder cleaning method for the pad of the BGA package device further includes: Solder paste is evenly coated on the surface of the pad corresponding to the ball grid array package BGA device.

3. The method for cleaning solder pads of a ball grid array package (BGA) device as claimed in claim 2, characterized in that: The coating methods of the solder paste include spot coating, screen printing and spray printing; the solder paste includes lead eutectic solder and lead-free solder.

4. The method for cleaning solder pads of a ball grid array package (BGA) device as claimed in claim 3, characterized in that: In the case where the solder paste is applied by screen printing, the step of uniformly applying the solder paste on the surface of the pad corresponding to the ball grid array package BGA device includes: Apply solder paste on the surface of the pad by screen printing; wherein the thickness of the steel screen is 0.15 mm; The pressure and speed of the scraper are set so that the scraper reaches a calibrated state; wherein the pressure of the scraper in the calibrated state is 50 psi and the speed is 15 mm / s; The scraper in the calibrated state is moved to level the solder paste, and the solder paste is pushed from one end of the steel mesh to the other end, so that the solder paste evenly covers the surface of the steel mesh.

5. The method for cleaning solder pads of a ball grid array package (BGA) device according to any one of claims 1 to 4, characterized in that: The packaging forms of the ball grid array package BGA device include plastic packaging, ceramic packaging, ceramic column packaging and carrier tape packaging.

6. The method for cleaning solder pads of a ball grid array package (BGA) device according to any one of claims 1 to 4, characterized in that: The temperature of the medium temperature heating stage is set to be less than or equal to the activation temperature of the soldering flux, and the temperature of the high temperature heating stage is set to be 20° C.-30° C. higher than the melting point of the solder.

7. The method for cleaning solder pads of a ball grid array package (BGA) device as claimed in claim 6, characterized in that: The temperature of the medium temperature heating stage is 130° C., and the time for the ball grid array package BGA device to be preheated by the medium temperature heating stage is 3 minutes; the temperature of the high temperature heating stage is 205° C.

8. The method for cleaning solder pads of a ball grid array package (BGA) device according to any one of claims 1 to 4, characterized in that: The base material of the cotton ball includes one of cotton and dust-free cloth to resist high temperature and absorb soldering flux; the activation temperature of the soldering flux is used in conjunction with the solder.

9. The method for cleaning solder pads of a ball grid array package (BGA) device according to any one of claims 1 to 4, characterized in that: The cleaning method of the ball grid array package BGA device after the solder cleaning includes vapor phase cleaning and alcohol immersion cleaning.

10. The method for cleaning solder pads of a ball grid array package (BGA) device according to any one of claims 1 to 4, characterized in that: In the process of wiping the pad surface with the cotton ball coated with solder flux in the same direction, the high-temperature heating platform, the ball grid array package BGA device and the pad are stacked in sequence, and the pad is located on the side of the ball grid array package BGA device facing the cotton ball.

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