Method for improving oxidation of FPC (Flexible Printed Circuit) bonding pad with electronic connector
By installing SMT pad thermal insulation fixtures and OSP treatment on FPC pads, the problems of high-temperature oxidation and manual cleaning of pads are solved, achieving efficient and low-cost improvement in soldering yield.
Patent Information
- Application Number
- CN202511249396.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-03
- Publication Date
- 2025-12-05
AI Technical Summary
In existing technologies, FPC pads are severely oxidized during high-temperature processes, resulting in a high rate of soldering defects. Furthermore, traditional manual cleaning methods are costly and incomplete, and easily leave rubber shavings residue.
The SMT pad heat insulation fixture, including cover plate, base plate and SMT carrier board, is adopted. The heat input of the pad is reduced by magnetic attraction and multi-layer heat insulation material. Combined with OSP treatment to enhance the oxidation resistance of the pad, the automated operation avoids high temperature deformation and cleaning residue.
Significantly reduces the risk of solder pad oxidation, increases soldering yield to 99.8%, saves labor costs, avoids rubber shavings residue, and improves production efficiency and product quality.
Smart Images
Figure CN121078643A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of flexible circuit board processing, in particular to an FPC pad oxidation improvement method with an electronic connector. BACKGROUND
[0002] The connection process of the connector and the FPC light plate generally includes SMT reflow soldering (high-temperature process 1) → FR4 / PI pasting → FR4 / PI pressing (high-temperature process 2) → baking (high-temperature process 3) → wave soldering.
[0003] Firstly, the pads of the connector are seriously oxidized after the multiple high-temperature processes of SMT reflow soldering, pressing and oven. The oxidation of the pads leads to serious tin shortage and bridging defects in the wave soldering process, and the product failure rate after wave soldering is as high as 90% or more. The traditional solution is to manually wipe off the oxidation layer on the pads with a rubber eraser before wave soldering, and then clean the residual rubber crumbs by using an air gun manually. Although this method can reduce the failure rate to 1-5%, it greatly increases the labor cost, and the pads cannot be completely wiped clean by using the rubber eraser, and there are still residual rubber crumbs. The residual rubber crumbs will eventually flow to the customer end with the product, causing customer complaints.
[0004] Secondly, these high-temperature processes also have a significant impact on the FPC light plate. Before wave soldering, the FPC light plate is subjected to a long high-temperature process, which causes the surface of the pads to be seriously oxidized, directly causing 100% tin shortage failure in the wave soldering process. Therefore, the high-temperature oxidation problem of both the connector pads and the FPC pads has brought great difficulties and challenges to production.
[0005] In addition, in the existing solution, although the pads can be temporarily solved by wiping them with a rubber eraser, the labor cost is high, and it cannot be guaranteed that the oxidation layer is completely wiped off, and the debris generated during the use of the rubber eraser is easy to remain on the pads, leading to more wave soldering defects, and the rubber crumbs will further flow to the customer end, causing customer dissatisfaction and complaints. Therefore, it is urgent to find a more effective solution that does not produce residues to improve the current production situation.
[0006] Therefore, the present application is developed based on the deep thinking and active research on the many deficiencies and inconveniences of the existing connector wave soldering packaging process. SUMMARY
[0007] The present application aims to overcome the shortcomings of the prior art and provide an FPC pad oxidation improvement method with an electronic connector to solve the problems of high labor cost and debris residue caused by manually wiping the pads with a rubber eraser due to high-temperature oxidation of the pads in the prior art.
[0008] To achieve the above object, the solution of the present application is: The present application discloses a method for improving the oxidation of FPC pad with electronic connector, which comprises the following steps: Step S1, SMT pad heat insulation jig preparation: select the SMT pad heat insulation jig corresponding to the model of FPC, the SMT pad heat insulation jig comprises a cover plate, a bottom plate and an SMT carrier plate, the cover plate is detachably arranged on the SMT carrier plate to place the top surface of the one end of FPC provided with the connector, and the bottom plate is fixedly arranged on the bottom surface of the one end of the SMT carrier plate corresponding to the cover plate; the cover plate comprises upper synthetic stone, upper silica gel skin and steel sheet arranged in sequence, the upper synthetic stone faces the SMT carrier plate, and a magnet is embedded on the side of the upper synthetic stone facing the SMT carrier plate, so that the cover plate is magnetically attracted to the SMT carrier plate; the bottom plate comprises lower synthetic stone and lower silica gel skin, and the lower synthetic stone faces the back surface of the SMT carrier plate; Step S2, assembly of SMT pad heat insulation jig and SMT carrier plate: install the FPC on the SMT carrier plate, and then assemble the SMT pad heat insulation jig with the SMT carrier plate, so that the heat insulation part completely covers the connector pad of the FPC, and the assembly gap is less than or equal to 0.1 mm, so as to ensure that no pad is exposed; Step S3, high-temperature process execution: sequentially perform SMT reflow soldering, FR4 / PI pressing and FR4 pressing baking on the SMT carrier plate assembled with the SMT pad heat insulation jig; Step S4, disassembly and reuse of SMT pad heat insulation jig: after the high-temperature process is completed, the SMT carrier plate is cooled to below 50℃, the SMT pad heat insulation jig is disassembled, the surface of the SMT pad heat insulation jig is cleaned to remove residual impurities, and the SMT pad heat insulation jig is stored for reuse after being detected to be undamaged; Step S5, wave soldering process: directly send the FPC after the SMT pad heat insulation jig is disassembled into a wave soldering device to complete welding.
[0009] Further, in step S1, the upper synthetic stone of the cover plate is provided with a slot at a position corresponding to the electronic connector; in step S2, the front surface of the SMT carrier plate is provided with a plurality of product positioning grooves corresponding to the FPC, and the SMT carrier plate is provided with a sink groove for placing the electronic connector at one end of the product positioning grooves, and the FPC is placed on the SMT carrier plate according to the positions of the product positioning grooves and the sink groove, and after the FPC is placed on the SMT carrier plate, the cover plate of the SMT pad heat insulation jig is adsorbed on the SMT carrier plate through the magnet, so that the slot on the cover plate corresponds to the connector.
[0010] Further, in step S3, the high-temperature parameters of SMT reflow soldering are as follows: the control temperature curve is 150-180℃ (84-93s), 220℃ (51-57s) and the highest temperature is 236-239℃ (6.5s); The high-temperature parameters of FR4 / PI pressing are: maintaining at 180℃ for 120s, and the pressure control is 0.3-0.5MPa; The high-temperature parameters of FR4 pressing baking are: maintaining at 160-320℃ for 3600-7200s; Further, the upper synthetic stone and the lower synthetic stone of the SMT pad heat insulation jig are respectively attached with heat insulation cotton, and the material of the heat insulation cotton is glass fiber, and the thickness is 0.5-1mm.
[0011] Further, the assembly and disassembly of the jig in steps 2 and 4 are automatically operated by a mechanical arm, the positioning accuracy of the mechanical arm is ≤0.05mm, the grabbing speed is controlled to be 50-80mm / s, and the production efficiency is improved.
[0012] Further, the step S2 further includes FPC light plate pretreatment: before the assembly of the SMT pad heat insulation jig, the FPC light plate is subjected to OSP treatment, including pretreatment to remove FPC surface contaminants→micro-etching→acid pickling→film forming, film thickness 0.2-0.5μm→drying, pre-baking: 60℃ / 3min explosion hole, and then curing 85℃ / 10min. The OSP treatment enhances the oxidation resistance basic performance of the pad, and cooperates with the SMT pad heat insulation jig to improve the anti-oxidation effect.
[0013] Further, before the wave soldering process in step S5, the water drop angle of the FPC pad is tested, and if the test value is ≥14°, it is determined that the pad is not oxidized, and directly enters the welding without additional cleaning treatment.
[0014] Further, in step S3, before the SMT reflow soldering process, a furnace temperature tester is used to monitor the temperature of the pad area to ensure that the maximum temperature of the pad covered by the heat insulation part is ≤180℃, and if the temperature is too high, the reflow soldering temperature curve is adjusted.
[0015] Further, in step S3, the FR4 pressing baking process is carried out at 180℃, and the baking time is shortened to 15-20min, and at the same time, the FR4 peeling force is detected to be ≥5N / mm, to ensure that the pressing quality meets the standards and the pad is not oxidized.
[0016] Further, in step S4, the jig cleaning uses compressed air to blow the surface of the heat insulation part, and then uses a dust-free cloth dipped in isopropyl alcohol to wipe, to avoid the influence of residual impurities on the subsequent pad covering effect.
[0017] After the above scheme, the FPC pad oxidation improvement method with an electronic connector of the present application installs the SMT pad heat insulation jig at the pad position of the FPC connector before the high-temperature process, the SMT carrier plate of the SMT pad heat insulation jig forms a thermal resistance through the upper synthetic stone of the cover plate and the lower synthetic stone of the bottom plate, reduces the heat input of the FPC pad and the connector pad area, the elasticity of the upper silica gel skin and the lower silica gel skin can compensate for the thermal expansion difference between materials, and the steel sheet provides structural rigidity and reflects heat radiation. The magnet of the upper synthetic stone can realize contactless positioning with the SMT carrier plate, avoiding the deformation problem of traditional mechanical buckles under high temperature, and through the synergistic effect of multi-stage heat insulation and rapid positioning, the oxidation risk of the pad in the high-temperature process is significantly reduced.
[0018] Compared with the prior art, the traditional scheme relies on manual dry cleaning of the oxide layer, while the present application reduces the oxidation of the pad from the source through active heat management. The existing SMT carrier plate lacks directional heat insulation design, resulting in heat accumulation in the pad area. After assembling the connector on one end of the SMT carrier plate with the pad heat insulation jig of the present application, the temperature is about 65℃ lower than that of the conventional jig, and after passing through the furnace, the pads of the connector and the pads of the FPC are not oxidized and discolored. Among the 985 FPCs before wave soldering, only 2 of the less tin ones were not cleaned, with a pass rate of 99.8%, greatly improving the yield of the product, and eliminating the need for personnel to clean the blister tray with an air gun after the rubber eraser is removed, saving labor costs, and avoiding the problem of customer complaints caused by the retention of rubber crumbs on the pads. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 It is a schematic diagram of the layer structure of the SMT pad heat insulation jig of the present application.
[0020] Figure 2 It is a front view schematic diagram of the SMT pad heat insulation jig of the present application.
[0021] Figure 3 It is a back view schematic diagram of the SMT pad heat insulation jig of the present application.
[0022] Figure 4 It is a schematic diagram of one side of the SMT pad heat insulation jig cover plate and the SMT carrier plate magnetic attraction of the present application.
[0023] Figure 5 It is a schematic diagram of the structure of the SMT pad heat insulation jig of the present application installing the FPC and the cover plate not covering.
[0024] Figure 6 It is a schematic diagram of the structure of the FPC of the present application.
[0025] Label explanation: 10, heat insulation jig; 1, cover plate; 11, upper synthetic stone; 12, upper silica gel skin; 13, steel sheet; 14, magnet; 15, displacement slot; 2, bottom plate; 21, lower synthetic stone; 22, lower silica gel skin; 3, SMT carrier plate; 31, product positioning slot; 32, sink; 4, heat insulation cotton; 20, FPC; 201, connector. DETAILED DESCRIPTION
[0026] In order to further explain the technical solutions of the present application, the present application will be described in detail below through specific embodiments.
[0027] As shown in the drawings, Figures 1 to 5 The present application discloses a kind of SMT pad heat insulation jig 10, including cover plate 1, bottom plate 2 and SMT carrier plate 3, cover plate 1 can be detachably fixed in SMT carrier plate 3 to place the top surface of one end of FPC connector, the bottom plate 2 is fixedly arranged in SMT carrier plate 3 corresponding to the bottom surface of one end of cover plate 1.The cover plate 1 includes sequentially arranged upper synthetic stone 11, upper silica gel skin 12 and steel sheet 13, upper synthetic stone 11 is towards SMT carrier plate 3, one side of upper synthetic stone 11 towards SMT carrier plate 3 is embedded with magnet 14, so that cover plate 1 can be matched with SMT carrier plate 3 magnetic suction;The bottom plate 1 includes lower synthetic stone 21 and lower silica gel skin 22, lower synthetic stone 21 is towards the back surface of SMT carrier plate 3.
[0028] The SMT pad heat insulation jig 10 of the present application is provided with detachable cover plate 1 on the front surface of SMT carrier plate 3, and bottom plate 2 is provided on the back surface, upper synthetic stone 11 of cover plate 1 and lower synthetic stone 21 of bottom plate 2 have low thermal conductivity characteristics, which can inhibit the spread of heat to FPC and connector pad area, and the steel sheet 13, upper silica gel skin 12, upper synthetic stone 11, lower synthetic stone 21 and lower silica gel skin 22 form a multilayer heterogeneous material interface to reflect thermal radiation and block the heat conduction path.The magnet 14 provided on the upper synthetic stone 11 can be quickly matched together with the SMT carrier plate 3 by magnetic suction, avoiding the deviation caused by mechanical deformation in high temperature environment.
[0029] SMT carrier plate 3 forms a thermal barrier through upper synthetic stone 11 of cover plate 1 and lower synthetic stone 21 of bottom plate 2, reducing the heat input of FPC pad and connector pad area.The elasticity of upper silica gel skin 12 and lower silica gel skin 22 can compensate for the difference in thermal expansion between materials, and the steel sheet 13 provides structural rigidity and reflects thermal radiation.The magnet of upper synthetic stone 11 can realize non-contact positioning with SMT carrier plate 3, avoiding the deformation problem of traditional mechanical buckle in high temperature.By the synergistic effect of multi-stage heat insulation and rapid positioning, the oxidation risk of pad in high temperature process is significantly reduced.
[0030] In this embodiment, the upper synthetic stone 11 and the lower synthetic stone 21 are respectively attached with the heat insulation cotton 4 away from one side of the SMT carrier plate 3. The material of the heat insulation cotton 12 can be glass fiber, and the thickness is 0.5-1mm. The low thermal conductivity of the glass fiber heat insulation cotton 12 blocks the heat conduction path. The thickness range of 0.5-1mm can ensure the heat insulation performance while avoiding excessive increase of the overall thickness of the SMT pad heat insulation jig. The heat insulation cotton can use chopped glass fiber felt, which can realize stable heat insulation by using the low thermal conductivity and high temperature resistance of the material itself.
[0031] The upper synthetic stone 11 of the cover plate 1 is provided with a let slot 15 at the position corresponding to the connector. When assembling, the let slot 15 of the cover plate 1 is magnetically attracted to the SMT carrier plate corresponding to the connector of the FPC. The SMT carrier plate 3 can place multiple FPCs 20 at the same time, and the cover plate 1 is provided with the let slot 15 corresponding to the connector of each FPC.
[0032] In this embodiment, the thickness of the upper synthetic stone 11 and the lower synthetic stone 21 is 4mm respectively, the thickness of the upper silica gel skin 12 and the lower silica gel skin 22 is 3mm respectively, and the thickness of the steel sheet 13 is 0.2mm.
[0033] In this embodiment, the upper synthetic stone 11 of the cover plate 1 is provided with a plurality of mounting holes around it, and the steel sheet 13 is provided with a mounting hole corresponding to the upper synthetic stone 11. The upper silica gel skin 12 is arranged between the synthetic stone 11 and the steel sheet 13. One of the corners of the upper silica gel skin 12 is provided with a limiting hole, and the upper synthetic stone 11 is provided with a limiting hole corresponding to the upper silica gel skin 12. When installing, the upper synthetic stone 11 and the upper silica gel skin are installed together through the limiting hole, and then the upper synthetic stone 11, the upper silica gel skin 12 and the steel sheet 13 are fixed together through the screw after being aligned with the steel sheet 13.
[0034] In this embodiment, the lower synthetic stone 21 and the lower silica gel skin 22 of the bottom plate 2 are provided with corresponding mounting holes, and the lower synthetic stone 21 and the lower silica gel skin 22 are locked to the bottom surface of the SMT carrier plate 3 through the screw.
[0035] As Figure 4As shown, the SMT carrier plate 3 of the present application is set according to the model of the FPC. Before the SMT carrier plate 3 is used for the first time, the bottom plate 2 is fastened to the back of the SMT carrier plate 3. The front of the SMT carrier plate 3 is provided with a plurality of product positioning grooves 31 corresponding to the FPC 20. The SMT carrier plate 3 is provided with a sink 32 for placing the connector at one end of the product positioning groove 31. The FPC is placed on the SMT carrier plate 3 according to the positions of the product positioning groove 31 and the sink 32. After the FPC 20 is placed on the SMT carrier plate 3, the cover plate 1 is adsorbed on the SMT carrier plate 3 by the magnet 14, so that the gap slot 15 on the cover plate 1 corresponds to the connector 201. Then, the SMT solder pad heat insulation jig of the present application on which the FPC is placed can be sequentially subjected to the high-temperature processes of SMT reflow soldering, FR4 / PI pasting, FR4 / PI pressing, and baking.
[0036] Specifically, the present application discloses an FPC pad oxidation improvement method with an electronic connector, which comprises the following steps: Step S1, SMT solder pad heat insulation jig preparation: select an SMT solder pad heat insulation jig corresponding to the model of the FPC. The SMT solder pad heat insulation jig comprises a cover plate, a bottom plate, and an SMT carrier plate. The cover plate is detachably arranged on the SMT carrier plate to place the FPC on the top surface of one end of the connector. The bottom plate is fixedly arranged on the bottom surface of one end of the SMT carrier plate corresponding to the cover plate. The cover plate comprises, in sequence, an upper synthetic stone, an upper silica gel skin, and a steel sheet. The upper synthetic stone faces the SMT carrier plate. A magnet is embedded on the side of the upper synthetic stone facing the SMT carrier plate, so that the cover plate and the SMT carrier plate are magnetically attracted and matched. The bottom plate comprises a lower synthetic stone and a lower silica gel skin. The lower synthetic stone faces the back of the SMT carrier plate. Step S2, SMT solder pad heat insulation jig and SMT carrier plate assembly: install the FPC on the SMT carrier plate, and then butt joint the SMT solder pad heat insulation jig and the SMT carrier plate, so that the heat insulation part completely covers the connector pad of the FPC. The assembly gap is ≤0.1 mm, and it is ensured that no pad is exposed. Step S3, high-temperature process execution: sequentially perform SMT reflow soldering, FR4 / PI pressing, and FR4 pressing and baking on the SMT carrier plate with the assembled SMT solder pad heat insulation jig. Step S4, SMT solder pad heat insulation jig disassembly and reuse: after the high-temperature process is completed, wait for the SMT carrier plate to cool down to below 50℃, disassemble the SMT solder pad heat insulation jig, clean the surface of the SMT solder pad heat insulation jig of residual impurities, and store it for reuse after detection of no damage. Step S5, wave soldering process: directly send the FPC after disassembling the SMT solder pad heat insulation jig into a wave soldering device to complete the welding.
[0037] In step S1, the upper synthetic stone of the cover plate is provided with a clearance slot corresponding to the position of the electronic connector; in step S2, the front surface of the SMT carrier plate is provided with a plurality of product positioning slots corresponding to the FPC, and the SMT carrier plate is provided with a sink for placing the electronic connector at one end of the product positioning slot; the FPC is placed on the SMT carrier plate according to the position of the product positioning slot and the sink; after the FPC is placed on the SMT carrier plate, the cover plate of the SMT pad heat insulation jig is adsorbed on the SMT carrier plate by a magnet, so that the clearance slot on the cover plate corresponds to the connector.
[0038] The upper synthetic stone and the lower synthetic stone of the SMT pad heat insulation jig are respectively attached with heat insulation cotton on the side away from the SMT carrier plate, and the material of the heat insulation cotton is glass fiber with a thickness of 0.5-1mm.
[0039] In steps S2 and S4, the assembly and disassembly of the SMT pad heat insulation jig are automatically operated by a mechanical arm, the positioning accuracy of the mechanical arm is ≤0.05mm, the grabbing speed is controlled to be 50-80mm / s, and the production efficiency is improved.
[0040] Before step S2, the FPC light plate is pretreated: before the assembly of the SMT pad heat insulation jig, the FPC light plate is subjected to OSP treatment, including removing surface contaminants of the FPC→micro-etching→acid washing→film forming, film thickness 0.2-0.5μm→drying, pre-baking: 60℃ / 3min explosion hole, and then solidifying at 85℃ / 10min. The OSP treatment enhances the basic oxidation resistance performance of the pad and cooperates with the SMT pad heat insulation jig to improve the anti-oxidation effect.
[0041] In step S3, before the SMT reflow soldering process, the temperature of the pad area is monitored by a furnace temperature tester to ensure that the maximum temperature of the pad covered by the heat insulation part is ≤180℃, and if the temperature is too high, the reflow soldering temperature curve is adjusted. The high temperature parameters of SMT reflow soldering are: the control temperature curve is 150-180℃ (84-93s), 220℃ (51-57s), and the maximum temperature is 236-239℃ (6.5s); The high temperature parameters of FR4 / PI pressing are: keeping at 180℃ for 120s, and the pressure control is 0.3-0.5MPa; The high temperature parameters of FR4 pressing and baking are: keeping at 160-320℃ for 3600-7200s; preferably, the FR4 pressing and baking process is carried out at 180℃, the baking time is shortened to 15-20min, and at the same time, the FR4 peeling force is detected to be ≥5N / mm, so as to ensure that the pressing quality meets the standard and the pad is not oxidized.
[0042] In step S4, the SMT pad heat insulation jig is cleaned by blowing the surface of the heat insulation part with compressed air, and then wiping with isopropanol dipped in a dust-free cloth, so as to avoid the influence of residual impurities on the subsequent pad covering effect.
[0043] Before the wave-soldering process, the water drop angle of the FPC pad is tested, and if the test value is greater than or equal to 14°, it is determined that the pad is not oxidized, and the pad directly enters the welding without additional cleaning treatment.
[0044] The above examples and drawings are not intended to limit the product form and style of the present application, and any appropriate changes or modifications made by those skilled in the art shall be considered as not departing from the patent scope of the present application.
Claims
1. A method for improving oxidation of an FPC pad with an electronic connector, characterized by, The method comprises the following steps: Step S1, SMT pad heat insulation jig preparation: select the SMT pad heat insulation jig corresponding to the model of FPC, the SMT pad heat insulation jig comprises a cover plate, a bottom plate and an SMT carrier plate, the cover plate is detachably arranged on the SMT carrier plate to place the top surface of the one end of the FPC connected with the connector, and the bottom plate is fixedly arranged on the bottom surface of the one end of the SMT carrier plate corresponding to the cover plate; the cover plate comprises upper synthetic stone, upper silica gel skin and steel sheet arranged in sequence, the upper synthetic stone faces the SMT carrier plate, and a magnet is embedded on the side of the upper synthetic stone facing the SMT carrier plate, so that the cover plate and the SMT carrier plate are magnetically attracted and matched; the bottom plate comprises lower synthetic stone and lower silica gel skin, and the lower synthetic stone faces the back surface of the SMT carrier plate; Step S2, SMT pad heat insulation jig and SMT carrier plate assembly: the FPC is installed on the SMT carrier plate, and then the SMT pad heat insulation jig is butted with the SMT carrier plate, so that the heat insulation part completely covers the connector pad of the FPC, the assembly gap is ≤0.1mm, and it is ensured that no pad is exposed; Step S3, high-temperature process execution: the SMT carrier plate with the assembled SMT pad heat insulation jig is sequentially subjected to SMT reflow soldering, FR4 / PI pressing and FR4 pressing baking; Step S4, SMT pad heat insulation jig removal and reuse: after the high-temperature process is completed, the SMT carrier plate is cooled to below 50℃, the SMT pad heat insulation jig is removed, the surface of the SMT pad heat insulation jig is cleaned to remove residual impurities, and the SMT pad heat insulation jig is stored for reuse after detection of no damage; Step S5, wave soldering process: the FPC after the SMT pad heat insulation jig is removed is directly sent to a wave soldering device to complete welding.
2. The method of claim 1, wherein the FPC pad is an electronic connector pad. In step S1, the upper synthetic stone of the cover plate is provided with a recess at a position corresponding to the electronic connector; in step S2, the front surface of the SMT carrier plate is provided with a plurality of product positioning grooves corresponding to the FPC, and the SMT carrier plate is provided with a sink groove for placing the electronic connector at one end of the product positioning grooves; the FPC is placed on the SMT carrier plate according to the positions of the product positioning grooves and the sink groove; after the FPC is placed on the SMT carrier plate, the cover plate of the SMT pad heat insulation jig is adsorbed on the SMT carrier plate through the magnet, so that the recess on the cover plate corresponds to the connector.
3. The method of claim 1, wherein the FPC pad is an electronic connector pad. In step S3, the high-temperature parameters of SMT reflow soldering are as follows: the control temperature curve is 150-180℃ (84-93s), 220℃ (51-57s) and the highest temperature is 236-239℃ (6.5s); The high-temperature parameters of FR4 / PI pressing are as follows: the temperature is kept at 180℃ for 120s, and the pressure control is 0.3-0.5MPa; The high-temperature parameters of FR4 pressing baking are as follows: the temperature is kept at 160-320℃ for 3600-7200s.
4. The method of claim 1, wherein the FPC pad is an electronic connector pad. The upper synthetic stone and the lower synthetic stone of the SMT pad heat insulation jig are respectively attached with heat insulation cotton away from the SMT carrier plate, and the material of the heat insulation cotton is glass fiber with a thickness of 0.5-1mm.
5. The method of claim 1, wherein the FPC pad is an electronic connector pad. In steps S2 and S4, the assembly and removal of the SMT pad heat insulation jig are automatically operated by a mechanical arm, the positioning accuracy of the mechanical arm is ≤0.05mm, and the grabbing speed control is 50-80mm / s.
6. The method of claim 1, wherein the FPC pad is an electronic connector pad. The step S2 further comprises FPC light plate pretreatment: before the assembly of the SMT pad heat insulation jig, the FPC light plate is subjected to OSP treatment, including pretreatment to remove FPC surface contaminants → micro-etching → acid washing → film forming, film thickness 0.2-0.5 μm, → drying, pre-baking: 60°C / 3 minutes anti-explosion hole, and then solidification 85°C / 10 minutes.
7. The method of claim 1, wherein the FPC pad is an electronic connector pad. Before the wave-soldering procedure of step S5, the FPC pad is subjected to water drop angle test, and if the test value is greater than or equal to 14°, it is determined that the pad is not oxidized, and directly enters the welding without additional cleaning treatment.
8. The method of claim 1, wherein the FPC pad is an electronic connector.
8. The method of claim 1, wherein the FPC pad is an electronic connector. In step S3, before the SMT reflow soldering procedure, the pad area temperature is monitored by a furnace temperature tester to ensure that the maximum temperature of the pad covered by the heat insulation part is less than or equal to 180°C, and if the temperature is too high, the reflow soldering temperature curve is adjusted.
9. The method of claim 1, wherein the FPC pad oxidation improvement with electronic connector is characterized by: In step S3, the FR4 compression baking procedure is adopted at 180°C, the baking time is shortened to 15-20 minutes, and at the same time, the FR4 peeling force is detected to be greater than or equal to 5N / mm, to ensure that the compression quality meets the standards and the pad is not oxidized.
10. The method of claim 1, wherein the FPC pad oxidation improvement with electronic connector is characterized by: In step S4, the jig cleaning adopts compressed air to blow the surface of the heat insulation part, and then isopropanol is used to wipe the surface with a dust-free cloth, to avoid the influence of residual impurities on the subsequent pad covering effect.