A high process soldering technology combining reflow soldering and wave soldering

Abstract

The application discloses a high-process welding process combining reflow soldering and wave soldering, comprising the following steps: identifying the reflow soldering and wave soldering areas on a welding object; sequentially performing tin paste printing and detection operations in the reflow soldering area; performing automatic dispensing and automatic patching operations on the area after the operation in the previous step; performing reflow soldering and optical detection operations on the area after the operation in the previous step; loading a carrier on a circuit board in the wave soldering area and installing a plug-in component; merging the area, in which the range around each plug-in component is limited and coincides with the reflow soldering area, with the wave soldering area to form a new wave soldering area; and performing wave soldering on the new wave soldering area. The application can greatly improve the process capability limit of an enterprise itself and improve the welding pass rate.

Description

TECHNICAL FIELD

[0001] The present application relates to a welding process, in particular to a high-process welding process combining reflow soldering and wave soldering. BACKGROUND

[0002] In the traditional welding of integrated circuit electronic products, when the surface-mounted device and the plug-in device are less than 15mm in the inner distance, the process method of the initial surface welding has the following disadvantages:

[0003] I. When using full-tin paste welding and wave soldering, due to the close distance between the surface-mounted device and the plug-in device, a carrier needs to be used for shielding. However, the base material cannot be shielded while opening the welding interface, resulting in that the welding shadow area cannot be effectively 100% welded due to the shielding height of the carrier;

[0004] II. Due to the need for hole avoidance of the surface-mounted device on the base material by the wave soldering carrier, the close distance of the circuit design causes the device to be easily damaged during manual operation, resulting in appearance damage and potential functional failure of the product;

[0005] III. When using glue to adhere the surface-mounted device on the entire surface of the product, reflow soldering is used for glue curing and adhesion welding. However, due to the circuit board design, integrated circuit chips such as BGA, BTC, and temperature-sensitive devices may appear on the welding starting surface, which can only be implemented on a small range of passive and separated devices that are not temperature-sensitive and have welding gaps. The overall welding assembly process capability is limited, and batch implementation is not possible, which greatly increases the production cost and production cycle of the product;

[0006] IV. After surface mounting reflow soldering, the enterprise invests in the purchase of selective wave soldering for welding. However, due to the fact that selective wave soldering is not suitable for large-scale operations, the enterprise will increase the number of selective wave soldering equipment due to production capacity and delivery cycle, resulting in excessive investment in fixed assets and an increase in the number of technical personnel, which is not conducive to the development of small and medium-sized enterprises and affects the cash flow of the enterprise itself.

[0007] In summary, the traditional welding process of electronic products has obvious disadvantages whether it is wave soldering or reflow soldering alone. SUMMARY

[0008] In order to solve the above technical problems, the present application provides a high-process welding process combining reflow soldering and wave soldering.

[0009] In order to solve the above technical problems, the present application adopts the technical scheme of: a high-process welding process combining reflow soldering and wave soldering, comprising the following steps:

[0010] S1, identifying the reflow soldering and wave soldering areas on the soldering object;

[0011] S2, sequentially performing the solder paste printing and detection operations in the reflow soldering area identified in S1;

[0012] S3, performing the automatic dispensing and automatic placement operations on the area after the operation in S2;

[0013] S4, performing the reflow soldering and optical detection operations on the area after the operation in S3;

[0014] S5, loading the carrier on the circuit board in the wave soldering area in S1 and performing the component mounting;

[0015] S6, merging the area where the range around each component is overlapped with the reflow soldering area with the wave soldering area in S1 to form a new wave soldering area;

[0016] S7, performing the wave soldering on the new wave soldering area formed in S6.

[0017] Further, the soldering starting face electronic design drawing of the circuit board in S1 is the soldering starting face electronic design drawing, and the data is confirmed based on the GerberView software to identify the reflow soldering and wave soldering areas.

[0018] Further, the steps of the solder paste printing and detection operations in S2 are:

[0019] S21, designing the solder paste printing transfer steel mesh;

[0020] S22, ambiently warming and stirring the solder paste;

[0021] S23, setting up the solder paste printing transfer steel mesh by using the solder paste printing machine and performing the visual angle positioning;

[0022] S24, transferring the solder paste by using the solder paste printing machine, mounting the squeegee, and filling the solder paste;

[0023] S25, detecting the solder paste transfer pattern by using the automatic 3D optical equipment.

[0024] Further, the steps of the automatic dispensing and automatic placement operations in S3 are:

[0025] S31, ambiently warming the high-temperature resistant adhesive;

[0026] S32, automatically dispensing the area after the operation in S2 by using the online dispensing machine;

[0027] S33, automatically placing the electronic components by using the full-automatic placement equipment;

[0028] S34 uses a KIC furnace temperature profile tester to measure the temperature of the formula and automatically analyzes the formula's curve parameters.

[0029] Furthermore, the steps for reflow soldering and optical inspection operations in S4 are as follows:

[0030] S41, using air-medium reflow soldering equipment to perform reflow soldering with temperature recipes;

[0031] S42, using an automatic optical inspection machine to perform optical inspection on the area after reflow soldering in S41;

[0032] S43 uses a microscope to examine the morphology of the area after optical inspection by S42.

[0033] Furthermore, after S7 welding, the solder joints and components are inspected for morphology.

[0034] Furthermore, the area around each insert in S6 is limited to within 15mm.

[0035] Furthermore, the thickness range of the solder paste printing transfer stencil in S21 is 80–120 μm.

[0036] Furthermore, the welding temperature range in S41 is 230–245°C.

[0037] Furthermore, during reflux in S41, the temperature is controlled within the range of 217–220°C for 30–80 seconds.

[0038] Furthermore, the S41 temperature is controlled within the range of 150–190°C for 60–120 seconds during constant temperature operation.

[0039] This invention discloses a high-process soldering process that combines reflow soldering and wave soldering. When surface mount and through-hole components are soldered on the same starting surface in electronic products, the combination of reflow soldering and wave soldering avoids various soldering problems caused by soldering shadows, improves the soldering first pass rate, significantly enhances the company's own process capability limits, reduces the need for additional technical personnel, and avoids repeated large-scale equipment capital investment. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0042] Example 1, as Figure 1 The high-efficiency soldering process combining reflow soldering and wave soldering, as shown, includes the following steps:

[0043] S1 identifies the reflow soldering and wave soldering areas on the soldering object; wherein, the soldering object in S1 is the electronic design draft of the soldering starting surface of the circuit board, and the data is confirmed based on Gerber View software to identify the reflow soldering and wave soldering areas.

[0044] S2, in the reflow soldering area identified in S1, solder paste printing and inspection operations are performed sequentially; the steps of the solder paste printing and inspection operations in S2 are as follows: S21, design and generate solder paste printing transfer stencil; S22, warm and stir the SAC305 solder paste No. 3-4 powder to meet the working conditions; S23, use the solder paste printer to set up the solder paste printing transfer stencil and perform viewing angle positioning; S24, use the solder paste printer to transfer solder paste, install the squeegee, and fill the solder paste; S25, use automatic 3D optical equipment to inspect the solder paste transfer pattern and check whether the volume of the printed pattern meets the set requirements.

[0045] S3 involves automatic dispensing and placement of components in the area treated in S2. The steps for automatic dispensing and placement in S3 are as follows: S31, allowing the high-temperature adhesive to warm to ambient temperature; S32, automatically dispensing adhesive into the area treated in S2 using an online dispensing machine; S33, automatically placing electronic components using fully automated placement equipment; and S34, measuring the temperature profile using a KIC oven temperature profile tester and automatically analyzing the profile parameters.

[0046] S4 involves reflow soldering and optical inspection of the area after operation S3. The steps of reflow soldering and optical inspection in S4 are as follows: S41, reflow soldering is performed using an air-medium reflow soldering machine with the specified temperature and formula; S42, optical inspection is performed on the area after reflow soldering in S41 using an automatic optical inspection machine to check the accuracy of the actual coordinates; S43, morphological examination is performed on the area after optical inspection in S42 using a microscope to confirm the flatness and adhesion strength after welding.

[0047] S5, In the wave soldering area of ​​S1, a carrier is installed on the circuit board and the insert is installed;

[0048] S6, the area overlapping the reflow soldering area and the wave soldering area around each through-hole component is merged with the wave soldering area in S1 to form a new wave soldering area. In this embodiment, the defined area around each through-hole component in S6 is 15mm. Thus, within the wave soldering area, a new wave soldering area is defined within a 15mm radius around each through-hole component. The overlapping portion of this newly defined wave soldering area and the reflow soldering area serves as a new open soldering interface. This solves various soldering problems caused by soldering shadows when surface mount and through-hole components are soldered on the same starting surface in electronic products using traditional soldering processes. It also extends the company's soldering delivery cycle and improves the consistency of soldering first-pass yield. This enhances the company's process capability limits, reduces the need for additional technical personnel, and avoids repeated large-scale equipment capital investments—features not available in traditional methods, overcoming various shortcomings of the prior art.

[0049] S7 performs wave soldering on the new wave soldering area formed by S6. After S7 soldering, the solder joints and components are inspected for morphology.

[0050] Preferably, the thickness of the solder paste printing transfer stencil in S21 ranges from 80 to 120 μm. The soldering temperature in S41 ranges from 230 to 245°C. During reflow in S41, the temperature is controlled within the range of 217 to 220°C for 30 to 80 seconds. During isothermal operation in S41, the temperature is controlled within the range of 150 to 190°C for 60 to 120 seconds.

[0051] Example 2, as Figure 1 The high-efficiency soldering process combining reflow soldering and wave soldering, as shown, includes the following steps:

[0052] S1 identifies the reflow soldering and wave soldering areas on the soldering object; wherein, the soldering object in S1 is the electronic design draft of the soldering starting surface of the circuit board, and the data is confirmed based on Gerber View software to identify the reflow soldering and wave soldering areas.

[0053] S2, in the reflow soldering area identified in S1, solder paste printing and inspection operations are performed sequentially; the steps of the solder paste printing and inspection operations in S2 are as follows: S21, design and generate solder paste printing transfer stencil; S22, warm and stir the SAC305 solder paste No. 3-4 powder to meet the working conditions; S23, use the solder paste printer to set up the solder paste printing transfer stencil and perform viewing angle positioning; S24, use the solder paste printer to transfer solder paste, install the squeegee, and fill the solder paste; S25, use automatic 3D optical equipment to inspect the solder paste transfer pattern and check whether the volume of the printed pattern meets the set requirements.

[0054] S3 involves automatic dispensing and placement of components in the area treated in S2. The steps for automatic dispensing and placement in S3 are as follows: S31, allowing the high-temperature adhesive to warm to ambient temperature; S32, automatically dispensing adhesive into the area treated in S2 using an online dispensing machine; S33, automatically placing electronic components using fully automated placement equipment; and S34, measuring the temperature profile using a KIC oven temperature profile tester and automatically analyzing the profile parameters.

[0055] S4 involves reflow soldering and optical inspection of the area after operation S3. The steps of reflow soldering and optical inspection in S4 are as follows: S41, reflow soldering is performed using an air-medium reflow soldering machine with the specified temperature and formula; S42, optical inspection is performed on the area after reflow soldering in S41 using an automatic optical inspection machine to check the accuracy of the actual coordinates; S43, morphological examination is performed on the area after optical inspection in S42 using a microscope to confirm the flatness and adhesion strength after welding.

[0056] S5, In the wave soldering area of ​​S1, a carrier is installed on the circuit board and the insert is installed;

[0057] In step S6, the area overlapping the reflow soldering area and the wave soldering area around each through-hole component is merged with the wave soldering area in step S1 to form a new wave soldering area. In this embodiment, the defined area around each through-hole component in step S6 is 12mm. Thus, within the wave soldering area, a new wave soldering area is defined within a 12mm radius around each through-hole component. The overlapping portion of this newly defined wave soldering area and the reflow soldering area serves as a new open soldering interface. This solves various soldering problems caused by soldering shadows when surface mount and through-hole components are soldered on the same starting surface in electronic products using traditional soldering processes. It also extends the company's soldering delivery cycle and improves the consistency of soldering first-pass yield. This significantly enhances the company's process capability limits, reduces the need for additional technical personnel, and avoids repeated large-scale equipment capital investments—features not available in traditional methods, overcoming various shortcomings of the prior art.

[0058] S7 performs wave soldering on the new wave soldering area formed by S6. After S7 soldering, the solder joints and components are inspected for morphology.

[0059] Preferably, the thickness of the solder paste printing transfer stencil in S21 ranges from 80 to 120 μm. The soldering temperature in S41 ranges from 230 to 245°C. During reflow in S41, the temperature is controlled within the range of 217 to 220°C for 30 to 80 seconds. During isothermal operation in S41, the temperature is controlled within the range of 150 to 190°C for 60 to 120 seconds.

[0060] The above embodiments are not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the technical solution of the present invention are also within the protection scope of the present invention.

Claims

1. A high-process welding technology combining reflow soldering and wave soldering, characterized in that, Includes the following steps: S1, Identify the reflow soldering and wave soldering areas on the soldering object; the soldering object in S1 is the electronic design draft of the soldering starting surface of the circuit board, and the data is confirmed based on Gerber View software to identify the reflow soldering and wave soldering areas. S2, in the reflow soldering area identified by S1, solder paste printing and inspection operations are performed sequentially; S3 performs automatic dispensing and automatic patch placement on the area after the S2 operation. S4, performs reflow soldering and optical inspection on the area after the S3 operation; S5, In the wave soldering area of ​​S1, a carrier is installed on the circuit board and the insert is installed; S6, the area around each insert that overlaps with the area of ​​reflow soldering is merged with the area of ​​wave soldering in S1 to form a new area of ​​wave soldering; S7 performs wave soldering on the new wave soldering area formed by S6.

2. The high-process welding process combining reflow soldering and wave soldering according to claim 1, characterized in that: The steps for solder paste printing and inspection in S2 are as follows: S21, Design and generate solder paste printing transfer stencil; S22, the solder paste is brought to ambient temperature and stirred; S23, using a solder paste printing machine to set up a solder paste printing transfer stencil and perform viewing angle positioning; S24, using a solder paste printer to transfer solder paste, install a squeegee, and fill solder paste; S25 utilizes automated 3D optical equipment to inspect solder paste transfer patterns.

3. The high-process welding process combining reflow soldering and wave soldering according to claim 1, characterized in that, The steps of the automatic dispensing and automatic patch placement operations in S3 are as follows: S31, the high-temperature resistant adhesive is subjected to environmental warming; S32 uses an online dispensing machine to automatically dispense adhesive into the area after the S2 operation; S33 utilizes fully automated placement equipment to automatically place electronic components; S34 uses a KIC furnace temperature profile tester to measure the temperature of the formula and automatically analyzes the formula's curve parameters.

4. The high-process welding process combining reflow soldering and wave soldering according to claim 1, characterized in that, The steps for the reflow soldering and optical inspection operations in S4 are as follows: S41, using air-medium reflow soldering equipment to perform reflow soldering with temperature recipes; S42, using an automatic optical inspection machine to perform optical inspection on the area after reflow soldering in S41; S43 uses a microscope to examine the morphology of the area after optical inspection by S42.

5. The high-process welding process combining reflow soldering and wave soldering according to claim 1, characterized in that, After the S7 welding, the weld points and components are inspected for morphology.

6. The high-process welding process combining reflow soldering and wave soldering according to claim 1, characterized in that, The defined area around each insert in S6 is within 15 mm.

7. The high-process welding process combining reflow soldering and wave soldering according to claim 2, characterized in that, The thickness range of the solder paste printing transfer stencil in S21 is 80~120um.

8. The high-process welding process combining reflow soldering and wave soldering according to claim 4, characterized in that, The welding temperature range in S41 is 230~245℃.

9. The high-process welding process combining reflow soldering and wave soldering according to claim 4, characterized in that, During the reflux in step S41, the temperature is controlled within the range of 217~220℃ for 30~80 seconds; during the isothermal operation in step S41, the temperature is controlled within the range of 150~190℃ for 60~120 seconds.

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