A method for preparing a DIP26 package product avoiding pin damage and contact contamination

Abstract

The application relates to the technical field of DIP26 packaging of electronic components, and discloses a DIP26 packaging product preparation method capable of avoiding pin damage and contact pollution, which comprises pretreatment, passivation protection electroplating, gradient flexible cutting, protection packaging and transportation; through sequentially adopting alkaline degreasing liquid and acidic activation liquid to remove oil and oxidation and to activate cleaning, then rinsing with deionized water and drying with constant temperature hot air, the pin surface is ensured to be clean and activated; then the pretreated pin is immersed into a tinning liquid to electroplate, and then the tinned pin is immersed into a passivation liquid to form a dense protection film, so that the corrosion resistance and weldability of the pin are improved, the contact resistance is reduced, and the performance of the pin is prevented from being reduced due to surface pollution; the DIP26 product after cutting is loaded into a customized anti-static pipe with an inner wall provided with isolation grooves matched with the pin number and spacing, so that the pin is isolated and protected.

Description

Technical Field

[0001] This invention relates to the field of DIP26 packaging technology for electronic components, specifically a method for preparing DIP26 packaged products that avoids pin damage and contact contamination. Background Technology

[0002] DIP26 is a ruggedized power stage dual in-line package. With its wide lead pitch and high insulation withstand voltage, it is widely used in high-voltage and high-reliability power electronics applications and is a common packaging form in industrial and home appliance fields. The manufacturing process of existing DIP26 packaged products mainly includes wafer mounting, wire bonding, molding, electroplating protection, lead trimming, lead forming, and finished product sorting and packaging. The finished product usage process includes unpacking, transportation, insertion, soldering, and quality inspection.

[0003] Currently, due to the multiple processes involved in the manufacturing of DIP26 packaged products, existing processes lack systematic protective measures in the lead pretreatment, lead cutting and forming, and packaging and transportation stages. This results in oil and oxide layers easily remaining on the lead surface, cracks or deformations easily occurring at the root during lead cutting, and direct contact between human hands and leads during transportation and sorting causing contamination or physical damage. Consequently, the corrosion resistance and solderability of the leads are affected, making it impossible to guarantee the reliability and consistency of the product in subsequent use.

[0004] Therefore, a method for manufacturing DIP26 packaged products that avoids pin damage and contact contamination is proposed to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for manufacturing DIP26 packaged products that avoids pin damage and contact contamination, solving the problems mentioned in the background art that affect the corrosion resistance and solderability of the pins, and cannot guarantee the reliability and consistency of the product in subsequent use.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for manufacturing a DIP26 packaged product that avoids pin damage and contact contamination, comprising the following steps: Step 1: Pre-treatment. The DIP26 semi-finished product pins that have been plastic-encapsulated and cured are immersed in alkaline degreasing solution and acidic activation solution in sequence for degreasing, deoxidation and activation cleaning, then rinsed with deionized water and dried with constant temperature hot air. Step 2: Passivation and protective electroplating. The pre-treated pins are immersed in tin plating solution for electroplating, and the thickness of the tin plating layer is controlled to be 8-12μm. Then, the tin-plated pins are immersed in passivation solution and kept at 60-80℃ for 10-20 minutes to form a dense protective film. Step 3: Gradient flexible lead cutting. A two-stage gradient forming mold is used. The first-stage pre-forming mold pre-forms the lead with a pressure of 0.3MPa, and the second-stage precision forming mold precision forms the lead with a pressure of 0.5MPa. The forming speed is 4-6mm / s, which completes the lead cutting and shaping. Step 4: Protective packaging and transportation. The DIP26 products after the pins have been cut are loaded into a custom anti-static tubing. The inner wall of the tubing has isolation grooves that match the number and spacing of the pins. For products marked as defective, a non-contact removal and replenishment operation is performed using a material pouring tool. The material pouring tool includes a tubing interface, a product receiving groove, and a flip cover.

[0007] Preferably, in step one, the alkaline degreasing solution is an aqueous solution of sodium hydroxide with a concentration of 5%-10%, a temperature of 60-80℃, and a cleaning time of 5-10 minutes; The acidic activation solution is an aqueous sulfuric acid solution with a concentration of 10%-15%, a temperature of 40-60℃, and a cleaning time of 3-5 minutes. The resistivity of the deionized water is ≥18MΩ·cm. The water is rinsed 2-3 times, with each rinse lasting 2-5 minutes. The constant temperature hot air drying temperature is 50-80℃, and the drying time is 5-10 minutes. Nitrogen gas is introduced during the drying process at a flow rate of 10-30L / min.

[0008] Preferably, in step two, the tin plating solution is a sulfate-based tin plating solution, the composition of which is: 30-50 g / L stannous sulfate, 80-120 g / L sulfuric acid, 2-5 mL / L brightener, and 1-3 mL / L stabilizer. The brightening agent is polyethyleneimine or polyethylene glycol, and the stabilizer is gelatin or gum arabic. Preferably, in step two, the current density during electroplating is 1.5-3.0 A / dm², the temperature of the electroplating solution is 25-35℃, and the electroplating time is 10-20 min; the passivation solution is a chromate passivation solution or a chromium-free passivation solution, the concentration of the passivation solution is 5-15 g / L, and the pH value of the passivation solution is 3.5-5.0.

[0009] Preferably, in step three, the mold gap of the first-stage preforming mold is 1.2-1.5 times the pin thickness, and the mold cutting edge angle is 30°-45°; The die gap of the second-stage precision forming die is 1.0-1.1 times the lead thickness, and the die cutting edge angle is 15°-25°; the switching time between the two dies is 0.5-1.5s. During the cutting process, a nitrogen purging device is activated simultaneously, with a nitrogen pressure of 0.2-0.4 MPa, to remove metal debris generated during the cutting process.

[0010] Preferably, the custom antistatic tubing is made of polycarbonate or acrylonitrile-butadiene-styrene copolymer; the depth of the isolation groove is 1 / 3 to 1 / 2 of the pin length; the groove width is 1.5 to 2.0 times the pin thickness; and the center-to-center distance between adjacent grooves is equal to the pin-to-center distance of the DIP26 package product. The inner wall surface of the antistatic tubing is treated with antistatic agents, and its surface resistivity is 10 Ω·cm. 6 -10 9 Ω / sq.

[0011] Preferably, the main frame of the material feeding tube is a cuboid structure, and the material tube interface is located at the top of the main frame, with the difference between its inner diameter and the outer diameter of the antistatic material tube being 0.1-0.3 mm. The product receiving groove is located inside the main frame. A buffer pad is fixed at the bottom of the receiving groove. The buffer pad is made of silicone rubber or polyurethane and has a hardness of Shore A 30-50. The flip cover is connected to the side of the main frame via a hinge. The flip cover can open at an angle of 90°-120°. The flip cover has a latch that engages with the main frame.

[0012] Preferably, the contactless removal operation steps of the material discharge control tool are as follows: Insert the antistatic tubing containing the DIP26 product into the tubing interface with the open end facing down, and let the product slide from the tubing into the product receiving groove by gravity. Remove the empty material tube, open the flip cover, and use anti-static tweezers to pick up the plastic seal of the product and take it out. Close the flip cover, reinsert the empty material tube into the material tube interface, and flip the material tube tool so that the product slides back from the receiving groove into the material tube by gravity to complete the removal operation. The replenishment operation steps are as follows: the product to be replenished is placed into the receiving groove through the flip cover, then the open end of the material pipe containing part of the product is inserted upward into the material pipe interface, and the material pipe tool is flipped to make the product slide into the material pipe.

[0013] Preferably, in step four, the antistatic tubing filled with DIP26 products is placed into an antistatic aluminum foil bag for sealing and packaging. The antistatic aluminum foil bag consists of a polyethylene film layer, a nylon reinforcement layer, and an aluminum foil layer from the inside out. Nitrogen gas is filled into the bag during packaging, with a nitrogen purity of ≥99.99%, and the oxygen concentration in the bag after filling is ≤0.5%.

[0014] Preferably, in step three, the mold material of the secondary gradient forming mold is cemented carbide steel, and the surface roughness of the mold working surface Ra≤0.2μm; after the bead cutting is completed, products with cracks or deformation at the root of the lead are marked as defective.

[0015] Compared with the prior art, the present invention provides a method for manufacturing DIP26 packaged products that avoids pin damage and contact contamination, and has the following beneficial effects: 1. In this invention, during the pretreatment and passivation protection electroplating of the DIP26 packaged product pins, the pins are cleaned and activated by sequentially using alkaline degreasing solution and acidic activation solution, followed by rinsing with deionized water and drying with constant temperature hot air to ensure the pin surface is clean and activated. Subsequently, the pretreated pins are immersed in tin plating solution for electroplating, and then the tin-plated pins are immersed in passivation solution to form a dense protective film, which improves the corrosion resistance and solderability of the pins, reduces contact resistance, and prevents the pins from degrading due to surface contamination.

[0016] 2. In this invention, when performing gradient flexible rib cutting, a two-stage gradient forming mold is used. The first-stage pre-forming mold pre-forms the pin, and the second-stage precision forming mold performs precision forming. The forming speed is controlled, and the mold gap and cutting edge angle are set to achieve a flexible transition between pin cutting and shaping, avoid cracks and deformation at the root of the pin, improve the bending strength of the pin, and ensure the pin forming accuracy.

[0017] 3. In this invention, during protective packaging and transportation, the DIP26 products after rib cutting are placed into a customized anti-static tubing with isolation grooves on the inner wall that match the number and spacing of the pins, thereby achieving pin isolation and protection. For products marked as defective, a non-contact material handling tool including a tubing interface, a product receiving groove, and a flip cover is used to perform non-contact removal and replenishment operations, avoiding direct contact between human hands and the pins, thus preventing damage and contamination and ensuring the integrity and cleanliness of the products during transportation and sorting. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: A method for manufacturing a DIP26 packaged product that avoids pin damage and contact contamination, comprising the following steps: Step 1: Pre-treatment. The DIP26 semi-finished product pins that have been plastic-encapsulated and cured are immersed in alkaline degreasing solution and acidic activation solution in sequence for degreasing, deoxidation and activation cleaning, then rinsed with deionized water and dried with constant temperature hot air. Step 2: Passivation and protective electroplating. The pre-treated pins are immersed in tin plating solution for electroplating, and the thickness of the tin plating layer is controlled to be 8μm. Then, the tin-plated pins are immersed in passivation solution and kept at 60℃ for 10 minutes to form a dense protective film. Step 3: Gradient flexible lead cutting. A two-stage gradient forming mold is used. The first-stage pre-forming mold pre-forms the lead with a pressure of 0.3MPa, and the second-stage precision forming mold precision forms the lead with a pressure of 0.5MPa. The forming speed is 4mm / s, which completes the lead cutting and shaping. Step 4: Protective packaging and transportation. The DIP26 products after lead trimming are loaded into a custom anti-static tubing. The inner wall of the tubing has isolation grooves that match the number and spacing of the leads. For products marked as defective, a non-contact removal and replenishment operation is performed using a material handling tool. The material handling tool includes a tubing interface, a product receiving groove, and a flip cover.

[0020] In step one, the alkaline degreasing solution is an aqueous solution of sodium hydroxide with a concentration of 5%, a temperature of 60°C, and a washing time of 5 minutes. The acidic activation solution is an aqueous sulfuric acid solution with a concentration of 10%, a temperature of 40℃, and a cleaning time of 3 minutes. The resistivity of the deionized water is ≥18MΩ·cm. The water is rinsed twice, with each rinse lasting 2 minutes. The constant temperature hot air drying temperature is 50℃, and the drying time is 5 minutes. Nitrogen gas is introduced during the drying process at a flow rate of 10L / min.

[0021] In step two, the tin plating solution is a sulfate-based tin plating solution, which consists of: 30 g / L stannous sulfate, 80 g / L sulfuric acid, 2 mL / L brightener, and 1 mL / L stabilizer. The brightener is polyethyleneimine, and the stabilizer is gelatin; In step two, the current density during electroplating is 1.5 A / dm², the temperature of the electroplating solution is 25℃, and the electroplating time is 10 min; the passivation solution is a chromate passivation solution with a concentration of 5 g / L and a pH value of 3.5.

[0022] In step three, the mold clearance of the first-stage preforming mold is 1.2 times the pin thickness, and the mold cutting edge angle is 30°. The die gap of the second-stage precision forming die is 1.0 times the lead thickness, and the die cutting edge angle is 15°; the switching time between the two dies is 0.5s. During the cutting process, a nitrogen purging device is activated simultaneously, with a nitrogen pressure of 0.2 MPa, to remove metal debris generated during the cutting process.

[0023] The custom antistatic tubing is made of polycarbonate. The depth of the isolation groove is 1 / 3 of the lead length, and the groove width is 1.5 times the lead thickness. The center-to-center distance between adjacent grooves is equal to the lead-to-center distance of the DIP26 package. The inner surface of the antistatic tubing is treated with antistatic agents, and its surface resistivity is 10 Ω·cm. 6 Ω / sq.

[0024] The main frame of the material feeding pipe is a cuboid structure, and the material pipe interface is located at the top of the main frame. The difference between its inner diameter and the outer diameter of the anti-static material pipe is 0.1mm. The product receiving groove is located inside the main frame. A buffer pad is fixed at the bottom of the receiving groove. The buffer pad is made of silicone rubber with a Shore A hardness of 30. The flip cover is connected to the side of the main frame via a hinge. The flip cover opens at a 90° angle and has a latch that engages with the main frame.

[0025] The non-contact removal procedure for the material discharge control fixture is as follows: Insert the antistatic tubing containing the DIP26 product into the tubing interface with the open end facing down, and let the product slide from the tubing into the product receiving groove by gravity. Remove the empty material tube, open the flip cover, and use anti-static tweezers to pick up the plastic seal of the product and take it out. Close the flip cover, reinsert the empty material tube into the material tube interface, and flip the material tube tool so that the product slides back from the receiving groove into the material tube by gravity to complete the removal operation. The replenishment operation steps are as follows: Place the product to be replenished into the receiving groove through the flip cover, then insert the open end of the material pipe containing part of the product upward into the material pipe interface, and flip the material pipe tool to make the product slide into the material pipe.

[0026] In step four, the antistatic tubing filled with DIP26 products is placed into an antistatic aluminum foil bag for sealing. The antistatic aluminum foil bag consists of a polyethylene film layer, a nylon reinforcement layer, and an aluminum foil layer from the inside out. Nitrogen gas is filled into the bag during packaging. The nitrogen purity is ≥99.99%, and the oxygen concentration in the bag after filling is ≤0.5%.

[0027] In step three, the mold material of the secondary gradient forming mold is cemented carbide steel, and the surface roughness of the mold working surface Ra≤0.2μm; after the rib cutting is completed, products with cracks or deformation at the root of the pin are marked as defective.

[0028] Example 2: A method for manufacturing a DIP26 packaged product that avoids pin damage and contact contamination, comprising the following steps: Step 1: Pre-treatment. The DIP26 semi-finished product pins that have been plastic-encapsulated and cured are immersed in alkaline degreasing solution and acidic activation solution in sequence for degreasing, deoxidation and activation cleaning, then rinsed with deionized water and dried with constant temperature hot air. Step 2: Passivation and protective electroplating. The pre-treated pins are immersed in tin plating solution for electroplating, and the thickness of the tin plating layer is controlled to be 10μm. Then, the tin-plated pins are immersed in passivation solution and kept at 70℃ for 15 minutes to form a dense protective film. Step 3: Gradient flexible lead cutting. A two-stage gradient forming mold is used. The first-stage pre-forming mold pre-forms the lead with a pressure of 0.3MPa, and the second-stage precision forming mold precision forms the lead with a pressure of 0.5MPa. The forming speed is 5mm / s, which completes the lead cutting and shaping. Step 4: Protective packaging and transportation. The DIP26 products after lead trimming are loaded into a custom anti-static tubing. The inner wall of the tubing has isolation grooves that match the number and spacing of the leads. For products marked as defective, a non-contact removal and replenishment operation is performed using a material handling tool. The material handling tool includes a tubing interface, a product receiving groove, and a flip cover.

[0029] In step one, the alkaline degreasing solution is an aqueous solution of sodium hydroxide with a concentration of 7%, a temperature of 75°C, and a washing time of 7 minutes. The acidic activation solution is an aqueous sulfuric acid solution with a concentration of 12%, a temperature of 50℃, and a cleaning time of 4 minutes. The resistivity of the deionized water is ≥18MΩ·cm. The water is rinsed 3 times, with each rinse lasting 3 minutes. The constant temperature hot air drying temperature is 65℃, and the drying time is 7 minutes. Nitrogen gas is introduced during the drying process at a flow rate of 20L / min.

[0030] In step two, the tin plating solution is a sulfate-based tin plating solution, which consists of: 40 g / L stannous sulfate, 100 g / L sulfuric acid, 3 mL / L brightener, and 2 mL / L stabilizer. The brightener is polyethylene glycol, and the stabilizer is gum arabic; In step two, the current density during electroplating is 2.2 A / dm², the temperature of the electroplating solution is 30℃, and the electroplating time is 15 min; the passivation solution is a chromium-free passivation solution with a concentration of 10 g / L and a pH value of 4.2.

[0031] In step three, the mold gap of the first-stage preforming mold is 1.3 times the pin thickness, and the mold cutting edge angle is 37°. The die gap of the second-stage precision forming die is 1.05 times the lead thickness, and the die cutting edge angle is 20°; the switching time between the two dies is 1.0s. During the cutting process, a nitrogen purging device is activated simultaneously, with a nitrogen pressure of 0.3 MPa, to remove metal debris generated during the cutting process.

[0032] The custom antistatic tubing is made of acrylonitrile-butadiene-styrene copolymer. The depth of the isolation groove is 5 / 12 of the lead length, and the groove width is 1.7 times the lead thickness. The center-to-center distance between adjacent grooves is equal to the lead-to-center distance of the DIP26 package. The inner surface of the antistatic tubing is treated with antistatic agents, and its surface resistivity is 10 Ω·cm. 7.5 Ω / sq.

[0033] The main frame of the material feeding pipe is a cuboid structure, and the material pipe interface is located at the top of the main frame. The difference between its inner diameter and the outer diameter of the anti-static material pipe is 0.2mm. The product receiving groove is located inside the main frame. A buffer pad is fixed at the bottom of the receiving groove. The buffer pad is made of polyurethane and has a hardness of Shore A40. The flip cover is connected to the side of the main frame via a hinge. The flip cover opens at an angle of 105° and has a latch that engages with the main frame.

[0034] The non-contact removal procedure for the material discharge control fixture is as follows: Insert the antistatic tubing containing the DIP26 product into the tubing interface with the open end facing down, and let the product slide from the tubing into the product receiving groove by gravity. Remove the empty material tube, open the flip cover, and use anti-static tweezers to pick up the plastic seal of the product and take it out. Close the flip cover, reinsert the empty material tube into the material tube interface, and flip the material tube tool so that the product slides back from the receiving groove into the material tube by gravity to complete the removal operation. The replenishment operation steps are as follows: Place the product to be replenished into the receiving groove through the flip cover, then insert the open end of the material pipe containing part of the product upward into the material pipe interface, and flip the material pipe tool to make the product slide into the material pipe.

[0035] In step four, the antistatic tubing filled with DIP26 products is placed into an antistatic aluminum foil bag for sealing. The antistatic aluminum foil bag consists of a polyethylene film layer, a nylon reinforcement layer, and an aluminum foil layer from the inside out. Nitrogen gas is filled into the bag during packaging. The nitrogen purity is ≥99.99%, and the oxygen concentration in the bag after filling is ≤0.5%.

[0036] In step three, the mold material of the secondary gradient forming mold is cemented carbide steel, and the surface roughness of the mold working surface Ra≤0.2μm; after the rib cutting is completed, products with cracks or deformation at the root of the pin are marked as defective.

[0037] Example 3: A method for manufacturing a DIP26 packaged product that avoids pin damage and contact contamination, comprising the following steps: Step 1: Pre-treatment. The DIP26 semi-finished product pins that have been plastic-encapsulated and cured are immersed in alkaline degreasing solution and acidic activation solution in sequence for degreasing, deoxidation and activation cleaning, then rinsed with deionized water and dried with constant temperature hot air. Step 2: Passivation and protective electroplating. The pre-treated pins are immersed in tin plating solution for electroplating, and the thickness of the tin plating layer is controlled to be 12μm. Then, the tin-plated pins are immersed in passivation solution and kept at 80℃ for 20 minutes to form a dense protective film. Step 3: Gradient flexible lead cutting. A two-stage gradient forming mold is used. The first-stage pre-forming mold pre-forms the lead with a pressure of 0.3MPa, and the second-stage precision forming mold precision forms the lead with a pressure of 0.5MPa. The forming speed is 6mm / s, which completes the lead cutting and shaping. Step 4: Protective packaging and transportation. The DIP26 products after lead trimming are loaded into a custom anti-static tubing. The inner wall of the tubing has isolation grooves that match the number and spacing of the leads. For products marked as defective, a non-contact removal and replenishment operation is performed using a material handling tool. The material handling tool includes a tubing interface, a product receiving groove, and a flip cover.

[0038] In step one, the alkaline degreasing solution is an aqueous solution of sodium hydroxide with a concentration of 10%, a temperature of 80°C, and a cleaning time of 10 minutes. The acidic activation solution is an aqueous sulfuric acid solution with a concentration of 15%, a temperature of 60℃, and a cleaning time of 5 minutes. The resistivity of the deionized water is ≥18MΩ·cm. The water is rinsed 3 times, with each rinse lasting 5 minutes. The constant temperature hot air drying temperature is 80℃, and the drying time is 10 minutes. Nitrogen gas is introduced during the drying process at a flow rate of 30L / min.

[0039] In step two, the tin plating solution is a sulfate-based tin plating solution, which consists of: 50 g / L stannous sulfate, 120 g / L sulfuric acid, 5 mL / L brightener, and 3 mL / L stabilizer. The brightener is polyethyleneimine, and the stabilizer is gelatin; In step two, the current density during electroplating is 3.0 A / dm², the temperature of the electroplating solution is 35℃, and the electroplating time is 20 min; the passivation solution is a chromate passivation solution with a concentration of 15 g / L and a pH value of 5.0.

[0040] In step three, the mold gap of the first-stage preforming mold is 1.5 times the pin thickness, and the mold cutting edge angle is 45°. The die clearance of the second-stage precision forming die is 1.1 times the lead thickness, and the die cutting edge angle is 25°; the switching time between the two dies is 1.5s. During the cutting process, a nitrogen purging device is activated simultaneously, with a nitrogen pressure of 0.4 MPa, to remove metal debris generated during the cutting process.

[0041] The custom antistatic tubing is made of polycarbonate. The depth of the isolation groove is half the lead length, and the groove width is 2.0 times the lead thickness. The center-to-center distance between adjacent grooves is equal to the lead-to-center distance of the DIP26 package. The inner surface of the antistatic tubing is treated with antistatic agents, and its surface resistivity is 10 Ω·cm. 9 Ω / sq.

[0042] The main frame of the material feeding device is a cuboid structure, and the material tube interface is located at the top of the main frame. The difference between its inner diameter and the outer diameter of the anti-static material tube is 0.3mm. The product receiving groove is located inside the main frame. A buffer pad is fixed at the bottom of the receiving groove. The buffer pad is made of silicone rubber with a Shore A50 hardness. The flip cover is connected to the side of the main frame via a hinge. The flip cover opens at a 120° angle and has a latch that engages with the main frame.

[0043] The non-contact removal procedure for the material discharge control fixture is as follows: Insert the antistatic tubing containing the DIP26 product into the tubing interface with the open end facing down, and let the product slide from the tubing into the product receiving groove by gravity. Remove the empty material tube, open the flip cover, and use anti-static tweezers to pick up the plastic seal of the product and take it out. Close the flip cover, reinsert the empty material tube into the material tube interface, and flip the material tube tool so that the product slides back from the receiving groove into the material tube by gravity to complete the removal operation. The replenishment operation steps are as follows: Place the product to be replenished into the receiving groove through the flip cover, then insert the open end of the material pipe containing part of the product upward into the material pipe interface, and flip the material pipe tool to make the product slide into the material pipe.

[0044] In step four, the antistatic tubing filled with DIP26 products is placed into an antistatic aluminum foil bag for sealing. The antistatic aluminum foil bag consists of a polyethylene film layer, a nylon reinforcement layer, and an aluminum foil layer from the inside out. Nitrogen gas is filled into the bag during packaging. The nitrogen purity is ≥99.99%, and the oxygen concentration in the bag after filling is ≤0.5%.

[0045] In step three, the mold material of the secondary gradient forming mold is cemented carbide steel, and the surface roughness of the mold working surface Ra≤0.2μm; after the rib cutting is completed, products with cracks or deformation at the root of the pin are marked as defective.

[0046] Comparative Example 1: The difference between this comparative example and Example 1 is that this comparative example did not perform passivation protection treatment in step two. That is, after the pins were tin-plated, it directly entered step three for lead cutting and did not form a dense protective film by heat preservation in the passivation solution.

[0047] Comparative Example 2 differs from Example 1 in that: in step three, this comparative example uses a single-stage bead cutting mold to complete the pin cutting and shaping in one go with a pressure of 0.5 MPa, instead of using a two-stage gradient flexible forming mold.

[0048] Comparative Example 3 differs from Example 1 in that: in step four, this comparative example uses a common antistatic tubing without isolation grooves for product loading and transfer, instead of a customized antistatic tubing.

[0049] Comparative Example 4 differs from Example 1 in that the acidic activation solution cleaning step is omitted in step one of this comparative example. That is, after degreasing with alkaline degreasing solution, the sample is directly rinsed with deionized water and dried without activation treatment.

[0050] The DIP26 packaged products prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests. The test items and test methods are as follows: For the pin bending strength test, a force perpendicular to the pin plane is applied to the pin using a push-pull force gauge until the pin undergoes plastic deformation and breaks. The maximum push force value is recorded. The sample size for each test group is 20 pins, and the average value is taken. For the solderability test of the pins, immerse the pins in a lead-free solder bath at a temperature of 245±5℃ for 5±0.5 seconds. After removing the pins, observe the percentage of wetted area on the pin surface with a magnifying glass. A wetted area of ​​≥95% is considered acceptable. For contact resistance testing, the resistance value of the contact point between the pin and the test socket is measured using the four-probe method. The test current is 100mA, and the sample size is 20 per group. The average value is taken. For the salt spray corrosion test, the sample is placed in a neutral salt spray test chamber with a sodium chloride solution concentration of 5%, a pH value of 6.8, and a chamber temperature of 35°C. After continuous spraying for 48 hours, the sample is removed and the percentage of corrosion area on the pin surface is checked.

[0051] The test data of the DIP26 packaged products prepared in Examples 1-3 and Comparative Examples 1-4 are recorded in Table 1 below: Table 1 - Performance test data for DIP26 packaged products to avoid pin damage and contact contamination.

[0052] By comparing and analyzing the data in Table 1, it can be seen that the DIP26 packaged products prepared using the processes in Examples 1-3 exhibit superior performance in all aspects compared to the products prepared using the processes in Comparative Examples 1-4. This indicates that the present invention, through sequentially using alkaline degreasing solution and acidic activating solution for degreasing, deoxidation, and activation cleaning, followed by rinsing with deionized water and drying with constant-temperature hot air, ensures the cleanliness and activation of the pin surface. Subsequently, the pre-treated pins are immersed in tin plating solution for electroplating, and then the tin-plated pins are immersed in passivation solution for heat preservation to form a dense protective film, improving the corrosion resistance and solderability of the pins, reducing contact resistance, and preventing performance degradation due to surface contamination. By employing a two-stage gradient forming mold, the first stage pre-forming mold... The first stage pre-forms the leads, followed by precision forming using a second-stage precision forming mold. The forming speed is controlled, and the mold gap and cutting edge angle are adjusted to achieve a smooth transition between lead cutting and shaping, preventing cracks and deformation at the lead root, improving lead bending strength, and ensuring lead forming accuracy. The DIP26 products, after lead trimming, are placed into a custom-designed anti-static tubing with isolation grooves on the inner wall matching the number and spacing of the leads, thus isolating and protecting the leads. For products marked as defective, a non-contact removal and replenishment operation is performed using a material handling system including a tubing interface, product receiving groove, and flip-top, avoiding direct human contact with the leads and preventing damage or contamination, ensuring the integrity and cleanliness of the products during transport and sorting.

[0053] By comparing and analyzing the relevant data in Table 1, it can be seen that the DIP26 packaged product prepared by the method of the present invention has high pin strength, excellent solderability, low and stable contact resistance, and excellent corrosion resistance.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a DIP26 packaged product that avoids pin damage and contact contamination, characterized in that: Includes the following steps: Step 1: Pre-treatment. The DIP26 semi-finished product pins that have been plastic-encapsulated and cured are immersed in alkaline degreasing solution and acidic activation solution in sequence for degreasing, deoxidation and activation cleaning, then rinsed with deionized water and dried with constant temperature hot air. Step 2: Passivation and protective electroplating. The pre-treated pins are immersed in tin plating solution for electroplating, and the thickness of the tin plating layer is controlled to be 8-12μm. Then, the tin-plated pins are immersed in passivation solution and kept at 60-80℃ for 10-20 minutes to form a dense protective film. Step 3: Gradient flexible lead cutting. A two-stage gradient forming mold is used. The first-stage pre-forming mold pre-forms the lead with a pressure of 0.3MPa, and the second-stage precision forming mold precision forms the lead with a pressure of 0.5MPa. The forming speed is 4-6mm / s, which completes the lead cutting and shaping. Step 4: Protective packaging and transportation. The DIP26 products after the pins have been cut are loaded into a custom anti-static tubing. The inner wall of the tubing has isolation grooves that match the number and spacing of the pins. For products marked as defective, a non-contact removal and replenishment operation is performed using a material pouring tool. The material pouring tool includes a tubing interface, a product receiving groove, and a flip cover.

2. The method for manufacturing a DIP26 packaged product to avoid pin damage and contact contamination according to claim 1, characterized in that: In step one, the alkaline degreasing solution is an aqueous solution of sodium hydroxide with a concentration of 5%-10%, a temperature of 60-80℃, and a cleaning time of 5-10 minutes. The acidic activation solution is an aqueous sulfuric acid solution with a concentration of 10%-15%, a temperature of 40-60℃, and a cleaning time of 3-5 minutes. The resistivity of the deionized water is ≥18MΩ·cm. The water is rinsed 2-3 times, with each rinse lasting 2-5 minutes. The constant temperature hot air drying temperature is 50-80℃, and the drying time is 5-10 minutes. Nitrogen gas is introduced during the drying process at a flow rate of 10-30L / min.

3. The method for manufacturing a DIP26 packaged product to avoid pin damage and contact contamination according to claim 1, characterized in that: In step two, the tin plating solution is a sulfate-based tin plating solution, which consists of: 30-50 g / L stannous sulfate, 80-120 g / L sulfuric acid, 2-5 mL / L brightener, and 1-3 mL / L stabilizer. The brightening agent is polyethyleneimine or polyethylene glycol, and the stabilizer is gelatin or gum arabic.

4. The method for manufacturing a DIP26 packaged product to avoid pin damage and contact contamination according to claim 1, characterized in that: In step two, the current density during electroplating is 1.5-3.0 A / dm², the temperature of the electroplating solution is 25-35℃, and the electroplating time is 10-20 min; the passivation solution is a chromate passivation solution or a chromium-free passivation solution, the concentration of the passivation solution is 5-15 g / L, and the pH value of the passivation solution is 3.5-5.

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5. The method for manufacturing a DIP26 packaged product to avoid pin damage and contact contamination according to claim 1, characterized in that: In step three, the mold gap of the first-stage preforming mold is 1.2-1.5 times the thickness of the pin, and the mold cutting edge angle is 30°-45°. The die gap of the second-stage precision forming die is 1.0-1.1 times the lead thickness, and the die cutting edge angle is 15°-25°; the switching time between the two dies is 0.5-1.5s. During the cutting process, a nitrogen purging device is activated simultaneously, with a nitrogen pressure of 0.2-0.4 MPa, to remove metal debris generated during the cutting process.

6. The method for manufacturing a DIP26 packaged product to avoid pin damage and contact contamination according to claim 1, characterized in that: The custom antistatic tubing is made of polycarbonate or acrylonitrile-butadiene-styrene copolymer. The depth of the isolation groove is 1 / 3 to 1 / 2 of the pin length, and the groove width is 1.5 to 2.0 times the pin thickness. The center-to-center distance between adjacent grooves is equal to the pin center-to-center distance of the DIP26 package product. The inner wall surface of the antistatic tubing is treated with antistatic agents, and its surface resistivity is 10 Ω·cm. 6 -10 9 Ω / sq.

7. The method for manufacturing a DIP26 packaged product to avoid pin damage and contact contamination according to claim 1, characterized in that: The main frame of the material feeding tube is a cuboid structure, and the material tube interface is located at the top of the main frame. The difference between its inner diameter and the outer diameter of the anti-static material tube is 0.1-0.3mm. The product receiving groove is located inside the main frame. A buffer pad is fixed at the bottom of the receiving groove. The buffer pad is made of silicone rubber or polyurethane and has a hardness of Shore A 30-50. The flip cover is connected to the side of the main frame via a hinge. The flip cover can open at an angle of 90°-120°. The flip cover has a latch that engages with the main frame.

8. The method for manufacturing a DIP26 packaged product to avoid pin damage and contact contamination according to claim 1, characterized in that: The contactless removal procedure for the material discharge control tool is as follows: Insert the antistatic tubing containing the DIP26 product into the tubing interface with the open end facing down, and let the product slide from the tubing into the product receiving groove by gravity. Remove the empty material tube, open the flip cover, and use anti-static tweezers to pick up the plastic seal of the product and take it out. Close the flip cover, reinsert the empty material tube into the material tube interface, and flip the material tube tool so that the product slides back from the receiving groove into the material tube by gravity to complete the removal operation. The replenishment operation steps are as follows: the product to be replenished is placed into the receiving groove through the flip cover, then the open end of the material pipe containing part of the product is inserted upward into the material pipe interface, and the material pipe tool is flipped to make the product slide into the material pipe.

9. The method for manufacturing a DIP26 packaged product to avoid pin damage and contact contamination according to claim 1, characterized in that: In step four, the antistatic tubing filled with DIP26 products is placed into an antistatic aluminum foil bag for sealing. The antistatic aluminum foil bag consists of a polyethylene film layer, a nylon reinforcement layer, and an aluminum foil layer from the inside out. Nitrogen gas is filled into the bag during packaging. The nitrogen purity is ≥99.99%, and the oxygen concentration in the bag after filling is ≤0.5%.

10. A method for manufacturing a DIP26 packaged product to avoid pin damage and contact contamination according to claim 1, characterized in that: In step three, the mold material of the secondary gradient forming mold is cemented carbide steel, and the surface roughness of the mold working surface Ra≤0.2μm; after the rib cutting is completed, products with cracks or deformation at the root of the pin are marked as defective.

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