A high I 2 tStructure and process of high breaking capacity chip current slow-blow fuse

Abstract

The invention discloses a high I 2 tHigh breaking capacity chip current slow blow fuse structure and process, this kind of high I 2 The structure and process of the high breaking capacity chip current slow-blow fuse include a left terminal, a right terminal, a tube body, a melt element, a left solder, a right solder, a left arc-extinguishing glue, a right arc-extinguishing glue and a traction wire. The left terminal and the right terminal are installed at both ends of the tube body. The left solder and the right solder are installed in the grooves relative to the left terminal and the right terminal respectively. The traction wire is inserted on the left solder and the right solder. The melt element is wound on the traction wire. The melt element is also installed with the left arc-extinguishing glue and the right arc-extinguishing glue. Through the above method, the present invention meets the market demand for chip fuses with high breaking capacity and high I 2 The small size requirement can make the product yield stable at more than 97% and the cycle time more than 40pcs / min, which greatly reduces the cost and speeds up the process.

Description

Technical Field

[0001] The present invention relates to the technical field of fuses, and in particular to a high I 2 tStructure and process of high breaking capacity chip current slow-blow fuse. Background Art

[0002] Chip fuses, commonly known as chip fuses, are one-time passive components used to protect circuits. When the current is too large, the inherent resistance of the melt conductor itself hinders the passage of current and causes heat to rise. The heat dissipation is less than the heat generation, and the accumulated temperature rise exceeds its melting point, melting and disconnecting, cutting off the loop current, protecting other components and circuits from dangers such as fire and explosion.

[0003] Chip fuses are relatively small in size, but have high performance requirements. Before they are introduced to the market, they must be approved by relevant authoritative organizations: such as the United States UL, Germany TUV, and China CQC certification. Certification standards include UL248-1 / 14, IEC60127-1 / 4 / 7, and G9364-1 / 4 / 7. To stay ahead in the market, they must have excellent product performance and manufacturability - high production yield and low production cost.

[0004] Traditional SMD FUSE is made of metal film / oxide attached to a ceramic substrate. 2 t and breaking capacity are low. Taking SMD FUSE 1206 rated current In 5A as an example, usually I 2 t in 7A 2 S, the breaking capacity is up to 50A@63VDC, which cannot meet the requirements of most modern electrical appliances: high I 2 Based on the above defects and shortcomings, it is necessary to improve the existing technology and design a high I 2 tStructure and process of high breaking capacity chip current slow-blow fuse. Summary of the invention

[0005] The main technical problem solved by the present invention is to provide a high I 2 tHigh breaking capacity chip current slow-blow fuse structure and process, meet the market demand for chip fuses with high breaking capacity and high I 2 The small size requirement can make the product yield stable at more than 97% and the cycle time more than 40pcs / min, which greatly reduces the cost and speeds up the process.

[0006] In order to solve the above technical problems, a technical solution adopted by the present invention is: to provide a high I 2 tHigh breaking capacity chip current slow blow fuse structure, this kind of high I 2The high breaking capacity chip current slow-blow fuse structure includes a left terminal, a right terminal, a tube body, a melt element, a left solder, a right solder, a left arc-extinguishing glue, a right arc-extinguishing glue and a traction wire. The left terminal and the right terminal are installed at both ends of the tube body. The left solder and the right solder are respectively installed in the relative grooves of the left terminal and the right terminal. The traction wire is inserted on the left solder and the right solder. The melt element is wound on the traction wire. The left arc-extinguishing glue and the right arc-extinguishing glue are also installed on the melt element.

[0007] Preferably, the left terminal and the right terminal are in the shape of a back-convex rectangular groove or a back-convex circular groove.

[0008] Preferably, the left terminal and the right terminal are made of H65 brass (copper-zinc alloy) or aluminum alloy.

[0009] Preferably, the surfaces of the left terminal and the right terminal are tin-plated, nickel-plated, silver-plated or gold-plated, and the thickness of the plating layer is 30nm-200μm.

[0010] Preferably, the tube body has a double-step structure at both ends, and the tube body is made of 95%, 75% or 99% alumina ceramic or 35% zirconia ceramic.

[0011] Preferably, the shape of the melt element is wire-like, flat or narrow, and the material of the melt element is copper, manganese-copper alloy or constantan alloy with tin or silver plated on the surface; silver-copper alloy or copper-clad steel with tin plated on the surface.

[0012] Preferably, the left solder and the right solder are made of 75%-95% high-lead solder wire or tin ribbon, and the flux mass fraction content is 0.5%-2%.

[0013] Preferably, the left arc-extinguishing glue and the right arc-extinguishing glue are silicone or epoxy resin glue, and have a 2mm-4mm spindle-shaped structure that wraps the melt element. The left arc-extinguishing glue and the right arc-extinguishing glue are 2mm-4mm away from the bottom of the left terminal and the bottom of the right terminal respectively.

[0014] Preferably, the traction wire is composed of 2-6 strands of twisted wire or straight wire, usually with a diameter of 0.2mm-1.2mm, white or gray in color, and is made of a mixture of calcium oxide, magnesium oxide and silicon oxide, and can withstand high temperatures above 700 degrees.

[0015] A high I 2 The manufacturing process of the high breaking capacity chip current slow-blow fuse structure is characterized by comprising the following steps:

[0016] a. Solder processing: The high-temperature solder wire is mechanically cut into a specified length to control the amount of solder used, usually between 12mg-60mg, flattened and inserted into the left and right terminals, and sent to the high-temperature heating area with the vibration plate, so that the solder in the left and right terminals melts and fuses with the terminals to form a good conductor;

[0017] b. Processing and winding. The melt element is mechanically wound on the traction line. The density is adjusted by pitch. Different specifications have different rated currents In and resistance values. The length L of the melt element is adjusted and corrected through experimental design and assembly product testing. The resistance value of the same melt element is controlled by L and density. The wound melt element is coated with arc-extinguishing glue and cut into monomers.

[0018] c. Assembly welding of tube body, terminal and melt element: first combine the welding sequence to weld the left terminal, tube body and melt element vertically, with the left terminal 1 at the bottom and the tube body in the middle. The melt element is fed from top to bottom. The assembly welding equipment applies a certain force to the tube body from top to bottom so that the tube body is inserted into the bottom of the left terminal under high temperature heating, so that the melt element and the solder wire are infiltrated and welded for 0.2s-2s, and then immediately blow air (dry filtered natural wind) to the side wall of the left terminal 1 for 0.1s-1s;

[0019] d. The robot arm holds the tube body and rotates it to leave the high-temperature heating area and align it with the blanking port of the right terminal. The tube body and the right terminal are pre-pressed and combined. The solder in the right terminal is melted by current welding. The current is 50A-300A and the holding time is within 0.05-1S. At the end time, blow air (dry filtered natural wind) to the side wall of the right terminal for 0.1s-1s to complete the assembly.

[0020] e. Cold resistance screening: The mechanical arm clamp transfers the product to the cold resistance test area, and the probe pneumatic valve is activated, so that the probe (four-point probe, the needle is tungsten steel, the diameter is 0.1mm-0.3mm) is in electrical contact with the left terminal and the right terminal, and the resistance value is tested, which is usually 0.1mΩ-700mΩ. The test current input for different resistance values ​​is different. 1mΩ usually tests the output current of 3A, 10mΩ and 100mΩ are 1A, and 1Ω and 10Ω are 100mA test input current. If the gear is selected incorrectly, especially for fuses with a smaller rated current such as less than 2A, the test will burn out and fail;

[0021] f. Re-screening of cold resistors before marking and taping: After the test is completed, according to the program set for the resistor meter, the qualified, large and small cold resistors are dropped into the corresponding bins;

[0022] g. Appearance inspection, marking, and taping packaging: Automatic appearance size screening and marking and taping are then carried out. The coil packaging is completed, the product is transported by a vibrating plate, and then the robot arm grabs the middle tube of the product by suction, moves it to the front of the CCD lens, and the upper and lower sets of lenses are used to compare the size and appearance. If it is qualified, it will continue to be marked. The marking is done by a laser burning the set path pattern on the surface of the tube to form a logo, which is then grabbed by a mechanical gripper and transferred to the carrier tape, covered with a tape, heat-sealed and pressed, and the reel is pulled to complete the packaging.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] Through the above structure and process improvement, it can make up for the 2 t and low breaking energy, it can achieve I 2 t at 230A 2 S, breaking capacity 50A@250VAC, meeting the market demand for SMD fuses with high breaking capacity and high I 2 tSmall size requirement;

[0025] Through the above process, the product yield can be stabilized at more than 97%, and the cycle time can be more than 40pcs / min, which greatly reduces the cost and speeds up the process, and meets the market requirements very well. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A high I 2 tStructural diagram of the high breaking capacity chip current slow-blow fuse structure.

[0027] Figure 2 A high I 2 tThe manufacturing process flow chart of the high breaking capacity chip current slow-blow fuse structure. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0029] See also Figure 1 and Figure 2 , the embodiment of the present invention includes:

[0030] A high I 2 tHigh breaking capacity chip current slow blow fuse structure and process, this kind of high I 2 The high breaking capacity chip current slow-blow fuse structure includes a left terminal 1, a right terminal 2, a tube body 3, a melt element 4, a left solder 5, a right solder 6, a left arc-extinguishing glue 7, a right arc-extinguishing glue 8 and a traction wire 9. The left terminal 1 and the right terminal 2 are installed at both ends of the tube body 3. The left solder 5 and the right solder 6 are respectively installed in the relative grooves of the left terminal 1 and the right terminal 2. The traction wire 9 is inserted on the left solder 5 and the right solder 6. The melt element 4 is wound on the traction wire 9. The melt element 4 is also equipped with a left arc-extinguishing glue 7 and a right arc-extinguishing glue 9.

[0031] The left terminal 1 and the right terminal 2 are in the shape of a back-convex rectangular groove or a back-convex circular groove.

[0032] The left terminal 1 and the right terminal 2 are made of H65 brass (copper-zinc alloy) or aluminum alloy.

[0033] The surfaces of the left terminal 1 and the right terminal 2 are tin-plated, nickel-plated, silver-plated or gold-plated, and the thickness of the coating is 30nm-200μm.

[0034] The tube body 3 has a double-step structure at both ends, and the material of the tube body 3 is 95%, 75% or 99% alumina ceramic or 35% zirconia ceramic.

[0035] The shape of the melt element 4 is wire-like, flat or narrow-diameter, and the material of the melt element 4 is copper, manganese-copper alloy or constantan alloy with tin or silver plated on the surface; silver-copper alloy or copper-clad steel with tin plated on the surface.

[0036] The left solder 5 and the right solder 6 are made of 75%-95% high-lead solder wire or tin ribbon, and the flux mass fraction content is: 0.5%-2%.

[0037] The left arc-extinguishing glue 7 and the right arc-extinguishing glue 8 are made of silicone or epoxy resin glue, and have a 2mm-4mm spindle-shaped structure that wraps the melt element. The left arc-extinguishing glue 7 and the right arc-extinguishing glue 8 are 2mm-4mm away from the bottom of the left terminal 1 and the bottom of the right terminal 2 respectively.

[0038] The traction wire 9 is composed of 2-6 strands of twisted wire or straight wire, usually with a diameter of 0.2mm-1.2mm, white or gray in color, and is made of a mixture of calcium oxide, magnesium oxide and silicon oxide, and can withstand temperatures above 700 degrees.

[0039] A high I 2 The manufacturing process of the high breaking capacity chip current slow-blow fuse structure is characterized by comprising the following steps:

[0040] a. Solder processing: The high-temperature solder wire is mechanically cut into a specified length to control the amount of solder used, usually between 12mg-60mg, flattened and inserted into the left and right terminals, and sent to the high-temperature heating area with the vibration plate, so that the solder in the left and right terminals melts and fuses with the terminals to form a good conductor;

[0041] b. Processing and winding. The melt element is mechanically wound on the traction line. The density is adjusted by pitch. Different specifications have different rated currents In and resistance values. The length L of the melt element is adjusted and corrected through experimental design and assembly product testing. The resistance value of the same melt element is controlled by L and density. The wound melt element is coated with arc-extinguishing glue and cut into monomers.

[0042] c. Assembly welding of tube body, terminal and melt element: first combine the welding sequence to weld the left terminal 1, tube body 3 and melt element 4 vertically, with the left terminal 1 at the bottom and the tube body 3 in the middle. The melt element 4 is fed in from top to bottom. The assembly welding equipment applies a certain force to the tube body 3 from top to bottom so that the tube body is inserted into the bottom of the left terminal 1 in a high-temperature heating state, so that the melt element 4 and the solder wire are infiltrated and welded for 0.2s-2s, and then the side wall of the left terminal 1 is immediately blown (dry filtered natural wind) for 0.1s-1s;

[0043] d. The robot arm holds the tube body 3 and rotates it to leave the high-temperature heating zone and align it with the blanking port of the right terminal 2. The tube body 3 and the right terminal 2 are assembled and pre-pressed and combined. The solder in the right terminal 2 is melted by current welding. The current is 50A-300A and the holding time is within 0.05-1S. At the end time, blow air (dry filtered natural wind) to the side wall of the right terminal 2 for 0.1s-1s to complete the assembly.

[0044] e. Cold resistance screening: The mechanical arm clamp transfers the product to the cold resistance test area, and the probe pneumatic valve is activated, so that the probe (four-point probe, the needle is tungsten steel, the diameter is 0.1mm-0.3mm) is in electrical contact with the left terminal 1 and the right terminal 2, and the resistance value is tested, which is usually 0.1mΩ-700mΩ. The test current input for different resistance values ​​is different. 1mΩ usually tests the output current of 3A, 10mΩ and 100mΩ are 1A, and 1Ω and 10Ω are 100mA test input current. If the gear is selected incorrectly, especially for fuses with a smaller rated current such as less than 2A, the test will burn out and fail;

[0045] f. Re-screening of cold resistors before marking and taping: After the test is completed, according to the program set for the resistor meter, the qualified, large and small cold resistors are dropped into the corresponding bins;

[0046] g. Appearance inspection, marking, and taping packaging: Automatic appearance size screening and marking and taping are then carried out. The coil packaging is completed, the product is transported by a vibrating plate, and then the robot arm grabs the middle tube of the product by suction, moves it to the front of the CCD lens, and the upper and lower sets of lenses are used to compare the size and appearance. If it is qualified, it will continue to be marked. The marking is done by a laser burning the set path pattern on the surface of the tube to form a logo, which is then grabbed by a mechanical gripper and transferred to the carrier tape, covered with a tape, heat-sealed and pressed, and the reel is pulled to complete the packaging.

[0047] The present invention is a high I 2 tHigh breaking capacity chip current slow-blow fuse structure and process, through the above structure and process improvement, make up for its I 2 t and low breaking energy, it can achieve I 2 t at 230A 2S, breaking capacity 50A@250VAC, meeting the market demand for SMD fuses with high breaking capacity and high I 2 The small size requirement can make the product yield stable at more than 97% and the cycle time more than 40pcs / min, which greatly reduces the cost and speeds up the process.

[0048] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A manufacturing process of a high I²t high breaking capacity chip current slow-blow fuse structure, characterized in that: The high I²t high breaking capacity chip current slow-blow fuse structure comprises a left terminal, a right terminal, a tube body, a melt element, a left solder, a right solder, a left arc-extinguishing glue, a right arc-extinguishing glue and a traction wire. The left terminal and the right terminal are installed at both ends of the tube body. The left solder and the right solder are installed in the grooves opposite to each other, respectively. The left solder and the right solder are inserted with a traction wire. The melt element is wound on the traction wire. The melt element is also installed with a left arc-extinguishing glue and a right arc-extinguishing glue. The specific steps of its production process are as follows: Solder processing: The high-temperature solder wire is mechanically cut into a specified length to control the amount of solder used, usually between 12mg-60mg, flattened and inserted into the left and right terminals, and sent to the high-temperature heating area with the vibration plate, so that the solder in the left and right terminals melts and fuses with the terminals to form a good conductor; Processing and winding: the melt element is mechanically wound on the traction line, and the density is adjusted by the pitch. Different specifications have different rated currents In and resistance values. The length L of the melt element is adjusted and corrected through experimental design and assembly product testing. The resistance value of the same melt element is controlled by L and the density. The wound melt element is coated with arc-extinguishing glue and cut into monomers. Assembly welding of tube body, terminal and molten element: first combine the welding sequence to weld the left terminal, tube body and molten element vertically, with the left terminal at the bottom and the tube body in the middle. The molten element is fed from top to bottom. The assembly welding equipment applies a certain force to the tube body from top to bottom so that the tube body is inserted into the bottom of the left terminal under high temperature heating, so that the molten element and the solder wire are infiltrated and welded for 0.2s-2s, and then immediately blow air (dry filtered natural wind) to the side wall of the left terminal for 0.1s-1s; The robot arm holds the tube body and rotates it to leave the high-temperature heating area and align it with the blanking port of the right terminal. The assembled tube body and the right terminal are pre-pressed and combined. The solder in the right terminal is melted by current welding. The current is 50A-300A and the holding time is within 0.05-1S. The end time is to blow air (dry filtered natural wind) to the side wall of the right terminal for 0.1s-1s to complete the assembly. Cold resistance screening: The mechanical arm clamp transfers the product to the cold resistance test area, and the probe pneumatic valve is activated, so that the probe (four-point probe, the needle is tungsten steel, the diameter is 0.1mm-0.3mm) is in electrical contact with the left terminal and the right terminal, and the resistance value is tested, which is usually 0.1mΩ-700mΩ. The test input current of different resistance values ​​is different. The test output current of 1mΩ is 3A, 10mΩ and 100mΩ are 1A, and 1Ω and 10Ω are 100mA test input current; Cold resistance re-screening before marking and taping: After the test is completed, according to the program set for the resistance meter, the qualified, large and small cold resistances are dropped into the corresponding bins respectively; Appearance inspection, marking, and taping packaging: Automatic appearance size screening and marking and taping are then carried out. The coil packaging is completed, the product is transported by a vibrating plate, and then the robot arm grabs the middle tube of the product by suction, moves it to the front of the CCD lens, and the upper and lower sets of lenses are used for size and appearance comparison inspection. If it is qualified, it will continue to be marked. The marking is done by a laser burning the set path pattern on the surface of the tube to form a logo, which is then grabbed by a mechanical gripper and transferred to the carrier tape, covered with a tape, heat-sealed and pressed, and the reel is pulled to complete the packaging.

2. The manufacturing process of a high I²t high breaking capacity chip current slow-blow fuse structure according to claim 1, characterized in that: The left terminal and the right terminal are in the shape of a back-convex rectangular groove or a back-convex circular groove.

3. The manufacturing process of a high I²t high breaking capacity chip current slow-blow fuse structure according to claim 1, characterized in that: The left terminal and the right terminal are made of H65 brass (copper-zinc alloy) or aluminum alloy.

4. The manufacturing process of a high I²t high breaking capacity chip current slow-blow fuse structure according to claim 1, characterized in that: The surfaces of the left terminal and the right terminal are tin-plated, nickel-plated, silver-plated or gold-plated, and the thickness of the plating layer is 30nm-200μm.

5. The manufacturing process of a high I²t high breaking capacity chip current slow-blow fuse structure according to claim 1, characterized in that: The tube body has a double-step structure at both ends, and the tube body is made of 95%, 75% or 99% alumina ceramic or 35% zirconia ceramic.

6. The manufacturing process of a high I²t high breaking capacity chip current slow-blow fuse structure according to claim 1, characterized in that: The shape of the melt element is wire-like, flat or narrow-diameter, and the material of the melt element is copper, manganese-copper alloy or constantan alloy with tin or silver plated on the surface; silver-copper alloy or copper-clad steel with tin plated on the surface.

7. The manufacturing process of a high I²t high breaking capacity chip current slow-blow fuse structure according to claim 1, characterized in that: The left solder and the right solder are made of 75%-95% high-lead solder wire or tin ribbon, and the flux mass fraction content is: 0.5%-2%.

8. The manufacturing process of a high I²t high breaking capacity chip current slow blow fuse structure according to claim 1, characterized in that: The left arc-extinguishing glue and the right arc-extinguishing glue are silicone or epoxy resin glue, and have a 2mm-4mm spindle-shaped structure that wraps the melt element. The left arc-extinguishing glue and the right arc-extinguishing glue are 2mm-4mm away from the bottom of the left terminal and the bottom of the right terminal respectively.

9. The manufacturing process of a high I²t high breaking capacity chip current slow blow fuse structure according to claim 1, characterized in that: The traction wire is composed of 2-6 strands of twisted wires or straight wires, and the diameter is usually 0.2mm-1.2mm. It is made of a mixture of calcium oxide, magnesium oxide and silicon oxide.

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