A method for manufacturing an axial diode and a carrier thereof

Abstract

A method for manufacturing an axial diode and its carrier, belonging to the technical field of axial diode structure and manufacturing method, including the following steps: S1: the first punching, punching to form two frames and a plurality of independent bridges; the first pin and the second pin are respectively formed on the opposite sides of the two frames, and the front ends of the first pin and the second pin are formed with a support plate; the two ends of the bridge are formed with a pressing plate; S2: placing a chip on the top surface of the support plate; S3: using the pressing plates at both ends of the bridge to press on the chips on the top surfaces of the two support plates respectively; S4: sending the metal sheet into a sintering furnace for sintering treatment; S5: plastic sealing on the outside of the pressing plate and the support plate to form a plastic sealing body; S6: the second punching, cutting off the connection between the first pin and the second pin and the frame and the middle position of the bridge to form a separate axial diode. This scheme reduces the manufacturing process of the axial diode, reduces the degree of dependence on manual labor, and effectively improves production efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of axial diode structure design and manufacturing method, and in particular relates to an axial diode manufacturing method and a carrier thereof. Background Art

[0002] Diodes come in three main types: SMD, bridge, and axial. SMD diodes typically operate at lower currents than bridge and axial diodes, and their size is also much smaller. Bridge diodes are typically rectifier diodes integrated into a bridge rectifier circuit. These components are typically power components, with relatively high currents, so they are also relatively larger. Axial diodes, also known as axial diodes, have electrodes generally extending along the axial direction. Their mounting structure and application conditions differ from those of SMD and bridge diodes. Therefore, the three types of diodes differ in both internal and external pin structures, leading to significant differences in their manufacturing processes.

[0003] The axial diode consists of two coaxial leads, with pads formed at opposite ends by cold heading. A chip is soldered between the two pads. The traditional axial diode production process primarily involves preparing leads of a predetermined length; cold heading each lead individually to form a vertical pad at the end of the lead; loading the leads into a graphite boat, which is divided into upper and lower molds; applying flux to the pads; manually assembling the chip between the two pads, and soldering lugs between the chip and the pads on either side; then performing die bonding, mold closing, and tunnel furnace sintering. After sintering, the exposed leads and the semi-finished core are arranged one by one in an injection mold for plastic encapsulation, forming a plastic encapsulation body around the chip and pads, thus forming the axial diode. The entire production process is lengthy, involves numerous steps, and is highly dependent on manual labor, resulting in low production efficiency and high costs. Summary of the Invention

[0004] To address the deficiencies in the prior art, the present invention provides a method for manufacturing an axial diode and a carrier thereof, which reduces the process flow, reduces the reliance on manual labor, and effectively improves production efficiency.

[0005] In order to achieve the purpose of the present invention, the following scheme is proposed:

[0006] A method for manufacturing an axial diode comprises the following steps:

[0007] S1: The metal sheet is punched for the first time to form two parallel and spaced-apart frames and a plurality of bridges separated from the metal sheet; first pins and second pins arranged along the same straight line are formed on opposite sides of the two frames, and multiple groups of first pins and second pins are provided along the length direction of the frame, with a spacing groove 16 between each group; opposite ends of the first pins and second pins are bent downward to form a support plate; both ends of the bridge are bent upward to form a pressure plate, and both the pressure plate and the support plate are parallel to the metal sheet; the distance between the support plates on each group of first pins and second pins is the same as the distance between the pressure plates at both ends of the bridge;

[0008] S2: Apply solder paste to the top surface of the support plate, place the chip on top of the solder paste, and apply solder paste to the top surface of the chip;

[0009] S3: Set up the bridge and use the pressure plates at both ends of the bridge to press the chips on the top surfaces of the two support plates respectively;

[0010] S4: sending the metal sheet into the sintering furnace for sintering;

[0011] S5: The cooled metal sheet is placed into a plastic encapsulation mold to form a plastic encapsulation body outside the pressing plate and the supporting plate, wherein the radius of the plastic encapsulation body is smaller than the width of the spacing groove 16;

[0012] S6: performing a second stamping process on the metal sheet to cut off the connection between the first pin and the second pin and the frame and the middle position of the bridge to form a separate axial diode.

[0013] The beneficial effects of the present invention are: this solution uses the same piece of metal sheet to form the first pin, the second pin and the support plate as a whole, reducing the process flow of manual arrangement, and conveniently using automated equipment to achieve automatic core bonding and gluing, which helps to further improve production efficiency; while the metal sheet forms the pin, it uses the remaining material to manufacture the bridge frame and form the pressure plate at the same time, which can effectively save raw materials and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present invention.

[0015] Figure 1 A process flow chart showing an axial diode manufacturing method.

[0016] Figure 2 It shows a schematic diagram of the structure of the metal sheet after the first stamping.

[0017] Figure 3 It shows a schematic diagram of the structure of the metal sheet after the bridge is erected.

[0018] Figure 4 It shows a schematic structural diagram of the metal sheet after the pressure plate, support plate and chip connection part are plastic-sealed.

[0019] Figure 5 A preferred arrangement of the frame on the metal sheet is shown.

[0020] Figure 6 A schematic diagram of the packaging structure of the axial diode manufactured by this solution is shown.

[0021] Figure 7 The schematic diagram of the structure of the axial diode manufactured by this scheme is shown.

[0022] Markings in the figure: frame-11, first pin-12, second pin-13, support plate-123, middle residual material-14, plastic package-15, spacing groove-16, strip piece-2, bridge-21, pressure plate-22, edge residual material-23, chip-3. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the embodiments described in the present invention are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] Example 1, as Figure 1 As shown, a method for manufacturing an axial diode includes the following steps:

[0025] S1: The metal sheet is punched for the first time, e.g. Figure 2 、 Figure 3 As shown, two parallel and spaced frames 11 are formed by stamping, and a first pin 12, a second pin 13, and a middle residual material 14 of the same width are formed vertically between the two frames 11. One end of the first pin 12 and the second pin 13 is respectively connected to one of the frames 11, and the other end of the first pin 12 and the second pin 13 is disconnected from the middle residual material 14. The middle residual material 14 is removed during the stamping process, thereby forming a gap between the first pin 12 and the second pin 13. The first pin 12, the second pin 13, and the middle residual material 14 are arranged in an array along the length of the frame 11. A bridge 21 separated from the metal sheet is formed between adjacent first pins 12, second pins 13, and middle residual material 14. After the bridge 21 is separated from the metal sheet and the middle residual material 14 is removed, a spacing groove 16 is formed between adjacent first pins 12 and second pins 13. In order to facilitate the transfer and use of the bridge 21 , the bridge 21 can be collected separately after being stamped and separated, and then laid in a tray with a groove matching the shape of the bridge 21 .

[0026] During the first stamping process, support plates 123 are bent downward at the opposing ends of the first and second pins 12, 13, toward the metal sheet. Pressure plates 22 are also bent upward at both ends of the bridge 21, parallel to the metal sheet. The distance between the support plates 123 on the paired first and second pins 12, 13 is equal to the distance between the pressure plates 22 at both ends of the bridge 21. When the bridge 21 is placed in the recess on the tray, the pressure plates 22 face downward.

[0027] S2: Apply solder paste to the top surface of the support plate 123, place the chip 3 on top of the solder paste, and apply solder paste to the top surface of the chip 3. Because the first pin 12 and the second pin 13 are both formed on the metal sheet of the entire structure, it is convenient to realize automated production and avoid the manual material arrangement link. Therefore, both the application of solder paste and the installation of the chip 3 can be achieved by automated equipment. For example, the automatic gluing work can be completed by referring to the equipment similar to the principle of the utility model patent application number CN202021318806.2, and the core bonding work can be automatically completed by referring to the equipment similar to the principle of the invention patent application number CN202410240249.3, so as to further improve production efficiency.

[0028] S3: Set up the bridge frame 21, use the negative pressure suction pipe to suck the bridge frame 21 in the tray, and then transfer the bridge frame 21 to the metal sheet through a mechanical arm or an automatic transfer device, such as Figure 3 As shown, the pressing plates 22 at both ends of the bridge 21 are used to press the chips 3 on the top surfaces of the two support plates 123 respectively.

[0029] S4: The metal sheet is sent to a sintering furnace for sintering, and all the chips 3 are solidified at the same time, which is more efficient.

[0030] S5: Put the cooled metal sheet into the plastic packaging mold, such as Figure 4 、 Figure 6 As shown, a plastic encapsulation body 15 is formed outside the pressing plate 22 and the support plate 123. The radius of the plastic encapsulation body 15 is smaller than the width of the spacing groove 16. Because the plastic encapsulation body 15 covers the outside of the pressing plate 22 and the support plate 123, the diameter of the plastic encapsulation body 15 is necessarily larger than the width of the support plate 123 and the pressing plate 22.

[0031] S51: Tin plating. After the metal sheet cools, the first pin 12, the second pin 13, and the bridge 21 exposed outside the plastic package 15 are electroplated. The traditional axial diode manufacturing process produces a single independent axial diode. The axial diode is in a bulk state and can only be electroplated by barrel plating. The electroplating process easily causes the pins to bend and deform. Therefore, the pins need to be manually straightened after electroplating before testing. However, this solution can perform tin plating on the entire board, which can effectively prevent pin deformation and reduce the manual straightening process.

[0032] S6: The metal sheet is punched for the second time to cut off the connection between the first pin 12 and the second pin 13 and the frame 11 and the middle position of the bridge 21 to form a Figure 6 、 Figure 7 The individual axial diodes shown. In the axial diodes formed in this way, the pins at both ends of the plastic package 15 must be on the same straight line; after being cut, the same bridge 21 will form two independent axial diodes with the first pin 12 and the second pin 13 at both ends. The first pin 12 and the second pin 13 are respectively located on two independent axial diodes, and the other pin of the axial diode is formed by the bridge 21. There are multiple groups of first pins 12 and second pins 13 arranged in an array on the same metal sheet, so multiple axial diodes can be manufactured simultaneously in one stamping. Not only that, the first pin 12, the second pin 13, the support plate 123, the bridge 21 and the pressure plate 22 are all formed simultaneously by the first stamping, which greatly improves the manufacturing efficiency and shortens the process flow.

[0033] Because the plastic package 15 needs to occupy the space on both sides of the first pin 12 and the second pin 13, and the first pin 12 and the second pin 13 are arranged in an array in multiple groups along the length of the frame 11, the space occupied by the plastic package 15 between adjacent pins will be doubled. Therefore, a strip-shaped spacing groove 16 is provided between the pins to make sufficient space for the plastic package 15. However, forming the spacing groove 16 in this way will waste a lot of material, resulting in a waste of raw materials.

[0034] As an initial solution, the first pin 12 and the second pin 13 arranged in the same group only form an axial diode. This solution installs the chip 3 on the top surface of the end of the first pin 12, and then uses a separately formed connecting piece to press one end on the chip 3, and the other end is connected to the second pin 13. However, this solution will also have a spacing groove 16, and there will inevitably be a waste of raw materials. Based on the same waste of raw materials, this solution first removes part of the material between the first pin 12 and the second pin 13, and the removed material forms the middle residual material 14. Since the opposite ends of the first pin 12 and the second pin 13 are both formed with support plates 123 by bending, the distance between the two support plates 123 must be greater than the length of the middle residual material 14.

[0035] In this solution, the length of the bridge 21 generated when the spacing groove 16 is formed can meet the length requirement of covering the two support plates 123. In this way, the two ends of the bridge 21 are combined with the first pin 12 and the second pin 13 to form an axial diode. In this way, the output of the axial diode can be doubled on the basis of the original waste of materials, which not only improves production efficiency, but also increases output and reduces production costs.

[0036] Preferably, Figure 2 As shown, during the first stamping process, a strip piece 2 is formed between the adjacent first pin 12, the second pin 13 and the middle residual material 14. After the strip piece 2 is separated from the metal sheet, a spacing groove 16 is formed. The two ends of the strip piece 2 are cut to form edge residual materials 23, and the middle part of the strip piece 2 forms a bridge 21. During the specific stamping, the strip piece 2 is first separated from the metal sheet to form a spacing groove 16 with neat incisions. The edge residual materials 23 at both ends are removed in the process of continuing to close the stamping die, and then pressure plates 22 are formed at both ends of the bridge 21.

[0037] As a further preferred solution, the strip sheet 2 and the middle residual material 14 are separated from the metal sheet at the same time, so as to unify the shearing surface of the mold and simplify the mold structure.

[0038] Preferably, Figure 5 As shown, the frame 11 is provided with a plurality of arrays along the length direction of the metal sheet, and the two sides of the metal sheet have connecting ribs for connecting the two ends of the frame 11; or adopting Figures 2 to 4 In the solution shown, the frame 11 is formed on both sides of the metal sheet in the width direction.

[0039] Example 2, as Figure 3 As shown, an axial diode carrier is manufactured using the axial diode manufacturing method described in Example 1. The carrier includes a frame 11, a first pin 12, a second pin 13, a bridge 21, etc.

[0040] A pair of frames 11 are provided in parallel; the rear end of the first pin 12 is vertically connected to one of the frames 11; the rear end of the second pin 13 is vertically connected to the other frame 11; the first pin 12 and the second pin 13 are in the same plane and are arranged along the same straight line, and the front ends of the first pin 12 and the second pin 13 both have a support plate 123, and the front end support plates 123 of the first pin 12 and the second pin 13 are arranged opposite to each other, and multiple groups of first pins 12 and second pins 13 are arranged at intervals along the length direction of the frame 11.

[0041] The number of bridges 21 is consistent with the number of groups of first pins 12 and second pins 13, and pressure plates 22 are provided at both ends of the bridge 21;

[0042] Chips 3 are provided on the same side of the support plate 123, and the pressure plates 22 at both ends of the bridge 21 are respectively pressed against the top surfaces of the chips 3 on the two oppositely arranged support plates 123, and the bridge 21 and the first pin 12 and the second pin 13 are in the same plane; the chip 3 is connected to the pressure plate 22 and the support plate 123 by welding.

[0043] Preferably, the width of the bridge 21 is the same as the width of the first pin 12 and the second pin 13 .

[0044] The above description is only a preferred embodiment of the present invention and is not intended to be the only one or to limit the present invention. It should be understood by those skilled in the art that various changes or equivalent replacements made to the present invention without departing from the scope of the present invention are within the scope of protection of the present invention.

Claims

1. A method for manufacturing an axial diode, characterized in that: The following steps are involved: S1: The metal sheet is punched for the first time to form two mutually parallel and spaced frames (11) and a plurality of bridges (21) separated from the metal sheet; first pins (12) and second pins (13) arranged along the same straight line are formed on opposite sides of the two frames (11), and a plurality of groups of the first pins (12) and the second pins (13) are arranged along the length direction of the frame (11), and a spacing groove (16) is provided between each group; the opposite ends of the first pins (12) and the second pins (13) are bent toward the bottom of the metal sheet to form a support plate (123); the two ends of the bridge (21) are bent toward the top of the metal sheet to form a pressure plate (22), and the pressure plate (22) and the support plate (123) are parallel to the metal sheet; the distance between the support plates (123) on each group of the first pins (12) and the second pins (13) is the same as the distance between the pressure plates (22) at both ends of the bridge (21); S2: applying solder paste to the top surface of the support plate (123), placing the chip (3) on the solder paste, and applying solder paste to the top surface of the chip (3); S3: erecting a bridge frame (21), and using the pressing plates (22) at both ends of the bridge frame (21) to press the chips (3) on the top surfaces of the two support plates (123) respectively; S4: sending the metal sheet into a sintering furnace for sintering; S5: loading the cooled metal sheet into a plastic encapsulation mold to form a plastic encapsulation body (15) outside the pressing plate (22) and the supporting plate (123), wherein the radius of the plastic encapsulation body (15) is smaller than the width of the spacing groove (16); S6: performing a second stamping process on the metal sheet to cut off the connection between the first pin (12) and the second pin (13) and the frame (11) and the middle position of the bridge (21), so as to form a separate axial diode.

2. The method for manufacturing an axial diode according to claim 1, characterized in that: During the first stamping process, a strip sheet (2) is formed between adjacent first pins (12) and second pins (13), the strip sheet (2) is separated from the metal sheet to form a spacing groove (16), both ends of the strip sheet (2) are cut off to form edge surplus (23), and the middle of the strip sheet (2) forms a bridge frame (21).

3. The method for manufacturing an axial diode according to claim 1, characterized in that: The first pin (12) and the second pin (13) are arranged in a vertical direction on opposite sides of the two frames (11); during the first punching, a middle residual material (14) is formed between the first pin (12) and the second pin (13); the first pin (12) and the second pin (13) are disconnected from the middle residual material (14), thereby forming a gap between the first pin (12) and the second pin (13).

4. The method for manufacturing an axial diode according to claim 1, characterized in that: Step S5 also includes step S51 of tinning, wherein after the metal sheet is cooled, the first pin (12), the second pin (13) and the bridge (21) exposed outside the plastic package (15) are tinned.

5. The method for manufacturing an axial diode according to claim 1, characterized in that: A plurality of frames (11) are arranged in an array along the length direction of the metal sheet, and connecting ribs are provided on both sides of the metal sheet for connecting the two ends of the frame (11); or the frame (11) is formed on both sides of the metal sheet in the width direction.

6. An axial diode carrier, characterized in that: The axial diode carrier is manufactured by the axial diode manufacturing method according to any one of claims 1 to 5, and comprises: A pair of frames (11) are provided in parallel; A first pin (12), a rear end of which is vertically connected to one of the frames (11); The second pin (13) has a rear end vertically connected to another frame (11); the first pin (12) and the second pin (13) are located in the same plane and arranged along the same straight line, the front ends of the first pin (12) and the second pin (13) both have a support plate (123), the front end support plates (123) of the first pin (12) and the second pin (13) are arranged opposite to each other, and a plurality of groups of the first pin (12) and the second pin (13) are arranged at intervals along the length direction of the frame (11); The number of bridge frames (21) is the same as the number of groups of first pins (12) and second pins (13), and the two ends of the bridge frame (21) have pressure plates (22); The chips (3) are arranged on the same side of the support plates (123); the pressure plates (22) at both ends of the bridge frame (21) are respectively pressed against the top surfaces of the chips (3) on the two support plates (123) arranged opposite to each other; and the bridge frame (21) and the first pin (12) and the second pin (13) are located in the same plane; the chip (3) is connected to the pressure plate (22) and the support plate (123) by welding.

7. An axial diode carrier according to claim 6, characterized in that: The width of the bridge (21) is the same as the width of the first pin (12) and the second pin (13).

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