Ceramic tube shell and manufacturing method thereof

Abstract

The invention provides a ceramic tube shell and a manufacturing method thereof, and belongs to the technical field of electronic device packaging, and the manufacturing method of the ceramic tube shell comprises the following steps: respectively obtaining a pin line and a positioning ring through stamping process molding; carrying out clearance fit on the terminal pin and the positioning ring; in the brazing process, all the terminal pins are correspondingly placed in a fixing plate of a brazing jig, then a sucker is used for slowly placing a porcelain body into the fixing plate, a fixing block is used for limiting the porcelain body, then a bottom plate is buckled, the brazing jig is reversed to enable the pin wires to be located above the porcelain body, an upper cover pressing block is placed above the fixing plate, the pin wires and the porcelain body are pressed tightly, and the pin wires and the porcelain body are pressed tightly. And finally, brazing in a brazing furnace. According to the invention, the operation is carried out twice through stamping, the positioning ring is firstly stamped, then the pin line is stamped, and then the positioning ring is fixed on the terminal pin through brazing, so that compared with an extrusion integral forming process, the difficulty is reduced, the cost is reduced, the height of the positioning ring is uniform, and the yield of the ceramic tube shell is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic device packaging, and in particular to a ceramic tube shell and a manufacturing method thereof. Background Art

[0002] Electronic device packaging shells are an important part of the field of electronic packaging technology and are widely used in the packaging and protection of various electronic devices. There are many types of electronic device packaging shells. Among them, ceramic shells are the most common type of shells for packaged electronic devices. Ceramic shells are based on high-performance ceramic materials, which are resistant to high temperatures, have excellent insulation properties, high mechanical strength, and a small thermal expansion coefficient.

[0003] Among them, PGA ceramic shell is the most common ceramic shell. PGA shell is an important electronic packaging component, mainly used for packaging high-end IC (such as ASIC and other high-function chips), and is widely used in computer MPU or communication equipment. PGA, or Pin Grid Array, is one of the plug-in packages, and the vertical pins on the bottom are arranged in a display. Common structures of PGA ceramic shells are as follows: Figure 1 As shown, it includes a ceramic body, the upper surface of which is provided with a groove for packaging electronic devices, and the upper surface of the ceramic body is welded with a plurality of lead wires along the outer circumference of the groove, wherein four lead pins need to be provided with positioning steps, and the original processing method of the lead wires with positioning steps is stamping and extrusion integrally formed, and then welded and assembled to the tube shell, and the existing production process mainly has the following problems: 1. Difficult process: The positioning step and the lead pin are stamped into one piece, which is difficult to process and leads to increased production costs.

[0004] 2. High defect rate: The size tolerance of the extruded boss is difficult to guarantee, the positioning height has deviations, and the positioning height often shows deviations. The process is difficult and leads to a high defect rate. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a ceramic tube shell and a method for manufacturing the same, which solve the problems of high process difficulty and high defect rate in the manufacturing process of the prior ceramic tube shell.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: A ceramic tube shell comprises a ceramic body, wherein the upper surface of the ceramic body is provided with a groove for encapsulating electronic devices, and a plurality of pin wires are welded along the outer circumference of the groove on the upper surface of the ceramic body, namely an inner circle pin wire group and an outer circle pin wire group, wherein the inner circle pin wire group and the outer circle pin wire group are each provided with a plurality of evenly arranged pin wires, and positioning rings are welded on the four pin wires located at the four corners of the inner circle pin wire group.

[0007] Wherein, the lower end of the lead foot is fixedly connected to the ceramic body through a frustum-shaped welding portion.

[0008] A method for manufacturing a ceramic tube shell comprises the following steps: (1) The lead wire and the positioning ring are obtained by stamping process; (2) Clearance fit between the lead pin and the positioning ring; (3) During the brazing process, all lead pins are placed in the fixed plate of the brazing jig in sequence. Manual intervention is performed under a microscope to ensure that all the lead wires are located in the fixed plate. Then, a suction cup is used to slowly place the porcelain body into the fixed plate, and the porcelain body is restrained by a fixed block. Then, the bottom plate is buckled on. The brazing jig is turned over so that the lead wires are above the porcelain body and an upper cover pressure block is placed above the fixed plate to press the lead wires against the porcelain body to prevent empty welding. Finally, the lead wires are placed into the brazing furnace for brazing.

[0009] In step (2), a gap of 0.01-0.03 mm is left between the pin line and the positioning ring, and the height of the positioning ring is 1.15-1.35 mm.

[0010] Wherein, in step (3), the brazing jig comprises a base plate, a fixing plate and an upper cover plate, the upper surface of the base plate is provided with a fixing plate groove cooperating with the fixing plate, lower welding notches are provided in the middle of the four sides of the groove, the upper surface of the fixing plate is provided with an upper cover plate groove for accommodating the upper cover plate, and the lower surface of the fixing plate is provided with a fixing mechanism for fixing the ceramic tube shell.

[0011] Among them, the fixing mechanism includes a plurality of lead pin fixing holes and a fixing block, the lead pin fixing holes penetrate the bottom wall of the groove of the upper cover plate, the plurality of lead pin fixing holes correspond to the positions of the inner circle pin wire and the outer circle pin wire group, and positioning block fixing holes are provided at the four corners corresponding to the inner circle pin wire group; a fixing groove for placing a fixing block is provided at a triangle on the lower surface of the fixing plate, and an L-shaped fixing block is provided at the other corner of the fixing plate, the fixing groove and the fixing block corresponding to a corner at the center of the fixing plate are both notched, and the ceramic body is just stuck in the area enclosed by the three fixed blocks and the L-shaped fixing block.

[0012] Wherein, a lower welding notch is formed between the fixing groove and the adjacent fixing groove or L-shaped fixing block, and the position of the lower welding notch corresponds to the position of the upper welding notch. Beneficial Effects

[0013] The present invention provides a ceramic tube shell and a manufacturing method thereof, which have the following beneficial effects: 1. The present invention performs the operation by stamping twice, first stamping the positioning ring, then stamping the lead wire, and then fixing the positioning ring on the lead pin by brazing. Compared with the extrusion one-piece molding process, the difficulty is reduced, the cost is reduced, and the height of the positioning ring is unified, which effectively improves the yield rate of the ceramic tube shell.

[0014] 2. The present invention can significantly improve the processing quality and positioning height consistency of the lead pins and the positioning blocks, reduce the scrap rate, and improve the production efficiency and economic benefits of the ceramic tube shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a ceramic tube shell in the prior art; Figure 2 It is a structural schematic diagram of the brazing fixture in the present invention; Figure 3 It is a structural schematic diagram of the brazing fixture of the present invention (without the upper cover plate); Figure 4 It is a structural schematic diagram of the bottom plate in the brazing jig of the present invention; Figure 5 It is a schematic diagram of the structure of the fixing plate in the brazing jig of the present invention; In the figure, 1. Ceramic body, 2. Groove, 3. Pin wire, 3-1. Inner ring pin wire group, 3-2. Outer ring pin wire group, 4. Positioning ring, 5. Welding part, 6. Bottom plate, 7. Fixing plate, 8. Upper cover plate, 9. Fixing plate groove, 10. Lower welding notch, 11. Upper cover groove, 12. Lead pin fixing hole, 13. Fixing block, 14. Positioning block fixing hole, 15. Fixing groove, 16. L-shaped fixing block, 17. Upper welding notch DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0017] like Figure 1As shown, this embodiment provides a ceramic tube shell, including a ceramic body 1, the upper surface of the ceramic body 1 is provided with a groove 2 for packaging electronic devices, and the upper surface of the ceramic body 1 is welded with a plurality of pin wires 3 along the outer circumference of the groove 2, which are an inner circle pin wire group 3-1 and an outer circle pin wire group 3-2, respectively, the inner circle pin wire group 3-1 and the outer circle pin wire group 3-2 are provided with a plurality of evenly arranged pin wires 3, and a positioning ring 4 is welded on the four pin wires 3 located at the four corners of the inner circle pin wire group 3-1. Among them, the lower end of the lead foot is fixedly connected to the ceramic body 1 through a frustum-shaped welding portion 5. Compared with the ceramic tube shell in the prior art, the positioning ring 4 in this embodiment is welded to the pin wire 3. In the prior art, the positioning ring 4 and the lead foot are stamped into one piece, the manufacturing process is difficult, the manufacturing cost is high, and the height of the positioning ring 4 is not easy to be unified, and the defective rate is high. Example 2

[0018] The present embodiment provides a method for manufacturing a ceramic tube shell, comprising the following steps: (1) The pin wire 3 and the positioning ring 4 are respectively obtained by stamping process; the pin wire 3 and the positioning ring 4 must ensure that the pin surface is flat, without collapsed corners, pits, deformation, scratches, pressure damage, and burrs.

[0019] (2) Make clearance fit between the lead pin and the positioning ring 4; leave a gap of 0.02mm between the lead wire 3 and the positioning ring 4, and the height of the positioning ring 4 is 1.25mm. After processing, the surface treatment should be done to ensure that there is no burr, rust, discoloration, foreign matter adhesion and processing lines on the surface; (3) During the brazing process, all lead pins are placed in the fixed plate 7 of the brazing jig in sequence. Manual intervention is performed under a microscope to ensure that all the lead wires 3 are located in the fixed plate 7. A suction cup is then used to slowly place the porcelain body into the fixed plate 7. The porcelain body is restrained by the fixed block 13. The bottom plate 6 is then buckled. The brazing jig is turned over so that the lead wires 3 are above the porcelain body and the upper cover block is placed above the fixed plate 7 to press the lead wires 3 against the porcelain body to prevent empty welding. Finally, the lead wires 3 are placed into the brazing furnace for brazing.

[0020] The process flow of ceramic shell production is as follows: (1) Use a tape-cast raw ceramic tape suitable for HTCC and perform layer-by-layer punching, hole filling and printing operations according to the product metallization wiring requirements; (2) Place the green ceramic with metallized pattern filling and printing into the designated position of the laser machine, perform laser scanning and punching on the surface of the green ceramic, and process the punched part of the green ceramic sheet according to the size required by the product; (3) During the processing, the laser machine uses a dust collector to extract dust and a wind knife to blow air. This method mainly collects the smoke and dust during the processing; then it moves to the next link to collect the residues generated during the operation into the waste box through a brush; then it flows down to the dust-sticking rubber roller and the cleaning wind knife to clean the dust on the surface of the product; (4) The processed multi-layer green sheets are subjected to isostatic pressing and pre-cut by a hot cutting machine. The cutting die must be highly accurate and the tolerance must be controlled within 0.01 mm. Finally, they are sent together to a sintering furnace to obtain cooked porcelain. After surface treatment, the product is cracked into single products to obtain a ceramic tube shell.

[0021] The specific steps of the above process are: 1. Ball milling: Ceramic powder is mixed with solvent, adhesive, etc., and mixed and refined by ball mill to obtain uniform ceramic slurry; 2. Casting: Use a casting machine to evenly coat the ball-milled slurry on the carrier to form a continuous film.

[0022] 3. Slicing: Cut the cast film into the required size and shape; 4. Sticking: Stick the cut ceramic sheets to the support plate to prepare for subsequent processing; 5. Punching: Use laser punching technology / stamping technology to make the required holes on the ceramic sheet; 6. Filling: Filling the punched holes with metal paste to form a circuit or structure; 7. Printing: Printing circuit patterns on ceramic sheets using screen printing or other printing techniques; 8. Backwash: Laser drilling of printed ceramic sheets to form a finer circuit structure; 9. Slurry coating: Coat a layer of slurry on the slurry holes on the side walls of the ceramic sheet to achieve conduction; 10. Stacking: Stack multiple ceramic sheets according to design requirements to form a multi-layer structure; 11. Lamination: Multiple layers are stacked and pressed together by equipment; 12. Cutting with a hot cutter: Use a hot cutter to pre-cut the pressed ceramic substrate for subsequent splitting; 13. Sintering: Sintering the ceramic substrate at high temperature to harden it and form the required physical and chemical properties; 14. Electroplating: The sintered ceramic substrate is electroplated to improve its conductivity or add a protective layer to obtain a ceramic tube shell. Example 3

[0023] like Figure 2-Figure 5 As shown, this embodiment provides a brazing jig used in step (3) of embodiment 2, the brazing jig comprising a base plate 6, a fixing plate 7 and an upper cover plate 8, the upper surface of the base plate 6 is provided with a fixing plate groove 9 that cooperates with the fixing plate 7, the middle of the four edges of the groove are provided with a lower welding notch 10, the upper surface of the fixing plate 7 is provided with an upper cover plate groove 11 for accommodating the upper cover plate 8, and the lower surface of the fixing plate 7 is provided with a fixing mechanism for fixing the ceramic tube shell.

[0024] Among them, the fixing mechanism includes a plurality of lead pin fixing holes 12 and a fixing block 13. The lead pin fixing hole 12 penetrates the bottom wall of the upper cover groove 11. After installation, the lead pin passes through the bottom wall of the cover groove and is slightly higher than the cover groove. After being placed in the upper cover 8, the upper cover 8 can press the lead wire 3 to prevent the lead wire from moving during the movement of the fixture and the soldering process, thereby preventing the problem of empty welding and improving the yield rate.

[0025] Multiple lead pin fixing holes 12 correspond to the positions of the inner circle pin wire 3 and the outer circle pin wire group 3-2, and positioning block fixing holes 14 are provided at the four corners of the corresponding inner circle pin wire group 3-1; the positioning block fixing holes 14 are provided to cooperate with the positioning ring 4 on the one hand, and on the other hand, it is also convenient for positioning during installation, thereby improving installation efficiency. A fixing groove 15 for placing a fixing block 13 is provided at the triangle on the lower surface of the fixing plate 7, and an L-shaped fixing block 13 is provided at the other corner of the fixing plate 7. The fixing groove 15 and the fixing block 13 corresponding to the corner at the center of the fixing plate 7 are both notched, which has a very good limiting effect. The ceramic body 1 is just stuck into the area enclosed by the three fixed blocks 13 and the L-shaped fixing block 13. Compared with the prior art, the positioning column is eliminated, and the fixation of the ceramic body 1 is more convenient. Even if the ceramic body 1 contracts after expanding due to heat, it is easier to take it out of the fixture. A gap is left between the L-shaped fixing block and the inserted ceramic body 1 to avoid the problem of corner chipping and collapse when the ceramic body 1 expands due to heat, thereby improving the yield rate, and at the same time further avoiding the wear of the fixture itself, thereby increasing the service life of the fixture.

[0026] A lower welding notch 10 is formed between the fixing groove 15 and the adjacent fixing groove 15 or the L-shaped fixing block, and the position of the lower welding notch 10 corresponds to the position of the upper welding notch 17 .

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A ceramic tube shell, comprising a ceramic body, wherein the upper surface of the ceramic body is provided with a groove for packaging electronic devices, characterized in that: The upper surface of the ceramic body is welded with multiple pin wires along the outer circumference of the groove, which are an inner circle pin wire group and an outer circle pin wire group. Both the inner circle pin wire group and the outer circle pin wire group are provided with multiple evenly arranged pin wires, and positioning rings are welded on the four pin wires located at the four corners of the inner circle pin wire group.

2. The ceramic tube shell according to claim 1, characterized in that: The lower end of the lead foot is fixedly connected to the ceramic body through a frustum-shaped welding portion.

3. A method for manufacturing a ceramic tube shell according to claim 1 or 2, characterized in that The steps include: (1) The lead wire and the positioning ring are obtained by stamping process; (2) Clearance fit between the lead pin and the positioning ring; (3) During the brazing process, all lead pins are placed in the fixed plate of the brazing jig in sequence. Manual intervention is performed under a microscope to ensure that all the lead wires are located in the fixed plate. Then, a suction cup is used to slowly place the porcelain body into the fixed plate, and the porcelain body is restrained by a fixed block. Then, the bottom plate is buckled on. The brazing jig is turned over so that the lead wires are above the porcelain body and an upper cover pressure block is placed above the fixed plate to press the lead wires against the porcelain body. Finally, the lead wires are placed into the brazing furnace for brazing.

4. The method for manufacturing a ceramic tube shell according to claim 3, characterized in that: In step (2), a gap of 0.01-0.03 mm is left between the pin line and the positioning ring, and the height of the positioning ring is 1.15-1.35 mm.

5. The method for manufacturing a ceramic tube shell according to claim 3, characterized in that: In step (3), the brazing jig includes a base plate, a fixing plate and an upper cover plate, the upper surface of the base plate is provided with a fixing plate groove that cooperates with the fixing plate, the middle of the four sides of the groove are provided with lower welding notches, the upper surface of the fixing plate is provided with an upper cover plate groove for accommodating the upper cover plate, and the lower surface of the fixing plate is provided with a fixing mechanism for fixing the ceramic tube shell.

6. The method for manufacturing a ceramic tube shell according to claim 5, characterized in that: The fixing mechanism includes a plurality of lead pin fixing holes and a fixing block, the lead pin fixing holes penetrate the bottom wall of the groove of the upper cover plate, the plurality of lead pin fixing holes correspond to the positions of the inner circle pin wire and the outer circle pin wire group, and positioning block fixing holes are provided at the four corners corresponding to the inner circle pin wire group; a fixing groove for placing a fixing block is provided at a triangle on the lower surface of the fixing plate, and an L-shaped fixing block is provided at the other corner of the fixing plate, the fixing groove and the fixing block corresponding to a corner at the center of the fixing plate are both notched, and the ceramic body is just stuck in the area enclosed by the three fixed blocks and the L-shaped fixing block.

7. The method for manufacturing a ceramic tube shell according to claim 5, characterized in that: A lower welding notch is formed between the fixing groove and an adjacent fixing groove or L-shaped fixing block, and the position of the lower welding notch corresponds to the position of the upper welding notch.

Images