Ceramic packaging device and reworking method

Abstract

The invention discloses a ceramic packaging device and a reworking method, the ceramic packaging device comprises a metal cover plate, a ceramic tube shell, a solder piece and a chip, the solder piece is arranged between the metal cover plate and the ceramic tube shell and welds the metal cover plate and the ceramic tube shell together, an accommodating cavity is arranged between the metal cover plate and the ceramic tube shell, and the chip is arranged in the accommodating cavity. And the chip is arranged in the accommodating cavity and is fixed with the ceramic tube shell. The reworking method comprises the following steps: separating a metal cover plate and a ceramic tube shell of a poorly packaged ceramic packaging device, and forming an old metal cover plate and an old ceramic tube shell; a new metal cover plate and a new solder piece are provided, and the new metal cover plate and the old ceramic tube shell are welded together through the new solder piece. According to the invention, the solder sheet is designed between the metal cover plate and the ceramic tube shell, and the metal cover plate and the ceramic tube shell are welded together, thereby facilitating the packaging of the chip, facilitating the implementation of the reworking method, improving the packaging yield, and reducing the loss of the material cost.

Description

Technical Field

[0001] This invention relates to the field of ceramic packaging technology, and in particular to a ceramic packaging device and a rework method. Background Technology

[0002] Chip packaging is a critical step in semiconductor manufacturing, involving the protection of exposed semiconductor dies for use in electronic devices. Chip packaging typically employs ceramic encapsulation, which offers high reliability and is increasingly used in the aerospace, automotive, and consumer electronics markets. However, the ceramic casing and chip in ceramic encapsulation products are relatively expensive, thus requiring high yield rates. However, during the ceramic encapsulation sealing process, issues such as material inconsistencies, improper human operation, equipment malfunctions, and abnormal gas supply can lead to defects like gold / solder overflow onto the top of the cover plate, uneven overflow, and voids. Figure 1 , Figure 2 As shown in the image, this results in the entire product being scrapped. The current common practice is to simply discard the scrapped product, which leads to problems such as loss of product yield, loss of material costs, decreased customer satisfaction, and reduced market competitiveness. Summary of the Invention

[0003] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a ceramic packaging device and a rework method to solve the problems of low yield and high cost of ceramic packaging in the existing technology.

[0004] The objective of this invention is achieved through the following technical solution: This invention provides a rework method for ceramic packaging devices, providing a ceramic packaging device with defective packaging. The ceramic packaging device includes a metal cover plate, a ceramic shell, a solder pad, and a chip. The solder pad is disposed between the metal cover plate and the ceramic shell and welds the metal cover plate and the ceramic shell together. There is a receiving cavity between the metal cover plate and the ceramic shell. The chip is installed in the receiving cavity and fixed to the ceramic shell. The rework methods include: Separate the metal cover plate from the ceramic housing of the poorly packaged ceramic device to form a used metal cover plate and a used ceramic housing; A new metal cover plate and a new solder sheet are provided, and the new metal cover plate is welded to the old ceramic tube shell by means of the new solder sheet.

[0005] Furthermore, the step of separating the metal cover plate of the poorly packaged ceramic device from the ceramic casing includes: The defective ceramic packaged device is placed in a vacuum reflow oven, and the separation operation program of the vacuum reflow oven is started.

[0006] Furthermore, the step of separating the metal cover plate of the poorly packaged ceramic device from the ceramic casing also includes: A rework fixture is provided, on which the poorly packaged ceramic packaged device is placed, and the metal cover of the ceramic packaged device is in contact with the rework fixture.

[0007] Furthermore, the step of welding the new metal cover plate to the old ceramic tube shell includes: The new solder sheet is sandwiched between the new metal cover plate and the old ceramic tube shell, and then placed together in the vacuum reflow oven. The sealing operation program of the vacuum reflow oven is then started.

[0008] Furthermore, the step of welding the new metal cover plate to the old ceramic tube shell also includes: A rework fixture is provided, on which the new metal cover plate, the new solder sheet, and the old ceramic tube shell are placed overlapping each other, with the new metal cover plate in contact with the rework fixture.

[0009] Furthermore, the step of welding the new metal cover plate to the old ceramic tube shell also includes: First, the new solder sheet is placed on one side of the new metal cover plate, and then the side of the new metal cover plate with the solder sheet is attached to the old ceramic tube shell.

[0010] Furthermore, the rework method includes: The reworked ceramic packaged device is then inspected. If the reworked ceramic packaged device is found to have a defective structure, the rework method for the ceramic packaged device described above shall be repeated.

[0011] This application also provides a ceramic packaging device, which is reworked using the ceramic packaging device rework method described above. The ceramic packaging device includes a metal cover plate, a ceramic shell, a solder pad, and a chip. The solder pad is disposed between the metal cover plate and the ceramic shell and welds the metal cover plate and the ceramic shell together. There is a receiving cavity between the metal cover plate and the ceramic shell. The chip is installed in the receiving cavity and fixed to the ceramic shell.

[0012] Furthermore, the ceramic tube shell is provided with a groove, a first protrusion and a second protrusion facing the metal cover plate. The first protrusion is located at the periphery of the groove, the second protrusion is located at the periphery of the first protrusion, and the chip is fixed in the groove. The first protrusion is provided with a plurality of first pads, and the chip is provided with a plurality of second pads corresponding to the first pads. The first pads and the second pads are electrically connected by bonding wires. The second protrusion is provided with a connecting metal layer, which is in contact with the solder sheet.

[0013] Furthermore, the bottom wall of the groove is provided with a first thermally conductive metal layer, and the ceramic tube shell is provided with a second thermally conductive metal layer and a third pad located around the second thermally conductive metal layer on the side away from the metal cover plate. The third pad extends from the edge of the ceramic tube shell away from the metal cover plate to the side of the ceramic tube shell.

[0014] The beneficial effects of this invention are as follows: by designing the solder pad between the metal cover plate and the ceramic shell and welding the metal cover plate and the ceramic shell together, it is convenient to package the chip and also convenient to implement the rework method in this application; in addition, by separating the metal cover plate and the ceramic shell of the poorly packaged ceramic packaged device and using a new metal cover plate and a new solder pad to package the old ceramic shell, the yield rate of packaging can be improved and the loss of material costs can be reduced. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a ceramic packaging device exhibiting overflow defects in existing technology.

[0016] Figure 2 This is a schematic diagram of a ceramic packaging device with void defects in the existing technology.

[0017] Figure 3 This is a three-dimensional structural diagram of the ceramic packaging device in this invention.

[0018] Figure 4 This is a schematic diagram of the cross-sectional structure of the ceramic packaging device in this invention.

[0019] Figure 5 This is a frontal three-dimensional structural diagram of the ceramic tube shell in this invention.

[0020] Figure 6 This is a schematic diagram of the three-dimensional structure of the back of the ceramic tube shell in this invention.

[0021] Figure 7 This is a schematic diagram of the three-dimensional structure of the back side of the metal cover plate and solder sheet in this invention.

[0022] Figure 8This is a schematic diagram of the cross-sectional structure of the metal cover plate and solder sheet in this invention.

[0023] Figure 9 This is a flowchart illustrating the rework method for ceramic packaged devices in this invention. Detailed Implementation

[0024] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation methods, structures, features, and effects of the ceramic packaging device and rework method proposed according to the present invention: Figure 3 This is a three-dimensional structural diagram of the ceramic packaging device in this invention. Figure 4 This is a schematic diagram of the cross-sectional structure of the ceramic packaging device in this invention. Figure 5 This is a frontal three-dimensional structural diagram of the ceramic tube shell in this invention. Figure 6 This is a schematic diagram of the three-dimensional structure of the back of the ceramic tube shell in this invention. Figure 7 This is a schematic diagram of the three-dimensional structure of the back side of the metal cover plate and solder sheet in this invention. Figure 8 This is a schematic diagram of the cross-sectional structure of the metal cover plate and solder sheet in this invention.

[0025] like Figures 3 to 8 As shown, the present invention provides a ceramic packaging device 10, including a metal cover plate 11, a ceramic shell 12, a solder pad 13, and a chip 14. The solder pad 13 is disposed between the metal cover plate 11 and the ceramic shell 12 and welds the metal cover plate 11 and the ceramic shell 12 together. There is a receiving cavity 101 between the metal cover plate 11 and the ceramic shell 12. The chip 14 is installed in the receiving cavity 101 and fixed to the ceramic shell 12.

[0026] Furthermore, the ceramic housing 12 facing the metal cover plate 11 is provided with a groove 121, a first boss 122, and a second boss 123. The first boss 122 is located at the periphery of the groove 121, and the second boss 123 is located at the periphery of the first boss 122. The chip 14 is fixed in the groove 121. The first boss 122 has multiple first pads 122a, and the chip 14 has multiple second pads 141 corresponding to the first pads 122a. The first pads 122a and the second pads 141 are electrically connected by bonding wires 15. The second boss 123 has a connecting metal layer 123a, which contacts the solder sheet 13. The shape of the solder sheet 13 matches the shape of the connecting metal layer 123a; that is, the solder sheet 13 is only located at the periphery of the metal cover plate 11.

[0027] Furthermore, the bottom wall of the groove 121 is provided with a first thermally conductive metal layer 121a, and the ceramic tube shell 12 is provided with a second thermally conductive metal layer 124 and a third pad 125 located around the second thermally conductive metal layer 124 on the side away from the metal cover plate 11. The third pad 125 extends from the edge of the ceramic tube shell 12 away from the metal cover plate 11 to the side of the ceramic tube shell 12.

[0028] The insulating medium of the ceramic tube shell 12 is generally 92% alumina. The first thermally conductive metal layer 121a, the first pad 122a, the connecting metal layer 123a, the second thermally conductive metal layer 124, and the third pad 125 are all first gold-plated metal layers on the surface of the ceramic tube shell 12, and are deposited on the surface of the ceramic tube shell 12 using a gold plating process. The first gold-plated metal layer includes a nickel layer and a gold layer electroplated on the surface of the nickel layer. The thickness of the nickel layer is 1.3-8.9 μm, and the thickness of the gold layer is 1.3-5.9 μm.

[0029] like Figure 7 and Figure 8 As shown, the surface of the metal cover plate 11 is provided with a second gold-plated metal layer, which includes a nickel layer and a gold layer electroplated on the surface of the nickel layer. The thickness of the nickel layer is 2.5-8.9 μm, and the thickness of the gold layer is 1.3-5.9 μm. Solder sheets 13 with a width b of 0.3 mm, a thickness d of 40-50 μm, and a type AU80SN20 are pre-fabricated around the metal cover plate 11. For example, if the thickness h of the metal cover plate 11 is 0.25 mm, and AU80SN20 solder sheets 13 with a thickness b of 0.04 mm are pre-fabricated around the metal cover plate 11, the ceramic tube shell 12 and the metal cover plate 11 are welded together by fusion sealing with these solder sheets 13.

[0030] The packaging process of the ceramic packaged device 10 mainly includes: die mounting, bonding, fusion sealing, flat sealing, leak detection, and marking. Specifically, in the die mounting process: the chip 14 is bonded to the bottom of the groove 121 inside the ceramic housing 12 using silver paste, and after high-temperature baking, the chip 14 is fixed in the groove 121 of the ceramic housing 12. In the bonding process: the second pad 141 on the chip 14 is electrically connected to the first pad 122a of the ceramic housing 12 using bonding wire 15 (gold or aluminum wire), enabling the chip 14 to output its function. In the fusion sealing process: after bonding, the product is sealed in a vacuum welding furnace using a metal cover plate 11 and a solder sheet 13 to the ceramic housing 12. Subsequent processes such as flat sealing, leak detection, and marking can be referenced from existing technologies and will not be elaborated here.

[0031] The specific steps of the fusion sealing process include: placing a solder sheet 13 on one side of a metal cover plate 11, then attaching the side of the metal cover plate 11 with the solder sheet 13 to the ceramic tube shell 12, with the solder sheet 13 sandwiched between the metal cover plate 11 and the ceramic tube shell 12. The metal cover plate 11, solder sheet 13, and ceramic tube shell 12 are then overlapped and placed on a welding fixture, with the metal cover plate 11 in contact with the welding fixture. Finally, the metal cover plate 11 and the welding fixture are placed together in a vacuum reflow oven, and the fusion sealing program of the vacuum reflow oven is started. Upon completion of the program, the fusion sealing is achieved.

[0032] Figure 9 This is a flowchart illustrating the rework method for ceramic packaged devices in this invention. For example... Figure 9 As shown, this application also provides a method for reworking a ceramic packaged device, the method comprising: The metal cover 11 of the poorly packaged ceramic packaged device 10 is separated from the ceramic shell 12, forming a used metal cover 11 and a used ceramic shell 12. During the fabrication of the ceramic packaged device 10, since the solder overflow of the solder pad 13 is primarily on the metal cover 11, the desoldering cost is high; therefore, the used metal cover 11 can be discarded. The chip 14, however, is fixed within the groove 121 of the ceramic shell 12, which is costly, and only a small amount of solder is located in the connecting metal layer 123a of the second protrusion 123. Therefore, the used ceramic shell 12 connected to the chip 14 within the groove 121 can be reused to reduce manufacturing costs.

[0033] Specifically: A rework fixture is provided, and the defective ceramic packaged device 10 is placed on the rework fixture, with the metal cover plate 11 of the ceramic packaged device 10 in contact with the rework fixture, i.e., the front of the defective ceramic packaged device 10 faces the rework fixture. Then, the defective ceramic packaged device 10 and the rework fixture are placed together in a vacuum reflow oven, and the separation operation program of the vacuum reflow oven is started. After the program is completed, the metal cover plate 11 separates from the ceramic shell 12 without damaging the first metal plating layer (first thermally conductive metal layer 121a, first pad 122a, connecting metal layer 123a, second thermally conductive metal layer 124, and third pad 125) on the ceramic shell 12, and does not affect the reuse of the ceramic shell 12. The chip 14 is still fixed in the groove 121 of the ceramic shell 12 and is separated from the metal cover plate 11 together with the ceramic shell 12, and can be reused.

[0034] A new metal cover plate 11 and a new solder tab 13 are provided, and the new metal cover plate 11 is welded to the old ceramic tube shell 12 by means of the new solder tab 13.

[0035] Specifically: First, a new solder sheet 13 is placed on one side of a new metal cover plate 11. Then, the side of the new metal cover plate 11 with the solder sheet 13 is attached to the old ceramic tube shell 12, with the new solder sheet 13 sandwiched between the new metal cover plate 11 and the old ceramic tube shell 12. A rework fixture is provided. The new metal cover plate 11, the new solder sheet 13, and the old ceramic tube shell 12 are stacked on top of each other and placed on the rework fixture, with the new metal cover plate 11 in contact with the rework fixture. Then, the new metal cover plate 11 and the rework fixture are placed together in a vacuum reflow oven, and the reflow oven's sealing operation program is started. After the operation is completed, the resealing is achieved.

[0036] Vacuum reflow ovens, also known as vacuum soldering furnaces (vacuum eutectic furnaces), provide a process environment for alloy soldering of electronic components. This equipment can perform LED chip soldering, MEMS device packaging, LD device soldering, power electronic device packaging, IGBT chip soldering, and casing sealing. Vacuum reflow ovens solder products under vacuum negative pressure to protect the products and solder from oxidation, thus improving soldering quality. In existing vacuum reflow ovens, removing finished products requires opening the furnace lid. This causes the temperature inside the furnace and the functional gas (such as nitrogen) to dissipate. After removing the finished product, placing the product to be reflowed in, and closing the lid again, the furnace needs to be reheated and refilled with nitrogen. This reheating and nitrogen refilling process takes a considerable amount of time, affecting soldering efficiency.

[0037] Furthermore, rework methods also include: The reworked ceramic packaged device 10 was inspected; If the reworked ceramic package 10 is found to be defective, the rework method for the ceramic package 10 described above is repeated until the old ceramic shell 12 is successfully welded to the new metal cover 11.

[0038] The price of the ceramic housing 12 (model CQFN4X4-24) is 24 yuan per unit, the metal cover plate 11 is 11 yuan per unit, and the chip 14 is approximately 100 yuan per chip. Based on an annual production of 30,000 ceramic packaged devices 10 and a defect rate of 3%, the non-destructive rework technology of this invention only requires replacing the metal cover plate 11 and solder pad 13, saving 30,000 * 0.03 * 24 = 21,600 yuan in material costs for the ceramic housing 12, and avoiding a cost loss of 30,000 * 0.03 * 100 = 90,000 yuan for the chip 14, for a total cost saving of 21,600 + 90,000 = 111,600 yuan. Therefore, this application not only avoids material cost losses but also achieves high packaging yield; it not only improves customer satisfaction but also enhances competitiveness in the ceramic packaging market.

[0039] The following is the product inspection form after the rework method of this application has been successfully used for sealing:

[0040]

[0041] As can be seen from Tables 1 and 2 above, products that have passed the rework sealing process using the method described in this application can all pass tests such as low temperature testing, stability baking, and temperature shock testing.

[0042] In this document, the directional terms such as up, down, left, right, front, and back are defined according to the position of the structures in the accompanying drawings and the relative positions of the structures, and are only used for clarity and convenience in expressing the technical solution. It should be understood that the use of these directional terms should not limit the scope of protection claimed in this application. It should also be understood that the terms "first" and "second," etc., used herein are only used for distinction in name and are not used to limit the number or order.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content without departing from the scope of the technical solution of the present invention, which are equivalent embodiments with equivalent changes. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for reworking ceramic packaged devices, characterized in that, A ceramic package device (10) with poor encapsulation is provided. The ceramic package device (10) includes a metal cover plate (11), a ceramic shell (12), a solder pad (13), and a chip (14). The solder pad (13) is disposed between the metal cover plate (11) and the ceramic shell (12) and welds the metal cover plate (11) and the ceramic shell (12) together. There is a receiving cavity (101) between the metal cover plate (11) and the ceramic shell (12). The chip (14) is installed in the receiving cavity (101) and fixed to the ceramic shell (12). The rework methods include: Separate the metal cover (11) of the poorly packaged ceramic packaged device (10) from the ceramic shell (12) to form an old metal cover (11) and an old ceramic shell (12); A new metal cover plate (11) and a new solder sheet (13) are provided, and the new metal cover plate (11) is welded to the old ceramic tube shell (12) by means of the new solder sheet (13).

2. The rework method for ceramic packaged devices according to claim 1, characterized in that, The step of separating the metal cover (11) of the poorly packaged ceramic packaged device (10) from the ceramic shell (12) includes: The poorly packaged ceramic packaged device (10) is placed into a vacuum reflow oven, and the separation operation program of the vacuum reflow oven is started.

3. The rework method for ceramic packaged devices according to claim 2, characterized in that, The step of separating the metal cover plate (11) of the poorly packaged ceramic packaged device (10) from the ceramic shell (12) further includes: A rework fixture is provided, on which the poorly packaged ceramic packaged device (10) is placed, and the metal cover plate (11) of the ceramic packaged device (10) is in contact with the rework fixture.

4. The rework method for ceramic packaged devices according to claim 1, characterized in that, The steps of welding the new metal cover plate (11) to the old ceramic tube shell (12) include: The new solder sheet (13) is sandwiched between the new metal cover plate (11) and the old ceramic tube shell (12), and then placed together in the vacuum reflow oven. The sealing operation program of the vacuum reflow oven is then started.

5. The rework method for ceramic packaged devices according to claim 4, characterized in that, The step of welding the new metal cover plate (11) to the old ceramic tube shell (12) also includes: A rework fixture is provided, on which the new metal cover plate (11), the new solder sheet (13), and the old ceramic tube shell (12) are stacked and placed, with the new metal cover plate (11) in contact with the rework fixture.

6. The rework method for ceramic packaged devices according to claim 4, characterized in that, The step of welding the new metal cover plate (11) to the old ceramic tube shell (12) also includes: First, place the new solder sheet (13) on one side of the new metal cover plate (11), and then attach the side of the new metal cover plate (11) with the solder sheet (13) to the old ceramic tube shell (12).

7. The rework method for the ceramic packaged device according to any one of claims 1-6, characterized in that, The rework methods include: The reworked ceramic packaged device (10) is then inspected; If the reworked ceramic packaged device (10) is found to have a defective structure, the rework method of the ceramic packaged device as described in any one of claims 1-6 shall be repeated.

8. A ceramic packaged device, characterized in that, The ceramic package device (10) is reworked using the rework method described in any one of claims 1-7. The ceramic package device (10) includes a metal cover plate (11), a ceramic shell (12), a solder pad (13), and a chip (14). The solder pad (13) is disposed between the metal cover plate (11) and the ceramic shell (12) and welds the metal cover plate (11) and the ceramic shell (12) together. A receiving cavity (101) is provided between the metal cover plate (11) and the ceramic shell (12). The chip (14) is installed in the receiving cavity (101) and fixed to the ceramic shell (12).

9. The ceramic packaging device according to claim 8, characterized in that, The ceramic tube shell (12) facing the metal cover plate (11) is provided with a groove (121), a first boss (122) and a second boss (123). The first boss (122) is located at the periphery of the groove (121), and the second boss (123) is located at the periphery of the first boss (122). The chip (14) is fixed in the groove (121). The first boss (122) is provided with a plurality of first pads (122a), and the chip (14) is provided with a plurality of second pads (141) corresponding to the first pads (122a). The first pads (122a) and the second pads (141) are electrically connected by bonding wires (15). The second boss (123) is provided with a connecting metal layer (123a), which is in contact with the solder sheet (13).

10. The ceramic packaging device according to claim 8, characterized in that, The bottom wall of the groove (121) is provided with a first thermally conductive metal layer (121a), and the ceramic tube shell (12) is provided with a second thermally conductive metal layer (124) on the side away from the metal cover plate (11) and a third pad (125) located around the second thermally conductive metal layer (124). The third pad (125) extends from the edge of the ceramic tube shell (12) away from the metal cover plate (11) to the side of the ceramic tube shell (12).

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