High-reliability ceramic metal shell and preparation method thereof

Abstract

The invention discloses a high-reliability ceramic metal shell and a preparation method thereof. The structure comprises a ceramic bottom plate, a metal enclosure frame, a lead and a sintering mold, the metal shell is arranged in a double-row in-line mode, and the upper end of the metal shell is open. The ceramic bottom plate is made of a high-thermal-conductivity ceramic material; the metal enclosure frame is made of a high-thermal-conductivity material; the lead wire is a T-head end surface in the cavity of the metal shell and is used for bonding a back channel and an internal chip; and the sintering mold is divided into an intra-cavity positioning mold and an outer lead positioning mold. According to the utility model, the high-thermal-conductivity ceramic material is used as a carrier for bearing the chip at the bottom, and the high-thermal-conductivity metal enclosure frame is used as a protective wall body, so that the chip is protected in all directions, heat generated during working of the chip can be effectively and rapidly dissipated, and the transmission efficiency and the service life of the chip are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic-metal sealing, and in particular to a high-reliability ceramic-metal housing and a preparation method thereof. Background Art

[0002] With the rapid development of modern electronic information technology, electronic information systems and equipment are developing towards large-scale integration, miniaturization, and high reliability, and the thermal conductivity of the basic materials used to carry them is becoming increasingly demanding. The protective shell that carries the chip externally must have high thermal conductivity so that the heat generated by the chip can be effectively transferred out while the chip is working continuously, thereby achieving stable operation of the chip and improving its service life. And its thermal expansion coefficient needs to match that of the chip to avoid chip failure due to large expansion differences when the chip is working.

[0003] Therefore, there is an urgent need to develop a highly reliable ceramic metal housing with good strength, excellent heat dissipation performance and a thermal expansion coefficient that matches the chip to ensure the stable operation of the final device. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention aims to provide a highly reliable ceramic metal housing and a preparation method thereof, which aims to quickly transfer the heat generated by the chip so that it can operate efficiently and stably.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a high-reliability ceramic metal shell, including a ceramic base plate, a metal frame and leads, the metal frame is welded to the ceramic base plate by solder, the ceramic base plate is provided with a plurality of first through holes, the leads are passed through the first through holes, and the leads are welded to the ceramic base plate by solder rings; the inner walls of the first through holes are metallized, the surface of the ceramic base plate is provided with a metallized coating, and the metal frame adopts a sandwich composite structure material.

[0006] Among them, the metallization treatment and the metallization coating are both carried out by brushing the molybdenum-manganese slurry on the surface, in order to facilitate the subsequent welding with the metal.

[0007] Furthermore, the ceramic base plate is made of high thermal conductivity ceramic material; the metal frame is made of high thermal conductivity material. The material of the ceramic base plate is aluminum nitride ceramic, and the grade is one of AN-170, AN-200 or AN-230; the sandwich composite structure material used by the metal frame is CMC.

[0008] Furthermore, the metallization thickness of the inner wall of the first through hole is 0.05-0.1 mm; and the four sides of the ceramic bottom plate are all coated with a metallization coating with a width of 1.9-2.1 mm.

[0009] Furthermore, one end face of the lead is a D-face, which is used for subsequent bonding with an internal chip; the diameter of the D-face is 1.3 to 1.5 times the diameter of the lead.

[0010] A method for preparing a high-reliability ceramic metal housing comprises the following steps:

[0011] 1) Fit the metal frame to the cavity positioning mold and place the AgCu28 molded solder sheet on the end surface of the metal frame;

[0012] 2) Place the ceramic base plate on the end surface of the metal frame for bonding;

[0013] 3) inserting the lead wire into the corresponding first through hole on the ceramic base plate, and sleeved the lead wire with a AgCu28 solder ring matching its diameter;

[0014] 4) Adapt the outer lead positioning mold to the lead;

[0015] 5) Place the assembled metal shell product into a nitrogen-hydrogen mixed atmosphere furnace for welding at a welding temperature of 795-805°C.

[0016] Furthermore, the cavity positioning mold is provided with a frame blind hole for positioning the metal frame, a first positioning hole for positioning the ceramic base plate, and a lead blind hole for positioning the lead; the first positioning hole has a depth of 0.9 to 1 mm, which is used to ensure the bonding strength when bonding with the chip later.

[0017] Furthermore, the diameter of the lead blind hole in the intra-cavity positioning mold for positioning the lead is 1.2 to 1.4 times the diameter of the lead, so as to release residual stress after welding.

[0018] Furthermore, the outer lead positioning mold is provided with a second through hole for positioning the lead, and the outer lead positioning mold is provided with a second positioning hole for positioning the ceramic base plate; the depth of the second positioning hole is 5.3-5.7 mm.

[0019] Furthermore, during welding, a nitrogen-hydrogen gas mixture is used, and the concentration of hydrogen is 1 to 1.5 times that of nitrogen.

[0020] Furthermore, the welding time is 6 to 8 minutes, and then the sealing is completed at a cooling rate of 3 to 5°C / min.

[0021] The beneficial effects of the present invention are as follows: compared with the prior art, a high-reliability ceramic metal shell prepared by the present invention adopts a high thermal conductivity ceramic material as a carrier for the bottom chip, and a high thermal conductivity metal frame as a protective wall, so that the chip can be fully protected and can effectively dissipate the heat during operation, and has excellent electrical insulation, sealing, corrosion resistance and thermal expansion matching. Its excellent thermal conductivity can make the internal chip output signals stably and efficiently, greatly improving the efficiency of signal transmission and increasing the service life of the entire sealing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of ceramic metal shell.

[0023] Figure 2 This is a cross-sectional view of the ceramic metal shell.

[0024] Figure 3 Schematic diagram of the positioning mold in the ceramic metal shell cavity.

[0025] Figure 4 Schematic diagram of the mold for positioning the external leads of the ceramic metal shell.

[0026] Figure 5 Schematic diagram of the ceramic-metal shell matching mold.

[0027] Among them, 1-ceramic base plate; 2-metal frame; 3-lead; 4-solder; 5-intracavity positioning mold; 6-external lead positioning mold; 7-frame blind hole; 8-lead blind hole; 9-first positioning hole; 10-second positioning hole; 11-second through hole; 12-first through hole. DETAILED DESCRIPTION

[0028] The present invention is further described below by specific examples, but these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0029] Example

[0030] like Figures 1 to 5 As shown, a high-reliability ceramic-metal housing comprises a ceramic base plate 1, a metal frame 2 and leads 3. The metal frame 2 is welded to the ceramic base plate 1 via solder 4. The ceramic base plate 1 is provided with a plurality of first through holes 12. The leads 3 are passed through the first through holes 12 and welded to the ceramic base plate 1 via solder rings. The inner walls of the first through holes 12 are metallized, the surface of the ceramic base plate 1 is provided with a metallized coating, and the metal frame 2 is made of a sandwich composite structure material.

[0031] Among them, the metallization treatment and the metallization coating are both carried out by brushing the molybdenum-manganese slurry on the surface, in order to facilitate the subsequent welding with the metal.

[0032] The material of the ceramic base plate 1 is aluminum nitride ceramic, and the grade is selected from AN-170, AN-200 or AN-230; the sandwich composite structure material used by the metal frame 2 is CMC.

[0033] The metallization thickness of the inner wall of the first through hole 12 is 0.05-0.1 mm; the four sides of the ceramic bottom plate 1 are all coated with a metallization coating with a width of 1.9-2.1 mm.

[0034] One end face of the lead wire 3 is a D-face, and the diameter of the D-face is 1.3 to 1.5 times the diameter of the lead wire 3 .

[0035] A method for preparing a high-reliability ceramic metal housing comprises the following steps:

[0036] 1) Fit the metal frame 2 to the cavity positioning mold 5, and place AgCu28 molding solder 4 on the end surface of the metal frame 2;

[0037] 2) placing the ceramic base plate 1 on the end surface of the metal frame 2 for bonding;

[0038] 3) Insert the lead wire 3 into the corresponding first through hole 12 on the ceramic base plate 1, and sleeve an AgCu28 molded solder ring with a diameter matching that of the lead wire 3;

[0039] 4) Adapting the outer lead positioning mold 6 to the lead 3;

[0040] 5) Place the assembled metal shell product into a nitrogen-hydrogen mixed atmosphere furnace for welding at a welding temperature of 795-805°C.

[0041] The cavity positioning mold 5 is provided with a frame blind hole 7 for positioning the metal frame 2, a first positioning hole 9 for positioning the ceramic base plate 1, and a lead blind hole 8 for positioning the lead 3; the first positioning hole 9 has a depth of 0.9 to 1 mm, which is used to ensure the bonding strength when bonding with the chip later.

[0042] The diameter of the lead blind hole 8 in the intra-cavity positioning mold 5 for positioning the lead 3 is 1.2 to 1.4 times the diameter of the lead 3, and is used to release residual stress after welding.

[0043] The outer lead positioning mold 6 is provided with a second through hole 11 for positioning the lead 3 , and the outer lead positioning mold 6 is provided with a second positioning hole 10 for positioning the ceramic base plate 1 ; the depth of the second positioning hole 10 is 5.3-5.7 mm.

[0044] During welding, a mixture of nitrogen and hydrogen gases is used, with the hydrogen concentration being 1 to 1.5 times that of nitrogen.

[0045] The welding time is 6 to 8 minutes, and then the sealing is completed at a cooling rate of 3 to 5°C / min.

[0046] The present invention designs a highly reliable ceramic metal shell, the excellent thermal conductivity of the bottom material of which can make the internal chip output signals stably and efficiently. The ceramic metal shell prepared by this method has good electrical insulation performance (up to 1500V DC), sealing performance (≤1×10 -5 Pa cm 3 / s) and high reliability, which greatly improves the efficiency of signal transmission and increases the service life of the entire sealing device.

[0047] The above implementation modes are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention should be defined by the claims.

Claims

1. A high-reliability ceramic metal housing, characterized in that: It includes a ceramic base plate, a metal frame and leads. The metal frame is welded to the ceramic base plate by solder. The ceramic base plate is provided with a plurality of first through holes. The leads are passed through the first through holes and welded to the ceramic base plate by solder rings. The inner walls of the first through holes are metallized, the surface of the ceramic base plate is provided with a metallized coating, and the metal frame adopts a sandwich composite structure material.

2. A high-reliability ceramic metal housing as claimed in claim 1, characterized in that: The material of the ceramic base plate is aluminum nitride ceramic, and the grade is selected from AN-170, AN-200 or AN-230; the sandwich composite structure material used by the metal frame is CMC.

3. A high-reliability ceramic metal housing as claimed in claim 1, characterized in that: The metallization thickness of the inner wall of the first through hole is 0.05-0.1 mm; the four sides of the ceramic bottom plate are all coated with a metallization coating with a width of 1.9-2.1 mm.

4. A high-reliability ceramic metal housing as claimed in claim 1, characterized in that: One end face of the lead wire is a D-face, and the diameter of the D-face is 1.3 to 1.5 times the diameter of the lead wire.

5. The method for preparing a high-reliability ceramic metal housing according to claim 1, characterized in that: The steps include: 1) Fit the metal frame to the cavity positioning mold and place the AgCu28 molded solder sheet on the end surface of the metal frame; 2) Place the ceramic base plate on the end surface of the metal frame for bonding; 3) inserting the lead wire into the corresponding first through hole on the ceramic base plate, and sleeved the lead wire with a AgCu28 solder ring matching its diameter; 4) Adapt the outer lead positioning mold to the lead; 5) Place the assembled metal shell product into a nitrogen-hydrogen mixed atmosphere furnace for welding at a welding temperature of 795-805°C.

6. The method for preparing a high-reliability ceramic metal housing according to claim 5, characterized in that: The intra-cavity positioning mold is provided with a frame blind hole for positioning the metal frame, a first positioning hole for positioning the ceramic base plate, and a lead blind hole for positioning the lead; the depth of the first positioning hole is 0.9-1 mm.

7. The method for preparing a high-reliability ceramic metal housing according to claim 6, characterized in that: The diameter of the lead wire blind hole in the intra-cavity positioning mold for positioning the lead wire is 1.2 to 1.4 times the diameter of the lead wire.

8. The method for preparing a high-reliability ceramic-metal casing according to claim 5, characterized in that: The outer lead positioning mold is provided with a second through hole for positioning the lead, and the outer lead positioning mold is provided with a second positioning hole for positioning the ceramic base plate; the depth of the second positioning hole is 5.3-5.7 mm.

9. The method for preparing a high-reliability ceramic-metal casing according to claim 5, characterized in that: During welding, a mixture of nitrogen and hydrogen gases is used, with the concentration of hydrogen being 1 to 1.5 times that of nitrogen.

10. The method for preparing a high-reliability ceramic-metal casing according to claim 5, characterized in that: The welding time is 6 to 8 minutes, and then the sealing is completed at a cooling rate of 3 to 5°C / min.

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