High-voltage-resistant low-thermal-resistance metal ceramic patch shell packaging structure

Abstract

The utility model provides a packaging structure of a high-voltage-resistant low-thermal-resistance metal ceramic patch shell. The packaging structure comprises an insulating base, an electrode assembly is mounted at the bottom of the insulating base, and an outer frame is mounted on the side wall of the insulating base; the electrode assembly comprises a first electrode plate, a second electrode plate and a third electrode plate, the edges of the first electrode plate, the second electrode plate and the third electrode plate are machined to be in a thin-wall shape and attached to the bottom of the insulating base, and the middles of the first electrode plate, the second electrode plate and the third electrode plate extend into the insulating base from through holes machined in the bottom of the insulating base. The first electrode plate and the second electrode plate are installed at one end of the insulating base side by side, and the third electrode plate is installed at the other end of the insulating base. According to the utility model, a plurality of chips can be welded on the electrode plates, the power can be greatly improved after the electrode plates are connected in series, and the voltage withstanding value between the chips is ensured by the distance between the electrode plates; and the inner electrode and the outer electrode are integrated, so that the electrode has better heat transfer and electric transfer performance.

Description

Technical Field

[0001] The utility model relates to a high-voltage-resistant and low-thermal-resistance metal-ceramic patch housing packaging structure. Background Art

[0002] There are mainly two states for existing metal-ceramic patch housings. One is low thermal resistance but low voltage resistance, such as SMD-1, SMD-0.2, SMD-0.5 and other packaging housings. The other is high voltage resistance but high thermal resistance, such as SMD-0.1, SMD-0.3 and other packaging housings. It is difficult to balance high voltage resistance and good heat dissipation performance. With the development of semiconductor power devices towards high voltage and high power, the current housings are increasingly unable to meet the requirements of high voltage and high power. Content of the Utility Model

[0003] To solve the above technical problems, the utility model provides a high-voltage-resistant and low-thermal-resistance metal-ceramic patch housing packaging structure.

[0004] The utility model is realized through the following technical solutions.

[0005] A high-voltage-resistant and low-thermal-resistance metal-ceramic patch housing packaging structure provided by the utility model includes an insulating base; an electrode assembly is installed at the bottom of the insulating base, and an outer frame is installed on the side wall of the insulating base; the electrode assembly includes a first electrode plate, a second electrode plate and a third electrode plate. The edges of the first electrode plate, the second electrode plate and the third electrode plate are processed into thin-wall shapes and are attached to the bottom of the insulating base. The middle parts of the first electrode plate, the second electrode plate and the third electrode plate extend into the insulating base through through-holes processed at the bottom of the insulating base. The first electrode plate and the second electrode plate are arranged side by side at one end of the insulating base, and the third electrode plate is installed at the other end of the insulating base.

[0006] The minimum distance between the first electrode plate, the second electrode plate and the third electrode plate is 1.4 mm.

[0007] The sizes of the first electrode plate and the second electrode plate are 4.6 mm × 4.6 mm, and the size of the third electrode plate is 12.6 mm × 4.6 mm.

[0008] The insulating base is made of Al2O3 black ceramic material.

[0009] The material of the outer frame is iron-nickel alloy.

[0010] The materials of the first electrode plate, the second electrode plate and the third electrode plate are molybdenum-copper alloy.

[0011] The beneficial effects of the present utility model are as follows: Multiple chips can be welded to the electrode plates. After being connected in series, the power can be greatly improved. The distance between each electrode plate ensures the withstand voltage value between the chips. Moreover, the inner and outer electrodes are integrated, enabling the electrode to have better heat transfer and electrical transfer performance. Description of the Drawings

[0012] Figure 1 It is a schematic diagram of the system principle of the present utility model;

[0013] Figure 2 It is a schematic diagram of the system principle of the present utility model;

[0014] Figure 3 It is a schematic diagram of the system principle of the present utility model.

[0015] In the figure: 1 - insulating base, 2 - outer frame, 3 - first electrode plate, 4 - second electrode plate, 5 - third electrode plate. Detailed Implementation Manner

[0016] The technical solution of the present utility model will be further described below, but the scope of protection claimed is not limited thereto.

[0017] A high-voltage-resistant and low-thermal-resistance metal-ceramic patch shell packaging structure includes an insulating base 1; an electrode assembly is installed at the bottom of the insulating base 1, and an outer frame 2 is installed on the side wall of the insulating base 1; the electrode assembly includes a first electrode plate 3, a second electrode plate 4, and a third electrode plate 5. The edges of the first electrode plate 3, the second electrode plate 4, and the third electrode plate 5 are processed into thin-wall shapes and are attached to the bottom of the insulating base 1. The middle parts of the first electrode plate 3, the second electrode plate 4, and the third electrode plate 5 extend into the insulating base 1 through through-holes processed at the bottom of the insulating base 1. The first electrode plate 3 and the second electrode plate 4 are arranged side by side at one end of the insulating base 1, and the third electrode plate 5 is installed at the other end of the insulating base 1.

[0018] The distance between the first electrode plate 3, the second electrode plate 4, and the third electrode plate 5 is 1.4 mm (min) for each.

[0019] The sizes of the first electrode plate 3 and the second electrode plate 4 are 4.6 mm × 4.6 mm, and the size of the third electrode plate 5 is 12.6 mm × 4.6 mm.

[0020] The insulating base 1 is made of Al2O3 black ceramic material.

[0021] The material of the outer frame 2 is iron-nickel alloy.

[0022] The materials of the first electrode plate 3, the second electrode plate 4, and the third electrode plate 5 are molybdenum-copper alloy.

[0023] Such as Figure 1As shown, the bonding base is made of Al2O3 black ceramic, which has the advantages of high hardness, corrosion resistance, good insulation performance, high temperature resistance, light weight, good thermal conductivity, etc., and the insulation resistance is ≥1×1010 / Ω (DC / 500V); Mark 2 is the frame, which is used for sealing welding when the outer shell is sealed. The material is iron-nickel alloy. The iron-nickel alloy has the advantages of good thermal stability, easy processing, and corrosion resistance; Marks 3 and 4 are electrode plates. The materials are molybdenum copper. Molybdenum copper has the advantages of good electrical and thermal conductivity, low thermal expansion coefficient, and high strength.

[0024] The design dimensions are shown in the attached figure. The distance between the two small electrode plates and the distance between the small electrode plate and the large electrode plate is D=E=1.4mm(min). According to the air breakdown voltage of 3000V / mm, the withstand voltage between the two small electrodes can theoretically reach 4200V. The thickness of the electrode plate is F=0.8mm(MAX). Since the inner and outer shells of the electrode plate are designed as one body, the thickness is only 0.8mm. While taking into account the strength, it has a very short heat transfer and electrical transfer path, and the thermal resistance can reach below 0.2℃ / W. The length and width of the part G=H=4.6mm(Min), and can weld chips with an area of ​​4mm×4mm or less. The internal width and length of the large electrode plate are I=4.6mm(Min), J=12.6mm(Min), and can weld two chips with a size of 4mm×4mm or less. If used to weld transient voltage suppression diode chips, the transient power of a single 4mm×4mm chip is 3000W, and a total of 8 4mm×4mm chips can be welded, and the series transient power can reach 24000W.

[0025] In general, the shell adopts an integrated design of internal and external electrodes, which greatly improves the heat conduction efficiency. The thermal resistance is only 0.2℃ / W. The thermal matching between each part is good, and the withstand voltage between different electrodes reaches 4200V, taking into account both high voltage resistance and heat dissipation performance.

[0026] Example: Figures 1 to 3 The structure shown in the figure is used to produce the shell. The insulating base, electrode and frame in the figure are connected together by welding. Since the thermal expansion coefficients of the four selected materials are close, they can meet the requirements of GJB923A-2004 General Specification for Semiconductor Discrete Device Shells, temperature cycle 500 times, conditions: -55℃~+175℃, leakage rate ≦1x10-3 / Pa.cm3 / s, and can meet the environmental requirements of aerospace. At the same time, after insulation testing, the withstand voltage between the two electrodes in normal temperature and pressure air environment is as follows:

[0027] Serial number 1 2 3 4 5 Voltage withstand value between small electrodes 3658V 3647V 3655V 3653V 3640V Voltage withstand value between large and small electrodes 3637V 3558V 3654V 3607V 3614V

[0028] It can be seen that due to the tip discharge effect at the four corners of the electrode, the withstand voltage between the two electrodes can actually reach more than 3500V; to test the internal and external thermal resistances of the electrode, a 4mm×4mm diode chip was welded onto the electrode for steady-state thermal resistance testing. The steady-state thermal resistance test data for the inside and outside of the electrode are as follows:

[0029] Serial number 1 2 3 4 5 Steady-state thermal resistance of small electrode 0.16℃ / W 0.17℃ / W 0.16℃ / W 0.18℃ / W 0.17℃ / W Steady-state thermal resistance of large electrode 0.17℃ / W 0.16℃ / W 0.18℃ / W 0.17℃ / W 0.18℃ / W

[0030] It can be seen that the steady-state thermal resistance of the inside and outside of the electrode can reach below 0.2℃ / W.

[0031] Application scenarios: This housing has 3 electrode plates, each of which is independent. Each electrode plate can be welded with a chip, and both the inside and outside of each electrode plate are integrated, with consistent thermal and electrical conduction efficiency. It can be widely used in discrete devices such as diodes, triodes, and half-bridges; in addition, chips can be welded to all 3 electrodes, and after internal interconnection, parallel, series, and other usage scenarios can be formed; for example, by connecting diodes in series inside, different voltages can be obtained between every two electrodes, and up to 3 voltage segments can be obtained, which has a wide range of applications for high-voltage series usage scenarios.

[0032] The design drawing of the cermet housing is shown in the attached drawing. The dimensions in the attached drawing are in mm. For the dimensions not marked with tolerances, they follow the GB / T1804-m level. Dimensions A, B, and C are the length, width, and height of the housing, where A = B = 15mm (MAX), C = 5mm (MAX), D is the distance between the outer sides of the two small electrode plates, D = 1.4mm (min), E is the distance between the outer side of the small electrode plate and the outer side of the large electrode plate, E = 1.4mm (min), F is the thickness of the electrode plate, F = 0.8mm (MAX), G and H are the length and width dimensions inside the small electrode plate, G = H = 4.6mm (Min), I and J are the width and length dimensions inside the large electrode plate, I = 4.6mm (Min), and J = 12.6mm (Min).

Claims

1. A high-voltage-resistant and low-thermal-resistance cermet patch housing encapsulation structure, comprising an insulating base (1), characterized in that: An electrode assembly is installed at the bottom of the insulating base (1), and an outer frame (2) is installed on the side wall of the insulating base (1); the electrode assembly includes a first electrode plate (3), a second electrode plate (4), and a third electrode plate (5). The edges of the first electrode plate (3), the second electrode plate (4), and the third electrode plate (5) are processed into thin-wall shapes and are attached to the bottom of the insulating base (1). The middle parts of the first electrode plate (3), the second electrode plate (4), and the third electrode plate (5) extend into the insulating base (1) through through-holes processed at the bottom of the insulating base (1). The first electrode plate (3) and the second electrode plate (4) are arranged side by side at one end of the insulating base (1), and the third electrode plate (5) is installed at the other end of the insulating base (1).

2. The high-voltage-resistant and low-thermal-resistance cermet patch housing encapsulation structure according to claim 1, characterized in that: The minimum distance between the first electrode plate (3), the second electrode plate (4), and the third electrode plate (5) is 1.4 mm.

3. The high-voltage-resistant and low-thermal-resistance cermet patch housing encapsulation structure according to claim 1, wherein: The sizes of the first electrode plate (3) and the second electrode plate (4) are 4.6 mm × 4.6 mm, and the size of the third electrode plate (5) is 12.6 mm × 4.6 mm.

4. The high-voltage-resistant and low-thermal-resistance cermet patch housing encapsulation structure according to claim 1, characterized in that: The insulating base (1) is made of Al2O3 black ceramic material.

5. The high-voltage-resistant and low-thermal-resistance cermet patch housing encapsulation structure according to claim 1, characterized in that: The material of the outer frame (2) is iron-nickel alloy.

6. The high-voltage-resistant and low-thermal-resistance cermet patch housing encapsulation structure according to claim 1, characterized in that: The materials of the first electrode plate (3), the second electrode plate (4), and the third electrode plate (5) are molybdenum-copper alloy.

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