A positioning jig for AMB ceramic substrate sintering

Abstract

The utility model discloses a kind of positioning fixture for AMB ceramic substrate sintering in the technical field of ceramic substrate sintering jig, including bottom plate, the bottom plate is provided with clamping block, the number of clamping block is multiple, multiple The clamping block is arrayed distribution, clamping groove is opened in the clamping block, positioning groove is formed between multiple clamping block and clamping groove, inner flow hole is opened in the bottom plate, positioning hole is opened in the bottom plate, the bottom plate is provided with pressing plate, the pressing plate is used to adjust positioning pressure, the bottom plate is provided with connecting assembly. The utility model is by setting array clamping block and the multiple-point constraint of ladder type positioning groove, improve substrate positioning accuracy, solve the problem of brazing micro-displacement caused by single-side positioning, simultaneously, the gradient cooling flow passage of inner flow hole, can improve volatile gas discharge efficiency, reduce porosity, inhibit interface delamination risk caused by the difference of thermal expansion coefficient.

Description

Technical Field

[0001] This utility model relates to the field of ceramic substrate sintering fixtures, and in particular to a positioning fixture for AMB ceramic substrate sintering. Background Technology

[0002] AMB (Active Metal Brazing) technology is an advanced welding method for high-strength connections between ceramics and metals, primarily used in power electronic module packaging. This technology uses a solder containing active metals, which reacts chemically with the ceramic at high temperatures (usually in a vacuum or inert atmosphere) to form a stable interface transition layer, thereby achieving a reliable metallurgical bond between the ceramic substrate and the metal.

[0003] The process requires precise control of temperature profiles, pressure, and atmosphere to avoid warping, porosity, or delamination. AMB connectors feature high thermal conductivity, high mechanical strength, and excellent thermal cycling reliability, making them widely used in high-power-density device packaging for applications such as new energy vehicles, rail transportation, and aerospace.

[0004] However, existing technologies have some problems: the positioning groove of traditional fixtures has a large tolerance for matching with the substrate. Therefore, the substrate is prone to micro-displacement during high-temperature brazing, which leads to misalignment between the metal layer and the ceramic substrate, affecting the connection accuracy. Due to the offset deviation, the difference in thermal expansion coefficients between the ceramic substrate and the metal layer during cooling will cause uneven shrinkage, resulting in local stress concentration, which will lead to substrate warping or interface delamination, affecting the long-term reliability of the module. Therefore, we propose a positioning fixture for sintering AMB ceramic substrates. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a positioning fixture for sintering AMB ceramic substrates, which incorporates a multi-level positioning structure and a pressure adjustment structure to improve the positioning accuracy between the ceramic substrate and the metal layer.

[0006] The purpose of this utility model is achieved as follows: a positioning fixture for sintering AMB ceramic substrates includes a base plate, a plurality of locking blocks arranged in an array on the base plate, a locking groove formed on each locking block, a positioning groove formed between the plurality of locking blocks and the locking groove, an internal flow hole and a positioning hole on the base plate, a pressure plate for adjusting the positioning pressure on the base plate, and a connecting component on the base plate.

[0007] Optionally, there are multiple positioning grooves, which are interconnected and are arranged in a stepped groove shape.

[0008] Optionally, the internal flow hole is located inside the bottom plate, the internal flow hole is open at both ends, the internal flow hole is S-shaped, and the internal flow hole and the positioning groove are distributed vertically.

[0009] Optionally, a positioning screw is provided between the pressure plate and the base plate. The positioning screw is rotatably connected to the pressure plate and threadedly connected to the positioning hole. A pressure pin is threadedly connected to the pressure plate and is used for positioning pressure adjustment.

[0010] Optionally, the connecting component includes a connecting block and a dovetail block. The connecting block has a dovetail groove with openings at both ends. The dovetail groove is correspondingly arranged with the dovetail block, and the dovetail block is inserted into the dovetail groove.

[0011] Optionally, the connecting block is fixedly connected to one side of the base plate, and the swallow-shaped block is fixedly connected to the other side of the base plate.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0013] 1. By setting up multi-point constraints of array card blocks and stepped positioning slots, the positioning accuracy of the substrate is improved, and the problem of brazing micro-displacement caused by single-sided positioning is solved. At the same time, the gradient cooling channel of the internal flow hole can improve the efficiency of volatile gas discharge, reduce porosity, and suppress the risk of interface delamination caused by the difference in thermal expansion coefficient.

[0014] 2. Through modular design, the quick insertion of dove-shaped blocks and connecting blocks supports multi-module adaptation of the substrate, improves changeover efficiency, meets the needs of substrates of different sizes, and the modular base plate can reduce maintenance costs, while also having the advantages of high precision, high rigidity and high compatibility. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall structure provided by this utility model.

[0017] Figure 2 This is a schematic diagram of the pressure plate structure provided by this utility model.

[0018] Figure 3 This is a schematic diagram of the positioning groove structure provided by this utility model.

[0019] Figure 4This is a cross-sectional view of the internal flow hole structure provided by this utility model.

[0020] Figure 5 This is a structural diagram of the connection component provided by this utility model.

[0021] In the diagram: 1. Base plate; 11. Locking block; 12. Locking groove; 13. Internal flow hole; 14. Positioning hole; 2. Positioning groove; 3. Pressure plate; 31. Positioning screw; 32. Pressure pin; 4. Connecting assembly; 41. Connecting block; 42. Dovetail groove; 43. Dovetail block. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] like Figures 1 to 5 The positioning fixture shown includes a base plate 1, on which multiple locking blocks 11 are arranged in an array. Each locking block 11 has a locking groove 12, and a positioning groove 2 is formed between the multiple locking blocks 11 and the locking groove 12. The base plate 1 has an internal flow hole 13 and a positioning hole 14. A pressure plate 3 is provided on the base plate 1 for adjusting the positioning pressure. A connecting component 4 is provided on the base plate 1.

[0024] It should be noted that the base plate 1, as the base, is made of graphite or silicon carbide material, taking advantage of its high thermal conductivity and low coefficient of thermal expansion to match the ceramic substrate.

[0025] Furthermore, the contact surface of the base plate 1 needs to be coated with a high-temperature resistant and anti-oxidation layer (such as a SiC coating) so that it can form a dense SiO2 passivation layer in a high-temperature brazing environment of 800~900℃, reduce the oxidation rate, and thus improve the service life.

[0026] Furthermore, in the embodiments provided by this utility model, graphite or silicon carbide is used as the base, and a stepped positioning groove 2 is provided on the upper surface of the base. The tolerance of the inner wall of the groove is ±0.02mm. A pressure plate 3 is provided on the upper side, and a height-adjustable ceramic pin is embedded therein. An external pressure adjustment knob is connected to provide positioning pressure for the substrate. An S-shaped internal flow hole 13 is provided inside the base as a cooling channel. The two ends of the internal flow hole 13 are open and connected to an external circulation device. Connecting components 4 are provided on both sides of the base plate 1 for connecting the expansion adapter block.

[0027] Specifically, there are multiple positioning grooves 2, which are connected to each other and are arranged in a stepped groove shape.

[0028] Furthermore, the card slots 12 are set at each corner of the card blocks 11, and the card blocks 11 are arranged in a row. Thus, four adjacent card blocks 11 and the card slots 12 at their corners form a stepped groove, forming multiple constraints. This can control the substrate offset within ±0.02mm. At the same time, the stepped groove can disperse thermal stress through multi-point contact, reduce the warping of the ceramic substrate at high temperatures, and avoid interface delamination.

[0029] Furthermore, the size of the positioning slot 2 can be controlled by setting the distribution of the card blocks 11, thereby adapting to substrates of different sizes.

[0030] Furthermore, the gaps between the blocks 11 form an intermittent channel, allowing the brazing filler metal vapors to escape quickly, reducing porosity, and facilitating fixture cleaning.

[0031] Specifically, the internal flow hole 13 is located inside the base plate 1. The internal flow hole 13 is open at both ends and is S-shaped. The internal flow hole 13 and the positioning groove 2 are distributed vertically.

[0032] It should be noted that the path density of the cooling channel decreases from the center to the edge, and the channel cross-section is semi-circular with a diameter of 1 to 3 mm.

[0033] Furthermore, an S-shaped layout is adopted and distributed vertically with the positioning groove 2 to form a three-dimensional airflow channel, which improves the efficiency of brazing volatile gas discharge and suppresses the formation of pores. The cooling channel adopts a gradient setting with denser centers and sparser edges to adapt to the thermal field distribution during substrate sintering. Generally, the center temperature is 20-30°C higher than the edge temperature. Combined with the semi-circular cross-section, turbulent cooling is achieved, the substrate cooling rate is controlled, microcracks caused by rapid cooling are avoided, and the cooling efficiency is improved, thereby shortening the production cycle.

[0034] Specifically, a positioning screw 31 is provided between the pressure plate 3 and the base plate 1. The positioning screw 31 is rotatably connected to the pressure plate 3 and threadedly connected to the positioning hole 14. A pressure pin 32 is threadedly connected to the pressure plate 3 and is used for positioning pressure adjustment.

[0035] Furthermore, by connecting the positioning screw 31 to the base plate 1 by thread, quick locking and precise alignment can be achieved. At the same time, the threaded adjustment structure of the pressure pin 32 can control the pressing pressure to adapt to the sintering requirements of substrates of different thicknesses. The rotating positioning screw 31 allows the pressure plate 3 to finely adjust the angle, compensate for the assembly tolerance between the substrate and the fixture, avoid warping or cracks caused by local stress concentration, shorten the fixture changeover time, and improve work and production efficiency.

[0036] Specifically, the connecting component 4 includes a connecting block 41 and a dovetail block 43. The connecting block 41 has a dovetail groove 42 with openings at both ends. The dovetail groove 42 is correspondingly set with the dovetail block 43. The dovetail block 43 is inserted into the dovetail groove 42. The connecting block 41 is fixedly connected to one side of the base plate 1, and the dovetail block 43 is fixedly connected to the other side of the base plate 1.

[0037] Furthermore, a dove-shaped block 43 is provided on one side of the base plate 1, and a connecting block 41 is provided on the other side. The dove-shaped block 43 and the connecting block 41 are inserted to realize the rapid splicing of the expansion adapter block, improve the compatibility of the fixture and the flexibility of the production line. The self-locking characteristic of the dovetail structure ensures the connection is stable at high temperature, while allowing a certain thermal expansion tolerance to avoid stress concentration caused by temperature changes.

[0038] At the same time, it adapts to the sintering requirements of substrates of different sizes, improves the efficiency of changeover, and the interlocking surface needs to be precision ground, thereby reducing the expansion and maintenance costs of the fixture.

[0039] The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A positioning fixture for sintering AMB ceramic substrates, comprising a base plate (1), characterized in that: The base plate (1) is provided with a number of locking blocks (11), which are arranged in an array. The locking blocks (11) are provided with a slot (12), and a positioning groove (2) is formed between the multiple locking blocks (11) and the slot (12). The base plate (1) is provided with an internal flow hole (13) and a positioning hole (14). The base plate (1) is provided with a pressure plate (3) for adjusting the positioning pressure. The base plate (1) is provided with a connecting component (4).

2. The positioning fixture for sintering AMB ceramic substrates according to claim 1, characterized in that: The number of positioning grooves (2) is multiple, and the multiple positioning grooves (2) are connected to each other. The positioning grooves (2) are arranged in a stepped groove shape.

3. A positioning fixture for sintering AMB ceramic substrates according to claim 1, characterized in that: The internal flow hole (13) is located inside the bottom plate (1). The internal flow hole (13) is open at both ends and is S-shaped. The internal flow hole (13) and the positioning groove (2) are distributed vertically.

4. A positioning fixture for sintering AMB ceramic substrates according to claim 1, characterized in that: A positioning screw (31) is provided between the pressure plate (3) and the base plate (1). The positioning screw (31) is rotatably connected to the pressure plate (3). The positioning screw (31) is threadedly connected to the positioning hole (14). A pressure pin (32) is threadedly connected to the pressure plate (3). The pressure pin (32) is used for positioning pressure adjustment.

5. A positioning fixture for sintering AMB ceramic substrates according to claim 1, characterized in that: The connecting component (4) includes a connecting block (41) and a dovetail block (43). The connecting block (41) has a dovetail groove (42) with openings at both ends. The dovetail groove (42) is correspondingly arranged with the dovetail block (43), and the dovetail block (43) is inserted into the dovetail groove (42).

6. A positioning fixture for sintering AMB ceramic substrates according to claim 5, characterized in that: The connecting block (41) is fixedly connected to one side of the base plate (1), and the swallow-shaped block (43) is fixedly connected to the other side of the base plate (1).

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