High temperature co-fired ceramic flat package welding method

Abstract

The application discloses a high-temperature co-fired ceramic flat shell welding method, which comprises the following steps: step 1, placing a high-temperature co-fired flat ceramic body in a reserved ceramic clamping groove on a tool base, and making the metallized lead area of the high-temperature co-fired flat ceramic body that needs to be welded face upward; step 2, placing a solder sheet on the welding surface of the high-temperature co-fired flat ceramic body; step 3, placing a flat shell in a reserved shell clamping groove on the tool base and simultaneously pressing the solder sheet; step 4, placing a frame into a positioning clamping groove on the tool base; step 5, placing a pressing block into a guide groove of the frame, the guide groove and the shell clamping groove in the tool base are one-to-one corresponding, so that the pressing block presses the flat shell in the shell clamping groove of the tool base through the guide groove; and step 6, placing the tool assembly assembled through the above steps into a high-temperature furnace for heating. The method is simple to operate and easy to master, has strong welding firmness, avoids the problem of adhesion between the solder and the tool, and greatly improves the qualified rate of welding.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-power micro-assembly circuit, in particular to a high-temperature co-fired ceramic flat shell welding method. BACKGROUND

[0002] High-temperature co-fired ceramic is a kind of substrate used by semiconductor integrated circuits, which adopts high-melting-point metal heating resistance paste such as tungsten, molybdenum, molybdenum, manganese, etc. to print on 92-96% alumina tape casting ceramic green body according to the requirements of heating circuit design, 4-8% sintering aid, then multi-layer superposition, co-fired at 1500-1600℃ high temperature, so as to have the advantages of corrosion resistance, high temperature resistance, long service life, high efficiency, energy saving, uniform temperature, good heat conduction performance, fast heat compensation speed, etc., and does not contain harmful substances such as lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl, polybrominated diphenyl ether, etc., which meets the requirements of environmental protection.

[0003] High-temperature co-fired ceramic flat shell is a kind of small-sized surface-mounted shell, and the wing-shaped lead is beneficial to relieve the stress between the shell and the PCB and improve the reliability. However, the existing high-temperature co-fired ceramic flat shell welding operation is complex, the welding effect is poor, and the welding firmness is poor, which directly leads to low qualified rate in the production and processing process. SUMMARY

[0004] The purpose of the present application is to provide a high-temperature co-fired ceramic flat shell welding method, which is easy to operate and has strong welding firmness, avoids the problem of adhesion of solder and tooling, and greatly improves the qualified rate of welding.

[0005] In order to achieve the above-mentioned purpose, the present application provides a high-temperature co-fired ceramic flat shell welding method, which comprises:

[0006] Step 1, placing the high-temperature co-fired flat ceramic body in the ceramic clamping groove reserved on the tooling base, and making the metallized lead area of the high-temperature co-fired flat ceramic body which needs to be welded face upward;

[0007] Step 2, placing the solder sheet on the welding surface of the high-temperature co-fired flat ceramic body;

[0008] Step 3, placing the flat shell in the shell clamping groove reserved on the tooling base and pressing the solder sheet at the same time;

[0009] Step 4, installing the frame into the positioning clamping groove on the tooling base;

[0010] Step 5, installing the pressing block into the guide groove of the frame, and the guide groove and the shell clamping groove in the tooling base are one-to-one corresponding, so that the pressing block presses the flat shell in the shell clamping groove of the tooling base through the guide groove;

[0011] Step 6, the tool assembly assembled through the above steps is put into a high-temperature furnace for heating;

[0012] In step 6, the temperature curve of heating is as follows:

[0013] 0-45min, continuously heated to 585℃;

[0014] 45-60min, maintained at 585℃;

[0015] 60-64min, continuously heated to 855℃;

[0016] 64-68min, maintained at 855℃;

[0017] 68-72min, gradually cooled to 550℃;

[0018] 72-74min, maintained at 550℃;

[0019] After 74min, gradually cooled to 25℃.

[0020] Preferably, in step 2, the outer contour of the solder sheet is consistent with the contour of the lead area of the high-temperature co-fired flat ceramic body.

[0021] Preferably, the solder sheet is a ring-shaped silver-copper-indium-tin solder sheet with a thickness of 0.05mm.

[0022] Preferably, the tool base is made of three high graphite.

[0023] Preferably, the pressing block is a graphite pressing block made of three high graphite.

[0024] Preferably, the frame is a graphite frame made of three high graphite.

[0025] Preferably, the ceramic card slot on the tool base is provided with a ventilation hole.

[0026] According to the above technical solution, the three high graphite is used as the tool for welding, the high-temperature co-fired ceramic is placed inside the tool base, the lead area of the ceramic is placed with the solder sheet, the solder sheet is placed with the flat shell, the graphite frame required for positioning is placed on the base, the pressing block is placed through the guide slot on the graphite frame, a pressure is applied to the flat shell, the effective welding of the ceramic and the flat shell during the soldering process is ensured, the tool with the workpiece is placed into the high-temperature furnace for heating according to the specific temperature curve. In this way, the graphite is used to quickly heat and cool the tool and the workpiece with the high thermal conductivity, which can not only ensure the firmness of the workpiece, but also ensure that the solder does not overflow and diffuse on the workpiece, thereby improving the qualified rate of the ceramic flat shell.

[0027] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and are

[0029] Figure 1 is a side view of an assembly component in a high-temperature co-fired ceramic flat package welding method provided by the present application;

[0030] Figure 2 is a top view of an assembly component in a high-temperature co-fired ceramic flat package welding method provided by the present application;

[0031] Figure 3 is a sectional view of A-A in Figure 2

[0032] Figure 4 is an enlarged view of I part in Figure 3

[0033] Figure 5 is a heating temperature curve diagram in a high-temperature co-fired ceramic flat package welding method provided by the present application.

[0034] BRIEF DESCRIPTION OF DRAWINGS

[0035] 1 - tool base 2 - pressing block

[0036] 3 - frame 4 - high-temperature co-fired flat ceramic body

[0037] 5 - solder sheet 6 - flat package DETAILED DESCRIPTION

[0038] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0039] In the present application, the orientation words contained in the terms "inner, outer, upper, lower" and the like represent only the orientation of the terms in the normal use state or the common name understood by those skilled in the art, unless otherwise stated, and should not be considered as a limitation of the terms.

[0040] Referring to Figures 1 to 4 , the present application provides a high-temperature co-fired ceramic flat package welding method, which comprises:

[0041] Step 1, placing the high-temperature co-fired flat ceramic body 4 into the ceramic clamping slot reserved on the tool base 1, and making the metallized lead area of the high-temperature co-fired flat ceramic body 4 that needs to be welded face upward;

[0042] ​​Step 2: Place the solder sheet 5 on the welding surface of the high-temperature co-fired flat ceramic body 4;

[0043] Step 3: Place the flat outer shell 6 into the reserved outer shell slot on the tooling base 1 and press down the solder sheet 5 at the same time;

[0044] Step 4: Insert frame 3 into the positioning slot on tooling base 1;

[0045] Step 5: Insert the pressure block 2 into the guide groove of the frame 3. The guide groove and the outer shell slot in the tooling base 1 correspond one-to-one, so that the pressure block 2 presses the flat outer shell 6 in the outer shell slot of the tooling base 1 through the guide groove.

[0046] Step 6: Place the tooling components assembled through the above steps into a high-temperature furnace for heating;

[0047] Among them, such as Figure 5 As shown, the temperature curve for heating in step 6 is as follows:

[0048] 0-45 minutes, continue heating to 585℃;

[0049] Maintain at 585℃ for 45-60 minutes;

[0050] Continue heating for 60-64 minutes, raising the temperature to 855℃;

[0051] Maintain at 855℃ for 64-68 minutes;

[0052] 68-72 minutes, gradually cool down to 550℃;

[0053] 72-74 minutes, maintain at 550℃;

[0054] After 74 minutes, the temperature was gradually reduced to 25°C.

[0055] In step 2, the solder sheet 5 can be a ring-shaped silver-copper-indium-tin solder sheet with a thickness of 0.05 mm. At the same time, the outer contour of the solder sheet 5 is consistent with the contour of the lead area of ​​the high-temperature co-fired flat ceramic body 4. In this way, the outer contour fits the lead area of ​​the high-temperature co-fired ceramic. This type of solder can ensure that the solder accumulates in the connection area between the flat shell and the high-temperature co-fired ceramic, while also ensuring that there is no excessive wetting on the shell.

[0056] In addition, the tooling base 1 is made of high-quality graphite. The base has multiple holes for placing ceramics. Ventilation holes are provided in the ceramic holes to ensure that the workpiece is in full contact with gas during the welding process. The holes for placing ceramics are slightly lower than the ceramics, exposing the welding surface to be welded. At the same time, square grooves are provided on the base for placing flat shells to ensure the relative position of the ceramics and flat shells.

[0057] The graphite block 2 is made of high-purity graphite, and is positioned on the frame 3. The graphite block 2 can press the flat shell 6 on the tool base 1 through the guide slot on the frame 3 and the square slot on the flat shell 6.

[0058] The graphite frame 3 is made of high-purity graphite, and is positioned on the positioning slot on the tool base 1. The relative position of the guide slot on the frame 3 and the positioning slot on the tool base 1 is ensured.

[0059] The high-purity, high-density and high-strength graphite can avoid the influence of graphite powder on the welding firmness. Meanwhile, the graphite material has the characteristic of fast temperature rising and falling. The temperature of the high-temperature co-fired ceramic body 4, the solder sheet 5 and the flat shell 6 assembled on the tool base 1 is rapidly increased, so that the solder sheet 5 is rapidly melted to form solder accumulation in the connection area between the ceramic lead area and the flat shell 6. The temperature is rapidly decreased to ensure that the solder does not excessively wet the ceramic metallization layer and climb to the welding surface that does not need to be welded. Thus, the welding firmness of the workpiece is ensured, and the solder does not overflow and spread on the workpiece.

[0060] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the specific details in the above-described embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all belong to the protection scope of the present application.

[0061] In addition, it should be noted that each specific technical feature described in the above-described specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0062] In addition, various different embodiments of the present application can be combined in any manner, as long as they do not deviate from the technical concept of the present application, and they should be considered as disclosed content of the present application.

Claims

1. A method for welding a flat shell of high-temperature co-fired ceramic, characterized in that, The welding method comprises the following steps: Step 1, placing the high-temperature co-fired flat ceramic body (4) in the ceramic clamping groove reserved on the tool base (1), and making the metallized lead area of the high-temperature co-fired flat ceramic body (4) to be welded face upward; Step 2, placing the solder sheet (5) on the welding surface of the high-temperature co-fired flat ceramic body (4); Step 3, placing the flat shell (6) in the shell clamping groove reserved on the tool base (1) and pressing the solder sheet (5) at the same time; Step 4, placing the frame (3) into the positioning clamping groove on the tool base (1); Step 5, placing the pressing block (2) into the guide groove of the frame (3), the guide groove and the shell clamping groove in the tool base (1) are one-to-one corresponding, so that the pressing block (2) presses the flat shell (6) in the shell clamping groove of the tool base (1) through the guide groove; Step 6, placing the tool assembly assembled through the above steps into a high-temperature furnace for heating; In step 6, the temperature curve of heating is as follows: 0-45min, continuously heating to 585℃; 45-60min, maintaining 585℃; 60-64min, continuously heating to 855℃; 64-68min, maintaining 855℃; 68-72min, gradually cooling to 550℃; 72-74min, maintaining 550℃; After 74min, gradually cooling to 25℃; The ceramic clamping groove on the tool base (1) is provided with a ventilation hole.

2. The high temperature co-fired ceramic flat package welding method according to claim 1, characterized by, In step 2, the outer contour of the solder sheet (5) is consistent with the lead area contour of the high-temperature co-fired flat ceramic body (4).

3. The method of claim 2, wherein the method further comprises, The solder sheet (5) is a ring-shaped silver-copper-indium-tin solder sheet with a thickness of 0.05mm.

4. The method of claim 1, wherein, The tool base (1) is made of three high graphite.

5. The method of claim 1, wherein, The pressing block (2) is a graphite pressing block made of three high graphite.

6. The method of claim 1, wherein, The frame (3) is a graphite frame made of three high graphite.

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