A method for improving the heat treatment characteristics of ZTA products

Abstract

This method discloses a method for improving the heat treatment characteristics of ZTA products, including the following steps: S1: preparing raw materials; S2: applying AMB paste; S3: processing copper sheets; S4: bonding process; S5: etching with the ZTA substrate; S6: post-etching treatment. This method for improving the heat treatment characteristics of ZTA products, by using an improved AMB method on the ZTA substrate, eliminates small and minute gaps in the substrate after bonding, improving yield and quality. Bonding thicker copper sheets improves electrical and thermal characteristics. When forming solder protrusion structures, it effectively suppresses (disperses) stress on the substrate. Due to this effect, when using copper of 0.4t or more, it ensures more stable performance than DCB 0.3t. Under the same thermal shock conditions, at least twice the significant improvement can be observed. It also exhibits higher thermal conductivity, higher current consumption, faster heat dissipation, and superior reliability after thermal cycling.

Description

Technical Field

[0001] This method relates to the processing of ZTA products, and in particular to a method for improving the heat treatment characteristics of ZTA products. Background Technology

[0002] AMB, defined as active metal brazing, is used for essentially the same purpose as DCB, but overall has higher thermal conductivity, faster heat dissipation, and faster thermal cycling compared to DCB. It is used in higher-configuration products. The manufacturing method involves applying (printing, sputtering, etc.) additional AMB paste to the desired bonding area to bond the copper sheet onto ceramic (typically AlN & Si3N4). Bonding is then achieved through heat treatment in a vacuum or reducing atmosphere. Using AMB on ZTA substrates can improve thermal properties. Currently, ZTA substrates are made by directly bonding copper sheets with an oxide layer on the surface. Compared to DCB using Al2O3, it has superior physical properties, and demand is gradually increasing. Currently, ZTA... In the case of DCB, which contains approximately 10-20% ZrO2 in the substrate, the wettability of Cu+Cu2O liquid is poor compared to the original AL2O3 during high-temperature bonding. During the bonding process, small gaps and fine gaps are generated. Small gaps are greater than 1 mm, and fine gaps are less than 1 mm. There will be more of these gaps compared to AL2O3. Depending on the size and area of ​​the gaps, this will lead to a decrease in yield and the thermal properties of the substrate.

[0003] Therefore, it is necessary to propose a method to improve the heat treatment characteristics of ZTA products to solve the above problems.

[0004] Method content

[0005] The main purpose of this method is to provide a way to improve the heat treatment characteristics of ZTA products, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted in this method is as follows:

[0007] A method for improving the heat treatment properties of ZTA products includes the following steps:

[0008] S1: Prepare raw materials: including ZTA substrate, AMBpaste, copper sheets; prepare processing tools: printing press, ultrasonic cleaner, dryer.

[0009] S2: AMB paste application: AMB paste is applied to the ZTA substrate using a printer to achieve a certain thickness. Further details: The AMB paste, fixed to the SUS mesh screen on the printer, is applied using a polyurethane squeezer to the substrate placed below the screen. It is then dried at 100-200 degrees Celsius for approximately 10 minutes. The screen pattern typically uses #150-#300, and the printing thickness is approximately 5-30µm.

[0010] S3: Copper sheet processing: Take out the processed ZTA substrate and prepare copper sheets of the appropriate size. Clean the copper sheets by soaking them in hot water for 10 minutes. After cleaning, rinse them with deionized water 2-3 times. Place them in an ultrasonic cleaner with cleaning solution and detergent. The number of cleaning cycles depends on the degree of dirt and contamination on the copper sheets. After cleaning, rinse them with deionized water 2-3 times. Place them in a dryer to dry. After drying, perform electrolytic degreasing to remove the oxide film and oil from the surface.

[0011] S4: Bonding process: The cleaned copper sheets are loaded onto both sides of the ZTA substrate and placed in a vacuum or reducing atmosphere while the temperature is maintained at 780-900 degrees Celsius for bonding.

[0012] S5: Etching with ZTA substrate: For wet UV film, a screen printing stencil with graphics is fixed on a screen printing machine. SR (solder resister) ink is used to print the required graphics on the copper sheets. After drying, etching can be performed. For dry UV film, the dry UV film is laminated to the surface of the ZTA product with copper on both sides. An exposure device is used to cure the UV film to the desired shape. The uncured UV film is then removed through a developing process. The exposed copper is etched to form the desired shape.

[0013] S6: Post-etching treatment: After etching the copper to the desired shape, remove the remaining AMB solder from the ceramic surface with chemicals, and then further etch the copper pattern to give the solder in the etched copper part a partially protruding structure.

[0014] As a preferred technical solution of this application, when applying the AMB paste, approximately 100-300g of AMB paste needs to be applied to one square meter of ZTA substrate. When applying the AMB paste, the ambient temperature needs to be maintained at 20-30 degrees Celsius, and the humidity needs to be maintained at 10-40%. At the same time, it is necessary to ensure that there is no dust or debris in the work area. No foreign objects should come into contact with the AMB paste during the application process.

[0015] As a preferred technical solution of this application, the bonding can be carried out under vacuum or reducing atmosphere conditions depending on the on-site situation.

[0016] As a preferred technical solution of this application, the etching process involves first etching the copper sheets, then etching the solder, and finally etching a portion of the copper sheets.

[0017] As a preferred technical solution of this application, when using the DCB method, the copper sheet is generally 0.2-0.3t. When using the AMB method with a protruding solder layer, a copper sheet of 0.4t or more can be used.

[0018] Beneficial effects

[0019] Compared with existing technologies, this method provides a way to improve the heat treatment characteristics of ZTA products, which has the following beneficial effects:

[0020] 1. The method for improving the heat treatment characteristics of this ZTA product involves using an improved AMB bonding method on the ZTA substrate. After bonding, small and minute gaps in the substrate are eliminated, improving yield and quality. Bonding thicker copper sheets improves electrical and thermal properties. When forming solder protrusion structures, it effectively suppresses (disperses) stress on the substrate. Due to this effect, when using copper of 0.4t or more, it ensures more stable performance than DCB 0.3t. Under the same thermal shock conditions, at least twice the significant improvement can be observed. It also has higher thermal conductivity, higher current consumption, faster heat dissipation, and superior reliability after thermal cycling. Furthermore, after etching, it ensures good adhesion between the ink and the substrate. By limiting the ink drying temperature, it ensures normal alkali solubility of the ink, ensuring clean removal of the ink and preventing it from falling off arbitrarily, thus preventing blurring and distortion, and ensuring etching accuracy and decorative results. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the protruding solder layer structure in this method;

[0022] Figure 2 This is a schematic diagram of the product structure using AMB bonding in this method;

[0023] Figure 3 This is an image comparing the bonding surfaces of ZTADCB and ZTAAMB methods using ultrasound in this method.

[0024] Figure 4 This is an image showing the difference in the number of thermal shocks between ZTADCB and ZTAAMB products using this method. Detailed Implementation

[0025] To make the technical means, creative features, objectives and effects of this method easier to understand, the following describes the method in more detail with reference to specific implementation methods.

[0026] A method for improving the heat treatment properties of ZTA products includes the following steps:

[0027] S1: Prepare raw materials: including ZTA substrate, AMBpaste, copper sheets; prepare processing tools: printing press, ultrasonic cleaner, dryer.

[0028] S2: AMB paste application: AMB paste is applied to the ZTA substrate using a printer to achieve a certain thickness. Further details: The AMB paste, fixed to the SUS mesh screen on the printer, is applied using a polyurethane squeezer to the substrate placed below the screen. It is then dried at 100-200 degrees Celsius for approximately 10 minutes. The screen pattern typically uses #150-#300, and the printing thickness is approximately 5-30µm.

[0029] S3: Copper sheet processing: Take out the processed ZTA substrate and prepare copper sheets of the appropriate size. Clean the copper sheets by soaking them in hot water for 10 minutes. After cleaning, rinse them with deionized water 2-3 times. Place them in an ultrasonic cleaner with cleaning solution and detergent. The number of cleaning cycles depends on the degree of dirt and contamination on the copper sheets. After cleaning, rinse them with deionized water 2-3 times. Place them in a dryer to dry. After drying, perform electrolytic degreasing to remove the oxide film and oil from the surface.

[0030] S4: Bonding process: The cleaned copper sheets are loaded onto both sides of the ZTA substrate and placed in a vacuum or reducing atmosphere while the temperature is maintained at 780-900 degrees Celsius for bonding.

[0031] S5: Etching with ZTA substrate: For wet UV film, a screen printing stencil with graphics is fixed on a screen printing machine. SR (solder resister) ink is used to print the required graphics on the copper sheets. After drying, etching can be performed. For dry UV film, the dry UV film is laminated to the surface of the ZTA product with copper on both sides. An exposure device is used to cure the UV film to the desired shape. The uncured UV film is then removed through a developing process. The exposed copper is etched to form the desired shape.

[0032] S6: Post-etching treatment: After etching the copper to the desired shape, remove the remaining AMB solder from the ceramic surface with chemicals, and then further etch the copper pattern to give the solder in the etched copper part a partially protruding structure. Specific Implementation Example 1:

[0034] like Figure 1 As shown, Figure 1 The left side shows a structure that makes the solder layer protrude, forming a thermal shock resistant structure. Based on this improvement, a thicker copper layer than existing copper is bonded, making it usable. Specific Implementation Example 2:

[0036] like Figure 2 As shown, Figure 2 It is a product that uses AMB bonding. When forming the solder protrusion structure, it visualizes the phenomenon of suppressing stress on the substrate (stress has been dispersed). Due to this effect, when using copper of 0.4t or more, it can ensure more stable performance than DCB 0.3t. Specific Implementation Example 3:

[0038] like Figure 3 As shown, Figure 3 These are ultrasonic comparison images of the bonding surfaces of ZTADCB and ZTAAMB, which confirm that ZTADCB has relatively more fine gaps. Specific Implementation Example 4:

[0040] like Figure 4 As shown, Figure 4Based on images showing different thermal shock cycles, ZTADCB and ZTAAMB products, with their protruding slurry structure, exhibit at least a 2-fold significant improvement under the same thermal shock conditions.

[0041] It should be noted that this method is a method for improving the heat treatment characteristics of ZTA products. By using an improved AMB method on the ZTA substrate, small and fine gaps on the substrate are eliminated after bonding, which can improve yield and quality. Bonding thicker copper sheets can improve electrical and thermal characteristics. When forming solder protrusion structures, it vividly suppresses (stress is dispersed) the phenomenon of stress on the substrate. Due to this effect, when using copper of 0.4t or more, it can ensure more stable performance than DCB 0.3t. Under the same thermal shock conditions, at least 2 times the significant improvement effect can be seen. At the same time, it has higher thermal conductivity, higher current consumption, faster heat dissipation and superior reliability after thermal cycling. In addition, after etching, it can ensure good adhesion between ink and board. When the ink drying temperature is limited, the alkali solubility of ink can be guaranteed to be normal. When removing ink, it can be guaranteed to be completely removed and will not fall off randomly. It can prevent blurring and distortion and ensure the etching accuracy and decorative result.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of this method. Those skilled in the art should understand that this method is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this method. Various changes and modifications can be made to this method without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed method. The scope of protection of this method is defined by the appended claims and their equivalents.

Claims

1. A method for improving the heat treatment characteristics of ZTA products, characterized in that: The following steps are included: S1: Prepare raw materials: including ZTA substrate, AMBpaste, copper sheets; prepare processing tools: printing press, ultrasonic cleaner, dryer. S2: AMB paste application: AMB paste is applied to the ZTA substrate using a printing press to achieve a certain thickness. Further details: AMB paste is applied to the SUS mesh screen fixed on the printing press using a polyurethane squeezer to print onto the substrate placed below the screen. The substrate is then dried at 100-200 degrees Celsius for approximately 10 minutes. At this time, the screen pattern is generally #150-#300, and the printing thickness is approximately 5-30µm. S3: Copper sheet processing: Take out the processed ZTA substrate and prepare copper sheets that match its size. Clean the copper sheets by soaking them in hot water for 10 minutes. After cleaning, rinse them with deionized water 2-3 times. Place them in an ultrasonic cleaner with cleaning solution and detergent. The number of cleaning cycles depends on the degree of dirt and contamination on the copper sheets. After cleaning, rinse them with deionized water 2-3 times. Place them in a dryer to dry. After drying, perform electrolytic degreasing to remove the oxide film and oil from the surface. S4: Bonding process: The cleaned copper sheets are loaded onto both sides of the ZTA substrate and placed in a vacuum or reducing atmosphere while the temperature is maintained at 780-900 degrees Celsius for bonding. S5: Etching with ZTA substrate: For wet UV film, a screen printing stencil with graphics is fixed on a screen printing machine. SR (solder resister) ink is used to print the required graphics on the copper sheets. After drying, etching can be performed. For dry UV film, the dry UV film is laminated onto the surface of the ZTA product with copper on both sides. An exposure device is used to cure the UV film to the desired shape. The uncured UV film is then removed through a developing process. The exposed copper is etched to form the desired shape. S6: Post-etching treatment: After etching the copper to the desired shape, remove the remaining AMB solder from the ceramic surface with chemicals, and then further etch the copper pattern to give the solder in the etched copper part a partially protruding structure.

2. The method for improving the heat treatment characteristics of ZTA products according to claim 1, characterized in that: When applying the AMB paste, approximately 100-300g of AMB paste is required for one square meter of ZTA substrate. During the application of the AMB paste, the ambient temperature should be maintained at 20-30 degrees Celsius, and the humidity should be maintained at 10-40%. The work area should also be free of dust and debris. No foreign objects should come into contact with the AMB paste during the application process.

3. The method for improving the heat treatment characteristics of ZTA products according to claim 1, characterized in that: The bonding process can be carried out under vacuum or reducing atmosphere conditions, depending on the site conditions.

4. The method for improving the heat treatment characteristics of ZTA products according to claim 1, characterized in that: During the etching process, the copper sheets are etched first, then the solder is etched, and finally a portion of the copper sheets are etched.

5. The method for improving the heat treatment characteristics of ZTA products according to claim 1, characterized in that: When using the DCB method, the copper sheet size is generally 0.2-0.3t. When using the AMB method with a protruding solder layer, a copper sheet size of 0.4t or more can be used.

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