Ceramic Circuit Board Brazing Etching for Faster Jutting Control
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Solution Overview
Problem
Existing methods for manufacturing ceramic circuit boards using brazing material etching are not suitable for mass production due to their lengthy processing times, which hinder efficiency and scalability.
Innovation Solution
A method involving a reactive metal brazing material with Ag, Cu, and Ti, along with Sn and In, is used, combined with a brazing material etchant containing hydrogen peroxide, ammonium fluoride, and a pH-stabilizing agent, and an ultrasonic wave application to shorten the etching time, allowing for faster and more controlled removal of the brazing material layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional brazing material etching process using chelating agents and hydrogen peroxide is used, then the brazing material layer can be etched, but the etching time becomes excessively long (150 minutes)
Solution Approach 1:
The patent changes the chemical parameters of the etching solution by using ammonium fluoride instead of conventional chelating agents like EDTA. This parameter change in the etchant composition dramatically reduces the etching time from 150 minutes to a much shorter duration while maintaining precise control over the brazing material jutting portion size.
Solution Approach 2:
The patent replaces the conventional chemical etching mechanism with ammonium fluoride-based chemistry that acts more rapidly on the brazing material. The substitution of the etching chemistry system enables faster material removal rates without sacrificing precision in controlling the jutting portion dimensions.
2Manufacturing precision
If the etching time is extended to achieve proper brazing material removal, then the jutting portion size can be controlled, but the productivity decreases
Solution Approach 1:
By changing the etchant composition to use ammonium fluoride, the patent achieves both precise jutting portion control and high productivity. The new chemical parameters enable rapid etching that completes in minimal time while maintaining the precision needed for mass production applications.
Solution Approach 2:
The ammonium fluoride-based etching process enables continuous, rapid removal of brazing material without the prolonged exposure times required by conventional methods. This continuous efficient action allows the process to be adapted for high-volume mass production while maintaining quality standards.
3Strength
If a reactive metal brazing material including multiple components (Ag, Cu, Ti, Sn, In) is used, then strong bonding between ceramic substrate and copper plate is achieved, but the etching process becomes more complex
Solution Approach 1:
Ammonium fluoride acts as an intermediary etching agent that selectively removes the reactive metal components (Ti, Sn, In) from the brazing material layer without affecting the Ag-Cu bonding structure. This intermediary chemistry enables simplified etching of complex multi-component brazing materials while preserving the strong bonding properties.
Solution Approach 2:
The patent changes the etching chemistry to use ammonium fluoride, which has selective reactivity toward the reactive metal components in the brazing material. This parameter change in the etchant composition simplifies the etching process by targeting specific components (Ti, Sn, In) while leaving the Ag-Cu matrix intact, reducing overall process complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces the brazing material etching time to 15 minutes or less, improving the thermal cycle test (TCT) characteristics and making the process more suitable for mass production while maintaining control over the brazing material jutting portion size and surface roughness.
Implementation Method 1
a brazing material etchant in which a chelating agent, hydrogen peroxide, and a pH-adjusting agent are mixed
Implementation Method 2
an ultrasonic wave application to shorten the etching time
Data Source
Figure 1
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Figure 3A~3C
AI summary
A method for manufacturing a ceramic circuit board in which a copper plate is joined to at least one surface of a ceramic substrate via a brazing material layer containing Ag, Cu, and active metal, wherein the method is provided with: a first chemical polishing step for preparing a ceramic circuit board in which a copper plate is joined to a ceramic substrate via a brazing material layer, with a portion of the brazing material layer exposed between pattern shapes of the copper plate, and chemically polishing the portion of the brazing material layer; and a first brazing material etching step for etching the portion of the chemically polished brazing material layer with an etchant at pH of 6 or below that contains one or two selected from hydrogen peroxide and ammonium peroxodisulfate.