Leadframe Plating Burr Removal via Segmented Water Jet and Ultrasonic Treatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor device manufacturing methods generate plating burrs during etching, leading to peeling, reduced reliability, and short circuits due to inadequate burr removal techniques, such as water jet and ultrasonic waves, which fail to effectively remove burrs from the entire leadframe surface without causing deformation.
Innovation Solution
A manufacturing method that selectively uses different plating burr removal techniques like water jet, ultrasonic wave, laser, and brushing based on the shape and material of the leadframe, with ultrasonic waves applied in a protected area to prevent deformation and cavitation concentration near the outer frame, and water jet for etched areas, ensuring efficient and reliable burr removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If water jet is used to remove plating burrs from etched areas, then plating burrs in terminal areas are effectively removed, but plating burrs in outer frame areas cannot be removed sufficiently due to lack of reflection
Solution Approach 1:
The patent divides the leadframe into two distinct areas (etched area and outer frame area) and applies different plating burr removal methods to each area. Water jet is used for the etched area where terminal portions are formed, while ultrasonic wave is used for the outer frame area including pilot holes. This segmentation allows each method to be optimized for its specific application area, resolving the contradiction between effectiveness in one area and adaptability to another area.
2Manufacturing precision
If ultrasonic wave is used to remove plating burrs, then plating burrs in outer frame areas can be removed, but the leadframe deforms due to low strength in etched areas
Solution Approach 1:
The patent applies different treatment qualities to different locations on the leadframe. Ultrasonic wave is applied specifically to the outer frame area where the leadframe has sufficient structural strength to withstand the treatment without deformation. Water jet is applied to the etched area where the leadframe is more vulnerable. This local differentiation of treatment quality resolves the contradiction between effective burr removal and maintaining structural integrity.
3Ease of manufacture
If conventional etching process is performed, then terminal portions and outer frame are formed, but plating burrs are generated at edges
Solution Approach 1:
The patent converts the harmful effect of plating burr generation during conventional etching into a manageable intermediate state. Instead of attempting to prevent burr generation during etching (which would complicate the manufacturing process), the patent accepts burr formation as an inevitable byproduct and introduces dedicated plating burr removal steps using water jet and ultrasonic wave treatments. This approach maintains the simplicity of conventional etching while systematically eliminating the harmful burrs afterward.
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 method effectively removes plating burrs from both etched and outer frame areas, preventing defects like peeling and deformation, thereby enhancing the reliability and accuracy of semiconductor devices.
Implementation Method 1
when the ultrasonic wave is used instead of the water jet, another problem could be caused that the leadframe is deformed
Implementation Method 2
ultrasonic wave and water pressure are subjected, so that the plating burrs are removed
Implementation Method 3
the plating burrs in a half-etching area A in which terminals are formed are hit by the water jet with water pressure applied from the upper side as well as with the reflection of water pressure at side faces of the terminals
Data Source
AI summary
In order to remove plating burrs generated in etching step, there is provided a manufacturing method of semiconductor devices on each of unit leadframes in a leadframe material in which a plurality of the unit leadframes are arranged in plural rows or a single row, wherein at least two types of plating burr removals are conducted after a half-etching is performed onto a front surface side of the leadframe material, using a first plating layer as resist film.