Circuit Board Bonding Pad Plating Line Removal
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Solution Overview
Problem
Conventional wire bonding technology is limited by signal distortion due to the presence of electrically open stubs from plating lines in flip chip technology, which are costly to form using electroless plating and typically formed using electroplating, leading to unreliable signal transmission.
Innovation Solution
A method of forming a circuit board with rows of bonding pads and a central plating line that is later removed, allowing for electroplating layers to be formed on the pads without the central plating line, ensuring reliable connections between conductive studs and bonding pads, and reducing signal distortion by eliminating the open stubs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick metal finish layer is formed on bonding pads using electroless plating to ensure reliable connection with conductive studs, then connection reliability is improved, but manufacturing cost increases significantly
Solution Approach 1:
The patent extracts and removes the central plating line from the circuit board structure after it has served its purpose as an electroplating electrode. This allows the use of electroplating instead of electroless plating, reducing manufacturing cost while maintaining reliable connections through the formed metal finish layer on bonding pads
2Ease of manufacture
If a central plating line is formed to enable electroplating of bonding pads, then manufacturing cost is reduced, but signal distortion occurs due to electrically open stubs
Solution Approach 1:
The central plating line is extracted and removed from the final circuit board structure. It is used temporarily during the electroplating process and then eliminated to prevent it from causing signal distortion as an electrically open stub in the finished product
Solution Approach 2:
The central plating line is formed and used in advance to enable electroplating of the bonding pads. After serving this preliminary purpose, it is removed to prevent harmful effects in the final product
3Reliability
If electroless plating is used to form a thick metal finish layer on bonding pads, then connection reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The central plating line is extracted and removed after serving its purpose as an electroplating electrode, enabling the use of simpler and less expensive electroplating process instead of electroless plating to form the metal finish layer on bonding pads
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 enables reliable electrical connections between semiconductor chips and circuit boards without signal distortion, improving signal transmission quality and reducing noise, such as electromagnetic interference (EMI).
Implementation Method 1
the metal finish layer is typically formed by using an electroplating method
Data Source
AI summary
Provided are a circuit board, a semiconductor package including the circuit board, a method of fabricating the circuit board, and a method of fabricating the semiconductor package. The method of fabricating the circuit board includes: forming at least one pair of rows of first bonding pads arranged on a base substrate in a first direction, and a first central plating line formed between the rows of first bonding pads to commonly connect with the rows of first bonding pads; forming an electroplating layer on the first bonding pads; and exposing the base substrate by removing the first central plating line.