Pillar Structure Height Control via Wire Bonding and Plating
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Solution Overview
Problem
The existing process of manufacturing copper pillars on circuit boards faces challenges in maintaining consistency of height, requires long manufacturing time, and incurs high costs, making it difficult for mass production.
Innovation Solution
A pillar structure comprising a pad, a metal wire bump, and a metal plating layer, where the metal wire and wire bump are formed through wire bonding and subsequently plated to encapsulate the metal wire, allowing for controlled height adjustment and efficient production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If copper plating is used to manufacture copper pillars, then copper pillars can be formed, but it is difficult to maintain consistency of height and requires long manufacturing time
Solution Approach 1:
The invention changes the manufacturing parameters by switching from copper plating to wire bonding followed by encapsulation plating. The wire bonding process allows precise control of pillar height through wire length selection, while the subsequent encapsulation plating forms a uniform coating. This parameter change resolves the contradiction by achieving both height consistency and reduced manufacturing time.
Solution Approach 2:
The invention replaces the electrochemical copper plating process with a mechanical wire bonding process followed by encapsulation. The wire bonding mechanism physically deposits metal wire to form the pillar structure, allowing precise height control through wire length, while the subsequent plating process encapsulates the wire rather than building height through plating alone. This substitution eliminates the height consistency issues inherent in pure plating processes.
2Ease of manufacture
If copper plating is used to manufacture copper pillars, then copper pillars can be formed, but manufacturing costs are high and mass production is difficult
Solution Approach 1:
The invention changes the manufacturing approach from traditional copper plating to wire bonding with encapsulation plating. This parameter change enables mass production by using established wire bonding technology that can be rapidly automated, while the encapsulation plating process is more material-efficient and faster than building entire pillars through plating. This resolves the contradiction by improving ease of manufacture and reducing costs.
3Manufacturing precision
If the metal wire length is increased to achieve desired pillar height, then height control is improved, but the metal wire consumes more material
Solution Approach 1:
The invention applies the nesting principle by placing the metal wire inside the encapsulation plating layer. The metal wire serves as a core structure that provides height, while the encapsulation plating surrounds and protects it. This nested structure allows the metal wire to be shorter than the final pillar height, as the encapsulation plating contributes to the overall height, thereby reducing metal wire material consumption while maintaining precise height control.
Solution Approach 2:
The invention creates a composite structure where the metal wire and encapsulation plating material work together to form the final pillar. The metal wire provides the core structural support and partial height, while the encapsulation plating adds the remaining height and provides protective coating. This composite approach allows optimization of material usage, reducing the amount of expensive metal wire needed while achieving the desired pillar dimensions.
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
The method enables the formation of pillar structures with consistent heights and reduced manufacturing time and costs, facilitating efficient and cost-effective production.
Implementation Method 1
a plating process is performed to form a metal plating layer with use of the pad, the metal wire bump, and the metal wire as a plating seed layer, so as to cover the pad and completely encapsulate the metal wire bump and the metal wire
Data Source
AI summary
A pillar structure is disposed on a substrate. The pillar structure includes a pad, a metal wire bump, a metal wire, and a metal plating layer. The pad is disposed on the substrate. The metal wire bump is disposed on the pad. The metal wire is connected to the metal wire bump. The metal wire extends in a first extension direction, the substrate extends in a second extension direction, and the first extension direction is perpendicular to the second extension direction. The metal plating layer covers the pad and completely encapsulates the metal wire bump and the metal wire.