Wiring Board Surface Flatness via Front Grinding
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Solution Overview
Problem
Conventional copper-clad laminates used in wiring board manufacturing have thickness variations and large asperities, leading to potential poor connections between the electrodes of the wiring board and package device chips due to height variations in the wiring layer.
Innovation Solution
A method involving a sheet laminate formed by impregnating glass cloth with synthetic resin, stacking it with a release plate and an electrode plate, and using pressure to form a core member, followed by grinding to create a uniform and flat surface for the wiring layer, ensuring precise connection with package device chips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional copper-clad laminate is used, then manufacturing process is simple, but surface flatness is poor leading to connection reliability issues
Solution Approach 1:
The patent applies preliminary action by performing a front grinding step on the copper-clad laminate before forming the wiring layer. This grinding step预先 removes asperities and creates a flat surface, ensuring that when the wiring layer is subsequently formed, it sits at a uniform height without variations that would cause connection problems with package device chips.
2Ease of manufacture
If copper-clad laminate with asperities is used, then material cost is low, but wiring layer height uniformity deteriorates
Solution Approach 1:
The front grinding step is performed as a preliminary action before wiring layer formation. This grinding process removes the asperities from the copper-clad laminate surface, creating a flat substrate that enables uniform wiring layer height while still using conventional copper-clad laminate materials.
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 suppresses poor connections between the wiring board electrodes and package device chip electrodes by ensuring a flat and uniform surface for the wiring layer, enhancing the reliability of the electrical connections.
Implementation Method 1
a sheet laminate forming step of impregnating a glass cloth with a synthetic resin to form a plurality of sheets
Implementation Method 2
using a pressure plate to press the release plate, the sheet laminate, and the electrode plate in their stacked condition, thereby uniting the release plate, the sheet laminate, and the electrode plate to form a core member
Implementation Method 3
a front grinding step of grinding the release plate of the core member as the front side of the core member in a condition where the electrode plate of the core member as the back side of the core member is held on a chuck table
Data Source
AI summary
A wiring board manufacturing method includes a sheet laminate forming step of impregnating a glass cloth with a synthetic resin to form a plurality of sheets and next stacking these sheets to form a sheet laminate having a first surface and a second surface, a core member forming step of stacking a release plate on the first surface of the sheet laminate, stacking an electrode plate on the second surface of the sheet laminate, next using a pressure plate to press the release plate, the sheet laminate, and the electrode plate in their stacked condition, thereby uniting them together to form a core member, and a grinding step of grinding the release plate of the core member in a condition where the electrode plate of the core member is held on a chuck table, thereby making a thickness of the core member uniform.