Package Substrate Barrier Layer for Consistent Groove Depth
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Solution Overview
Problem
Conventional package substrates face issues with inconsistent groove depths and side etching during metal layer removal, leading to poor solder ball bonding and reliability, especially when miniaturizing circuit lines, hindering mass production.
Innovation Solution
A package substrate design featuring a dielectric layer with grooves filled by a first circuit layer, protected by a barrier layer flush with the metal layer, which prevents micro-etching and ensures consistent groove depth, allowing for miniaturized circuit lines without damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the metal layer is removed by etching, then the metal layer is completely removed, but the first circuit layer is also micro-etched causing inconsistent groove depths
Solution Approach 1:
A barrier layer is introduced as an intermediary between the metal layer and the first circuit layer. This barrier layer protects the first circuit layer from direct exposure to the etching solution, preventing micro-etching while allowing complete removal of the metal layer. The barrier layer acts as a selective mask that differentiates between the metal layer (to be removed) and the first circuit layer (to be protected), thereby ensuring consistent groove depths and reliable solder ball bonding.
2Productivity
If the first circuit layer is miniaturized to achieve high integration, then the circuit density increases, but the first circuit layer becomes prone to side etching and breakage
Solution Approach 1:
The barrier layer serves as a protective intermediary that shields the miniaturized first circuit layer from side etching during the metal layer removal process. This protection is crucial for high-integration designs where circuit lines are narrow and more susceptible to damage. The barrier layer ensures that even when the first circuit layer is miniaturized to increase circuit density, the lines remain intact and functional.
3Volume of moving object
If the first circuit layer is miniaturized, then the substrate size is reduced, but the signal transmission between the first circuit layer and solder balls may breakage
Solution Approach 1:
The barrier layer acts as a protective intermediary that prevents side etching of the miniaturized first circuit layer, ensuring that the circuit lines maintain their structural integrity and continuity. This protection is essential for maintaining signal transmission between the miniaturized first circuit layer and the solder balls, preventing breakage even when the substrate size is reduced through circuit miniaturization.
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
Prevents micro-etching of the first circuit layer, ensuring consistent groove depth and reliable solder ball bonding, enabling mass production of miniaturized substrates with stable signal transmission.
Implementation Method 1
a barrier layer formed in the plurality of cavities... preventing micro-etching of the first circuit layer
Implementation Method 2
the metal layer is removed by etching
Implementation Method 3
copper is electroplated on the dielectric layer 12 and in the blind vias 120 to form a second circuit layer 13
Data Source
AI summary
Provided is a package substrate including a dielectric layer having a first surface and a second surface opposite to the first surface; an insulating layer formed on the first surface of the dielectric layer and having a plurality of grooves; a first circuit layer formed in the plurality of grooves and flush with the insulating layer; a second circuit layer formed on the second surface of the dielectric layer; and a plurality of conductive pillars formed in the dielectric layer and electrically connected to the first circuit layer and the second circuit layer. The present disclosure further provides a method of manufacturing the package substrate.