Circuit Board Intaglio Pattern via Barrier Layer Etching Control
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Solution Overview
Problem
Conventional circuit board manufacturing methods face challenges in achieving even conductive material distribution and thickness control, leading to potential short-circuits and improper thinning of embedded circuit layers, especially when forming fine lines.
Innovation Solution
A method involving a circuit board with a dielectric layer, a metal layer, and a barrier layer, where intaglio patterns and blind vias are formed using a laser beam, followed by sequential formation of conductive layers within these patterns, with the barrier layer acting as an etching stop to ensure accurate removal and prevent short-circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If electroplating is performed to form a conductive material layer filling the blind via and intaglio pattern, then the conductive material layer is formed, but the electroplating is not performed evenly, such that the conductive material layer is not distributed evenly with an even thickness
Solution Approach 1:
A metal layer is formed on the dielectric layer before the barrier layer, creating a preliminary conductive structure that ensures even thickness distribution. This preliminary action prevents the electroplating process from producing uneven thickness later, as the metal layer provides a uniform base for subsequent electroplating.
Solution Approach 2:
The conductive structure is formed as a composite of multiple layers: a metal layer, a barrier layer, and an electroplated conductive material layer. This composite structure combines the advantages of each layer - the metal layer provides even thickness, the barrier layer prevents contamination, and the electroplated layer provides the final conductive properties.
2Manufacturing precision
If a conventional conductive material layer is used to fill the blind via, then the blind via is filled, but the thickness removed from the conductive material layer is hard to be controlled when removing a portion outside the blind via and intaglio pattern
Solution Approach 1:
The barrier layer serves as an intermediary between the metal layer and the electroplated conductive material layer. During the etching process, the barrier layer acts as a protective intermediate layer that can be selectively removed, allowing precise control over the etching depth. This intermediary layer enables controlled removal of the conductive material layer thickness without damaging underlying structures.
3Reliability
If the conductive material layer is formed by electroplating, then the conductive material layer is formed, but a portion of the conductive material layer can be remained improperly to cause a short-circuit between circuits of the embedded circuit layer
Solution Approach 1:
The barrier layer is selectively removed in a controlled manner to extract or remove the electroplated conductive material layer from areas where it is not needed. This selective removal process prevents improper remaining portions of the conductive material layer that could cause short-circuits between adjacent circuits in the embedded circuit layer.
4Productivity
If fine lines are formed in the embedded circuit layer, then the circuit density is increased, but the aforementioned issues become more obvious when the circuits are fine lines
Solution Approach 1:
The metal layer is formed with local quality variations - it provides a uniform base layer throughout, but the barrier layer is selectively applied and removed in specific local areas. This local quality approach allows precise control of the conductive material layer thickness in fine line areas, preventing both excessive thickness that could cause short-circuits and insufficient thickness that would compromise conductivity.
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 enhances manufacturing yield and reliability by allowing precise control over the etching process, preventing over- or under-etching and ensuring even thickness, thus improving the quality of both fine line and conventional circuits within the same circuit layer.
Implementation Method 1
the surface of the dielectric layer is irradiated by a laser beam, so as to form an intaglio pattern and a blind via
Implementation Method 2
an electroplating process is performed to form a conductive material layer filling the blind via and the intaglio pattern
Data Source
AI summary
A circuit board includes a circuit substrate, a dielectric layer disposed on the circuit substrate and a patterned circuit structure. The dielectric layer covers a first surface and at least a first circuit of the circuit substrate. The dielectric layer has a second surface, at least a blind via, a second intaglio pattern and a third intaglio pattern connected to the blind via. The patterned circuit structure includes at least a second circuit disposed in the second intaglio pattern and third circuits disposed in the third intaglio pattern and the blind via. Each third circuit has a first conductive layer and a second conductive layer. The materials of the first conductive layer and the second circuit are the same. The line width of the second circuit is shorter than that of each third circuit. At least a third circuit is electrically connected to the first circuit of the circuit substrate.