Glass-Core Circuit Board Via Structure for Thin Reliable Interconnects
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Solution Overview
Problem
Existing circuit boards face challenges in achieving a compact, low-profile design while maintaining reliable interlayer connections, particularly as the integration of components in RF front end modules increases complexity and component count.
Innovation Solution
A circuit board design utilizing a glass core with through holes, featuring a conduction layer that connects wiring patterns on both surfaces via a laminate of a seed layer and a metal layer, such as copper, Ti, Cr, or Al, to form a solenoid coil and capacitor structure, with insulating resin layers ensuring reliable connections and reduced thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the thickness of the insulating resin layer is reduced to achieve a lower-profile RFFM, then the overall profile of the RFFM is reduced, but the reliability of connection between the inner wiring layer and the land deteriorates
Solution Approach 1:
The invention transitions from a planar connection structure to a three-dimensional structure by forming protrusions that extend vertically from the inner wiring layer through the insulating resin layer to the land. This vertical extension in the thickness dimension compensates for the reduced insulating resin layer thickness, maintaining connection reliability while achieving a lower-profile overall structure.
Solution Approach 2:
The conduction layer is formed to protrude from the inner wiring layer before final assembly, preliminarily establishing the connection path through the insulating resin layer. This preliminary formation of conductive protrusions ensures that even with reduced insulating resin thickness, the connection reliability is maintained by pre-positioning the conductive elements that will bridge the gap to the land.
2Productivity
If the wiring density of the inner wiring layer is improved with minimum land area, then the wiring efficiency is increased, but the connection reliability between the inner wiring layer and the land deteriorates
Solution Approach 1:
The invention resolves the conflict between compact wiring and reliable connection by extending the conduction layer vertically in the thickness dimension. This allows minimum land area to be used while the protruding conduction layer provides sufficient connection reliability by creating a three-dimensional connection path that is not constrained by the limited planar land area.
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 design enhances interlayer connection reliability and allows for a more compact, low-profile circuit board by increasing the contact area of the conduction layer, even as the board thickness decreases, effectively addressing the need for higher wiring density and minimal land area.
Implementation Method 1
a conduction layer formed in the through hole of the glass core, the conduction layer connecting the wiring patterns on the front and rear surfaces of the glass core
Implementation Method 2
the capacitor including a first electrode, a dielectric layer formed thereon, and a second electrode formed on the dielectric layer
Data Source
AI summary
A circuit board having excellent reliability of connection between layers while being capable of achieving a compact and low-profile electronic device. In the circuit board has an LC circuit built therein with the use of a glass core having a through hole, a conductor layer formed in the through hole is connected to a wiring pattern formed on one surface of the glass core, and connected to a wiring pattern formed on the other surface of the glass core, with the conduction layer projected from the surface of the glass core. Thus, the area of contact between the conduction layer and the through hole is increased, thus making it possible to prevent the reliability of connection between layers in the through hole from being decreased, even when the glass core is reduced in thickness for achieving a low-profile device.