Circuit Board Structure Integrating Conductive Bump and Die Side Area Utilization
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Solution Overview
Problem
Conventional circuit board manufacturing methods result in an annular ring at the periphery of conductive bumps, reducing area utilization and creating an interface between conductive bumps and underlying circuit layers due to different formation processes.
Innovation Solution
A method involving a sacrificial layer, metal layer, and patterned photoresist layer to form a first circuit layer that integrates with the conductive bump, eliminating the need for additional bump formation steps and ensuring no interface between the conductive bump and circuit layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a mask is used to form a conductive bump on the die side, then the conductive bump can be formed, but an annular ring occurs at the periphery reducing area utilization
Solution Approach 1:
The patent removes the mask step entirely from the process. Instead of using a mask to define the conductive bump pattern, the invention directly forms the circuit layer and conductive bump in an integrated manner, extracting the harmful mask-related annular ring effect from the manufacturing process.
Solution Approach 2:
The invention merges the circuit layer formation and conductive bump formation into a single integrated process. The circuit layer and conductive bump are formed simultaneously as one continuous structure, eliminating the interface and annular ring problems that arise from separate formation processes.
2Ease of manufacture
If conductive bump and circuit layer are formed by different processes, then each can be formed independently, but an interface is created between them
Solution Approach 1:
The invention combines the circuit layer formation and conductive bump formation into a single unified process. Both structures are formed simultaneously as one continuous operation, eliminating the interface that would otherwise exist between separately formed components and improving reliability.
3Manufacturing precision
If a mask is used to form conductive bump, then the conductive bump can be created, but additional process steps are required
Solution Approach 1:
The invention extracts and removes the mask step from the manufacturing process. By eliminating this intermediate step entirely and directly forming the conductive bump as part of the circuit layer, the process becomes more efficient with fewer steps, reducing both time and costs.
Solution Approach 2:
The invention performs the conductive bump formation as a preliminary integrated action during circuit layer formation, rather than as a subsequent separate step. This preliminary integration eliminates the need for additional mask application, patterning, and removal steps.
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 increases area utilization on the die side of the circuit board by eliminating the annular ring and integrally forming the conductive bump with the circuit layer, reducing process time and costs while avoiding interfaces between components.
Implementation Method 1
exposing the photoresist layer by using a first light source, in which the first light source and the sacrificial layer are respectively disposed on opposite sides of the substrate; exposing the photoresist layer by using a second light source, in which the second light source is disposed at the side of the substrate on which the sacrificial layer is disposed
Data Source
AI summary
A method of manufacturing circuit board structure includes forming a sacrificial layer having first openings on a substrate; forming a metal layer on the sacrificial layer; forming a patterned photoresist layer having second openings over the sacrificial layer, in which the second openings are connected to the first openings and expose a portion of the metal layer; forming a first circuit layer filling the second openings and the first openings; forming a first dielectric layer over the sacrificial layer and covering the metal layer, in which the first dielectric layer has third openings exposing the first circuit layer; forming a second circuit layer filling the third openings and covering a portion of the first dielectric layer; removing the substrate to expose the sacrificial layer, a portion of the metal layer and a portion of the first circuit layer; and removing the sacrificial layer and the metal layer.