Package Structure Fabrication Using Conductive Posts
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Solution Overview
Problem
The existing methods for fabricating chip scale packages are inefficient due to the time-consuming laser drilling process, residue accumulation, uneven hole surfaces leading to delamination, complex alignment requirements, and increased costs, which hinder miniaturization and product reliability.
Innovation Solution
The method involves forming a circuit layer and conductive posts first, followed by encapsulation with an encapsulant, eliminating the need for laser drilling, cleaning, and electroplating processes, and reducing carrier bonding/removing steps, allowing for miniaturization and simplified fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser drilling process is used to form through holes, then through holes can be formed to penetrate the encapsulant, but the process is time-consuming and reduces productivity
Solution Approach 1:
Conductive posts are formed on the circuit layer before encapsulation, eliminating the need for subsequent laser drilling through the encapsulant. This preliminary formation of conductive structures avoids the time-consuming laser drilling process while maintaining precise electrical connections.
Solution Approach 2:
Instead of drilling through holes after encapsulation (traditional approach), the invention forms conductive posts before encapsulation and uses non-destructive methods to create connection pathways. This inverts the sequence from destructive drilling to constructive formation, significantly reducing processing time.
2Manufacturing precision
If laser drilling process is used, then through holes can be formed, but residues accumulate on the bottom of holes requiring additional cleaning steps
Solution Approach 1:
The invention extracts and eliminates the laser drilling step from the fabrication process by forming conductive posts through alternative methods before encapsulation. This removes the source of residue accumulation and the need for subsequent cleaning operations, simplifying the overall process.
Solution Approach 2:
Instead of using high-energy laser drilling that creates residues, the invention employs a different formation mechanism for conductive posts that inherently avoids residue generation. The harmful laser drilling process is replaced with a beneficial approach that forms connections without contamination.
3Manufacturing precision
If laser drilling is performed, then through holes can be formed, but uneven wall surfaces result causing conductive material delamination
Solution Approach 1:
Conductive posts are formed with uniform surfaces before encapsulation through controlled deposition or growth processes. This preliminary formation ensures smooth, uniform surfaces that provide excellent adhesion for subsequent conductive materials, eliminating delamination issues associated with laser-drilled holes.
4Manufacturing precision
If laser drilling is performed on non-transparent encapsulant, then through holes can be formed, but special alignment processes and devices are required increasing costs
Solution Approach 1:
Conductive posts and their connection pathways are formed before encapsulation when the circuit layer is still accessible. This preliminary formation eliminates the need for complex alignment processes during or after encapsulation, as the conductive structures are already in their final positions.
5Manufacturing precision
If laser drilling is used to form through holes, then connection pathways can be created, but heat-affected zones damage nearby semiconductor elements
Solution Approach 1:
The invention extracts and removes the laser drilling process from the fabrication sequence by forming conductive posts through alternative methods before encapsulation. This eliminates the heat-affected zones and thermal damage to semiconductor elements while still achieving the desired electrical connections.
Solution Approach 2:
Conductive posts are formed before encapsulation when the circuit layer is accessible, using methods that do not generate intense heat. This preliminary formation avoids thermal damage to nearby semiconductor elements while establishing the necessary electrical pathways.
Data Source
AI summary
A method for fabricating a package structure is provided, which includes: providing a first carrier having a circuit layer thereon; forming a plurality of conductive posts on the circuit layer and disposing at least an electronic element on the first carrier; forming an encapsulant on the first carrier to encapsulate the conductive posts, the circuit layer and the electronic element; and removing the first carrier, thereby dispensing with the conventional hole opening process for forming the conductive posts and hence reducing the fabrication costs.