Package Substrate Single-Step Molding for Gap Elimination
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Solution Overview
Problem
Conventional package substrate fabrication methods using multiple-step molding processes result in gaps and chemical contamination, requiring a more efficient method to form a molding compound layer that covers all components in a single step while ensuring electrical connectivity.
Innovation Solution
A package substrate fabrication method involving a carrier with a first wiring layer, a conductive pillar layer, a single-step molding compound layer that covers the entire surface, and a second wiring layer formed on exposed metal pillars, followed by a protection layer, using materials like novolac-based resin, epoxy-based resin, or silicone-based resin for the molding compound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple-step molding process is used to form molding compound layers in grid regions, then the carrier can be covered, but gaps and recesses are formed between neighboring molding compound layers causing chemical contamination and requiring more processing time
Solution Approach 1:
The patent merges multiple separate molding operations into a single molding step by forming a continuous molding compound layer that covers the entire carrier surface including all grid regions simultaneously. This eliminates the gaps between separately formed molding compound layers and prevents chemical contamination while reducing processing time.
Solution Approach 2:
Instead of forming molding compound layers in discrete grid regions separately, the patent inverts the approach by forming a single continuous molding compound layer across the entire carrier surface in one step, then subsequently creating the grid structure through patterning or removal processes.
2Reliability
If multiple-step molding process is used to form molding compound layers in grid regions, then the carrier can be covered, but gaps and recesses are formed between neighboring molding compound layers
Solution Approach 1:
The patent merges multiple separate molding operations into a single molding step by forming a continuous molding compound layer that covers the entire carrier surface including all grid regions simultaneously. This eliminates the gaps between separately formed molding compound layers and prevents chemical contamination while reducing processing time.
3Reliability
If single-step molding process is used to form molding compound layer covering entire surface, then gaps and chemical contamination are eliminated, but electrical connectivity between wiring layers must be ensured through exposed metal pillars
Solution Approach 1:
The patent applies local quality by creating exposed metal pillars at specific locations within the continuous molding compound layer. These localized exposed conductive structures provide electrical connectivity between wiring layers while the rest of the molding compound layer remains continuous and protective, balancing contamination prevention with electrical functionality.
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 eliminates gaps and chemical contamination, simplifies the fabrication process by forming the molding compound layer in one step, and ensures reliable electrical connectivity between the wiring layers through exposed metal pillars, enhancing the robustness and efficiency of the package substrate.
Implementation Method 1
pressing the mold container against the carrier and concurrently curing the molding compound to form the molding compound layer
Data Source
AI summary
This disclosure provides a package substrate and its fabrication method. The package substrate includes: a carrier; a first wiring layer formed on the carrier; a conductive pillar layer having a plurality of metal pillars on the first wiring layer; a molding compound layer formed on the first wiring layer, covering all the first wiring layer and the metal pillars, and exposing one end face of each metal pillar; a second wiring layer formed on the molding compound layer and the exposed end faces of the metal pillars; and a protection layer formed on the second wiring layer.