Mold Chase Flow Control for Void-Free Electronic Packaging
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Solution Overview
Problem
Conventional mold chases for high-density electronic package arrays suffer from voids and incomplete molding, leading to defects like electric static discharge and short-circuits due to non-uniform mold fluid flow, which is not adequately addressed by existing designs.
Innovation Solution
A molding apparatus with a flow control structure at the side walls of the molding chamber to reduce mold fluid speed non-uniformity, using angled side walls or blockers to manage fluid flow and prevent air trapping, ensuring complete encapsulation of high-density package strips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional mold chase design is used for high-density package units, then manufacturing simplicity is maintained, but molding completeness deteriorates due to voids and incomplete mold
Solution Approach 1:
The patent introduces flow control structures (flow controllers or flow control elements) positioned at specific locations within the molding chamber, particularly near side walls and in regions where voids typically form. These local modifications create controlled flow resistance zones that redirect mold fluid flow patterns, ensuring complete filling of high-density package units without requiring a complete redesign of the entire mold chase structure.
Solution Approach 2:
The mold chase is segmented into multiple flow zones by introducing flow control structures that divide the molding chamber into regions with different flow characteristics. This segmentation allows independent control of fluid flow in different areas, enabling complete encapsulation of interconnection structures while maintaining overall system functionality.
2Productivity
If mold fluid flows quickly through the molding chamber, then productivity is improved, but flow uniformity deteriorates causing voids near side walls
Solution Approach 1:
The patent modifies flow parameters by introducing flow control structures that create localized flow resistance. These structures change the velocity distribution of the mold fluid, reducing flow speed near side walls where voids form, while maintaining overall high flow rates for productivity. The flow controllers adjust local flow parameters without significantly extending the overall molding cycle time.
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
The flow control structure effectively reduces mold defects by ensuring uniform fluid flow, preventing voids and enhancing yield by fully encapsulating interconnection structures, thereby improving the quality of high-density electronic packages.
Implementation Method 1
the molding chamber further comprises a flow control structure at or close to two side walls of the molding chamber relative to the flow direction to reduce a flow speed of the mold fluid close to the two side walls
Data Source
AI summary
AbstractA molding apparatus and a method for making an electronic package are provided. The molding apparatus comprises: a top chase; a bottom chase matable with the top chase, wherein the top chase and the bottom chase define together a molding chamber for accommodating a package strip, and the molding chamber comprises a flow input configured to receive a mold fluid and a flow output configured to output the mold fluid after the mold fluid flows through the molding chamber and across the package strip in a flow direction substantially from the flow input to the flow output, wherein the molding chamber further comprises a flow control structure at or close to two side walls of the molding chamber relative to the flow direction to reduce a flow speed of the mold fluid close to the two side walls.