Sheet Mold Compound Carrier for Semiconductor Encapsulation
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Solution Overview
Problem
Conventional mold transfer systems for semiconductor devices face issues with entrapped air leading to voids in the encapsulant, limited thickness due to fragile release films, and high manufacturing costs, which hinder efficient and cost-effective compression molding of semiconductor packages.
Innovation Solution
A mold compound transfer system using a sheet mold compound as a carrier for granular mold compound, eliminating the need for a release film and reducing entrapped air, allowing for thicker and more uniform encapsulation without premature gelation, and optimizing the weight ratio of sheet to granular compounds for enhanced support and reduced voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If granular mold compound is stacked in a conventional transfer system, then the mold compound can be transferred and molded, but entrapped air between grains leads to voids in the encapsulant
Solution Approach 1:
The patent changes the physical state of the mold compound from granular to sheet form. This parameter change eliminates the interstitial spaces between grains that trap air, thereby preventing voids in the encapsulant while maintaining the mold compound's functionality for compression molding
Solution Approach 2:
The patent uses a composite structure consisting of a sheet mold compound carrier combined with granular mold compound. The sheet provides a void-free base layer that supports the granular material, creating a composite system that eliminates entrapped air while allowing the granular material to flow and fill gaps during molding
2Length of moving object
If release film is used to carry granular mold compound, then transfer is enabled, but the film cannot withstand high elongation for thick semiconductor package molding
Solution Approach 1:
The patent replaces the fragile release film with a sheet mold compound that serves as a disposable carrier. The sheet is designed to be consumed during the molding process, providing structural support for thick encapsulation without the elongation limitations of release films
Solution Approach 2:
The patent changes the carrier material from thin release film to thick sheet mold compound. This parameter change in thickness and material properties enables the carrier to withstand the high elongation forces required for thick semiconductor package molding
3Productivity
If conventional mold transfer system is used, then manufacturing can proceed, but costs remain high due to material waste and process inefficiency
Solution Approach 1:
The patent performs preliminary consolidation of mold compound into a sheet form before transfer and molding. This preliminary action eliminates the need for excessive granular material that would otherwise be wasted during transfer, as the sheet provides precise material placement from the outset
Solution Approach 2:
The patent merges the carrier function and the mold compound function into a single sheet structure. This merging eliminates the need for separate carrier materials and reduces overall material waste by integrating the support structure with the molding material itself
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 system effectively decreases voids and allows for thicker, more uniform encapsulation of semiconductor devices, reducing manufacturing costs and improving efficiency by using a sheet mold compound to support and carry granular mold compound, ensuring consistent and high-quality molding results.
Implementation Method 1
The granular mold material 12 is melted via compression molding to form an encapsulant over the semiconductor device packages
Data Source
AI summary
Mold compound transfer systems and methods for making mold compound transfer systems are disclosed herein. A method configured in accordance with a particular embodiment includes providing a sheet mold compound, and dispensing a granular mold compound directly on the sheet mold compound. The sheet mold compound can have a first density and the overall granular mold compound can have a second density less than the first density. The method further comprises transferring the solid sheet carrying the dispensed granular mold compound to a molding machine without using a release film.