Compression Molding Plungers for Electronic Device Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional transfer molding is inefficient, leading to significant wastage of epoxy molding compound and inadequate compression force for larger electronic packages, which can damage delicate structures and result in defective products.
Innovation Solution
A compression molding system using first and second mold halves with motor-driven plungers to apply a variable compacting force, combined with a vacuum system to ensure precise shaping and minimize material overflow or voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional transfer molding is used, then molding compound can be forced into cavities, but significant material wastage occurs in runners and gating system
Solution Approach 1:
The invention extracts and eliminates the runner and gating system from the molding process. By using direct injection molding, the molding compound is delivered directly to the cavities without passing through runners, thereby removing the source of material wastage while maintaining productive molding capability
Solution Approach 2:
The invention changes the delivery method parameter from indirect (through runners) to direct (direct injection). This parameter change eliminates the gating system and associated material waste, improving both productivity and material efficiency simultaneously
2Speed
If high epoxy injection speed is used, then molding can be performed faster, but delicate dice or wires are damaged
Solution Approach 1:
The invention replaces the high-speed mechanical injection system with a direct, controlled dispensing system. This substitution allows for precise control of material delivery speed, eliminating the harmful high-speed injection that damages delicate structures while maintaining efficient molding throughput
Solution Approach 2:
The invention introduces a controlled dispensing mechanism as an intermediary between the molding compound source and the cavity. This intermediary provides precise control over material delivery, preventing direct high-speed impact on delicate dice or wires while still achieving complete cavity fill
3Volume of stationary object
If package size increases, then more encapsulation material is required, but spring force becomes inadequate to provide sufficient compression
Solution Approach 1:
The invention replaces the spring-based mechanical compression system with a motor-driven plunger system. This substitution provides controllable, scalable compression force that can reliably compress large volumes of encapsulation material in bigger packages, overcoming the limited range of spring force
Solution Approach 2:
The invention transitions from a static spring force system to a dynamic, motor-controlled plunger system. This allows the compression force to be actively adjusted and controlled based on package size and material volume, ensuring sufficient compression force for both small and large packages
4Loss of substance
If encapsulation material is dispensed directly on devices, then material wastage is reduced, but air voids may form in the molding cavity
Solution Approach 1:
The invention ensures continuous action by combining direct material dispensing with immediate vacuum application. The vacuum system continuously removes air as the material is dispensed and compressed, ensuring complete cavity fill without voids while maintaining the material efficiency benefits of direct dispensing
Solution Approach 2:
The invention applies vacuum pressure as a preliminary anti-action to counteract the formation of air voids. By creating negative pressure in the cavity before and during material compression, the system prevents air entrapment and ensures complete, void-free filling while maintaining direct dispensing efficiency
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 reduces material wastage, provides reliable and adjustable compression force for various package sizes, and ensures precise shaping without voids or protrusions, resulting in high-quality molded packages.
Implementation Method 1
a plurality of plungers located in the first mold half, each of which is drivable against a side of a respective cavity for applying a compacting force to encapsulation material located in the cavity during molding
Implementation Method 2
introduce a vacuum system to obtain molded packages that are more precisely shaped by avoiding voids in the encapsulation material
Data Source
AI summary
A compression molding system comprising first and second mold halves is provided for an electronic device wherein a plurality of cavities are formed in the first mold half corresponding to molding locations on the electronic device. A plurality of plungers are located in the first mold half, each of which is drivable against a side of a respective cavity for applying a compacting force to encapsulation material located in the cavity during molding. A motor is operatively connected to the plungers for driving the plungers relative to the cavities.