Semiconductor Package Molding Pressure Sequencing to Reduce Voids
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Solution Overview
Problem
Conventional molding techniques for semiconductor packages result in undesired voids due to decreasing thickness and resin thickness, which can damage the semiconductor chip and affect product integrity.
Innovation Solution
A molding apparatus with a chamber, upper and lower molds, ports, plungers, and actuators that control pressure and material flow to minimize voids by applying controlled pressures and maintaining a vacuum during the molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional molding techniques are used, then the molding process is simple, but voids are formed in the molding resin
Solution Approach 1:
The molding apparatus is divided into multiple functional modules: a plunger for material injection, a mold actuator for cavity pressurization, and a controller for coordinated operation. This segmentation allows each component to perform its specific function optimally, enabling void reduction through controlled material flow and pressure management without creating an overly complex integrated system.
Solution Approach 2:
The controller is configured to reduce the first pressure applied to the plunger after the mold actuator begins applying the second pressure to the upper mold. This preliminary coordination of pressure changes ensures that material is first supplied to fill the cavity, then excess pressure is reduced to prevent void formation, achieving high manufacturing precision through pre-planned pressure sequencing.
2Length of moving object
If the thickness of semiconductor package is decreased, then the product achieves small and thin requirements, but voids are more likely to form
Solution Approach 1:
The apparatus uses hydraulic or pneumatic pressure systems through the plunger and mold actuator to control material flow and cavity pressurization. By applying controlled first pressure to the plunger for material supply and second pressure to the upper mold for cavity compression, the system achieves uniform filling of thin packages without void formation, overcoming the challenges of decreased package thickness.
Solution Approach 2:
The controller dynamically changes pressure parameters during the molding process by reducing the first pressure applied to the plunger after the mold actuator begins applying the second pressure. This parameter change ensures proper material flow and compression in thin packages, preventing void formation while maintaining the required small thickness.
3Volume of moving object
If the thickness of molding resin is decreased, then the semiconductor product achieves lightweight and highly integrated goals, but voids appear in the completed product
Solution Approach 1:
The molding process maintains continuous useful action through coordinated operation of the plunger and mold actuator. The controller ensures that the first pressure for material supply and the second pressure for cavity compression work continuously and synchronously, ensuring complete and uniform filling of the thin molding resin without interruption that could cause voids.
Solution Approach 2:
The controller monitors and coordinates the pressure application from both the plunger and mold actuator, effectively implementing feedback control. By adjusting the first pressure based on the second pressure application, the system ensures continuous material flow and proper compression throughout the molding process, eliminating voids in thin resin layers.
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 apparatus effectively reduces voids in the molding resin, ensuring uniform filling and preventing damage to semiconductor chips, thereby enhancing the quality of semiconductor packages.
Implementation Method 1
a plunger configured to pressurize the molding material inside the port
Implementation Method 2
the mold actuator is configured to pressurize the molding material in the cavity by applying a second pressure to the upper mold
Data Source
AI summary
A molding apparatus for a semiconductor package includes a chamber including a lower mold configured to hold a substrate including a plurality of molding targets, an upper mold configured to move up and down with respect to the lower mold and define a cavity between the upper mold and the lower mold, and a port configured to provide a passage communicating with the cavity, a molding material supplier configured to supply a molding material to the port, a plunger configured to pressurize the molding material inside the port, a plunger actuator configured to apply a first pressure to the plunger such that the molding material provided in the port is supplied to the cavity, and a mold actuator configured to control actuation of the upper mold. The plunger actuator is configured to supply the molding material to the cavity by applying the first pressure to the plunger, and the mold actuator is configured to pressurize the molding material in the cavity by applying a second pressure to the upper mold. The mold apparatus further includes a controller configured to control the plunger actuator to reduce the first pressure applied to the plunger after the mold actuator begins applying the second pressure to the upper mold.