Semiconductor Package Fabrication Using Adhesive Sheet Separation
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Solution Overview
Problem
Existing methods for separating the substrate and adhesive sheet in semiconductor package fabrication are inadequate, as they either apply excessive stress to the semiconductor chips or expose them to harmful etching solutions, leading to breakage and poor protection of the function surface.
Innovation Solution
A method involving a semiconductor chip supporting carrier with a first supporting unit having an adhesive sheet with an adhesive layer on one surface and a non-adhesive layer on the other, supported by a second supporting unit, allowing for easy separation without applying stress to the chip surface, using a chip mounting device with suction units to manage the adhesive sheet and substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a hard substrate (such as metal SUS) is used to support semiconductor chips during mounting and resin-sealing, then the substrate provides sufficient hardness and stability, but the substrate deforms hardly making separation from the adhesive sheet extremely difficult
Solution Approach 1:
The adhesive sheet is divided into two distinct layers: an adhesive layer for mounting chips and a non-adhesive layer (release sheet) for easy separation. This segmentation allows the substrate to maintain hardness during processing while enabling straightforward separation by peeling off the release sheet without deforming the rigid substrate.
Solution Approach 2:
The non-adhesive layer (release sheet) acts as an intermediary between the adhesive layer and the external environment. It provides a temporary protective interface that facilitates easy separation from the substrate after chip mounting, eliminating the need to deform the hard substrate for separation.
2Ease of operation
If the adhesive sheet is heated to reduce adhesive force for separation, then separation between substrate and adhesive layer is facilitated, but the resin portion receives constant stress risking function surface breakage
Solution Approach 1:
The non-adhesive layer (release sheet) is extracted from the adhesive sheet structure to serve as a separate separation medium. This release sheet can be peeled off without heating, thereby eliminating thermal stress on the resin portion and protecting the function surface from breakage while still enabling easy separation.
Solution Approach 2:
The thermal method of separation (heating to reduce adhesive force) is replaced with a mechanical method (peeling the release sheet). This substitution eliminates the need for heat application that causes resin expansion and stress, thereby protecting the function surface while achieving separation.
3Ease of manufacture
If etching solution (such as ferric chloride aqueous solution) is used to remove copper substrate, then substrate removal is achieved, but semiconductor chips are exposed to harmful factors causing potential damage
Solution Approach 1:
The supporting substrate is replaced with a disposable paper sheet that serves its purpose during chip mounting and resin-sealing, then is easily removed without requiring chemical etching. This eliminates exposure of semiconductor chips to harmful etching solutions while achieving the necessary substrate removal function.
Solution Approach 2:
The harmful chemical etching process is converted into a benign mechanical removal process. The paper substrate, instead of requiring chemical dissolution, can be simply peeled or burned away, transforming a harmful chemical interaction into a safe physical separation that protects the semiconductor chips.
4Volume of moving object
If the resin portion is made thin to achieve CSP miniaturization, then package size is reduced, but the function surface receives constant stress during separation increasing breakage risk
Solution Approach 1:
The non-adhesive layer (release sheet) serves as a mediator between the thin resin portion and the separation process. It absorbs the separation force through its peeling action, preventing direct stress transmission to the thin resin and function surface, thereby enabling safe separation despite minimal resin thickness.
Solution Approach 2:
The mechanical separation method that directly pulls the adhesive sheet from the substrate is replaced with peeling the release sheet. This substitution changes the stress distribution, concentrating forces in the release sheet rather than transmitting them to the thin resin portion, thus protecting the function surface during separation.
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 enables the easy separation of the substrate and adhesive sheet while preventing breakage of semiconductor chips, facilitating the fabrication of semiconductor packages with improved protection and efficiency.
Implementation Method 1
a chip mounting device with suction units to manage the adhesive sheet and substrate
Data Source
AI summary
In fabricating semiconductor packages, a first supporting unit is supported by a supporting substrate with one surface of an adhesive sheet directed upward, the first supporting unit being constituted by attaching the adhesive sheet having an adhesive layer as the one surface thereof and a non-adhesive layer as the other surface thereof to a frame member; semiconductor chips are mounted on the one surface of the adhesive sheet; on the adhesive sheet, a resin portion containing the semiconductor chips is formed by resin-sealing the semiconductor chips; the first supporting unit is removed from the second supporting unit; the resin portion is stripped from the adhesive sheet; external connection members are formed at the semiconductor chips contained in the resin portion; and portions between the respective semiconductor chips contained in the resin portion are cut to obtain individual semiconductor packages.