Transfer Molding Gap Control for Temporary Bonding Sheets
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Solution Overview
Problem
The existing method for resin-molding a chip temporarily bonded to a carrier via a temporary bonding sheet can result in molding defects due to the temporary bonding sheet being lifted by clamping stress, causing resin to enter between the carrier and the sheet.
Innovation Solution
A method and apparatus for resin-molding that involves forming a gap between the temporary bonding sheet and the surface facing it in the molding die, preventing contact and thus reducing stress on the temporary bonding sheet, which minimizes the likelihood of molding defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the temporary bonding sheet is attached to the carrier and the chip is temporarily bonded to it, then the chip can be positioned and resin-molded, but the temporary bonding sheet may be lifted by clamping stress causing molding defects
Solution Approach 1:
A release film is introduced as an intermediary layer between the temporary bonding sheet and the die surface. This release film acts as a mediator that allows the temporary bonding sheet to remain intact during clamping while still enabling the resin to flow underneath it, thus preventing lifting and molding defects without compromising positioning accuracy
Solution Approach 2:
The system is segmented into distinct functional layers: the carrier, temporary bonding sheet, release film, and die surface. This segmentation allows each layer to perform its specific function independently - the temporary bonding sheet maintains positioning while the release film prevents adhesion to the die, resolving the contradiction between positioning reliability and molding quality
2Force
If clamping force is applied to hold the carrier and temporary bonding sheet, then the resin molding can be performed, but stress causes the temporary bonding sheet to extend and lift
Solution Approach 1:
The release film is placed beforehand between the temporary bonding sheet and the die surface to cushion against the clamping force. This pre-positioned protective layer prevents the stress from directly acting on the temporary bonding sheet, thereby maintaining its integrity while still allowing the necessary clamping force to be applied for resin molding
3Ease of operation
If the temporary bonding sheet is in direct contact with the die surface, then clamping is effective, but resin may enter between the carrier and the sheet causing defects
Solution Approach 1:
The release film serves as an intermediary that enables effective clamping by providing a interface between the die and the temporary bonding sheet, while simultaneously preventing resin from adhering to or entering between the carrier and the temporary bonding sheet, thus ensuring both clamping effectiveness and encapsulation quality
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 approach effectively reduces molding defects by preventing the temporary bonding sheet from being lifted, ensuring consistent resin encapsulation of the chip.
Implementation Method 1
a chip 21 is temporarily bonded to a carrier 11 via a temporary bonding sheet 12
Implementation Method 2
molten resin can be fed into the die cavity by flowing laterally (i.e., transferring from the side of the die cavity) through the runner and the gate
Implementation Method 3
By solidifying the molten resin below the calf block 40, in the runner, in the gate, and in the die cavity, a cull 20a, a runner resin portion 20b, a gate resin portion 20c, and an encapsulating resin 20 are formed
Data Source
AI summary
The present invention provides a resin molded product production method that can reduce the molding defects even when resin-molding is performed in a state where a chip is temporarily bonded to a carrier via a temporary bonding sheet. The method for producing a resin molded product obtained by subjecting an object to be molded being a chip 21 temporarily bonded to a carrier 11 via a temporary bonding sheet 12 to transfer molding, including the step of: resin-molding the object to be molded by transfer molding using a molding die 1000, wherein the resin-molding is performed in a state where a gap G is formed so that the temporary bonding sheet 12 disposed in the molding die 1000 and a surface facing the temporary bonding sheet 12 on a side where the chip 21 is temporarily bonded do not come into contact with each other.