Resin Molding Part with Hook-and-Hold Portions
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Solution Overview
Problem
Resin molding parts obtained by insert-molding lead frames with a sealing resin suffer from deformation or displacement due to resin pressure, and existing methods result in a large thickness of the resin molding part due to double sealing.
Innovation Solution
A primary molding product is fabricated with a hook-and-hold portion between lead frames, which are then integrally formed with a primary molding resin, and secondary molding is performed with a secondary resin portion, where the hook-and-hold portions on the lead frames equal the thickness of the secondary resin portion to prevent deformation and minimize thickness increase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If double sealing with resin is performed to prevent deformation and displacement of lead frames, then sealing performance is improved, but thickness of the resin molding part increases
Solution Approach 1:
The hook-and-hold portions are formed on the lead frames during primary molding before secondary molding is performed. These portions protrude from the lead frame surfaces by a height equal to the thickness of the secondary molding resin portion, creating preliminary structural features that will serve as spacers during the subsequent secondary molding process.
Solution Approach 2:
The hook-and-hold portions act as intermediary elements between the lead frames and the secondary molding resin. By setting their height equal to the desired secondary resin thickness, they mediate the spacing relationship, ensuring the secondary resin forms a uniform thin layer while still providing sealing function.
2Manufacturing precision
If low resin pressure is applied during primary molding to prevent lead frame deformation, then lead frame displacement is reduced, but manufacturing productivity decreases due to required secondary molding process
Solution Approach 1:
The hook-and-hold portions are formed during primary molding, creating preliminary attachment features that enable the lead frames to be securely held during secondary molding. This preliminary formation of positioning features allows the secondary molding process to proceed efficiently without requiring additional positioning steps.
Solution Approach 2:
The invention combines the primary molding and secondary molding processes into an integrated two-stage molding operation. The hook-and-hold portions formed in primary molding are utilized in secondary molding, merging the positioning function and sealing function into a coordinated process that improves both precision and productivity.
3Length of moving object
If hook-and-hold portions with height equal to secondary resin thickness are used, then thickness increase is suppressed, but manufacturing complexity increases due to precise height control requirement
Solution Approach 1:
The hook-and-hold portions serve a dual function: they provide mechanical attachment to prevent lead frame displacement, and they automatically establish the thickness of the secondary molding resin portion. The height of these portions self-determines the secondary resin thickness, eliminating the need for separate thickness control mechanisms.
Solution Approach 2:
The hook-and-hold portions perform multiple functions simultaneously: they act as attachment features for preventing lead frame displacement during molding, and they serve as spacers that define the thickness of the secondary molding resin. This multi-functionality reduces the need for additional components or process steps.
Data Source
AI summary
A primary molding product is formed by integrally forming a first lead frame and a second lead frame with a primary molding resin portion. In addition, in order to prevent separation of the first lead frame and the second lead frame from the primary molding resin portion, a hook-and-hold portion for preventing separation of the first lead frame from the primary molding resin portion and separation of the second lead frame from the primary molding resin portion is provided on an outer surface of each of the first lead frame and the second lead frame. Thus, a resin molding part capable of achieving suppression of increase in a thickness thereof without deformation or displacement of a lead frame and a manufacturing method thereof can be provided.