Lead Frame Outer Frame Uneven Edge Resin Adhesion
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Solution Overview
Problem
The existing manufacturing method for semiconductor devices using resin tape or adhesive tape results in poor adhesion properties of the noble metal plated layer to the resin, leading to peeling issues with the outer frame, which increases the risk of defective products and requires careful handling during conveyance.
Innovation Solution
A lead frame design with an outer frame featuring uneven inner edges, including T-shaped projections and recesses, and stepwise inner corners, which increases the contact area with resin, enhancing adhesion and preventing peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a noble metal plated layer is formed on the outer frame as a resist film, then wire bonding and resin enclosure can be performed, but the plated layer has poor adhesion to the resin causing the outer frame to peel
Solution Approach 1:
An uneven portion is formed on the inner edge of the outer frame before resin enclosure. This preliminary structural modification creates mechanical interlocking features that prevent peeling later during handling and conveyance, resolving the adhesion problem without affecting the manufacturing process
Solution Approach 2:
The solution transitions from a two-dimensional flat outer frame edge to a three-dimensional uneven structure with projections and recesses. This dimensional change increases the contact area and creates mechanical interlocking with the resin, significantly improving adhesion while maintaining manufacturing feasibility
2Device complexity
If the outer frame is surrounded with resin, then the semiconductor device structure is completed, but the outer frame peels from the resin requiring careful handling during conveyance
Solution Approach 1:
The uneven portion is formed on the outer frame before resin enclosure to create preemptive mechanical interlocking features. This preliminary action ensures that the outer frame remains securely bonded to the resin throughout subsequent handling and conveyance operations, eliminating the need for careful handling precautions
3Reliability
If the outer frame peels from the resin, then defective intermediate products occur, but the invention prevents this by enhancing bonding
Solution Approach 1:
The uneven portion is formed on the inner edge of the outer frame before resin enclosure to create preemptive mechanical interlocking features. This preliminary structural modification ensures strong bonding between the outer frame and resin, preventing peeling and defective intermediate products without significantly increasing device complexity
Solution Approach 2:
The solution transforms the flat two-dimensional outer frame edge into a three-dimensional uneven structure with projections and recesses. This dimensional change creates mechanical interlocking with the resin, significantly enhancing bonding strength while adding minimal structural complexity
Data Source
AI summary
In a lead frame used for manufacturing a semiconductor device by forming a circuit pattern group including unit lead frames having plural upper side terminal parts in the periphery of a semiconductor element mounting region in one line or plural lines and an outer frame surrounding the circuit pattern group in a state of having a gap in a lead frame material and then mounting a semiconductor element every the unit lead frame and carrying out necessary wiring and enclosing the entire surface of the circuit pattern group in which the semiconductor element is mounted and a part of the outer frame with a resin from an upper surface side and further etching from a lower surface side and forming lower side terminal parts joined to the upper side terminal parts of the circuit pattern group, the circuit pattern group and the outer frame are had and the inner edge of the outer frame is formed in an uneven portion in plan view and bonding between the resin and the outer frame is enhanced.