Stacked LED Lead Frame Structure to Prevent Resin Peeling
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Solution Overview
Problem
Existing light-emitting devices face challenges with insufficient adhesiveness between the resin molded product and the lead frame, leading to potential peeling and disconnection failures.
Innovation Solution
A light-emitting device design featuring a lead frame with a stacked structure of multiple layers, including a penetration portion with varying protrusions, and a resin frame that fills and surrounds the penetration portion, enhancing adhesiveness and preventing peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the resin molded product fills the cutout portion of the lead frame, then adhesiveness between the resin molded product and the lead frame is improved, but the contact area is limited because the height of the contact surface is at most the thickness of the lead frame
Solution Approach 1:
The invention transitions from a single-layer lead frame to a multi-layer stacked structure with penetration portions extending vertically through multiple layers. This dimensional change allows the resin to fill vertical cavities and form adhesive bonds in the thickness direction, significantly increasing the contact area between resin and lead frame beyond what a single-layer structure could provide.
Solution Approach 2:
The penetration portions are formed as vertical cavities within the stacked lead frame layers, creating a nested structure where the resin material is embedded within these cavities. This nesting approach allows the resin to deeply penetrate and bond with the lead frame structure, maximizing adhesive contact area without increasing the horizontal footprint.
2Strength
If a single-layer lead frame structure is used, then the structure is simple, but the adhesiveness between the resin molded product and the lead frame is insufficient
Solution Approach 1:
The lead frame is segmented into multiple stacked layers, each potentially serving different functional purposes. The penetration portions are formed by segmenting through these layers vertically, creating multiple bonding interfaces between the resin and different layers of the lead frame, thereby enhancing overall adhesiveness.
Solution Approach 2:
The invention creates a composite structure combining multiple metal layers with the resin material. The stacked lead frame layers form a composite assembly with the resin-filled penetration portions, leveraging the complementary properties of metal (structural integrity) and resin (adhesion and insulation) to achieve superior bonding performance.
Data Source
AI summary
A light-emitting device includes a lead frame, a frame body having an opening portion and formed integrally with the lead frame, and an LED that is connected to leads of the lead frame and is disposed within the opening portion. The lead frame has a stacked structure including an upper second layer metal plate and a lower third layer metal plate, and a penetration portion penetrates the stacked structure in an up-down direction. The second layer metal plate protrudes into the penetration portion from the third layer metal plate to form a step. A resin of the frame body fills the penetration portion.