Lead Frame Plating via Electrodeposited Resist Film
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Solution Overview
Problem
Existing methods for manufacturing light emitting devices face challenges in precisely applying plating only to desired regions of a lead frame, particularly at corners and lateral surfaces, due to difficulties in masking these areas.
Innovation Solution
A method involving a metal plate with pairs of metal parts, where a resist film is applied using electrodeposition to specific regions, followed by plating with silver or silver alloy, and then removing the resist film to facilitate precise plating deposition on the lead frame, which is then integrated with a resin molded body and separated into individual light emitting devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a mask is disposed on the lead frame to form plating on parts of the lead frame, then plating can be applied to specific regions, but precise disposal of the mask on corners and lateral surfaces becomes difficult
Solution Approach 1:
The patent extracts the masking step entirely from the process by using electrodeposition to directly deposit the resist film on the lead frame surface. This eliminates the mechanical mask disposal problem while achieving precise regional plating, as the electrodeposition naturally confines the resist film to specific regions through controlled electrical current distribution.
Solution Approach 2:
The patent replaces the mechanical masking system with an electrochemical system. Instead of physically placing and securing masks on complex lead frame geometries, the process uses electrodeposition to chemically deposit the resist film only where electrical current is applied, substituting mechanical precision requirements with electrical control.
2Manufacturing precision
If plating is applied to corners and lateral surfaces of the lead frame, then desired regions can be plated, but unintentional plating on undesired regions occurs
Solution Approach 1:
The patent introduces the resist film as an intermediary substance between the lead frame and the plating process. The electrodeposited resist film acts as a selective barrier that prevents plating on undesired regions while allowing plating on desired regions, thereby eliminating unintentional plating through chemical selectivity rather than mechanical precision.
3Manufacturing precision
If electrodeposition is used to dispose resist film, then precise plating deposition is facilitated, but additional process steps are required
Solution Approach 1:
The patent merges the resist film application and plating guidance functions into a single electrodeposition step. By using electrodeposition to deposit the resist film, the process combines what would traditionally be separate steps (masking and plating preparation) into one integrated operation, reducing overall process complexity despite introducing electrodeposition technology.
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 method enables efficient and precise plating deposition on desired regions of the lead frame, improving the manufacturing process for light emitting devices by reducing unintentional plating and enhancing the extraction of light from the emitting elements.
Implementation Method 1
using an electrodeposition technique, disposing a mask of a resist film on the at least one first region
Implementation Method 2
disposing a first plating containing silver or silver alloy on the at least one second region
Data Source
AI summary
A method of manufacturing light emitting devices, the method including: providing a first structure, the providing a first structure including: providing a lead frame, the providing a lead frame including: providing a metal plate having a plurality of pairs of first and second metal parts, each of the first and second metal parts including at least one first region and at least one second region; using an electrodeposition technique, disposing a mask of a resist film on the at least one first region; disposing a first plating containing silver or silver alloy on the at least one second region; and removing the resist film; molding a resin molded body in one piece with the lead frame with parts of a lower surface of the lead frame being exposed, in which, the first structure includes an upper surface defining a plurality of recesses each having an upward-facing surface, at least parts of the first plating being located at the upward-facing surface of each of the plurality of recesses; providing a second structure, the providing a second structure including: disposing at least one light-emitting element on the first plating located at the upward-facing surface of each of the plurality of recesses; and disposing a sealing member covering the at least one light-emitting element in each of the plurality of recesses; and separating the second structure into a plurality of individual light emitting devices.