Chip Package Leadframe Formation via Micro-Etched Trenches
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Solution Overview
Problem
The conventional method of forming a leadframe in a chip package process is complex and introduces difficulties due to the need for chemical etching and flipping the package body, leading to poor assembly properties and increased manufacturing costs.
Innovation Solution
A chip package method involving micro-etching a metal plate to form trenches, electroplating a metallic conductor within these trenches, and then peeling the metal plate off after encapsulation to expose the conductor, simplifying the process and reducing costs while enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a leadframe is formed in a package process by depositing or electroplating on a package substrate, then the leadframe can be compatible with subsequent steps, but the process requires chemical etching and turning upside down the package body, introducing difficulty and complexity
Solution Approach 1:
The leadframe is formed in advance on the package substrate through depositing or electroplating before the chip is mounted. This preliminary formation of the leadframe structure allows subsequent steps to proceed without additional complex operations like chemical etching or flipping the package body, thereby reducing process complexity while maintaining compatibility
Solution Approach 2:
Instead of the conventional approach where the package body is turned upside down after forming the leadframe, this invention maintains the original orientation throughout the process. The leadframe is formed on the substrate and remains in place, eliminating the need for flipping operations and associated complexity
2Ease of manufacture
If a leadframe is formed in a package process including chemical etching of the package substrate, then the leadframe structure can be created, but this introduces difficulty in the manufacture process
Solution Approach 1:
The chemical etching step is extracted and removed from the manufacturing process. Instead of using chemical etching to create the leadframe structure, the invention uses depositing or electroplating methods that directly form the conductive structures without requiring substrate etching, thereby eliminating process difficulty while maintaining leadframe formation capability
Solution Approach 2:
The chemical etching process is replaced with a physical deposition or electroplating process. This substitution eliminates the need for chemical treatments and associated complexity, providing a more straightforward manufacturing approach while achieving the same leadframe formation objective
3Ease of operation
If the package body is turned upside down to mount the chip, then the chip can be mounted on the opposite surface, but this step introduces complexity and causes poor property of the package assembly
Solution Approach 1:
The leadframe and its connection structures are formed in advance on the package substrate before chip mounting. This preliminary preparation ensures that when the chip is mounted, all necessary electrical connections are already in place, eliminating the need to flip the package body and associated reliability issues
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 simplifies the manufacturing process, reduces costs, and increases the reliability of the chip package assembly by eliminating complex etching steps and ensuring secure electrical connections.
Implementation Method 1
forming a metallic conductor at the at least one trench by electroplating
Data Source
AI summary
The present disclosure relates to a chip package method and a package assembly. A metal plate is micro-etched to form trenches having a predetermined depth. A metallic conductor is formed as a leadframe by filling the trenches with a material having relatively small adhesion with the metal plate. In such manner, the metal plate can be peeled off from a package body after the chip is electrically coupled to the metallic conductor and encapsulated by a molding process. A bottom of the metallic conductor is exposed from the package body. A chip package is thus completed. It simplifies a manufacture process for forming a chip package, reduces manufacture cost, and increases reliability of the chip package.