Lead Frame Land Grid Array Package Etching Method
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Solution Overview
Problem
Conventional semiconductor packaging methods involve numerous processing steps and result in packages with limitations, such as increased size and complexity, which hinder efficient handling and processing.
Innovation Solution
A method involving a metal layer with plated areas for die attach and contact pads, where the metal layer is etched away to expose these areas, forming a molded block for parallel processing, and subsequently singulating individual packages, reducing the number of fabrication steps and enabling high-speed bulk processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional semiconductor packaging methods are used, then packages are formed with reliable structure, but the number of processing steps increases and manufacturing complexity increases
Solution Approach 1:
The patent combines multiple packaging operations into a single molded block containing multiple packages, allowing parallel processing of die attachment, wire bonding, and encapsulation. This merging of operations maintains package reliability while reducing the total number of processing steps by factorizing the manufacturing process.
Solution Approach 2:
The metal layer with pre-formed plated areas is prepared in advance before die attachment. This preliminary preparation of the substrate with integrated circuit board simulation and contact pad formation eliminates subsequent processing steps and reduces manufacturing complexity while ensuring reliable electrical connections.
2Reliability
If conventional packaging methods are used, then packages are formed with adequate size, but package size increases beyond die dimensions
Solution Approach 1:
The patent applies local quality by providing plated areas only at specific locations where electrical connections are needed, rather than covering the entire package surface. This selective plating on the metal layer allows compact package design with area close to die dimensions while maintaining necessary electrical connectivity for reliable operation.
3Ease of operation
If conventional packaging methods are used, then individual packages can be handled, but handling efficiency decreases and processing speed reduces
Solution Approach 1:
Multiple packages are combined into a single molded block that can be handled as one unit during manufacturing processes. This merging enables parallel processing of multiple packages simultaneously, dramatically increasing productivity while the final singulation step provides individual packages for ease of operation and installation.
Solution Approach 2:
The molded block is subsequently singulated into individual packages, providing segmentation that enables easy handling and installation of single packages while the bulk processing of the block maintains high productivity. This two-stage approach resolves the contradiction between handling efficiency and processing speed.
4Reliability
If conventional packaging methods are used, then packages are formed with adequate structure, but manufacturing time and cost increase
Solution Approach 1:
The metal layer with integrated circuit board simulation and pre-formed contact pads is prepared in advance, eliminating subsequent plating and substrate preparation steps. This preliminary action maintains reliable package structure while significantly reducing manufacturing time and associated costs.
Solution Approach 2:
Multiple packages are manufactured simultaneously within a single molded block through parallel processing, reducing total manufacturing time while maintaining adequate structure for each individual package. The combined processing of multiple units preserves structural reliability through consistent manufacturing conditions.
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 approach reduces the number of processing steps, saves time and costs, allows for packages with sizes close to the die dimensions, and facilitates efficient handling and testing, enhancing throughput and reliability.
Implementation Method 1
The molded block is formed by using a metal layer and removing the metal layer from the molded block, such that the plated areas are exposed. For instance, the metal layer is removed by etching.
Implementation Method 2
A substrate is provided. A first plated area is formed on a first surface of the substrate. A second plated area is formed on a second surface of the substrate. The first and second plated areas may be formed by electroplating, for instance.
Data Source
AI summary
A package includes a first plated area, a second plated area, a die attached to the first plated area, and a bond coupling the die to the second plated area. The package further includes a molding encapsulating the die, the bond, and the top surfaces of the first and second plated areas, such that the bottom surfaces of the first and second plated areas are exposed exterior to the package. Additional embodiments include a method of making the package.