Surface-Mount Semiconductor Package Manufacturing Without Lead Frames
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Solution Overview
Problem
Existing manufacturing processes for surface-mount semiconductor packages, such as those using lead frames, are costly and result in packages with high weights due to the use of lead-frame strips.
Innovation Solution
A manufacturing process utilizing a watersoluble supporting structure with adhesive layers and sintering paste to form conductive contact, track, and pad regions, allowing for the elimination of lead-frame strips and enabling the creation of lighter, thinner packages through a flip-chip configuration or wire bonding, without the need for lead-frame strips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If lead-frame strips are used in traditional manufacturing processes, then packages can be produced with established methods, but the packages have high weights and high costs
Solution Approach 1:
The patent extracts and eliminates the lead-frame strip from the package structure, replacing it with a substrate that has conductive patterns formed directly on it. This removal of the heavy lead-frame component directly addresses the weight reduction goal while maintaining the essential electrical connection function through alternative means (conductive patterns and solder balls).
Solution Approach 2:
The patent changes the fundamental parameter of how electrical connections are achieved - moving from mechanical/electrical connections via lead-frame strips to electrical connections via conductive patterns printed on a substrate and terminated with solder balls. This parameter change enables weight reduction while preserving the package's electrical functionality.
2Ease of manufacture
If traditional lead-frame based processes are used, then packages can be manufactured with conventional methods, but the packages have relatively high thickness
Solution Approach 1:
The patent transitions from a three-dimensional lead-frame structure to a more planar, two-dimensional conductive pattern layout on the substrate. This dimensional simplification allows for thinner package construction by eliminating the need for thick lead-frame strips and their associated bending and folding structures, achieving reduced thickness while maintaining electrical connectivity.
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 process reduces package weight and thickness, achieving lighter and more compact semiconductor devices with improved thermal and mechanical stability, and allows for the production of packages like QFN without the need for lead-frame strips, offering cost and weight advantages.
Implementation Method 1
a second layer (6) arranged in contact with the first layer (4), which is formed by a film of polyvinyl acetate (PVA) or polyvinyl pyrrolidone (PVP)... the second layer (6) is formed, for example, by a pressure-sensitive adhesive film (PSA film)
Implementation Method 2
Heat is applied to disperse the suspension medium and sinter the metal powder to form the body portion
Implementation Method 3
The first and second supporting layers (4, 6) are dissolved by application of a jet of water
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
A process for manufacturing a surface-mount electronic device, including the steps of: forming a plurality of preliminary contact regions (30; 60; 90) of a sinterable material on a supporting structure (2); mechanically coupling a die (42; 72; 82) including a semiconductor body (44; 75) to the supporting structure (2); and sintering the sinterable material, in such a way that each preliminary contact region (30; 60; 90) forms a corresponding sintered preliminary contact (36; 66; 96).