Thin Metal Wire Bonding for Low-Profile Semiconductor Packages
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Solution Overview
Problem
The challenge is to further reduce the size and weight of semiconductor devices while preventing short-circuits in thin metal wire bonding, which is essential for advancing mobile equipment, as existing techniques like the M-loop configuration are not sufficient for achieving a low enough profile without compromising reliability.
Innovation Solution
A semiconductor device with a thin metal wire configuration that includes a curve portion connected to a bonding pad, a bend portion, and extending portions that are formed using a bonder with a capillary and spark means to create a recrystallized hard portion, allowing for a lower loop height and reduced risk of short-circuits, achieved by controlling the length of the hard portion and forming a fishhook-like shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a triangular loop thin metal wire is used, then the wire can be easily formed and bonded, but the top portion height is considerably high causing potential short-circuit to the semiconductor chip
Solution Approach 1:
The wire loop is transformed from a triangular shape with sharp corners to an M-loop shape with curved portions. The curve portions replace the oblique extending sections, creating a smoother trajectory that reduces the top portion height while maintaining structural integrity and preventing short-circuits to the semiconductor chip.
Solution Approach 2:
The geometry parameters of the wire loop are modified by changing from a triangular configuration to an M-loop configuration with specific curve portions. This parameter change optimizes the height profile while preserving the electrical connection function and reducing the risk of contact with the semiconductor chip surface.
2Length of stationary object
If the top portion of the thin metal wire is lowered to reduce package thickness, then the device becomes thinner, but the wire is likely to short-circuit to the semiconductor chip
Solution Approach 1:
The M-loop shape with curve portions creates a more efficient spatial configuration that lowers the top portion height without creating straight oblique sections that could contact the chip. The curved trajectory optimizes the wire path to minimize height while maintaining safe clearance from the semiconductor chip surface.
Solution Approach 2:
The M-loop configuration introduces asymmetric curve portions that strategically position the wire trajectory to avoid the semiconductor chip area. The asymmetric shape allows the wire to loop back without creating a symmetric triangular pattern that would require higher clearance.
3Length of stationary object
If an M-loop thin metal wire is used to reduce height, then the package thickness is reduced, but the manufacturing process becomes more complex
Solution Approach 1:
The M-loop wire configuration serves multiple functions: it reduces package thickness, maintains electrical connection, and prevents short-circuits. The same basic wire forming process can create different loop shapes (triangular or M-loop) by adjusting parameters, making the solution universally applicable to various packaging requirements.
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 configuration enables a thinner semiconductor device package with a highly reliable connection method, allowing for further miniaturization while maintaining reliability by adjusting the bend portion and reducing the height of the thin metal wire loop, thus preventing short-circuits and accommodating resin encapsulation.
Implementation Method 1
spark means located near an end portion of the capillary
Implementation Method 2
controlling a length of a hard portion of a thin metal wire extended from the metal ball, by controlling a period of time in which a current flows into the spark means, the hard portion being formed of a recrystallized portion
Data Source
AI summary
Provided is a thin semiconductor device using a thin metal wire and having a low top portion. The semiconductor device of the present invention has a structure in which a bonding pad 55 of a semiconductor chip 54 and an electrode 53B are connected to each other via a thin metal wire 51, and the thin metal wire 51 forms a curve portion 57. Specifically, the thin metal wire 51 exhibits the curve portion 57 from a first bond, and is provided with a linear second extending portion 60 with an end portion thereof being a first bend portion 59. A second bend portion 61 is located lower than a top portion 58 of the curve portion 57.