Semiconductor Die Interposer and Single-Layer Probe Card Design
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Solution Overview
Problem
Conventional lead frame-based packaging techniques struggle with smaller semiconductor dice due to diminishing bond pad size and pitch, leading to difficulties in wire bonding and high device density, and require complex probe cards with multiple layers to accommodate various bond pad configurations, resulting in excessive capacitance.
Innovation Solution
The development of semiconductor device packages with discrete conductive elements and guide posts or pins to facilitate bonding and stacking of dice, and the use of single-layer probe cards with pillar-shaped contacts and short conductive traces to minimize capacitance and accommodate diverse bond pad configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If lead frame-based packaging techniques are used with conventional wire bonds, then bonding can be achieved, but it becomes difficult or impossible to place inner ends of lead fingers in close proximity to bond pads as die size and pitch decrease
Solution Approach 1:
The patent introduces an interposer substrate as an intermediary component between the semiconductor die and the lead frame. This interposer carries conductive elements that can be precisely positioned near bond pads through advanced fabrication techniques, while wire bonds connect from the lead frame to the interposer rather than directly to the die. This mediator resolves the contradiction by decoupling the positioning requirements of the lead frame from the bond pad locations.
Solution Approach 2:
The patent utilizes a multi-layer interposer substrate structure that adds vertical dimensionality to the connection architecture. Conductive elements are distributed across multiple layers of the interposer, allowing three-dimensional routing paths that reduce the horizontal distance between lead finger ends and bond pads. This dimensional approach enables precise electrical connections without requiring extremely tight lateral spacing.
2Adaptability or versatility
If bond pads are arranged along a central axis of a semiconductor die, then conventional LOC package configuration is maintained, but lead fingers must be elongated and overcrowded or wire bonds must be made overly long risking breakage or shorting
Solution Approach 1:
The interposer substrate serves as a mediator that provides flexible routing paths for electrical connections. Instead of requiring direct, short wire bonds from lead fingers to centrally-arranged bond pads, the interposer offers alternative connection paths through its conductive elements and traces, eliminating the need for excessively long or overcrowded wire bonds and maintaining reliability.
Solution Approach 2:
The multi-layer interposer structure enables vertical and lateral routing paths that bypass the limitations of planar wire bond arrangements. Electrical connections can traverse through multiple layers of the interposer, providing shorter and more reliable current paths that avoid the risks of wire bond breakage and shorting associated with overly long horizontal bonds.
3Productivity
If conventional lead frame-based packages are used, then packaging can be achieved, but high device density in conjunction with high multi-die device yields cannot be facilitated
Solution Approach 1:
The patent segments the packaging system into distinct functional modules: the semiconductor die, the interposer substrate with conductive elements, and the lead frame. This segmentation allows each component to be optimized independently and facilitates high-density multi-die assemblies by enabling precise alignment and connection of multiple dice to the interposer, thereby improving productivity while managing complexity through modular design.
Solution Approach 2:
The interposer substrate serves multiple functions simultaneously: it provides electrical interconnection between the lead frame and die, enables precise positioning of multiple dice, facilitates heat dissipation pathways, and supports high-density routing. This multi-functionality allows the packaging system to achieve high device yields and density without proportionally increasing overall system complexity.
4Adaptability or versatility
If probe cards with multiple layers of conductive traces are used to accommodate various bond pad configurations, then probe testing can be performed, but excessive capacitance is induced along conductive paths
Solution Approach 1:
The patent employs an interposer substrate as an intermediary in the probe testing architecture. Instead of requiring long, complex conductive paths through multiple substrate layers to reach various bond pad configurations, the probe card makes direct contact with the interposer's conductive elements. This intermediary approach shortens the effective capacitance-carrying paths while maintaining the ability to accommodate diverse bond pad layouts.
Solution Approach 2:
The multi-layer interposer structure provides vertical routing paths that reduce the horizontal trace lengths required on the probe card substrate. By utilizing the vertical dimension for signal routing through the interposer layers, the patent minimizes the surface area of conductive traces exposed to capacitive coupling, thereby reducing overall capacitance while still accommodating various bond pad configurations.
Data Source
AI summary
A semiconductor die has conductors encapsulated in a dielectric material disposed on the active surface extending across the active surface from bond pads to one or more peripheral edges where the conductor ends are disposed at a side surface of the dielectric material. Stacks of such semiconductor dice, wherein one of the dice is configured with discrete conductive elements projecting from the active surface, and the exposed ends of the dice in the stack are connected with vertical interconnects. A probe card is disclosed having bond wires extending from one or more central contacts between one or more peripheral contacts to the edge of the probe card. A probe card having an upper layer bearing contacts and at least one window therethrough, a lower layer bearing conductive traces with ends exposed through the at least one window, and conductors extending from at least some of the contacts to conductive trace ends is also provided. Methods of making the foregoing structures are disclosed.