Edge-Notched Substrate Layout for Low-Height Wire Bond Packaging
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Solution Overview
Problem
Conventional semiconductor device packaging with window-type substrates is inefficient for dies with edge-mounted bond pads, leading to increased package height and incompatibility with certain types of semiconductor devices like NAND memory dies, as it requires upward and lateral wire loops that exceed height limits in high-volume manufacturing.
Innovation Solution
The use of an edge-notched substrate allows compact wire bonds to be routed from interconnect bond pads on a stack of dies to contacts on the opposite side, eliminating upward and lateral wire loops by positioning bond pads at the edge of the die for alignment with the notch, enabling a single mold cavity encapsulation and reducing package size and wire bond length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If window-type substrate with central opening is used, then bonding wire length is reduced, but package height increases due to upward and lateral wire loops
Solution Approach 1:
The patent transitions from a conventional central opening configuration to an edge-notched substrate configuration, changing the spatial dimension and location of the wire bond routing path. This dimensional change allows wires to route laterally along the edge rather than vertically through the center, reducing package height while maintaining wire length benefits
Solution Approach 2:
Instead of routing wires through the conventional central opening with upward loops, the patent inverts the approach by routing wires through an edge notch with lateral paths. This inversion of the routing strategy eliminates the height-increasing upward loops while achieving compact wire bonds
2Productivity
If edge-mounted bond pads are used, then interconnect density is improved, but compatibility with conventional packaging is reduced
Solution Approach 1:
The patent applies local quality by creating a specific edge-notched region on the substrate that is optimized for edge-mounted bond pads. This localized structural modification at the substrate edge enables high interconnect density for dies with edge-mounted pads while maintaining compatibility with conventional packaging processes and standards
3Reliability
If upward and lateral wire loops are used, then bond pads can be connected, but package size exceeds height limits
Solution Approach 1:
The patent extracts and eliminates the harmful upward and lateral wire loops from the packaging structure. By removing these height-increasing routing paths and replacing them with a lateral edge-notch routing solution, electrical connections are maintained while package height is reduced below conventional limits
Data Source
AI summary
Systems and methods for a semiconductor device having an edge-notched substrate are provided. The device generally includes a substrate having a front side, a backside having substrate contacts, and an inward notch at an edge of the substrate. The device includes a die having an active side attached to the front side of the substrate and positioned such that bond pads of the die are accessible from the backside of the substrate through the inward notch. The device includes wire bonds routed through the inward notch and electrically coupling the bond pads of the die to the substrate contacts. The device may further include a second die having an active side attached to the backside of the first die and positioned laterally offset from the first die such that the second bond pads are accessible by wire bonds around the edge of the first die and through the inward notch.