Backside Drill Embedded Die Substrate Interconnects
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Solution Overview
Problem
The challenge in embedded die substrates is to reduce costs while maintaining access to pads on the topside of a die from nodes adjacent to the backside, as existing methods like through substrate vias (TSVs) are costly and affect thermal conductivity, and traditional routing methods complicate thermal and electrical requirements.
Innovation Solution
The implementation of single-segment die-penetrating interconnects formed during the backside drilling process, which extend through the substrate and die, using a continuous conductive material like copper to minimize thermal dissipation ground resistance and maximize thermal conductivity, eliminating the need for costly TSVs and complex routing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If through substrate vias (TSVs) are used to access pads on the topside of a die from the backside, then electrical connectivity is achieved, but manufacturing cost increases and thermal conductivity deteriorates
Solution Approach 1:
The patent extracts the TSV structure from the die and relocates it to the substrate. Holes are formed in the substrate and filled with conductive material to create interconnects that pass through the substrate and make contact with pads on the topside of the die. This eliminates the need for costly TSV fabrication while maintaining electrical connectivity from the backside to the topside pads.
Solution Approach 2:
Instead of forming vias through the die (TSVs), the patent inverts the approach by forming holes through the substrate and extending them to contact the topside pads directly. This reversal of the via formation location from die-to-substrate becomes substrate-to-die, reducing manufacturing complexity and cost.
2Reliability
If through substrate vias (TSVs) are used for backside access to topside pads, then electrical connectivity is achieved, but thermal conductivity decreases
Solution Approach 1:
The patent removes the TSV structure from the die and relocates the conductive interconnect formation to the substrate. By forming holes in the substrate and filling them with highly thermally conductive material (such as copper), the patent achieves both electrical connectivity and superior thermal conduction, eliminating the thermal conductivity deterioration associated with TSVs.
3Reliability
If traditional routing methods are used to connect backside nodes to topside pads, then electrical connectivity is achieved, but device complexity increases
Solution Approach 1:
The patent segments the interconnect structure into distinct components: holes formed in the substrate, conductive material filling these holes, and contact regions on the topside pads. This segmentation allows for simplified fabrication processes and reduces routing complexity compared to traditional methods that require complex multi-layer interconnect structures.
Solution Approach 2:
The patent inverts the traditional routing approach by having conductors extend upward from the substrate through holes to contact the topside pads, rather than routing conductors through the die or using complex backside routing. This inversion dramatically simplifies the routing architecture and reduces device complexity.
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 cost of die integration, improves thermal conductivity by up to 30% compared to gold TSVs, and simplifies the routing process, enhancing the overall performance of the embedded die substrate.
Implementation Method 1
improves thermal conductivity by up to 30% compared to gold TSVs, and simplifies the routing process
Data Source
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AI summary
A device and method of fabricating are provided. The device includes a substrate having a first side and an opposite second side, a cavity defined within the substrate from the first side, a die coupled to a floor of the cavity and having a conductive pad on a side of the die distal to the floor of the cavity. A laminate layer coupled to the second side of the substrate may be included. A hole may be drilled, at one time, through layers of the device, through the die, and through the conductive pad. The hole extends through and is defined within the laminate layer (if present), the second side of the substrate, the die, and the conductive pad. A conductive material is provided within the hole and extends between and through the laminate layer (if provided), the second side of the substrate, the die, and the conductive pad.