Shaped Package Interconnects for Tighter Pitch Without Spacing Violations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Interconnects in packages and substrates are limited by minimum pitch and spacing requirements, which hinder performance.
Innovation Solution
The use of interconnects with semi-circular and trapezoid shapes allows for closer centroid-to-centroid distances without violating minimum spacing and pitch requirements, enhancing electrical performance by reducing coupling loss, increasing impedance, and improving cross talk and loop inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional fabrication processes are used, then existing manufacturing capabilities are maintained, but manufacturing precision deteriorates due to difficulty in forming right angles and planar surfaces
Solution Approach 1:
Instead of attempting to form right angles and planar surfaces directly through conventional fabrication processes, the invention inverts the approach by forming inclined surfaces and curved surfaces first, then using planarization layers and etch stops to create the required right angles and flat surfaces. This reverse engineering approach transforms difficult direct-forming operations into easier sequential processes.
Solution Approach 2:
The fabrication process is segmented into distinct stages: forming the inclined/curved interconnect surfaces, depositing etch stop layers, depositing planarization layers, and performing selective etching. This segmentation breaks down the complex task of creating precise right angles and planar surfaces into manageable steps, each optimized for specific functions.
2Adaptability or versatility
If interconnect density is increased to improve device functionality, then device performance improves, but stress control deteriorates due to crowding of interconnects
Solution Approach 1:
The invention applies different materials with different stress properties to different locations within the interconnect structure. Etch stop layers and planarization layers are selectively positioned in specific regions to provide local stress compensation. This allows high interconnect density in functional areas while maintaining stress control through strategically placed stress-balancing layers.
Solution Approach 2:
The interconnect structure uses composite material systems combining the interconnect material with etch stop layers and planarization layers. These composite structures are designed to balance stresses while maintaining high density. The different materials complement each other to achieve both high functionality and stress stability.
3Manufacturing precision
If new fabrication processes are developed to improve manufacturing precision, then formation of right angles and planar surfaces improves, but device complexity increases
Solution Approach 1:
The etch stop layers and planarization layers serve multiple functions simultaneously: they control stress, define geometry, enable selective etching, and provide structural support. This multi-functionality reduces the need for separate dedicated process steps, thereby limiting the increase in device complexity despite improved manufacturing precision.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A substrate that includes at least one dielectric layer, a plurality of first interconnects located in the at least one dielectric layer, at least one photo-imageable dielectric layer coupled to the at least one dielectric layer, and a plurality of second interconnects located in the at least one photo-imageable dielectric layer. The plurality of second interconnects includes at least one pair of adjacent interconnects having a centroid to centroid distance that is less than a pitch between the pair of interconnects. The pair of adjacent interconnects may include a pair of adjacent via interconnects and/or a pair of pad interconnects. The substrate may include a coreless substrate or a cored substrate.