Monolithic Conductive Columns for Reliable Stacked-Die Bonding
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Solution Overview
Problem
Conventional semiconductor dies face issues with ineffective bonding due to underfilling or overfilling of conductive columns, leading to concave or convex protrusions that cause connection failures and die separation, exacerbated by stress and pressure during cooling and solidification.
Innovation Solution
The implementation of monolithic conductive columns that extend through multiple semiconductor dies, formed in a single manufacturing step, eliminating the need for additional conductive material to connect adjacent dies and distributing stress along the column length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional conductive columns are used in semiconductor dies, then electrical interconnection between dies is achieved, but underfilling or overfilling occurs leading to bonding failures and die separation
Solution Approach 1:
The patent merges the conductive columns of multiple dies into a single continuous monolithic conductive structure that extends through the entire stacked assembly. This eliminates the discrete columns in each die that are prone to underfilling or overfilling, replacing them with one unified column formed by depositing conductive material across the entire stack, thereby ensuring consistent fill and reliable bonding.
Solution Approach 2:
The invention transitions from forming conductive columns within individual two-dimensional die planes to creating a three-dimensional monolithic conductive structure that spans multiple dies vertically. This dimensional extension allows the conductive material to be deposited as a continuous structure through the entire stack, eliminating the precision challenges of filling individual columns in each die.
2Volume of moving object
If bond line thickness is reduced to decrease assembly volume, then device compactness is improved, but bonding reliability deteriorates due to stress and pressure during cooling and solidification
Solution Approach 1:
The patent combines the conductive columns of multiple dies into a single monolithic structure, which distributes the thermal stress and pressure generated during cooling and solidification throughout the entire column length rather than concentrating it at the bond lines. This stress distribution mechanism maintains bonding reliability even when bond line thickness is reduced for compactness.
3Productivity
If multiple semiconductor dies are stacked vertically to increase capacity and speed, then device performance is improved, but manufacturing complexity increases due to precise alignment and bonding requirements
Solution Approach 1:
The patent merges the conductive column formation process across multiple dies into a single operation. Instead of forming and filling columns in each die separately, conductive material is deposited once across the entire stacked assembly, creating monolithic columns that electrically interconnect all dies. This significantly simplifies the manufacturing process while maintaining the high-density stacked architecture.
Data Source
AI summary
A semiconductor device having monolithic conductive columns, and associated systems and methods, are disclosed herein. The semiconductor device can include a semiconductor substrate, a conductive pad, an opening, a non-conductive liner, and a plug of non-conductive material. The conductive pad may be at a surface of the semiconductor substrate. The opening may extend through the semiconductor substrate from the conductive pad to a second surface and define a side wall. The liner may coat the side wall and the plug may fill the opening. A second opening may be formed through the semiconductor device and the opening and a conductive material sintering therein.