Direct-Bonded Metal Substrate Layout for Shorter Wire Bonds
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Solution Overview
Problem
Existing high-power semiconductor device modules have inefficient layouts, leading to increased material costs and vulnerability to damage due to excessive wiring, which affects reliability.
Innovation Solution
The implementation of a compact power module design featuring a direct bond metal (DBM) structure with a silicon nitride ceramic layer, a U-shaped metal clip for mechanical and electrical connections, and short wire bonds to reduce footprint and enhance reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If traditional layouts are used for high-power semiconductor device modules, then components can be connected with sufficient wiring, but the footprint is large and material costs increase
Solution Approach 1:
The patent transitions from a planar two-dimensional layout to a three-dimensional vertical architecture. The DBM structure with stacked metal layers (first metal layer, second metal layer, third metal layer) enables wiring to occur in multiple vertical dimensions, allowing components to be connected through vertical vias and stacked configurations rather than requiring extensive horizontal routing space.
Solution Approach 2:
The patent combines multiple functions into integrated structures. The DBM (direct bond metal) structure merges electrical interconnection, mechanical support, and thermal management functions into a single integrated substrate. The lead frame integrates multiple electrical connections (gate lead frame post, sense lead frame post, ground connection) into a unified structure that reduces the number of separate components needed.
2Reliability
If extensive wiring is used to connect components, then all electrical connections can be established, but reliability decreases due to vulnerability to damage
Solution Approach 1:
The patent reduces wiring vulnerability by moving connections from horizontal planes to vertical stacks. The multi-layer DBM structure with vias allows electrical connections to be made vertically through the substrate, shortening wire bond lengths and reducing the number of horizontal wiring paths that are susceptible to mechanical damage and electrical interference.
Solution Approach 2:
The patent extracts and eliminates unnecessary wiring by implementing direct bonding. The DBM structure provides direct electrical connections between metal layers through vias and conductive paths, removing the need for extensive wire bonds and external interconnectors that would increase reliability risks.
3Area of stationary object
If a compact layout is implemented, then footprint is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent performs preliminary alignment and bonding operations during the DBM fabrication process. The multi-layer metal structure with predefined via locations and conductive paths is prepared in advance, allowing components to be attached to predetermined locations with reduced alignment requirements during final assembly.
Solution Approach 2:
The patent changes material and structural parameters to accommodate compact dimensions. The DBM structure uses controlled via dimensions, metal layer thicknesses, and conductor trace widths that are optimized for high-precision manufacturing. The silicon nitride ceramic layer provides a stable substrate with controlled thermal and mechanical properties that maintain dimensional stability during manufacturing processes.
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 design achieves a reduced footprint by about 30% to 40% compared to current designs, leading to cost savings and improved reliability through reduced wire bond vulnerability.
Implementation Method 1
a direct bond metal (DBM) structure on the substrate, the DBM structure including a silicon nitride based ceramic layer; a first die and a second die attached side-by-side to the DBM structure
Implementation Method 2
a U-shaped metal clip coupling top sides of the first die and the second die to the lead frame using solder
Data Source
AI summary
A compact power inverter is efficiently laid out on a multi-layer direct bond metal (DBM) structure, having a reduced footprint and straight, short-run wire bonds. The compact layout reduces an amount of material needed to fabricate a multi-layer DBM that includes a silicon nitride ceramic layer. The layout is further designed so that wire bonds can be routed without bending around corners. The compact DBM structure and short wire bonds provide a solution that is both low-cost and highly reliable.