TSV Pressure Sensor Eliminates Wire Bonding
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Solution Overview
Problem
Existing pressure sensor devices face reliability issues and high manufacturing costs due to the use of bond wires, which are prone to damage and require additional processing steps, increasing the need for pressure-sensitive gel and package size.
Innovation Solution
The use of Through Silicon Vias (TSVs) to electrically connect the pressure-sensing die to the microcontrol unit (MCU) without bond wires, reducing the need for wire bonding and pressure-sensitive gel, thereby streamlining the assembly process and decreasing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bond wires are used to connect the pressure-sensing die to the MCU, then electrical connection is achieved, but reliability deteriorates due to kinking or breaking of the bond wires
Solution Approach 1:
The patent removes bond wires from the pressure sensor device entirely. Instead of using bond wires to connect the pressure-sensing die to the MCU, the invention uses a lead frame with integrated electrical connections and encapsulation that eliminates the need for separate bond wire connections, thereby eliminating the reliability issues associated with bond wire kinking or breaking
Solution Approach 2:
The patent combines the lead frame, encapsulation, and electrical connection functions into a single integrated structure. The lead frame serves both as the structural support and as the electrical connection pathway, merging multiple functions into one component system that eliminates the need for separate bond wires
2Ease of manufacture
If bond wires are used to connect the pressure-sensing die to the MCU, then electrical connection is achieved, but manufacturing cost increases due to larger cavity sizes and more pressure-sensitive gel
Solution Approach 1:
The patent removes bond wires and the associated large cavity structure, thereby reducing the quantity of pressure-sensitive gel needed to fill the cavity. The eliminated bond wire connections free up significant space that would otherwise require expensive gel filling
Solution Approach 2:
The patent transitions from a three-dimensional cavity-filling approach to a planar lead frame-based connection system. By moving the electrical connections to the plane of the lead frame rather than requiring vertical bond wire connections through a large cavity, the design reduces the volume of gel required
3Productivity
If bond wires are used to connect the pressure-sensing die to the MCU, then electrical connection is achieved, but manufacturing time increases due to additional wire bonding steps
Solution Approach 1:
The patent removes the wire bonding process entirely from the manufacturing sequence. By eliminating bond wires, the patent eliminates the time-consuming wire bonding steps including wire attachment, bonding, and inspection, thereby significantly reducing total manufacturing time
Solution Approach 2:
The patent incorporates electrical connection pathways directly into the lead frame structure during its initial fabrication, before the pressure-sensing die is mounted. This preliminary integration of connection paths eliminates the need for subsequent wire bonding steps during assembly
Data Source
AI summary
A semiconductor pressure sensor device having a pressure-sensing die electrically connected to a microcontrol unit (MCU) using either through silicon vias (TSVs) or flip-chip bumps. An active surface of the pressure-sensing die is in facing relationship with the MCU. These embodiments avoid the need to used bonds to electrically connect the pressure-sensing die to the MCU, thereby saving time, reducing size, and reducing cost.