Catheter Pressure Sensor Blocking Structure for Epoxy Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Pressure sensors with small, thin form factors are difficult to manufacture using traditional semiconductor assembly tools, leading to challenges in yield and cost due to issues with epoxy flow and device identifier protection during assembly and operation.

Innovation Solution

Incorporating a blocking structure, such as trenches or bars, to control epoxy flow and protect device identifiers, along with side tabs for improved handling and attachment, and staggered bond pads for easier wire bonding, to enhance manufacturability and reduce costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional semiconductor assembly tools are used for wire bonding or flip-chip assembly, then manufacturing process is standardized, but small form factor pressure sensors cannot be manufactured with adequate yield

Engineering Contradiction:
ImprovemanufacturabilityVSAvoidyield
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The pressure sensor is segmented into distinct functional regions: a sensing area with the membrane and Wheatstone bridge, a handle portion for manipulation, and a base portion with bond pads. This segmentation allows the sensor to be manufactured as a complete unit using glass blowing techniques, avoiding the need for traditional semiconductor assembly tools and enabling production of small form factor sensors with adequate yield.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A glass handle portion serves as an intermediary structure that facilitates manufacturing and handling. The handle portion allows the sensor to be manipulated during manufacturing processes and can be used to attach the sensor to catheters or other devices, enabling production of small sensors that would otherwise be too small for standard assembly tools.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If epoxy is applied over bond pads to provide electrical insulation and mechanical protection, then bond pads are protected, but epoxy flow may obscure device identifiers and reduce yield

Engineering Contradiction:
Improveelectrical insulationVSAvoidyield
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The device identifier is extracted from the area that would be covered by epoxy by placing it on the handle portion rather than the base portion. This separation allows epoxy to be applied over the bond pads for electrical insulation and mechanical protection without obscuring the identifier, maintaining both reliability and manufacturing yield.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The handle portion is designed with sufficient length to accommodate both the device identifier and provide a gripping area. This preliminary design consideration ensures that when epoxy is later applied to the base portion, the identifier remains exposed and readable, preventing yield reduction.

Inventive Principle:
Principle #10Preliminary action

3Volume of moving object

If pressure sensor form factor is reduced to fit inside small catheters, then application requirements are met, but traditional semiconductor packaging and assembly techniques cannot be employed

Engineering Contradiction:
Improveform factorVSAvoidmanufacturability
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The sensing element, handle, and packaging structure are merged into a single glass-blown component. The glass handle portion serves simultaneously as structural support, manipulation aid, and attachment interface, eliminating the need for separate packaging and assembly steps required by traditional semiconductor techniques.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The manufacturing approach changes from semiconductor fabrication to glass blowing techniques, fundamentally changing the manufacturing parameters. This allows production of ultra-small form factor sensors with integrated handles that can be manipulated and assembled despite their small size, meeting catheter application requirements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3353518B1Manufacturing catheter sensors
Publication Date: 2021.01.13 SMI CORPORATION
  • EP3353518B1 patent drawingFigure 1
  • EP3353518B1 patent drawingFigure 2
  • EP3353518B1 patent drawingFigure 3

AI summary

Pressure sensors and their methods of manufacturing, where the pressure sensors have a small, thin form factor and may include features designed to improve manufacturability and where the method of manufacturing may improve yield and reduce overall costs. A pressure sensor comprisis - a membrane (122) formed on a top surface of a handle portion of the pressure sensor - a base portion opposite the handle portion, the base portion wider and thicker than the handle portion - a plurality of bond pads formed on a top surface of the base portion - a device identifier (114) on a top surface of the pressure sensor - a blocking structure (116) on the top surface of the pressure sensor between the plurality of bond pads and the device identifier