Sensor Chip Calibration for Manufacturing Stress Compensation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Manufacturing steps subsequent to calibration can impact the measuring characteristics of sensor chips due to mechanical and chemical stress, affecting future measurement results.

Innovation Solution

A method involving two calibration measurements: the first on a wafer before manufacturing and the second after manufacturing steps, with calibration parameters determined as a function of both, accounting for stress-induced changes and stored in the sensor chip or production line, to compensate for these impacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If calibration is performed before manufacturing steps, then calibration efficiency is improved and large number of chips can be calibrated quickly, but manufacturing steps subsequently impact measuring characteristics due to stress

Engineering Contradiction:
Improvecalibration efficiencyVSAvoidmeasuring characteristic accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent performs a first calibration measurement before manufacturing steps (preliminary action) to efficiently calibrate large numbers of sensor chips on wafer level. This preliminary calibration captures baseline characteristics before stress-induced changes occur during manufacturing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent performs a second calibration measurement after manufacturing steps and uses feedback from both measurements to determine final calibration parameters. The system compares pre- and post-manufacturing calibration data to compensate for stress-induced changes and determine accurate calibration parameters for operational use.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If calibration is performed after manufacturing steps, then measurement accuracy is improved by accounting for stress, but calibration time and resources increase

Engineering Contradiction:
Improvemeasuring characteristic accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs initial calibration before manufacturing to establish baseline characteristics, avoiding the need to recalibrate all parameters after manufacturing. This preliminary calibration captures most calibration needs efficiently.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent performs a second calibration measurement after manufacturing, but only to the extent necessary to capture stress-induced changes. The system combines data from both measurements rather than performing a complete recalibration, using partial action to achieve the needed accuracy improvement.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If multiple calibration measurements are performed, then calibration accuracy is improved by compensating for manufacturing stress, but device complexity increases

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcalibration process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs a first calibration measurement before manufacturing steps as a preliminary action. This initial calibration establishes baseline characteristics and reduces the complexity of post-manufacturing calibration by capturing most calibration requirements upfront.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where calibration data from both pre- and post-manufacturing measurements are combined to determine final calibration parameters. This systematic feedback approach manages complexity by providing a clear methodology for integrating multiple measurements rather than ad-hoc adjustments.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2827145B1Sensor calibration
Publication Date: 2020.04.08 SENSIRION AG
  • EP2827145B1 patent drawingFigure 1~2
  • EP2827145B1 patent drawingFigure 3~4
  • EP2827145B1 patent drawing

AI summary

In a method for calibrating a sensor chip, a first calibration measurement is performed with the sensor chip (9) and first calibration data is determined. A manufacturing step is performed on the sensor chip (9), such as packaging, dicing or cutting out from a wafer said sensor chip . A further calibration measurement is performed with the sensor chip (9) and further calibration data is determined, said further calibration data being used to compensate for deviations introduced by the manufacturing step such as packaging-induced stress. Final calibration data is determined from the first and the further calibration data, and is stored in a memory (94) of the sensor chip (9).