Substrate Inspection Temperature Offset Control for Junction Accuracy
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Solution Overview
Problem
Existing inspection systems face challenges in accurately detecting junction temperature of electronic devices due to noise interference and thermal resistance, leading to improper temperature control during electrical characteristic inspections, which can reduce yield and increase packaging costs.
Innovation Solution
An inspection system with a temperature control mechanism that includes a substrate holder, detector, and controller, which estimates junction temperature, adjusts substrate holder temperature based on offset temperatures, and supplies inspection power to maintain accurate temperature control during inspections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If inspection power is supplied to the substrate during inspection, then electrical characteristics can be measured, but junction temperature increases due to heat generation which affects measurement accuracy
Solution Approach 1:
The system performs preliminary temperature estimation by supplying inspection power, then measures the temperature rise amount. Based on this preliminary measurement, it calculates an offset temperature in advance. This offset is then applied to adjust the substrate holder temperature control, ensuring accurate temperature compensation during actual inspection without requiring real-time temperature monitoring that would interfere with measurements.
Solution Approach 2:
The system establishes a feedback loop where temperature estimation results from preliminary inspection power supply are fed back to adjust the substrate holder temperature control. The controller modifies the holder temperature based on the measured temperature rise, creating a closed-loop system that continuously compensates for heat generation effects during inspection, thereby maintaining measurement accuracy.
2Measurement precision
If substrate holder temperature is controlled to compensate for heat generation, then measurement accuracy improves, but control complexity increases due to need for offset temperature calculation and dynamic adjustment
Solution Approach 1:
The system uses the inspection power supply itself to generate the temperature rise information needed for control. By utilizing the same inspection signal that causes the temperature problem, the system self-measures the temperature effect and self-adjusts the holder temperature accordingly. This eliminates the need for separate temperature sensing systems or complex external control mechanisms.
Solution Approach 2:
The inspection power supply serves dual functions: it both stimulates the device under test for electrical characteristic measurement and simultaneously generates the temperature information needed for compensation control. The same power supply mechanism that causes heat generation is also used to measure and control that heat generation, simplifying the overall system architecture.
3Measurement precision
If offset temperature is determined after inspection power is stopped, then temperature measurement interference is reduced, but temperature control response time increases
Solution Approach 1:
The system performs temperature estimation as a preliminary action before actual inspection measurements. By stopping the inspection power temporarily to measure the temperature rise amount, it obtains accurate temperature data without interference. The offset temperature is calculated in advance based on this preliminary measurement, allowing rapid adjustment of the substrate holder temperature control without delaying the actual inspection process.
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
Enables precise temperature control during inspections, reducing yield loss and packaging costs by accurately estimating junction temperature and maintaining device temperature at the desired inspection level.
Implementation Method 1
a detector configured to supply an inspection power to an electrode portion of the substrate
Implementation Method 2
The detector includes a temperature estimation part configured to estimate a junction temperature of a junction portion provided at the substrate
Implementation Method 3
adjusting the temperature of the substrate holder based on a control temperature offset by the offset temperature
Data Source
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AI summary
Provided are an inspection system and a temperature control method with which a substrate is inspected while temperature control is suitably performed. The inspection system inspects a substrate while performing temperature control by a temperature adjustment mechanism. The inspection system comprises: a substrate holding unit that holds the substrate; a detection unit that supplies an inspection power to an electrode of the substrate; and a control unit. The detection unit has a temperature estimation unit that estimates a bonding portion temperature of a bonding portion provided to the substrate. The control unit includes: a step for supplying the inspection power to the substrate; a step for obtaining information related to the bonding portion temperature after the supply of the inspection power has been stopped; a step for determining an offset temperature of the substrate holding unit on the basis of the information related to the bonding portion temperature; a step for adjusting the temperature of the substrate holding unit on the basis of a control temperature offset by the offset temperature; and a step for supplying the inspection power to the substrate after the temperature of the substrate holding unit has been adjusted, and inspecting the substrate.