Updated 02/23/2024

Wafer breakage at flash heating

Cause and Effect Chain #

Wafer breakage within the flash heating system:

The flash heating with the upper lamp created the gradient of the temperature of the air. The fast-changing of temperature results in the wind (tornado) formation that leads to the movement of the wafer. The moving of the wafer may result in a mechanical hit followed by the wafer breakage.

May 29 2022 3:12:51 pm
5 Whys #
Causes Chain
Root Cause Analysis

Wafer breakage occurs at flash heating


Run additional wafers to compensate for the broken wafers


A mechanical hit occurs


Redesign the pedestal or add a ring having no "walls" - no parts that the wafer can hit


Wafer moves due to air pressure difference appearing due to flash heating


Keep the wafer static - no movements at all (vacuum keeper?)


The pedestal has a special configuration: the wafer moves and can get a mechanical hit

This is the fundamental reason for the problem (FRP).

Redesign the pedestal to exclude a mechanical hit

Jun 12 2022 1:04:05 pm
Functional Modeling #

How wafer breakage occurs while the flash heating process:

Operational Effectiveness – OE



OE 0.67
Operational Perfectness - OP

Basic functions



OP 0.62
Functional rank
Problematic rank
Low lamp
Centering pins
Upper light (flash)
Atmosphere (N2)

The main conclusion is that we need to exclude either movement of the wafer or vertical solid parts that the wafer can hit

Jun 12 2022 1:18:45 pm
Inventive principles #
we exclude the wafer movement
no breakage will occur due to a mechanical hit
The thermal stress could appear and affect the parameters of the product or even result in breakage due to thermal stress
Improving parameter
Description of what is improving:
No breakage will occur
Selected improving parameter:
Worsening parameter
Description of what is worsening:
thermal stress will occur
Selected worsening parameter:
Matching principles:
  • 10
    Preliminary action
  • 14
    Spheroidality - Curvature
  • 30
    Flexible shells and thin films
  • 40
    Composite materials
  • Jun 12 2022 1:32:07 pm
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