Wafer Bonding Apparatus with Local Thermal Compensation
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Solution Overview
Problem
Conventional bonding methods for semiconductor wafers often result in local deformation due to unnecessary stress, despite countermeasures to reduce deformation, as the upper substrate is bent during bonding, leading to potential deformation in the bonded substrates.
Innovation Solution
A bonding apparatus comprising a first holding unit, a second holding unit, a striker, a moving unit, and a temperature control unit, where the second holding unit can be moved between facing and non-facing positions with respect to the first holding unit, and the temperature control unit locally adjusts the temperature of the second substrate to correct deformation before bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the upper substrate is bent to contact the lower substrate during bonding, then the bonding process can be initiated, but unnecessary stress is applied to the upper substrate causing local deformation
Solution Approach 1:
The lower substrate is pre-heated in a specific temperature distribution pattern before bonding to create preliminary thermal deformation that counteracts the stress-induced deformation during bonding. This preliminary action prepares the lower substrate to compensate for the harmful effects that will occur during the bonding process.
Solution Approach 2:
The invention uses composite heating structures with different heating zones (first heating unit and second heating unit) that apply different temperature distributions to different regions of the lower substrate, creating a composite thermal field that compensates for stress-induced deformation.
2Object-affected harmful factors
If the lower substrate is held flat to avoid deformation, then stress on substrates is reduced, but local deformation still occurs due to the upper substrate bending
Solution Approach 1:
The heating apparatus applies different temperature distributions to different local regions of the lower substrate. The first heating unit heats a first region while the second heating unit heats a second region, creating localized thermal compensation that addresses deformation in specific areas without affecting the entire substrate uniformly.
Solution Approach 2:
The invention changes the temperature parameter of the lower substrate in a controlled distribution pattern before bonding. By adjusting the temperature field, the thermal expansion and contraction of the lower substrate compensate for the stress-induced deformation caused by upper substrate bending during bonding.
3Stability of the object's composition
If temperature control is applied uniformly to the lower substrate, then overall substrate stability is improved, but local deformation compensation is insufficient
Solution Approach 1:
The heating apparatus is divided into multiple independent heating units (first heating unit and second heating unit) that can be controlled separately. Each heating unit targets a specific region of the lower substrate, allowing independent temperature control for different areas to compensate for local deformation while maintaining overall substrate stability.
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
The described bonding method effectively reduces local deformation in bonded substrates by allowing for precise temperature control and positioning of the second substrate, thereby minimizing stress and deformation during the bonding process.
Implementation Method 1
the temperature control unit locally adjusts a temperature of the second substrate attracted to and held by the second holding unit
Implementation Method 2
The first holding unit is configured to attract and hold a first substrate from above
Implementation Method 3
The second holding unit is configured to attract and hold a second substrate from below
Implementation Method 4
The striker is configured to bring the first substrate into contact with the second substrate by pressing a central portion of the first substrate from above
Implementation Method 5
The moving unit is configured to move the second holding unit between a non-facing position where the second holding unit does not face the first holding unit and a facing position where the second holding unit faces the first holding unit
Data Source
AI summary
A local deformation which is generated on bonded substrates can be reduced. A bonding apparatus includes a first holding unit configured to attract and hold a first substrate from above; a second holding unit configured to attract and hold a second substrate from below; a striker configured to bring the first substrate into contact with the second substrate by pressing a central portion of the first substrate from above; a moving unit configured to move the second holding unit between a non-facing position where the second holding unit does not face the first holding unit and a facing position where the second holding unit faces the first holding unit; and a temperature control unit disposed to face the second holding unit placed at the non-facing position and configured to locally adjust a temperature of the second substrate attracted to and held by the second holding unit.