Plasma-Activated Semiconductor Chip Bonding Without Solder Bumps
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Solution Overview
Problem
The challenge in bonding semiconductor chips to substrates is the thermal deformation and position shift due to differences in thermal expansion coefficients, which affects alignment accuracy and bonding strength, especially when using solder bumps and varying substrate sizes.
Innovation Solution
A plasma-activated bonding method where the semiconductor chip and substrate are temporarily bonded at normal temperature using plasma activation, followed by heating and pressurization to achieve a strong, accurate bond without interposing solder bumps, allowing for precise alignment and enhanced bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If solder bumps are used for bonding semiconductor chips to substrates, then bonding strength is improved, but thermal deformation and position shift occur due to differences in thermal expansion coefficients
Solution Approach 1:
The invention removes solder bumps from the bonding structure entirely, replacing them with a direct bonding interface between the semiconductor chip and substrate. This extraction eliminates the thermal expansion mismatch problem that causes position shift and alignment errors, while maintaining bonding strength through direct material contact and plasma activation.
Solution Approach 2:
The invention changes the bonding parameters by using plasma activation and direct bonding instead of solder bump bonding. This involves modifying the surface properties of the bonding interfaces through plasma treatment to enable strong adhesion without requiring thermal cycling and solder reflow, thereby preventing thermal deformation and position shift.
2Manufacturing precision
If plasma activation is used for bonding, then alignment accuracy and bonding strength are improved, but additional processing steps are required
Solution Approach 1:
The invention combines the alignment and bonding operations into a single integrated process. The plasma activation is performed in-situ within the bonding apparatus, allowing the chip to be aligned and bonded in one continuous operation without requiring separate surface treatment steps, thereby reducing overall process complexity despite adding plasma activation capability.
3Manufacturing precision
If direct bonding without solder bumps is used, then thermal deformation is minimized, but bonding strength may be insufficient
Solution Approach 1:
The invention changes the surface energy and chemical properties of the bonding interfaces through plasma activation. This treatment creates highly reactive surface groups that form strong chemical bonds upon contact, compensating for the absence of solder bumps and ensuring adequate bonding strength while maintaining thermal deformation control.
Solution Approach 2:
The invention replaces the mechanical interlocking provided by solder bumps with a chemical bonding mechanism. Plasma activation creates reactive surface groups that form strong chemical bonds directly between the chip and substrate, substituting the mechanical solder joint with a chemical adhesion system that is more resistant to thermal expansion differences.
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
This method ensures accurate alignment and strong bonding of semiconductor chips to substrates while minimizing thermal deformation, improving the bonding process by allowing for precise control over the bonding position and density of pad electrodes.
Implementation Method 1
A bonding method of a semiconductor chip includes arranging an activated front surface of a semiconductor chip and an activated front surface of a substrate so as to face each other
Implementation Method 2
followed by heating and pressurization to achieve a strong, accurate bond
Implementation Method 3
followed by heating and pressurization to achieve a strong, accurate bond
Data Source
AI summary
A bonding method of a first member includes arranging an activated front surface of a first member and an activated front surface of a second member so as to face each other with a back surface of the first member attached to a sheet, pushing a back surface of the first member through the sheet to closely attach the activated front surface of the first member and the activated front surface of the second member, and stripping the sheet from the back surface of the first member while maintaining a state in which the activated front surface of the first member is closely attached to the activated front surface of the second member.