Reciprocating Adhesive Dispense Nozzle for Warped Leadframes
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Solution Overview
Problem
The warping of leadframes in semiconductor devices causes positional inaccuracies during adhesive dispensing, leading to variable adhesive drop sizes and contamination, which affects the accuracy and speed of die attach processes in semiconductor bonding machines.
Innovation Solution
An adhesive dispense unit with a reciprocable pin member and a sheath portion, biased by a resilient member, ensures the leadframe is flattened against the work holder, allowing precise control of adhesive dispensing by maintaining a consistent distance between the dispense nozzle and the leadframe.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a fixed downstand member is used to flatten the leadframe, then the leadframe positioning is improved, but the adhesive droplet contact time becomes variable depending on leadframe warp amount
Solution Approach 1:
The downstand member is made reciprocating rather than fixed, allowing it to dynamically adjust its position. The downstand moves downward to contact and flatten the leadframe, then reciprocates upward to clear the leadframe after flattening. This dynamic motion ensures the adhesive droplet contacts the leadframe at a consistent, predetermined time regardless of the initial warp amount, while still achieving accurate leadframe positioning.
2Object-affected harmful factors
If the spacing between dispense head and leadframe is reduced to minimize adhesive contamination, then contamination is reduced, but adhesive drop size control becomes more sensitive to positioning variations
Solution Approach 1:
The downstand member performs the leadframe flattening action before the adhesive dispensing occurs. By pre-flattening the leadframe to a predetermined position, the system establishes a stable, consistent baseline position for the leadframe. This preliminary positioning action eliminates the need for large spacing margins, allowing the dispense head to operate at a smaller, optimized spacing that reduces contamination while maintaining precise drop size control through the stabilized leadframe position.
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 solution improves the repeatability and accuracy of adhesive dispensing, enabling smaller package sizes, increased throughput, and reduced downtime for cleaning, while maintaining high-speed operation in die bonding machines.
Implementation Method 1
the pin member comprising a down stand portion and a sheath portion, wherein the down stand is reciprocateable within the sheath portion
Implementation Method 2
The adhesive droplet at the opening of the adhesive dispense head 106 may be formed by capilliary action
Data Source
AI summary
This disclosure relates to an adhesive dispense unit for a semiconductor die bonding apparatus. The adhesive dispense unit includes an adhesive dispense nozzle and a pin member; the pin member comprising a down stand portion and a sheath portion, and the down stand is reciprocateable within the sheath portion.