Rigid Mold Decal for Fine Pitch Solder Bump Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for forming fine pitch solder bumps using dual decal layers in Injection Molded Soldering techniques face challenges in precise alignment and stability, especially at high temperatures, and decals have a limited lifetime, making it difficult to maintain accurate alignment and reuse.
Innovation Solution
A system using a rigid mold with aligned decal holes and mold openings, where the decal holes have a smaller top opening and larger bottom opening, filled with solder to create protruding solder structures, improving alignment and decal lifetime by using a rigid mold with precise alignment and solder injection techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dual decal layers are used for forming fine pitch solder bumps, then solder bump formation is achieved, but alignment precision deteriorates due to difficulty in controlling alignment between flexible decals
Solution Approach 1:
A rigid mold is introduced as an intermediary component between the decal layer and the substrate. The rigid mold provides a stable, non-flexible structure with precisely defined openings that serve as a reference framework for alignment. The decal layer is positioned relative to the rigid mold rather than relying on alignment between two flexible decal layers, thereby eliminating the alignment control difficulties associated with flexible-f flexible registration.
2Duration of action of moving object
If dual decal layers are used in IMS techniques, then solder bumps can be formed, but decal lifetime is limited requiring periodic replacement
Solution Approach 1:
The invention designates the decal layer as a disposable, single-use component. The decal is attached to the rigid mold, used for one injection molded soldering cycle, and then discarded. This eliminates the need for complex alignment procedures and extends the usable lifetime of the rigid mold structure, which can be reused with multiple decal layers over time.
3Temperature
If decals are used at high temperatures during IMS, then soldering process is completed, but alignment stability deteriorates
Solution Approach 1:
The rigid mold provides localized structural support and thermal stability at the regions where alignment is critical (the opening positions). While the decal layer may experience thermal effects, the rigid mold maintains its dimensional stability and precise opening geometry throughout the high-temperature soldering process, ensuring alignment stability is preserved at the interface between the decal and the mold.
Data Source
AI summary
Protruding solder structures are created for electrical attachment of semiconductor devices. A rigid mold having one or more mold openings is attached to and used in combination with a decal structure that has one or more decal holes. The decal structure is disposed on the rigid mold so that the decal openings are aligned over the mold openings. Each of the decal hole and mold opening in contact form a single combined volume. The single combined volumes are filled with solder to form protruding solder structures. Various structures and methods of making and using the structures are disclosed.