Acoustic IC Packaging Walls to Block Keep-Out Zone Encroachment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional packaging methods for acoustic devices in integrated circuits (ICs) result in encroachment of encapsulating material into keep out zones, leading to performance degradation and increased IC size, as they fail to effectively minimize the encroachment while maintaining the structural integrity and functionality of the acoustic elements.
Innovation Solution
The implementation of walls on the wiring substrate with a height shorter than the solder bumps, positioned on either side of the acoustic device, creates a small gap between the walls and the device, preventing encroachment of the encapsulating material and allowing more area for acoustic elements, thus reducing the overall size of the acoustic device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional packaging methods are used, then the acoustic device is protected and enclosed, but the encapsulating material encroaches into the keep out zone, degrading performance and increasing IC size
Solution Approach 1:
The patent divides the packaging structure into distinct segments: the acoustic device, the keep out zone, and the encapsulating material. By introducing a defined gap between the acoustic device and encapsulating material, the structure is segmented to prevent encroachment while maintaining protection. This segmentation allows the keep out zone to remain free of encapsulating material, preserving acoustic device performance.
2Manufacturing precision
If the gap between walls and acoustic device is reduced, then encroachment is minimized, but the area for acoustic elements is reduced
Solution Approach 1:
The patent applies local quality by creating a non-uniform gap structure. The gap is positioned specifically at the boundaries where encroachment occurs, while the central area containing acoustic elements maintains sufficient space. This localized approach to gap creation prevents encroachment in critical areas without sacrificing the overall area available for acoustic elements.
3Area of stationary object
If walls are positioned closer to the acoustic device, then more area is available for acoustic elements, but encroachment by encapsulating material increases
Solution Approach 1:
The patent introduces a gap as an intermediary space between the walls and the acoustic device. This gap acts as a mediator that prevents direct contact between the encapsulating material and the acoustic device, thereby preventing encroachment. The gap allows walls to be positioned closer to the acoustic device, maximizing the area for acoustic elements, while still providing protection through the intermediary gap space.
4Manufacturing precision
If the height of walls is increased, then encroachment is prevented, but the overall height of the IC increases
Solution Approach 1:
The patent applies partial action by creating walls with a height that is sufficient to prevent encroachment but not excessively tall. The walls extend only to the point needed to define the gap and prevent encapsulating material from entering the keep out zone, rather than extending to the full height of the acoustic device or IC. This partial height is sufficient to achieve the encroachment prevention goal while minimizing the overall IC height.
Data Source
AI summary
Systems and methods for packaging an acoustic device in an integrated circuit (IC) include walls formed on a wiring substrate. The walls have a height which is just shorter than an expected height of a solder bump on the acoustic device after solder reflow. The walls are positioned on either side of the acoustic device and a small portion lies underneath an exterior edge of the acoustic device such that a relatively small gap is formed between an upper surface of the wall and the lower surface of the acoustic device. By providing a small gap between wall and acoustic device, encroachment by an encapsulating material into a keep out zone of the acoustic device is minimized.