MEMS Sensor Packaging Thickness Reduction via Lead Frame Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic device packaging methods, such as full-mold packages, struggle to reduce the total thickness effectively due to the contribution of substrate and mold chase thickness, which is not applicable to MEMS and other sensor structures, and limited by the use of substrates and mold compounds.
Innovation Solution
A method involving arranging a MEMS sensor and a companion ASIC side-by-side on a support surface, providing electric coupling, and overmolding with packaging compound, allowing the support surface to be removed, resulting in a package thickness determined solely by the MEMS sensor's thickness, with both surfaces exposed and the companion chip's substrate not contributing to the overall thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a full-mold package is used to package electronic devices, then the device is well protected and electrically connected, but the total package thickness is increased due to substrate and mold chase contributions
Solution Approach 1:
The patent extracts and removes the substrate from the traditional packaging structure. The MEMS sensor is mounted directly on the lead frame without requiring a substrate, eliminating the substrate thickness contribution to the total package thickness while maintaining electrical connection and mechanical support functions through the lead frame structure
Solution Approach 2:
The patent merges the support function and electrical connection function into a single integrated lead frame structure. The lead frame simultaneously provides mechanical support for the MEMS sensor, electrical connection paths, and packaging structure, eliminating the need for separate substrate and mold chase components
2Length of stationary object
If substrate thickness is reduced to decrease package thickness, then package thickness is reduced, but mechanical strength and structural support are compromised
Solution Approach 1:
The patent applies local quality by designing the lead frame with varying thickness and reinforcement at critical locations. The lead frame has increased thickness and structural reinforcement at areas requiring mechanical strength while maintaining minimal thickness at areas where space reduction is prioritized, achieving both thin profile and adequate structural support
3Length of stationary object
If mold chase thickness is reduced by improving process tolerances, then package thickness is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent eliminates the mold chase component entirely by mounting the MEMS sensor directly on the lead frame. This removal of the mold chase structure simplifies the manufacturing process and eliminates the need for tight process tolerances related to mold chase thickness, reducing manufacturing complexity while achieving thin package profile
4Temperature
If both surfaces of the MEMS sensor are exposed, then thermal dissipation is improved and sensing ports are accessible, but electromagnetic interference susceptibility increases
Solution Approach 1:
The patent introduces an electromagnetic shielding layer as an intermediary between the exposed MEMS sensor surfaces and the external electromagnetic environment. This shielding layer protects the sensor from electromagnetic interference while allowing thermal dissipation and sensing port accessibility to be maintained through the lead frame structure
Data Source
Figure 1A~1E
Figure 2A~2E
Figure 3A~4B
AI summary
A method of manufacturing electronic devices (10), comprises providing on a support member (20) such as a tape: - a first electronic component (12), such as a sensor, having opposed first (12a) and second (12b) surfaces and arranged on the support member (20) with the second surface (12b) towards the support member (20), wherein the first electronic component (12) has a thickness between the opposed first (12a) and second (12b) surfaces, - a second electronic component (14), such as an IC, mounted on a substrate (16) and arranged on the support member (20) with a substrate surface opposed the second electronic component (14) and facing towards the support member (20), wherein the substrate (16) and the second electronic component (14) have a joint thickness which is less than the thickness of the first electronic component (12), - molding onto the support member (20) having arranged thereon the first (12) and second (14) electronic components package molding material (24) to encapsulate the second electronic component (14) and leaving exposed the first surface (12a) of the first electronic component (12), and - separating the support member (20) to expose the second surface (12b) of the first electronic component (12) and the substrate surface of the substrate (16) opposed the at least one second electronic component (14) .