Face-Up Integrated Package Cavity for Grinding Damage Prevention
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Solution Overview
Problem
Conventional face-down integrated package manufacturing methods damage nearby components during backside grinding, limiting the ability to achieve fine line and space in redistribution line processing and compromising board level reliability.
Innovation Solution
The method involves creating a cavity in the mold compound with an adhesive layer to hold a component, ensuring the top surface of the component is co-planar with the die, allowing backside grinding without damaging the component, and using a dielectric layer to isolate the component from the mold compound, facilitating finer lines and spaces, better electrical performance, and improved board level reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional passive components are placed next to the die on the carrier's adhesive layer, then component placement is simple, but it is impossible to grind the package to the desired thickness without damaging the passive component
Solution Approach 1:
The package structure is segmented into distinct functional zones: the die area with its adhesive layer and the component area with the recessed cavity. This segmentation allows the die to be ground to the desired thickness while the component sits protected in the recessed area, eliminating the contradiction between ease of placement and manufacturing precision.
Solution Approach 2:
The recessed cavity is formed in the substrate before placing the passive component. This preliminary action creates a protective structure that prevents the component from being damaged during subsequent grinding operations, while still allowing simple placement on the adhesive layer.
2Ease of manufacture
If the active face of the device is in a face down orientation during manufacturing, then traditional manufacturing processes can be used, but it prevents fine line and space in redistribution line processing and compromises board level reliability
Solution Approach 1:
The patent inverts the traditional face-down orientation to a face-up orientation during manufacturing. The die is mounted with its active surface facing upward on the substrate, allowing direct access for fine line and space redistribution line processing. After manufacturing, the package is flipped to the conventional face-up operational orientation, thus achieving both manufacturing precision and maintaining traditional operational benefits.
3Reliability
If a thick die and work piece are used, then die damage during placement and work piece damage during RDL processing is reduced, but it increases the overall package thickness making it impossible to achieve desired final thickness
Solution Approach 1:
The passive component is extracted from the plane of the die and placed in a recessed cavity in the substrate. This allows the die and work piece to be ground to the desired final thickness without compromising the passive component, which sits protected in the recessed area. The thick die and work piece provide the necessary reliability while the recessed component accommodation enables achieving the desired final package thickness.
Data Source
AI summary
An integrated package may be manufactured in a die face up orientation with a component proximate to the attached die by creating a cavity in the mold compound during fabrication. The cavity is created with an adhesive layer on the bottom to hold a component such that the top surface of the component is co-planar with the top surface of the attached die. This may allow backside grinding to take place that will not damage the component because the top surface alignment between the attached die and the component prevents the depth of the cavity from extending into the portion of the package that is ground away.