Semiconductor Package Cover Recess for Reliable Wire Bonding
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Solution Overview
Problem
The existing semiconductor packages face challenges in forming wire bonds on die bond pads due to the limited height between the cover and the die active surface, which affects the reliability and manufacturing productivity of these packages.
Innovation Solution
A method and structure for forming a semiconductor package with a protective cover having a recessed structure on its bottom surface, which creates an elevated space over the peak portions of wire bonds on the die bond pads, thereby increasing the clearance height and facilitating reliable wire bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transparent cover is provided over the sensor area with adhesive attachment, then the die is protected from the environment, but the height between the cover and die active surface is limited, making it challenging to form wire bonds
Solution Approach 1:
The recessed structure is formed on the bottom surface of the cover, creating a localized three-dimensional feature that provides additional vertical clearance space. This dimensional modification allows wire bonds to be formed without increasing the overall package height, as the recessed portion creates a localized elevated space specifically where the wire bonds are located.
Solution Approach 2:
The recessed structure is positioned specifically above the die bond pads where wire bonding is required, rather than modifying the entire cover structure. This localized modification provides the necessary clearance height only where needed for wire bond formation, while maintaining a compact overall package profile.
2Length of stationary object
If the package height is reduced for compactness, then the package becomes more compact, but the clearance height for wire bonding is insufficient
Solution Approach 1:
By forming a recessed structure on the bottom surface of the cover, the invention creates a localized vertical space that provides adequate clearance for wire bonding while maintaining a reduced overall package height. The recessed structure effectively utilizes the vertical dimension locally without increasing the global package profile.
Solution Approach 2:
The recessed structure is formed on the cover before the wire bonding process, pre-establishing the necessary clearance space. This preliminary structural modification ensures that when wire bonding is performed subsequently, adequate clearance is already available, facilitating easier manufacturing without requiring additional process steps.
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
The proposed solution effectively increases the clearance height between the cover and the wire bonds, enhancing the reliability and manufacturing productivity of semiconductor packages by allowing for more reliable wire bonding and reduced package height without compromising the integrity of the wire bonds.
Implementation Method 1
A protective cover with first and second major cover surfaces and side surfaces is attached to the die using the cover adhesive
Data Source
AI summary
A semiconductor package is disclosed. The package includes a package substrate having top and bottom major package substrate surfaces, the top major package surface including a die region. A die having first and second major die surfaces is attached onto the die region. The second major die surface is attached to the die region. The first major die surface includes a sensor region and a cover adhesive region surrounding the sensor region. The package also includes applying a cover adhesive to the cover adhesive region on the first major die surface. A protective cover with first and second major cover surfaces and side surfaces is attached to the die using the cover adhesive. The second major cover surface contacts the cover adhesive. The protective cover covers the sensor region. The protective cover includes a recessed structure on the second major cover surface. The recessed structure is located above die bond pads on the die to create an elevated space over peak portions of wire bonds on the die bond pads. An encapsulant is disposed on the package substrate to cover exposed portions of the package substrate, die and bond wires and side surfaces of the protective cover, while leaving the first major cover surface exposed.