Power Module Package Electrode Spacing to Prevent Molding Damage
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Solution Overview
Problem
Multichip power module packages face frequent electrode damage during transfer molding, leading to malfunctions and reduced reliability due to the absence of lead frames, which complicates the manufacturing process and affects the package's performance.
Innovation Solution
A power module package design featuring electrodes spaced apart from the encapsulation member, with a housing unit that maintains a closed or open cross-section, preventing direct contact with the mold die during the molding process, thus minimizing damage and enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If electrodes are mounted on substrate without lead frames, then structure is simplified and size is reduced, but electrodes are frequently damaged during transfer molding process
Solution Approach 1:
The patent introduces a housing unit as an intermediary protective structure that houses the electrodes. This housing unit acts as a mediator between the electrodes and the external environment, specifically protecting electrodes from damage during transfer molding while maintaining the simplified no-leadframe structure. The housing unit provides mechanical support and protection without adding lead frames.
Solution Approach 2:
The patent applies beforehand cushioning by designing the housing unit to provide protective spacing between electrodes and the encapsulation member before the molding process occurs. This pre-established protective barrier cushions the electrodes against potential damage during subsequent manufacturing steps, particularly during transfer molding when molten material is injected.
2Reliability
If electrodes are spaced apart from encapsulation member, then electrode damage is prevented, but manufacturing process becomes more complex
Solution Approach 1:
The patent merges the protective housing function with the existing substrate structure. The housing unit is integrated into the substrate design, combining multiple functions (electrode mounting, protection, and structural support) into a single unified component. This integration simplifies manufacturing by reducing the number of separate parts and assembly steps.
3Reliability
If housing unit has closed cross-section, then electrode protection is improved, but material usage and complexity increase
Solution Approach 1:
The patent applies local quality by providing protective housing only in specific areas where electrodes are located, rather than enclosing the entire package. The housing unit has open cross-section in some embodiments, providing protection only where needed while leaving other areas open. This localized protection reduces material usage while maintaining electrode safety.
Data Source
AI summary
A method can include coupling a semiconductor chip and an electrode with a substrate. Bottom and top mold die can be use, where the top mold die define a first space and a second space that is separated from the first space. The method can include injecting encapsulation material to form an encapsulation member coupled to and covering at least a portion of the substrate. The encapsulation member can include a housing unit housing the electrode. The electrode can have a conductive sidewall exposed to, and not in contact with the encapsulation member, such that there is open space between the conductive sidewall of the electrode and the encapsulation member from an uppermost surface to a bottommost surface of the encapsulation member, the substrate can having a portion exposed within the open space, and the encapsulation member can have an open cross-section perpendicular to an upper surface of the substrate.