Semiconductor Package Contact Structure for Uniform Solder Joints
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Solution Overview
Problem
Current semiconductor device packages face challenges in achieving optimal package density and reliable connections between solder balls and the motherboard due to issues with the exposure and encapsulation of electrical contacts within the molding compound, leading to inconsistent contact areas and difficulties in controlling the thickness and alignment of solder paste.
Innovation Solution
The semiconductor device package design includes a substrate with electrical contacts encapsulated by an insulation layer, where portions of the insulation layer and contacts are strategically removed to expose surfaces for solder paste application, allowing for controlled formation of neck portions and tapered protrusions that ensure reliable connections to the motherboard, with the solder paste being printed through a mask to unify the thickness and enhance contact reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If electrical contacts are fully encapsulated by molding compound to increase package density, then package density is improved, but connection reliability deteriorates due to inconsistent contact areas
Solution Approach 1:
The patent applies local quality by creating different exposure conditions for different parts of the electrical contacts. The first electrical contact has its tip exposed at a first level while the second electrical contact has its tip exposed at a second level, allowing each contact to have optimized local properties for its specific function - one for reliable soldering and the other for stable electrical connection.
Solution Approach 2:
The patent segments the electrical contacts into multiple contacts with different exposure levels. Instead of uniform encapsulation, the molding compound is configured to expose different portions of different contacts, creating a segmented exposure pattern that enables both high density and reliable connections for each contact type.
2Strength
If solder paste is applied to exposed contact surfaces, then connection strength is improved, but manufacturing precision deteriorates due to difficulty in controlling thickness and alignment
Solution Approach 1:
The patent applies preliminary action by pre-configuring the exposure levels of the electrical contacts during the molding process. The tips of the electrical contacts are exposed at predetermined levels before solder paste application, ensuring that when solder paste is applied, the contact surfaces are already optimally positioned for consistent thickness and alignment, thereby improving manufacturing precision.
3Ease of manufacture
If all electrical contacts are exposed at the same level, then manufacturing simplicity is improved, but connection consistency deteriorates due to varying contact areas
Solution Approach 1:
The patent implements local quality by assigning different exposure levels to different electrical contacts based on their specific requirements. The first electrical contact is exposed at a first level optimized for its connection needs, while the second electrical contact is exposed at a second level, ensuring each contact achieves optimal connection consistency for its particular function.
Data Source
AI summary
A semiconductor device package includes a substrate, a first insulation layer and an electrical contact. The first insulation layer is disposed on the first surface of the substrate. The electrical contact is disposed on the substrate and has a first portion surrounded by the first insulation layer and a second portion exposed from the first insulation layer, and a neck portion between the first portion and the second portion of the electrical contact. Further, the second portion tapers from the neck portion.