Solder Pillars on Solder Mask for Semiconductor Die Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor packages face issues with stress points and damage to memory die due to insufficient solder balls on the substrate, which are limited by the space taken up by vias, traces, and contact pads for electrical connections.
Innovation Solution
The formation of solder pillars directly on the solder mask layer allows for a larger number of pillars without interfering with electrical connections, providing adequate support for semiconductor die without stress points during the molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If solder balls are placed on substrate contact pads for supporting memory die, then electrical connections are established, but the number of available solder balls is insufficient due to space occupied by vias, traces and contact pads
Solution Approach 1:
The patent transitions from placing solder balls directly on the substrate surface (2D plane) to forming solder pillars on the solder mask layer (elevating to 3D space). This dimensional change allows solder support structures to occupy vertical space above the substrate rather than consuming horizontal substrate area, thereby increasing the number of available support points without expanding the substrate footprint.
Solution Approach 2:
The patent introduces a solder mask layer as an intermediary between the substrate and the solder support structures. The solder mask layer serves as a platform for forming pillar bases and solder pillars, decoupling the electrical connection function (handled by substrate contact pads) from the mechanical support function (handled by solder pillars on solder mask). This intermediary layer resolves the conflict between electrical connectivity requirements and mechanical support requirements.
2Reliability
If vias, traces and contact pads are used for electrical connections, then electrical connectivity is achieved, but stress points develop in memory die during high pressure molding encapsulation
Solution Approach 1:
The patent segments the functions of electrical connection and mechanical support into separate structural elements. The substrate's vias, traces and contact pads are dedicated solely to electrical connectivity, while the solder mask layer with its pillar bases and solder pillars handles mechanical support. This segmentation allows each subsystem to be optimized independently, preventing the complexity of combining both functions in a single structure.
Solution Approach 2:
The solder mask layer acts as an intermediary structure that provides mechanical support without interfering with the substrate's electrical connection architecture. By placing pillar bases on the solder mask rather than modifying the substrate's electrical structures, the patent avoids adding complexity to the electrical connection system while still achieving the necessary mechanical support function.
Data Source
AI summary
A semiconductor device, and a method of its manufacture, are disclosed. The semiconductor device includes a substrate having a solder mask. A plurality of pillar bases are formed on the solder mask, and a plurality of solder pillars are applied to the pillar bases. The plurality of solder pillars support one or more semiconductor die above the substrate and the number of solder pillars prevent stresses in the one or more semiconductor die which could otherwise damage the semiconductor die.