Discontinuous Solder Mask Opening for Reliable Semiconductor Bonding
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Solution Overview
Problem
The semiconductor packaging process often results in incomplete solder contacts due to defects, leading to packaging issues when attempting to omit solder balls, which can cause unintended consequences.
Innovation Solution
A bond site with a discontinuous profile is created on a packaging substrate, featuring a substrate, solder mask, contact, and metal layers, allowing for unobstructed access and promoting metallic bonding between solder balls and semiconductor chips without interference from the solder mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a continuous opening profile is used in the solder mask, then the manufacturing process is simpler, but the solder mask may interfere with or obstruct the bonding between solder balls and the substrate contact
Solution Approach 1:
The opening in the solder mask is divided into a first portion and a second portion that are discontinuous or separated. The first portion allows access to the solder ball while the second portion provides access to the substrate contact, preventing the solder mask from obstructing the bonding process while maintaining manufacturing feasibility
Solution Approach 2:
The solder mask opening has different profiles at different locations: the first portion has specific dimensions and shape optimized for solder ball access, while the second portion is optimized for substrate contact access. This local differentiation ensures optimal bonding conditions at each interface without requiring a completely different mask design
2Reliability
If solder balls are omitted from one component to avoid defects, then incomplete solder contacts are reduced, but unintended consequences and subsequent packaging problems occur
Solution Approach 1:
The discontinuous opening profile in the solder mask acts as an intermediary structure that facilitates reliable solder bonding without requiring the omission of solder balls. By optimizing the opening geometry, the invention enables complete and defect-free solder contacts to form, eliminating the need to remove solder balls and avoiding the packaging problems that result from such omissions
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
This solution enables reliable solder bond formation between semiconductor chips and packaging substrates, reducing defects and subsequent packaging problems by ensuring unobstructed contact and promoting metallic bonding.
Implementation Method 1
A subsequent heating step may be performed to assist with forming a solder contact between the two components
Implementation Method 2
The metallic connection locations may have a solder ball formed thereon to provide a bonding location for a solder ball of a semiconductor chip. The solder may be used to form a low temperature electrical connection between the semiconductor chip and the metallic traces on the substrate
Data Source
AI summary
Apparatuses and methods for formation of a bond site including an opening with a discontinuous profile are disclosed herein. An example apparatus may at least include a substrate, a contact on the substrate, and a mask layer formed on the substrate and at least a portion of the contact. The mask layer may also include an opening formed therein, with the opening having a discontinuous profile from a top surface of the mask layer to the contact.