Soldering Surface Plating Without Solder Mask
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Solution Overview
Problem
Current semiconductor processes that rely on solder masks are expensive, cumbersome, and limit the miniaturization of soldering pads and their spacing, hindering the reduction of semiconductor circuit and substrate footprints.
Innovation Solution
A multi-layer laminate or substrate manufacturing process that forms soldering surfaces without a solder mask by plating solderable regions and applying an anti-wetting treatment to prevent solder wetting on non-plated areas, using a patterned mask and oxidation processes to create a virtual solder mask effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solder mask is applied to control solder placement and prevent bridging, then soldering reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention extracts and eliminates the solder mask layer from the substrate structure. Instead of applying a separate solder mask material, the substrate itself is modified through plating and oxidation processes to create the solder-resistant functionality directly on the substrate surface, removing the need for the additional mask layer and its associated application processes.
Solution Approach 2:
The invention merges the solder resistance function with the substrate structure itself. By applying plating to specific regions and then performing an oxidation process, the substrate surface is transformed to provide both the solderable areas (plated regions) and solder-resistant areas (oxidized regions) as an integrated structure, eliminating the need for a separate solder mask layer.
2Reliability
If a solder mask is used to prevent solder bridging, then electrical shorting is prevented, but manufacturing cost and process time increase
Solution Approach 1:
The invention performs preliminary actions by applying the plating pattern and oxidation treatment to the substrate before the soldering process. This pre-establishes the solderable and solder-resistant areas, so that during final assembly, solder naturally flows only to the intended areas without requiring a separate mask application step, thereby reducing manufacturing cycle time.
Solution Approach 2:
The invention enables the substrate to serve its own solder masking function. The oxidized regions of the substrate automatically provide solder resistance, and the plated regions provide solderability, eliminating the need for an external solder mask material and its associated application and curing processes.
3Reliability
If traditional solder masking techniques are employed, then solder placement control is achieved, but miniaturization of soldering pads and spacing is limited
Solution Approach 1:
The invention applies local quality by creating distinct regions on the substrate surface with different properties. Specific local areas are plated to provide solderability, while adjacent areas are oxidized to provide solder resistance. This localized differentiation allows for precise control of solder placement at very small dimensions, enabling miniaturization that would be difficult to achieve with traditional mask techniques.
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
Enables smaller soldering pads with reduced spacing, eliminating the need for traditional solder masking techniques and materials, facilitating the miniaturization of semiconductor circuits and substrates while preventing electrical shorting.
Implementation Method 1
The soldering surfaces of the soldering pads are plated to create plated soldering surfaces over the soldering pads
Implementation Method 2
the anti-wetting treatment is an oxidation process, wherein the exposed metal surfaces are oxidized to form the treated surface
Implementation Method 3
The resulting structure is heated to remove residual moisture
Data Source
AI summary
The present invention relates to a multi-layer laminate or substrate manufacturing process for forming soldering surfaces on a substrate of a module without requiring a solder mask. In one embodiment, a substrate is provided having a substrate body, soldering pads, and a metal segment. A patterned mask is formed over the substrate such that soldering surfaces of the soldering pads remain exposed. The soldering surfaces of the soldering pads are plated to create plated soldering surfaces over the soldering pads. The plated soldering surfaces are the regions for solder placement. The patterned mask is then removed from the substrate. Next, an anti-wetting treatment is applied to the substrate such that any unplated metal surfaces react to the anti-wetting treatment to form treated surfaces. As such, the plated soldering surfaces will wet solder while the treated surface will not wet solder. In a preferred embodiment, the anti-wetting treatment is an oxidation process.