Via in Pad Balances fan-out and pad flatness
Placing vias inside pads helps create a compact layout, but the via mouth treatment must be tailored to the soldering requirements. Resin filling, post-curing grinding, and surface copper plating are processes that must be clearly defined separately.
To understand the process, start by clarifying these key points
Hole Design
Through-holes are defined by their location. When mechanical through-holes, blind holes, or microvias are located within a pad, separate solutions for filling and sealing must be determined.
Resin Pore Filling and Leveling
Fill, cure, and polish the applicable via structures, then perform the corresponding metallization and copper plating; resin via filling should not be equated with electroplated copper via filling.
Land Surface Requirements
Requirements regarding recesses, protrusions, copper plating, and surface treatment must be clearly defined to ensure compatibility with solder paste printing and component assembly. Specific acceptance criteria shall be determined in accordance with project agreements.
Design Boundaries and Manufacturing Reviews
- In-Plant Process Scope
- In-plate holes (POFV) have been specified; the specific hole diameters, plate thickness, and hole-filling structures are subject to engineering review.
- Drawing Annotations
- Separately mark the holes that require blind via plating, clearly specifying the applicable hole numbers and whether single- or double-sided processing is required.
- Filling Material
- Specify the resin system or performance requirements; do not assume that conductive fillers are superior to non-conductive resins.
- Copper Cladding and Flatness
- Clearly define the acceptance criteria for copper caps, embossing, and surface treatments; do not use the term “plugging holes” as a substitute.
- Assembly Verification
- Determine soldering validation requirements based on device type and application; bare board testing does not replace assembly validation.
The manufacturing values cited are based on this site’s existing process capabilities. The listed limit values do not imply that all can be achieved simultaneously; the manufacturing plan will be finalized after the complete stack-up, hole layout, and materials have been confirmed.
View Full Manufacturing CapabilitiesBefore requesting a quote, prepare these three sets of documents
Production and Layer Files
Gerber or ODB++ files, drill files, stack-up diagrams, and layer-to-hole mapping tables; ensure that file versions are consistent.
Key Process Requirements
Specify the hole diameter, plating material, copper-clad area, surface treatment, and required tolerances.
Quantity and Inspection Requirements
Please provide the quantity for prototypes and production runs, the desired delivery date, inspection reports, and reliability verification requirements.
Frequently Asked Questions
Can through-hole openings be covered with solder mask alone?
A cover layer should not be automatically considered a viable solution for a flat, solderable pad. Whether via filling and copper plating are required should be determined based on the via structure, the device, and the soldering process.
If the resin isn't conductive, can the holes still conduct electricity?
In this type of resin-filled via design, electrical connectivity relies primarily on the metallized via walls and the copper structure on the surface; the filling resin does not serve the same conductive function as copper.
Submit the via design for engineering review
Shenzhen Jingpeng Electronics | We provide stack-up and via tables to help you assess manufacturability, cost implications, and delivery requirements.
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