Connect the Dots: Best Practices for Prototyping
Designer’s Notebook: DFM Principles for Flexible Circuits
Elementary, Mr. Watson: Flex Designs—The Future and BeyondDFM 101: Final Finishes—Electrolytic Nickel/Gold
January 30, 2023 | Anaya Vardya, American Standard CircuitsEstimated reading time: 1 minute
Introduction
One of the biggest challenges facing PCB designers is not understanding the cost drivers in the PCB manufacturing process. This article is the latest in a series that will discuss these cost drivers (from the PCB manufacturer’s perspective) and the design decisions that will impact product reliability.
Final Finishes
Final finishes provide a surface for the component assembler to solder, wire bond, or conductively attach a component pad or lead to a pad, hole, or area of a PCB. The other use for a final finish is to provide a known contact resistance and life cycle for connectors, keys, or switches. The primary purpose of a final finish is to create electrical and thermal continuity with a surface of the PCB.
There are several final finishes in use in the industry today. These include:
- ENIG (electroless nickel, immersion gold)
- ENIPIG (electroless nickel, immersion palladium, immersion gold)
- ENEPIG (electroless nickel, electroless palladium, immersion gold)
- ImmAg (immersion silver)
- ImmSn (immersion tin)
- Sulfamate nickel/hard or soft gold (electrolytic nickel/gold)
- HASL (hot air solder leveling)
- SnPb (63/37 tin/lead)
- LF (lead-free)
- OSP (organic solderability preservative)
Final finishes are primarily application driven, so there are several considerations that should be part of any decision to choose a final finish:
- Lead-tolerant or lead-free (LF) process
- Shelf life
- Flatness
- Lead or ball pitch
- Wire bondability
- Lead insertion
- Solder joint integrity
- Corrosion resistance
- Potential problems
- Cost
To read this entire article, which appeared in the December 2022 issue of Design007 Magazine, click here.
Share on:
Suggested Items
ULT to Introduce New Soldering Fume Extractor at productronica
09/20/2023 | ULT AGAt this year's productronica, the world's leading trade show for electronics manufacturing, ULT will present a brand new extraction solution for solder fumes and vapor.
Hentec Industries/RPS Automation Expands Assembly Team with Addition of Experienced Technician
09/20/2023 | Hentec Industries/RPS AutomationHentec Industries/RPS Automation, a leading manufacturer of selective soldering, component lead tinning and solderability test equipment, announces that it has added assembly and production staff members to its team to accommodate its recent increase in sales and order demand.
2023 Charles Hutchins Educational Grant Winner Announced
09/19/2023 | SMTASMTA is honored to announce Qais Qasaimeh, a graduate student at Auburn University, has been selected as the winner of the 2023 Charles Hutchins Educational Grant.
SHENMAO Introduces Low-Temperature Ball Attachment Process Solutions
09/14/2023 | SHENMAOSHENMAO America, Inc. is proud to introduce its latest innovation in response to the growing demand for ultra-thin packages in the electronics industry.
Peters' New Machine Ensures High Quality
09/14/2023 | PetersFor Peters, the new Reflow 1.8. soldering machine from SEHO is an investment in the future. Like its predecessor, this machine is used in the laboratory for testing high-quality solder resists. Before the coatings are entrusted to the customers, Peters performs a thermal soldering simulation.