Wurth Elektronik India Private Limited

FLATcomp (complete) system solutions offer you a high degree of service and comfort:
Take advantage of the expertise and experience of our FLATcomp specialists and save time and costs in the development and production of your specific sensors and systems as a result. 

The basis for FLATcomp system solutions includes Würth Elektronik’s own Smart Conductive Polymer Technology (SCPT), with which exiting conductive polymer pastes can be adapted quickly and easily to customer-specific requirements.

• mmersion Silver  
• Typ. Ag-coat 0.2 – 0.4 µm  
• Process temperature ~ 50 °C  
• Shelf life 12 months  

Advantages:

• Smooth coating  
• Excellent wetting behaviour  
• No additional costs compared with SnPb-HASL  
• Good solderability /hole filling  
• Application of solder agents with or without lead possible  
• Easy multiple soldering  
• No intermetalic phase between copper and silver  
• No impairment of solderability after the drying process  

• Electroless Nickel Immersion Gold  
• Typ. Au-coat 0.07 – 0.12 µm  
• Typ. Ni- coat 4 - 7 µm  
• Process temperature ∼ 90 °C  
• Max. shelf life 12 months  

Advantages:

• Universally suitable surface finish  
• No Copper attack during soldering process, Nickel serves as diffusion barrier  
• Smooth surface  
• Soldering (with or without lead, mulitple soldering)  
• Storing between solder processes is possible  

staggered thermal microvias
possible across 4 layers

- high component density, and
also high wiring density possible

- low thermal resistance

- individual shapes possible

ramide epoxy in the core for CTE
control or FR4 material

- the buildup layers are RCC with
high Tg epoxy or FR4 prepreg
material

- photosensitive solder-stop,
surface chem. Ni/Au

suitable for Al wire bonding

- conductor tracks and separations
6 mil or 5 mil

- blind and buried microvias possible

pecified for ambient temperatures
of -40°C to +125°C

- thin circuit board for good heat
conduction and high cycle stability

- heat sink applications offer
optimised thermal management

- different heat sink thicknesses
possible

Joint tests with the process manufacturer have shown that circuit boards coated in immersion silver using the Würth Elektronik method demonstrate excellent solderability when stored under typical climate conditions in mounting operations (up to 35°C and 85% rel. humidity) even over 12 months. During storage the circuit boards should be kept in the package provided by Würth Elektronik to exclude the possibility of contamination from the surrounding air.

The image through the electron microscope shows: Very even surfaces are formed as a result of the production process described above. They are necessary for all fine pitch and HDI applications, but they also have a very positive effect on technically less sophisticated applications in the mounting process.

In the past it was said that silver surfaces have weaknesses in these areas. The latest research shows that the immersion silver surface used by Würth Elektronik compares very well. The values attained are very similar to other chemical surfaces.

The schematic structure of a solder joint with immersion silver shows that Ag diffuses into the tin-solder during the soldering process, and that the actual solder connection is thus formed between copper and tin. This diffusion process distinguishes immersion silver from other surfaces and makes the solder connection very reliable and stable.