The difference between PCB gold plating and tin plating

[taymoor2000]

Dear All;
Please I need to ask about
The difference between PCB Gold plated and tin plating?

And if any one has documentation about this issue it will be a good thing.

Thanks in advance

 

[House_Cat]

Re: Gold plated

Tin is cheaper than gold for PCB finishing. It has a limited shelf life of about 3-4 months due to corrosion and formation of "tin whiskers" which can short closely spaced features on the board.

Gold has a long shelf life and provides a very flat, uniform, surface for soldering of SMDs such as BGA. Care must be taken to control the thickness of the gold layer to avoid embrittlement of the soldered joint. There are two types of gold plating commonly used - ENIG and DIG.

You can read more about board finishes at:
https://www.multicircuits.com/pcb/tech/surface_finishes.html
https://www.smtnet.com/library/index.cfm?fuseaction=view_article_html&file=no_hasl
**broken link removed**

There are dozens of articles available on specific finishes if you do a Google search using each of the types (i.e. immersion tin, immersion silver, ENIG, direct immersion gold, HASL, etc.)

 

[flypcb]

Gold plated

Admire, house_cat, you are really a pcb manufacturing expert
Generally speaking, immersion tin is enough for most cases. Only some big and rich companies would like to ENIG for their most production.
In fact, the richest company I've been seen is Agilent, almost all their productions are gold-plating

 

[eswar_babu77]

Re: Gold plated

Yes, house_cat is right. But gold plating is also used in PCB with EDGE connector as reliability of gold is good when compared to tin_lead.

 

[flypcb]

Gold plated

aha, Agilent is not only used to edge or finger connector, but also the "whole" board.
That's really a crazy and luxurious style.
I guess the income in Agilent must be extremely high.