Hard or Soft Gold Plating Finishes
We pride ourselves on using the highest quality raw materials to Fabricate or Assemble our printed circuit boards. This means only using the electrolytic process to apply our 98% pure 24 carat gold finishes. At Precision Technologies, there are 2 types of Gold finishes we utilize: soft and hard. Although hard and soft gold have different applications, they behave similarly for manufacturing purposes. If the gold is not thick enough it will not work properly, and you will be wasting money if it’s too thick. Gold thickness is not the only cost driver. Full-body plating or full body gold means that the outer later copper will be completely gold plated.
Soft gold finishes are primarily used for gold wire bonding. It is used for gold wire bonding because it is softer than most finishes, which allows it to be bonded more easily. Most customers that choose soft gold finishes order a thickness of 25 micro inches of gold, but we can go up to 100 micro inches. Then, the soft gold is plated over 100 to 200 micro inches of pure nickel.
Hard gold or deep gold is used in high-wear areas such as edge connector fingers and keypads. Manufactures produce gold fingers made out of hard gold because it has hardeners added to it for durability purposes. We don’t use hard gold in solder-able places because of its high price point and its low heat resistance ability. The hard gold is generally 30 to 50 micro inches thick, followed by a barrier coat of 150 to 200 micro inches of nickel.
Available Lead Free Surface Finishes:
| Gold Finish |
May be Electrolytic Electroless, or Immersion
|
| -ENIG
(Electroless Nickel Immersion Gold) |
2-5 micro inches. Purpose: To prevent oxidation, extend shelf life, provide a wire bonding surface, and used to provide an electrically conductive surface on PCBs. Used for solderability when the flatness of the pad is critical.
|
| -Hard Gold |
Purpose: Used for Gold Fingers (minimum 30 micro inches), soldering (maximum 17 micro inches), to prevent oxidation and extend shelf life.
|
| -Soft Gold |
Purpose: Used for wire bonding (Ultrasonic minimum 2 micro inches/Thermasonic minimum 12 micro inches) and to prevent oxidation and extend shelf life.
|
| Immersion Silver |
Use for solderability purposes (2-5 micro inches). Used for solderability when the flatness of the pad is critical.
|
| Lead Free Solder |
Use for solderability purposes (2-5 micro inches). Used for solderability when the flatness of the pad is not critical.
|
| OSP
(Organic Solderability Preservatives) |
Used for solderability when the flatness of the pad is critical.
|
| White Tin
(Immersion Tin) |
Used for solderability when the flatness of the pad is critical.
|
