What was soft gold

Pyatigorsk is one of the oldest spa resorts in Russia thanks to its mineral springs. The city is a mix of different cultures and ethnicities, and where it is easy to forget you really are in Russia. Pyatigorsk has been evolving into the fur manufacturing center of Russia with more than 60 local manufacturers and decades of experience working with lamb skins for example. Recently manufacturers have started using also mink and fox skins and just in three years Soft Gold has become a really serious Fur Trade Fair, just like Kastoria in Greece, with the ambitious mission of becoming the fur capital of Russia, or maybe even the whole world one day.

Soft gold plating is the highest purity gold electrodeposit that essentially is pure gold without the addition of any alloying elements. Soft gold plating produces a more coarse grain structure that is free of any signficant codeposits.

In order to properly specify a gold electrodeposit for an application, five key design questions should be addressed:.

Each of these principle design questions are addressed below specific to the selection of hard gold plating or soft gold plating for an application. Hard gold plating is formed with the addition of non-noble metallic elements alloyed with the gold deposit — typically cobalt, nickel or iron. These elements alter the grain structure of the deposit resulting in a finer grain structure that is more lustrous and more resistant to sliding wear. Hard gold deposits consist of a very small grain size measuring nm whereas soft gold plating which has a typical grain size of um or approximately 60x larger than soft gold.

Hard gold commonly has a hardness between HK 25 with a hardness of up to HK 25 possible. Soft gold typically has a hardness of HK 25 making it very susceptible to sliding wear or wear from contact switching.

The normal force of a contact should be considered when specifying hard vs soft gold plating. Typically contact forces less than 50 grams is recommended for soft gold applications whereas hard gold plating performs well with applications of 50 grams or more normal contact force.

Due to the lack of insulating oxide or compound formation, soft gold contacts can be used with contact pressures as low as 10 grams and wipe distances as low as 0.

The number of life cycles is proportional to the thickness of the gold since a thicker gold deposit will be able to withstand more cycles. Common thicknesses of functional hard gold deposits range from 0. Amp 3 cites laboratory testing results for the wear-through of a hard gold deposit over a 0. The data provided in Table 1 summarizes this testing which was performed with a 0.

In addition to the proper selection of hard gold and gold thickness for a gold contact or interconnect, the proper selection of an underplate should be considered to promote gold wear resistance.

Common underplates include a high purity sulfamate nickel , bright electrolytic nickel or electroless nickel. A nickel underplate prior to hard or soft gold plating serves many functions including:. For very sensitive joining applications such as thermosonic bonding, or ultrasonic wire bonding, soft gold should only be considered.

The co-deposited metals of hard gold plating can oxidize at soldering temperatures reducing the integrity of the solder joint. In addition, the high purity of Type III soft gold plating is ideal for applications where thermal diffusion of the gold will occur such as thermocompression bonding.

The gold thickness should also be considered when soldering to gold deposits using tin-lead solder. To see what your friends thought of this book, please sign up. To ask other readers questions about Soft Gold , please sign up.

Lists with This Book. This book is not yet featured on Listopia. Add this book to your favorite list ». Community Reviews. Showing Average rating 4. Rating details. Sort order. Jan 28, Amanda rated it really liked it Shelves: xbooks-to-read Very throughly researched. A good overview of the impact of the fur trade on Indigenous society and culture. The author sprinkles his opinion in places where I would have liked to see studies or interviews with Indigenous groups. There are no discussion topics on this book yet.