Gold Finish Plating Specification MIL-G-45204 | Engineers Edge
https://www.engineersedge.com › gold_finish
Soft, pure gold plating is used in the semiconductor industry . The  
gold layer is easily soldered and wire bonded . Its Knoop hardness  
ranges between 60-85.
On Dec 18, 2019, at 5:44 PM, David Hillman wrote:

> Hi Nigel - define "soft gold" please. Electroplated gold for
> noncontact/abrasive applications?
>
> Dave Hillman
> Collins Aerospace
>
>
> On Wed, Dec 18, 2019 at 12:12 PM Nigel Burtt <[log in to unmask]>  
> wrote:
>
>> Thanks Dave, but I'm asking about any issues with aluminium wire  
>> wedge
>> bonding to soft gold PCB finish rather than ENIG, not gold wire  
>> bonds to
>> ENIG/ENEPIG
>>
>>