Besides hardness, our customer has indicated that underlying copper surface topography (i.e., roughness) is a key factor - that, for example, different surface prep methods prior to Ni/Au electroplate (e.g., peroxide-sulfuric u-etch, persulfate u-etch, pumice w/ brushes, pumice w/out brushes, even panel orientation relative to the brushes!!) will affect wire bond yields. Can anyone corroborate this?? And if this theory holds, wouldn't a final pumice of the plated gold surface itself improve things further? Is there a softness threshold below which an abrasive slurry could contaminate the gold?? J.Felts PC World, Toronto ______________________________ Reply Separator _________________________________ Subject: Re: Wire Bonding Author: [log in to unmask] at INET Date: 10/16/96 3:06 PM We also monitor Knoop hardness of the plated deposit from our soft gold bath on a monthly basis. Knoop hardness should be under 80 knoop for gold wire bonding. Kim Hadco Ca. ______________________________ Reply Separator _________________________________ Subject: Wire Bonding Author: [log in to unmask] at SMTPLINK-HADCO Date: 10/15/96 7:08 PM Advice please ! Is there a quantitative test that can be carried out on soft gold electroplate to qualify its suitability for wire bonding ? Gold thickness and purity already to customers spec. Note in this instance gold is on a nickel undercoat. Jim Douglas Kam Circuits *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************