Battery Nickel strips soldering in HASL PCB finish

#81430

Battery Nickel strips soldering in HASL PCB finish | 16 November, 2018

Hi all,

We have to solder a nickel tabs ( coming in SMT reels ) in to HASL PCB finish pads using refow oven & during this we facing poor wetting issues, more voids & we done pull strenth , its came out with in 1 kg ,I doubt that nickel coated material is tough to get solder in PCB pads & need to look in to alternate way like using best high flux solder paste , conductive epoxy, change the battery nickel part in to tin coated part - please suggest any best options to over come this issues from your expereinces

Prem

#81431

Battery Nickel strips soldering in HASL PCB finish | 16 November, 2018

Hi Prem,

We used to place millions of Nickel battery tabs using Cobar paste. We found it particularly aggressive.

Just contact your local Cobar distributor and ask them for samples of their most aggressive fluxed paste.

Kind regards, Rob.

davef

#81432

Battery Nickel strips soldering in HASL PCB finish | 16 November, 2018

Here's a similar thread earlier in SMTnet FORUM -- Soldering to a nickel plated battery terminal [ https://smtnet.com/Forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=17474&#Message71990 ]

We still have our neighborhood Batteries+ attach solderable tabs on rechargeable batteries for us.

#81434

Battery Nickel strips soldering in HASL PCB finish | 16 November, 2018

and here.... https://smtnet.com/Forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=9389&#Message37375

Which was in the days of leaded, but the ROHS paste had the same flux formulation.

#81470

Battery Nickel strips soldering in HASL PCB finish | 21 November, 2018

Hi Robl,

Thanks for your qucik reply!! , i understand if we use aggresive flux that we can impove solder wetting over nickel plate vs PCB pads & we need to solder through 12 zones reflow oven.

Prem

#81471

Battery Nickel strips soldering in HASL PCB finish | 21 November, 2018

Hi Davef,

Thanks for your quick reply , just my inputs - we using 99.99 % pure nickel strip for soldeirng & when we do manual soldering this nickle stips its working well but when coming to SMT reflow even after high peak temperature ,its removes even below 1 kg of power with more than 25 % voids. I confused flux role in this soldering which required igh or low that helps for reducing voids.

Prem

#81472

Battery Nickel strips soldering in HASL PCB finish | 21 November, 2018

Hi Prem,

Voiding has lots of causes, but boiling off flux to quickly really doesn't help, so maybe a more gentle profile. Also you do not need to print a solid block of paste, you can print a window pain style pad to help the flux escape. Also, the tabs should move less in reflow with a lower volume of paste.

Mermar

#81478

Battery Nickel strips soldering in HASL PCB finish | 22 November, 2018

Hey!Thanks for sharing.

#81482

Battery Nickel strips soldering in HASL PCB finish | 23 November, 2018

Hi RObl,

Thanks for response , sorry to ask again & again .

Is cobar paste solved the issues from poor wetting from nickel to PCB soldering,whether it will improve the peel off strenth more than 5 kg ?? as per our current last production , this nickel part will get peel off with in KG & voids looks some what better not beyond 25 %.

I have enquired cobar already & they are working under progress for some new paste like " solder paste ( ORL0 ) is OT2. "

Please provide your suggestion mainly on peel off strength.

Prem

#81492

Battery Nickel strips soldering in HASL PCB finish | 26 November, 2018

Hi Prem,

Yes, the flux in the Cobar paste helped with wetting and joint strength, as does reducing voids as there is more solder in the joint, as does cooling rate. Regarding peel test in KG, it depends on the pad size and volume of solder in the joint. From memory our pads were around 5mm x 8mm and would handle 5KG, but any more would strip the pad from the polyimide flexi circuit.