Soldering tiny SMD with pin to pin spacing of 0.65mm

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eem2am

Joined: 22 Jun 2008
Posts: 753
Helped: 13

19 Sep 2009 21:18 Soldering tiny SMD's

hello , i wish to solder small Surface Mount devices with pin to pin spacing of 0.65mm. There are 14 pins.

How do i do this.?

Small solder iron tip just dont get enough heat to it.

but big tip solder the pins together.

Do you say that the ONLY way to do this is to "blob" solder all the pins together and then try and mop up the excess with 0.9mm solder braid?

(Please also do you know what uis "drag soldering")

snafflekid

Joined: 09 May 2007
Posts: 118
Helped: 16
Location: USA

19 Sep 2009 22:33 Re: Soldering tiny SMD's

I think the common way is to apply solder paste to the flats, place the part and use a heat gun to solder in place.

Kripton2035

Joined: 19 Jul 2001
Posts: 587
Helped: 20
Location: Earth

19 Sep 2009 23:23 Soldering tiny SMD's

here is a very good video tutorial from sparkfun on how to do it !

http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=101

regards,

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jumper2high

Joined: 24 May 2009
Posts: 62
Helped: 3
Location: Serbia

20 Sep 2009 0:42 Re: Soldering tiny SMD's

I've been using a heat gun in conjunction with a Thermo-Couple thermometer. That allows me to follow manufacturer recommended soldering profiles by adjusting the distance between the PCB and the heat gun itself.

If you do a few 'test' runs with the thermometer alone, you get a general sense of which temperature requires what distance. You will be able to practically follow the soldering profile down to a few degrees.

I've been doing this mainly with Avago and Samsung power LEDs and it worked quite well. The only issue is the paste itself. It ain't too cheap, it's got a relatively short shelf life and you don't need much of it. I bought the smallest package, which was about 20$, soldered 20 power LEDs, and barely squeezed out 5mm from a 1/2in syringe.

FvM

Joined: 22 Jan 2008
Posts: 5154
Helped: 766
Location: Bochum, Germany

20 Sep 2009 11:26 Re: Soldering tiny SMD's

Quote:

Small solder iron tip just dont get enough heat to it.

Can't understand this statement. Possibly your solder iron is too cold or a bad quality product.

Personally, I prefer convenient solder paste and hot plate soldering. But the prototype production staff at my customer is soldering 0.5 mm pitch 240-pin FPGA in high quality with standard (Weller) tools. You have dfficulties to see a difference to reflow soldered PCBs.

I also have a collegue, who is complaining about difficult soldering of 1206 resistors.

E-design

Joined: 01 Jun 2002
Posts: 947
Helped: 68

20 Sep 2009 16:13 Re: Soldering tiny SMD's

I find that applying some liquid based flux works very well on soldering fine pitch QFP packages using nothing more than a 0.8mm Weller tip. If you get the occasional solder bridge, some solder braid cleans that up quickly.

siongboon

Joined: 24 Jan 2006
Posts: 288
Helped: 25
Location: Singapore

20 Sep 2009 16:54 Re: Soldering tiny SMD's

Ya. Flux is the key component.

http://www.siongboon.com/projects/2009-04-22_smd_soldering/index.htm

Best Regards,

GetDeviceInfo

Joined: 30 Mar 2009
Posts: 103

21 Sep 2009 6:29 Re: Soldering tiny SMD's

I tin the pads, clean all the flux off, align the device with a touch of flux and a bit of pressure, then solder each leg with a sharpened/tinned iron.

Use your flux sparingly as it's hard to clean from under the device once it's mounted, and can be a headache in high frequency circuits.