Tips for soldering with finer tips

[rthorntn]

Hi,

I don't solder a lot and for the life of me I cant really solder SMT with the finer tips (Hakko 888), I look at a SOIC-8 and I'm thinking fine hoof (0.8mm?) with lead solder, fumble around for 20 minutes with the fine tip, frustration, it's not flowing, start worrying that I'm going to cook the IC and remember that I always fail with the finer tips, move to a standard hoof (~1.2mm?) and 2 minutes later job done, what am I doing wrong?

Cheers
Richard

[inse]

The crucial part is using flux ( liquid or gel), then the solder tip almost cannot be too large.
Very thin tips always cause trouble with e.g. ground pads.

[rthorntn]

Thanks, it's not the lack of flux, I had a puddle of liquid flux.  It's got to be something to do with heat transfer, does the tip temperature have to be higher for the finer tips?

[jpanhalt]

I tried to find the Hako 888 tip to which you refer.  If you are talking about a long, skinny conical tip (attachment: right most), the rate of heat transfer will be considerably slower than with a shorter slightly fatter tip (left tip).  While solder melts at a certain temperature, the temperature at the very tip may be sufficiently high, but the temperature of what you are soldering probably is not.

I use a tip like the one on the left, and heat the pad/component mostly until the 0.015" solder flows into the joint.  It's a simultaneous action and doesn't take more than a couple of seconds.  Remember too, that unlike very early components, modern SMD devices are usually stable to reflow soldering.

[rthorntn]

Thanks, the troublesome hoof looks like a T12-BC1, my goto is a T18-C2, basically I have trouble with any fine tip but the T12-BC1 is not what you would call fine tipped.

[barshatriplee]

With SMT components, you need to use a smaller amount of solder and place it precisely on the pads. Make sure that you are using the right amount of solder and that you are not flooding the pads.SMT components require flux to help the solder flow onto the pads. Make sure that you are using enough flux to help the solder flow onto the pads.The tip size you are using may not be suitable for the size of the component you are soldering. While a 1.2mm tip can work for some SMT components, it may not be suitable for smaller components such as SOIC-8. You may need to use a finer tip to work with smaller components.
Here is a list of PCB Requirements for Typical SMT Equipment. You may find this helpful.


https://www.pcbway.com/blog/PCB_Assembly/PCB_Requirements_for_Typical_SMT_Equipment.html

[RoGeorge]

Use the thickest tip you can still use without making bridges.
For example, a chisel shape as wide as your soldering pad.

The general idea is the soldering tip has to be as big and as fat as possible, so to assure maximum heat flow and maximum heat inertia.

[agehall]

Flux and good vision are the two key components for me. Fine tips help but are not crucial imho.

[wraper]

I often solder 0603 SMT with 2.4mm chisel because I'm too lazy to change the tip. And 1.6 mm chisel is the smallest I would use for that. As for SOIC, 1.6mm chisel is about the smallest I would use for that too. Or I would use 2.4-3.2mm hoof or concave tip for drag soldering.