Steady Soldering

DIY SMD Soldering Jig

David Tuck

Issue 41, December 2020

How a maker overcame SMD soldering difficulties by making a handy SMD soldering jig to hold the component firmly in place as he soldered it.

We are always impressed by the clever project submissions we get via our website and to our email inbox each month. Makers of all ages can be very creative at solving real-world problems, and usually, with simple materials they have at hand.

This month, we were contacted by David Tuck who has been involved in electronics for over 70 years. David shared photos and details about his SMD soldering jig, which we of course, just had to share with you. Here’s what David had to say.

Having been involved for more than 70 years, I often ask “where does electronics end?”. Recently, I am starting to come to terms with SMD components, as I can see no way to avoid the slippery little buggers in the future.

I would have considered Silicon Chip’s reflow oven, except that, the week before it appeared, I had invested in a hot-air rework station.

Having tried my hand, I now have small soldering iron, flux pen, solder pen, solderwick and an assortment of tweezers, suction gadgets and other small tools. Bright light and magnification help, but they do not compensate completely for old-age and tremors. When I go to solder them, they move! (Perverse nature of the beast?).

Always up to a challenge, I first thought of gluing them down, then soldering. A survey of the local hardware store (Bunnings) did not provide much scope. A hard glue would not allow movement, as I understand there are forces which align the die as the solder is hot. Perhaps a contact adhesive would work, but these also become fairly rigid when set, so also do not appear likely. The other glues readily available are even more unlikely.

What is required is something like the old wood-working G clamp. Unfortunately, size and shape rule these out.

Being of Scottish ancestry, I wanted something cheap and easy to build.

I started with a wooden base plate approx 180 x 250mm and mounted two towel rail pillars at the rear, supporting a 16mm towel rail slide bar. Sliding along it, and at right angles was another bar, approx. 200mm long. The bars were connected at right angles by a slider unit, with 16mm holes for the bars.

Bunnings supplied a wing nut with attached thread to lock the top bar in place, although another bolt could also be used to lock the bottom slider.

There are many ways to construct this, of course.

As a project, it can be split into sections.

The base plate can be made out of a timber offcut. If you have a 3D printer, you could print it, but because of its size is probably not worth doing. The current size is satisfactory to me, but it could be made larger if desired.

The support pillars are 16mm. Towel rail pillars, which are cheap and easily available, however, if you have a printer they could be printed (with included mounting threads?).

The rails are 16mm plated towel rail, which is also cheap and readily available, although other rods could be used if on hand.

With the alternative sliders, cross rails of either wood or metal bar can be used, with multiple holes for adjustment as required.

The slider unit, which is the heart of the project, I made by welding 2 short sections of square tube together. This method, however, may not be available to many of your readers. It would be probably be best made by printing, particularly if threaded lock bolt holes could be included.

An alternative is to bore holes in a block of wood (With a spade bit?), or bend up a metal bracket from a strip of perforated plate. The large holes can be drilled or filed as required (I recommend a step drill for all hobbyists!).

The hold down was fabricated from two long bolts, with one filed to a sharp point at the end. The upper section was left long to allow weights to be held on top of the bar. It was locked to the cross bar with nuts. It was later found to be better made of non-magnetic material (The little blighters jump about near magnets!).

To use, the PCB is placed on the base, the SMD device is fluxed and solder pasted into position, the spike is used to hold it down, and heat is applied. I use a weight on top of the spike as required, otherwise, a small soldering iron is used to attach the device.

If you want to appear professional, you can paint or varnish the base, and cover it with soft plastic foam. A set of rubber feet also helps.

So, a simple project which should appeal to many of your readers. It could be made in different forms, dependant on the materials used, and skills available. The wing-nut with attached bolt is a stock item at Bunnings, as are all the other components.

We thank David for his project submission and hope you are inspired to make something similar for your next project.