Article 5:
“Tools and items needed for soldering using a toaster
oven” by Anthony Burch
Before you start to solder using a toaster oven, you will need several
tools and items. This article describes what is needed for the process,
including a modification to the oven, various tools, and a description
of how to make a low cost vacuum pickup tool.
The first item is the toaster oven. You can use any kind of toaster
oven, but generally I would not recommend the very small ones. The
medium sized ones seem to work best. Whichever one you get, it must
have a glass door on the front so that you can see what is happening
inside the oven without opening the door.
You will also need a digital thermometer and a thermocouple. You can
buy these from your local electronics store.
The thermocouple looks like a long wire with a connector on the end.
The connector end plugs into the digital thermometer outside the oven,
and the other end goes around the edge of the oven door and into the
oven cavity.
It is also important to have a stopwatch, so that you can monitor the
time as the temperature changes inside the oven.
You will need to make the following modification to your toaster oven
so that your boards don’t get toasted by direct infra red
radiation from the heating elements.
The objective is for the heater elements to simply heat the air inside
the oven, so a direct line of infra red heat straight from the elements
to the circuit board must be avoided.
The way to achieve this is to get some thin sheet aluminium and make a
cut-out shape that just covers up the elements. You can use a
disposable baking tray from the supermarket to make this aluminium
shield.
The aluminium sheet can be attached by weaving it through one oven the
oven rack slides. This will hold it in place.
Make one of these aluminium shields for both the top and bottom heating
elements inside your oven.
The next item is a solder paste gun. This is the easiest way to apply
little dots of solder paste to the surface mount pads for the chip
components.
I use AIM solder cream, but any kind of lead based solder paste is
suitable for this process. You can purchase a solder gun and solder
paste from your local specialist soldering equipment supplier. I
purchased these items from Okay electronic solutions here in Australia.
Now we will discuss how to make a vacuum pickup tool from a small fish
tank air pump, which you can get for about ten dollars from your local
aquarium shop or pet shop. I will describe the way that I made the
modifications.
I removed the case of the air pump so that I could access the air inlet
hole of the pump. Then I simply fitted a small plastic nozzle that I
got from a syringe dispenser. Attached to that is a short length of 3mm
vinyl air hose, which I got from the aquarium shop. Then another nozzle
made from metal, which came from another syringe dispenser.
You can get these nozzles from your local specialist soldering
equipment supplier. The nozzles generally come with some syringe
dispensing kits but you may also be able to purchase them separately.
To use this low cost but effective vacuum pickup tool, simply turn on
the pump and bring the nozzle down onto the top of the chip component.
The component will be sucked and held onto the end of the nozzle. Then
bring the chip component over to the circuit board pads which have been
dotted with solderpaste. Place the component down. The Solderpaste is
sticky enough to grab the component and hold it in place. No vacuum
release is necessary.
That covers all the items that you will need to solder using a toaster
oven, including a modification to the oven, various tools, and a
description of how to make a low cost vacuum pickup tool.
About the Author
There are many low cost tools and techniques for soldering small
batches of printed circuit boards or one-off prototypes. Some of these
techniques are well known while others have been invented and
reinvented by small tech companies and advanced hobbyists. A few good
tips can be worth their weight in gold (not just their weight in
solder). Discover the tips that can save you days of soldering time or
thousands of dollars in outsourcing costs. Anthony’s site has
many videos that reveal exactly these kinds of valuable soldering tips.
Go to
http://SuperSolderingSecrets.com