Amiga Technical Resource - Surface mount soldering tips

Tips for surface mount device (SMD) soldering

Introduction

Surface mount soldering is an acquired skill necessary for any detailed repair work on most modern electronics, including the A600, A1200, CD32 and A4000(T) computers.

Like learning to ride a bicycle, you can't simply learn SMD soldering by reading a book. These guides are intended to help the beginner, people who want to have a go, or even if you just want to see exactly what's involved.
It really isn't as difficult as most people make it out to be and with a bit of practise you'll soon become quite comfortable working with surface mount technology.

Before attempting SMD soldering, it is essential to have moderately good hand soldering (conventional soldering) skills to begin with. It is also necessary to develop SMD soldering skills using old/broken PCBs, as when learning, it's all too easy to overheat PCBs (causing scorching, blistering and delamination) and pull off solder pads.

The main problem with SMD soldering is that you require some specialist tools, mainly a hot air or infra-red soldering (rework) station. These are professional tools and cannot be bought from your typical hardware store. If you are seriously looking into a lot of SMD soldering, the tools can be bought from most professional electronics suppliers, such as element14 (formerly Farnell) and Radio Spares. Otherwise you may be able to access one through a friend, or shop around on one of the many auction websites.
Personally I'd recommend something like the Hakko 850.

Some of the other tools required are listed here.

It also helps to have good eyesight, or a good magnifying lens, such as those used by jewellers. Fortunately the surface mount technology used on the classic Amigas is the old 1206 size, which is enormous by today's SMD 0603 and 0402 standards. These larger SMD parts are still easy to obtain and their large size makes them very easy to work with.

This section is split up into three separate guides as they contain a large quantity of images. Most images in the guides can be expanded by clicking on them.

Select a section to view: (arranged in order of easiest to more difficult)


Replacing a SOIC How to remove and replace a Small Outline Integrated Circuit.	Replacing a SMD capacitor How to remove and replace a SMD electrolytic capacitor.	Fitting a PLCC socket How to fit a Plastic Leaded Chip Carrier socket to hold an existing device.

I have not included any guides for simple replacement of 1206 chip resistors and capacitors.
Techniques similar to those in the SOIC soldering guide are used, so refer to this if necessary.

In general, most two pin devices like SMD resistors can usually be replaced using a conventional hand soldering iron, though the job is usually quicker and tidier using a SMD rework tool and solder paste.