The changing face of PCB Assembly

Soumac have been involved in PCB assembly, test and repair for over 20 years.

In that period of time, the industry has experienced great change. From customer demand and globalisation through to environmental drivers and technological development, the industry has had to adapt to ensure it meets the needs of the 21st century client.

In the beginning…

The ‘Auto Sembly’ process was devised by the US Army in the 1950s. It was the invention of this technology that enabled PCBs to become commonplace in consumer goods, enabling cost-effective mass production.

Prior to this, every PCB had holes drilled through it to accommodate the wired leads of the electronic components, otherwise known as ‘through-hole’ construction. With the invention of ‘Auto Sembly’, dip soldering, board lamination & etching and wave soldering, we are left with the process broadly similar to what is still in use today, with the addition of surface mounting arriving in the 1980s.

The increase in complexity and high volume production has necessitated the advent of SMT placement machines, also known as ‘pick and place’, alongside reflow ovens; have automated much of the process.

However, despite the ever developing technology, there is still a place for manual soldering, particular on through hole and some low volume prototyping.

(Early Essemtec SMT placement machine)

(Board within an old Marconi Test System – late 1980s)

(Board within an old Marconi Test System – late 1980s)

(The Paraquda one of Essemtec’s latest SMT placement machine)

Whilst there have been many changes across the industry, our top 5 changes to impact on the sector are:

1. RoHS Compliance – Otherwise known as the ‘Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment’, the introduction of legislation designed to minimise the use of potentially dangerous substances within electronics has revolutionised the industry.

2. No clean flux – The introduction of no-clean flux has removed the need to clean the boards after assembly. The result is a quicker and more environmentally-friendly process.

3. Miniaturisation – Everything is getting smaller, including: the boards themselves, the tracking, gaps and the component devices.

4. Component Density – Component density has continued to dramatically increase in recent years. A single package will now often contain many 1000s of components.

5. PCB Layer Count – At their inception PCBs were created single sided. Now there are times when we encounter boards with 20 plus layers.