Design: Applying technology

Imagine that you are given the task of producing a printed circuit board that has to be drilled (using a small pillar drill) with 100, or so, 1 mm diameter holes through which component leads are to be inserted prior to soldering in place. In order that the component leads align with the copper pads on the track side of the circuit board, each of the holes has to be precisely positioned. Clearly, this task might take you some time but you would probably get there in the end!

Now imagine that you have to produce 1,000 similar boards. Not only will this task take you a very long time but it would be highly likely that a significant number of boards would be rejected because the holes were not in the right place. What you need, of course, is to apply some technology to the solution and set up a machine to do the drilling for you!

At this point, itís worth stepping back a few years and considering how electronic circuits were manufactured 50 years ago and comparing this with the way they are manufactured today. Take a look at the photo below which shows the internal construction of a radio receiver that was designed and manufactured in the 1950's:

This 1950's radio is built in a wooden case and uses valves and a metal chassis

Now look at the photo below which shows its modern equivalent:

This modern radio has a moulded ABS (plastic) enclosure and uses a single integrated circuit.

They donít seem to have a lot in commonĖeven though both items of equipment perform exactly the same function. So, why the difference? The answer to this question is simply that advances in technology (both that associated with the engineered product itself as well as the technology associated with its manufacture) has moved on! We can compare the technology used in these two engineered products by comparing their main features in a table:

Feature

1950's radio

Modern radio

Enclosure

Wooden case

Plastic case

Construction

Steel chassis

Printed circuit board

Components

Six thermionic valves

One integrated circuit

Wiring

Point-point soldered wires

Printed circuit board tracks

Coverage

Long wave and medium wave (AM)

Long wave and medium wave (AM)
VHF (FM)

Power source

AC mains

AC mains or four AA-cell batteries

Power consumption

30W

Less than 3W

Now think about the manufacturing technology used to produce these two radios. How has this changed in the last 50 years?
Take a careful look at the photos and see if you can complete the table below:

Production item

Manufacturing technology and processes applied

Steel chassis (1950's radio)

Machine cutting (guillotine), forming and drilling

Printed circuit board (modern radio)

 

Wooden case (1950's radio)

 

ABS enclosure (modern radio)

 

Wiring/interconnection (1950's radio)

 

Wiring/interconnection (modern radio)

Flow soldering

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  Copyright © 2002 Mike Tooley - All rights reserved.