Prototyping Boards

Surface Mount Board 15x40 SM-2 40mm x 105mm $2.50 each

14 x 20 Surface Mount $2.50

7 x 5 holes 50cents                                      10 x 4 holes   50cents


10 x 8 holes 50cents                      11 x 7 holes 50cents

12 x 11 holes $1.00

9 x 19 holes $1.50
also:
15 x 12 $1.50

20 x 15 holes $2.50

6 x 38 holes $1.50
also
6 x 40 holes $1.50
5 x 18 holes $1.00
5 x 23 holes $1.00

PIC Matrix Board with POWER SUPPLY $2.50
This board is specially designed for a PIC chip with the power rails
to the chip already provided.
It is designed to allow you to produce a very fast, neat prototype.
There is a 5v rail from the regulator and a 9v rail from the battery.
The battery clips directly to the board or via a battery-snap.

Some prototyping boards are not designed to look beautiful. They are designed to be functional and reduce frustration.
A prototype project is sometimes called a "rats-nest" or "birds-nest."
There are two levels of prototyping.
The first level requires no experimenting. It's simply building a "proven" circuit on a board and connecting it to other items.
The second level involves experimenting and changing component values. For this, the components should be on one side of the board.
The end-result is a jumble but it's the only way to be able to get-to-everything and see the whole circuit:

Rotating Beacon prototype, after the "rats-nest"
design and before the final board

Many prototyping boards on the market are quite useless. They are not really prototyping boards but rather "Universal Boards" that will accept different components and hand wiring.
The essential part of a prototyping board is the accessibility of each and every component so the voltage and waveforms can be measured.
But the most important reason is each component must be easily removed and/or replaced. That's why soldering components through holes is not suitable. Sometimes a component has to be changed 4 or 5 times. Imagine the difficulty in pulling out a component every time you want to alter the value.
Some of our prototype boards have certainly become over-crowded but that's how a circuit gets designed.
Initially you think the circuit will need a few components and choose a small PC board. It quickly gets over-crowded but as the circuit develops, you can easily see what each component is doing and it's really not complex at all.
You will notice many of the circuits in the photos above have been designed with surface-mount components.
These are just as cheap as normal components and since they take up less space on the board, it creates less clutter and you can see what you are doing.
Surface-mount kits are available from Talking Electronics and when combined with the prototyping boards, you will be able to develop circuits that are very compact.

THE SECOND STEP
The second step before making a PC board is to lay out the components on a matrix board in the same locations as they will appear in the final design.
This will give you two answers. It will let you know if the project will work and give you some idea of the size of the board and where each item is positioned. The underside of the board is generally a mass of fine wiring and it may need one more layout to produce wiring that does not cross at any location. Any wires that cross each other need a jumper and by carefully re-laying the board, no jumpers will be needed. Here is our example of the PIC Lab-1 before the final PC layout. The stage before this was a "rats-nest" and the final design you can see in the PIC Lab-1 article.
If you think our projects "magically appear from no-where" you should see our boxes of thousands of prototypes!

If you are thinking of going to the next step and designing a PC board for your project, here are a few tips:
DO NOT use PCB software associated with any PC manufacturer. You are LOCKED-IN to their costing and it is generally EXORBITANT.
Do not accept "touts" sending you emails from PCB manufacturers. These costings are also very high and generally the person behind the email is working from home as a "go-between." They MARK-UP the prices from the manufacturer and you don't get a bargain.

Here is a website that compares the cost of making a PCB from different manufacturers:
http://pcbshopper.com/

Many of the manufacturers are a RIP-OFF They quote $36.00 for 3 boards plus $15.00 delivery.
But the size of the board is 3cm x 3cm.
Who wants a board 3cm x 3cm ????
When you peel away all the SCAMs, there are only a few manufacturers who offer low prices.

The cheapest and best is: http://www.elecrow.com/
They produce 10 panels 10cm x 10cm double-sided green solder mask, PTH, HASL with white legend on top and bottom for $12.00 Plus $9.00 shipping.
The quality is perfect and you could not buy the materials for $12.00
The only problem with low-cost boards is the size. You have to keep the size smaller than 10cm x 10cm.
Any board over 10cm x 10cm costs 300% more and you will find this provides a very good learning-curve to producing modular systems with a maximum footprint of 10cm x 10cm.
You can stack the board on top of each other or provide plugs and sockets to join the edges.
This way you can produce an OUTPUT BOARD, POWER SUPPLY BOARD, display board and a number of INTERFACE BOARDS and create a whole range of different produces with a small number of modules.

SOFTWARE
If you really want the simplest software for designing a simple board, try this FREE software:

http://techdocs.altium.com/display/ALEG/Legacy+Downloads

Autotrax

DOS Freeware version 1.61 - Complete PCB layout package with output support for printers, pen plotters and Gerber.

To install: Download and run the file in the root directory of your hard drive to extract the install program. The install program must be run from the root directory.

Download (ZIP 821 KB)

EasyTrax
DOS Freeware version 2.06 - Complete PCB layout package with output support for printers, pen plotters and Gerber.

System requirements: PC-compatible; DOS 2.0 or later; 640K RAM; 2Mb of hard disk space.

10 EasyEDA
EasyEDA is a free, zero-install, Web and cloud-based EDA tool suite, integrating powerful schematic capture, mixed-mode circuit simulation and PCB layout in a seamless cross-platform browser environment, for electronic engineers, educators, students and hobbyists.

HOW A PCB IS MADE

These are the steps to make a PCB:

1 PPE - Pre Production Engineering

Customer supplied data (gerber) is used to produce the manufacturing data for the specific PCB (artworks for imaging processes and drill data for drilling programs). Engineers compare demands/specifications against capabilities to ensure compliance and also determine the process steps and associated checks.

2 Preparing the phototools

Artwork Master is PCB production in the key steps, which directly affect the quality of the final product quality. An accurately scaled configuration of electronic data used to produce the artwork master or production master. Artwork Master – The photographic image of the PCB pattern on film used to produce the circuit board, usually on a 1:1 scale. In general, there are three types of Artwork Master: (1) Conductive Pattern (2) solder mask (3) Silkscreen.

3 Print inner layers

Stage 1 is to transfer the image using an artwork film to the board surface, using photosensitive dry-film and UV light, which will polymerise the dry film exposed by the artwork. This step of the process is performed in a clean room. Imaging – The process of transferring electronic data to the photo-plotter, which in turn uses light to transfer a negative image circuitry pattern onto the panel or film.

4 Etch inner layers

Stage 2 is to remove the unwanted copper from the panel using etching. Once this copper has been removed, the remaining dry film is then removed leaving behind the copper circuitry that matches the design. Etching – The chemical, or chemical and electrolytic, removal of unwanted portions of conductive or resistive material.

5 Inner layer Automatic Optical Inspection (AOI)

Inspection of the circuitry against digital “images” to verify that the circuitry matches the design and that it is free from defects. Achieved through scanning of the board and then trained inspectors will verify any anomalies that the scanning process has highlighted.

6 Lay-up and bond (Lamination)

The inner layers have an oxide layer applied and then “stacked” together with pre-preg providing insulation between layers and copper foil is added to the top and bottom of the stack. The lamination process consists of placing the internal layers under extreme temperature (375 degrees Fahrenheit) and pressure (275 to 400 psi) while laminating with a photosensitive dry resist. The PCB is allowed to cure at a high temperature, the pressure is slowly released and then the material is slowly cooled.

7 Drilling the PCB

We now have to drill the holes that will subsequently create electrical connections within the multilayer PCB. This is a mechanical drilling process that must be optimised so that we can achieve registration to all of the the inner layer connections. The panels can be stacked at this process. The drilling can also be done by a laser drill.

8 Electroless copper deposition

The first step in the plating process is the chemical deposition of a very thin layer of copper on the hole walls. PTH provides a very thin deposit of copper that covers the hole wall and the complete panel. A complex chemical process that must be strictly controlled to allow a reliable deposit of copper to be plated even onto the non-metallic hole wall. Whilst not a sufficient amount of copper on its own, we now have electrical continuity between layers and through the holes. Panel plating follows on from PTH to provide a thicker deposit of copper on top of the PTH deposit – typically 5 to 8 um. The combination is used to optimise the amount of copper that is to be plated and etched in order to achieve the track and gap demands.

9 Image the outer layers

Similar to the inner layer process (image transfer using photosensitive dry film, exposure to UV light and etching), but with one main difference – we will remove the dry film where we want to keep the copper/define circuitry – so we can plate additional copper later in the process. This step of the process is performed in a clean room.

10 Plating

Second electrolytic plating stage, where the additional plating is deposited in areas without dry film (circuitry). Once the copper has been plated, tin is applied to protect the plated copper.

11 Etch outer layer

This is normally a three step process. The first step is to remove the blue dry film. The second step is to etch away the exposed/unwanted copper whilst the tin deposit acts an etch resist protecting the copper we need. The third and final step is to chemically remove the tin deposit leaving the circuitry.

12 Outer layer AOI

Just like with inner layer AOI the imaged and etched panel is scanned to make sure that the circuitry meets design and that it is free from defects.

13 Soldermask

Soldermask ink is applied over the whole PCB surface. Using artworks and UV light we expose certain areas to the UV and those areas not exposed are removed during the chemical development process – typically the areas which are to be used as solderable surfaces. The remaining soldermask is then fully cured making it a resilient finish. This step of the process is performed in a clean room.

14 Surface finish

Various finishes are then applied to the exposed copper areas. This is to enable protection of the surface and good solderability. The various finishes can include Electroless Nickel Immersion Gold, HASL, Immersion Silver etc. Thicknesses and solderability tests are always carried out.

15 Profile

This is the process of cutting the manufacturing panels into specific sizes and shapes based upon the customer design as defined within the gerber data. There are 3 main options available when providing the array or selling panel – scoring, routing or punching. All dimensions are measured against the customer supplied drawing to ensure the panel is dimensionally correct.

16 Electrical test

Used for checking the integrity of the tracks and the through hole interconnections – checking to ensure there are no open circuits or no short circuits on the finished board. There are two test methods, flying probe for smaller volumes and fixture based for volumes. We electrically test every multilayer PCB against the original board data. Using a flying probe tester we check each net to ensure that it is complete (no open circuits) and does not short to any other net. Good products come from good manufacturing but not inspection.

17 Final inspection

In the last step of the process a team of sharp-eyed inspectors give each PCB a final careful check-over. Visual checking the PCB against acceptance criteria. Using manual visual inspection and AVI – compares PCB to gerber and has a faster checking speed that human eyes, but still requires human verification. All orders are also subjected to a full inspection including dimensional, solderability, etc.

18 Packaging

Boards are wrapped using materials that comply with packaging demands (ESD etcetera) and then boxed prior to be being shipped using the requested mode of transport.

Email: jonny@apollopcb.com
Web: www.apollopcb.com