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Wednesday, December 30, 2009

Links Page

Here you'll find links to other PCB and Electronics related sites.

If you are a webmaster, please add or submit your url to our useful links section by emailing me, Zaakid Mata to kakinblogs@gmail.com. I'll answer with instructions on how to proceed.

Electronics Directory
AlphaLinks SEO Friendly Directory
EE HomePage.com
Cornerstone Labs
Smith Semiconductors
Mental Automation, inc.
EE Internet Resources - PCB Area
Circuit calculator
Circuit Board Fix 
Texas PCB Design
Milplex Circuits

Monday, December 28, 2009

ROHS Compliant Printed Circuit Board

A Rohs compliant pcb is one that does not use any lead in the manufacturing process or soldering. Rohs is a regulation for the use of lead in various products, and has slowly become a standard in printed circuit board manufacturing.

BGA Test Sockets

Ball Grid Array test sockets are a prototyping and testing tool that is used in verifying the effectiveness of a soldering process to the pcb when using BGA chips.

They are basically the same as production sockets, but may incorporate features that will allow measurement or analysis of the resulting product when testing for connectivity to the printed circuit board or assuring reliable solder points.

Sunday, December 27, 2009

Quick guide for buying printed circuit boards

As you know [ probably don't, but anyway... ], I love electronics, and getting your projects and design looking professional and mechanically stable is a great plus you get when assembling them in a printed circuit board.

When ordering PCB's there's a certain process you have to go through, from designing the circuit, to designing the board, then ordering and actually assembling the circuit. For this guide I'm assuming you know your basic electronics and are looking to order a batch of PCB's for your finished project.

First off, you need to have your project designed and tested. This is probably the hardest part of the process, since you need to be making schematics, some calculations and stuff related. In this process, make sure to have a dependable breadboard, power source and measurement tools around, because many times problems with the functioning of the circuit can be caused by irregularities in any of the equipment described.

Parallel to designing the circuit, you need to be making the schematic in a computer program, because you'll need them to generate the circuit board layouts. The program you choose is pretty much a matter of choice, since most of them work around the SPICE model and net lists, so choose one that you like or a friend recommended and get to work.

Next up is designing the circuit board. Before you start doing this, make sure to check with your manufacturer if they offer standard sizes, more often than not, these standard sizes will give you a better value for low volumes of circuit boards. Once you have the size, you can get started on the design of the circuit board. The actual designing of the traces and positioning of the components in the board is an art and science in itself, and that is outside the scope of this thing. Many top notch manufacturers offer tutorials on how to properly design a PCB [ they want to make their job easy too you know ].

Remember I told you you needed to have a PC version of the schematic?, well that's because you really should check, double check, simulate and re-simulate your circuit and confirm that all connections in the PCB design correspond to those in your schematics, because once you order, there's no going back [ except for manufacturing defects ], and circuit boards are not the cheapest thing to buy.

Now that you have your circuit and circuit board designed, its time to get them manufactured. If you took the time to check for standard sizes then this step should be very straightforward, you just select your standard order, upload the Gerber files [ which are the layout definition file of the circuit board ], depending on the manufacturer, you may need to compress [ zip ] the files before uploading.

Before purchasing your circuit boards, make sure to order the lead free finish. It's better for the environment, better for you [ lead can cause all sorts of bad stuff to your health, and specially to children ], and looks far better than the leaded variety.

One thing to have in mind for future orders, is that most manufacturer give special attention to large volumes of boards, mostly by price [ they set some pretty steep base prices for most production services ], so if you only need few boards, always make sure they have standard orders [ most likely small boards, 3 to 5 boards is common ]. Also make sure to consider all the options, because sometimes a little extra on a board can get you a long way on quality and looks.

Now that you have ordered your circuit boards, check each and every one as soon as you can get your hands on them. Should you find a defect such as broken traces, broken or chipped edges or anything like that, its better to have that checked before you start assembling your project so you can get a quick replacement without any hassle.

So there you go! If your boards arrived safe and sound, your project should be well on its way to be a professional looking piece of technology.

- Zakmata

Thursday, December 17, 2009

PCB Reverse Engineering

Reverse engineering is the process of obtaining a product specification directly from the product, and not from a manufacturer or designer.

Reverse engineering of a circuit board is necessary when production files (gerber) are unavailable, or to rework the design in order to bring an old circuit for new use, taking advantage of better materials or production processes.

The process is to identify all components, and their interconnections, in order to generate new spec files and schematics. Extra data such as trace width and length are needed for high frequency designs, as impedance and signal losses from "antenna like" behavior from tracks needs to be taken into account.

RF Printed Circuit Boards

RF PCB's are specialty circuit boards that are designed and optimized to work with radio frequencies. Extra care is taken to ensure the board doesn't radiate undesired signals or that it acts as an antenna and captures undesired interference and noise.

Multilayer Printed Circuit Boards

Multilayer PCB's are used when extra track density is needed. Layers of substrate and etched tracks are "sandwiched" to create this kind of board. Sometime extra heat or chemical processes are required in order to have reliable connections and mechanical stability.

Metal Core PCB

Metal core printed circuit boards are used when thermal losses or output of the components needs to be managed, since the core aids in dispersing and acting as a heat sink.

In this kind of pcb, a piece or plate of metal is laminated inside the regular insulating substrate, where the tracks are etched and components soldered.


IPC is a standards association, whose purpose is to set the rules for the interoperability of printed circuit designs and manufacturing processes.

Gerber PCB Format

The Gerber file format is the standard for PCB design and manufacture, it describes how the tracks are to be laid and any printing or etching additional to the conductor tracks, such as component identification or other notices.

FR4 Printed Circuit Board

FR4 is a flame retardant used in circuit board manufacturing. It is used to provide protection against fire that could start due to short circuits, sparks or other component failure.

Flexible Printed Circuit Boards

Flexible circuit boards are made from a flexible substrate, instead of the common rigid. They are used when space constraints or the difficulty to service rigid components limits the use of rigid circuit boards.

Circuit Board Etching

Etching refers to the process of laying the tracks on a circuit board, tracks that are used as interconnection for the components to be assembled on it.

There are many processes used for etching, some use a 'mask' that protects some parts of a copper layer in the board, that are to become the tracks. Other processes include electrolytic and immersion, where layer of conductive material are deposited where the tracks are supposed to be, or removed from where connections are not needed.

Double Sided PCB

Double sided PCB's, as the name suggests, is a kind of circuit board that has tracks etched on both sides of the board. This configuration allows for more compact designs, or when space limits the use of extra boards.

Circuit Board Prototype

A Prototype circuit board is used in low volume, test or design applications, when the circuit has not been tested or to improve the design before full scale production.

Sometimes, prototype boards are created by hobbyists in their own labs, in case an order of commercial PCB's becomes expensive or unneeded.

There are also some prototype boards that are similar in construction to breadboards, but require soldering for component connections.

Printed Circuit Board Fabrication

Fabrication includes all of the processes in pcb manufacturing, from etching, drilling, soldering and laminating. (see each for a more complete description)

Printed Circuit Board Assembly

Assembly is the process in which electronic components are soldered on to the PCB. There are many processes used for this, depending on the final use of the circuit, the types of signals used, and the sensitivity of the components used.

Assembly also includes testing of the soldering and signals, to check if the pcb is suitable for production and use.

Blank Circuit Boards, Copper Clad Boards

Blank circuit boards are PCB's that haven't been etched with the regular copper traces for component connection. These are sold for the DIY crowd, who want to experiment with PCB etching.

Other name for these kinds of PCB is copper-clad boards, and are sold for etching at most hobby and electronics shops.

BGA or Ball Grid Array PCB

A BGA PCB is a printed circuit board that instead of pins for connection to external circuitry, it has solder ball contacts, which come from the IC's that use that connection technology.

It has the advantage of having high 'pin' density, that other packaging technologies don't have, but a disadvantage is expensive testing of solder joints.

This kind of PCB is mostly use in the connections for CPU's.