If you prototype printed circuit boards , how can you ensure that laminates and prepregs you used will match those used in offshore volume production?

As an industry, those of us involved in designing and manufacturing electronic products can all agree that we now live and operate in a global supply chain environment. Since a lot of what is incorporated into current and next generation products is reflected in the software, this isn’t much of a concern. Take your favorite products, download the latest software update and newly developed apps and you’re ready to go.

When it comes to developing the pieces of hardware, the process is not so simple. And, when it comes to printed circuit board (PCB) development efforts, the process becomes even more challenging. That’s because PCBs are the launching points for hardware product development and the laminate and prepreg materials used in designing and manufacturing PCBs are the nuclei for those boards. (Prepreg is fiberglass cloth that has been saturated with resin that is not fully cured. As a PCB is placed under the heat and pressure of lamination this resin melts and flows into the voids in the adjacent copper layers filling them.)

• Gerber data, which board and stencil manufacturers still depend on for their processes. There will be a point when this is not required. Depending on your vendor base, that time may or may not be now.
• Valor ODB++, which  allows board and stencil manufacturers to gain insight into the design and offer feedback to improve processes, thus reducing production cost over time. It also allows use of Valor DFA software for reviewing an assembly to improve yields in production by PCB manufacturers with that level of sophistication. Since it can be used for programming pick-and-place lines, it could be a “one file” approach to all manufacturing requirements.
• CAD ACSII database, which supports the fastest approach to programming the pick-and-place lines and can support other programming efforts such as AOI.

PCB Etching Process

All PCB’s are made by bonding a layer of copper over the entire substrate, sometimes on both sides. Etching process has to be done to remove unnecessary copper after applying a temporary mask, leaving only the desired copper traces.

Though there are many methods available for etching, the most common method used by electronics hobbyists is etching using ferric chloride ir hydrochloric acid. Both are abundant and cheap. Dip the PCB inside the solution and keep it moving inside. Take it out at times and stop the process as soon as the copper layer has gone. After etching, rub the PCB with a little acetone to remove the black colour, thus giving the PCB a shining attractive look. The PCB layout is now complete.

PCB Drilling

The components that have to be attached to the multi-layered PCB can be done only by VIAS drilling. That is, a pated-through hole is drilled in the shape of annular rings. Small drill bits that are made out of tungsten carbide is used for the drilling. A dremel drill press is normally used to punch the holes. Usually, a 0.035 inch drill bit is used. For high volume production automated drilling machines are used.

Sometimes, very small holes may have to be drilled, and mechanical methods may permanently damage the PCB. In such cases, laser drilled VIAS may be used to produce an interior surface finish inside the holes.

Conductor Plating

The outer layer of the PCB contains copper connections (the part where the components are placed) which do not allow solderability of the components. To make it solderable, the surface of the material has to be plated with gold, tin, or nickel.

Solder Resist

The other areas which are not to be solderable are covered with a solder resist material. It is basically a polymer coating that prevents the solder from bringing traces and possibly creating shortcuts to nearby component leads.

PCB Testing

In industrial applications, PCB’s are tested by different methods such as Bed of Nails Test, Rigid Needle adaptor, CT scanning test, and so on. The basic of all tests include a computer program which will instruct the electrical test unit to apply a small voltage to each contact point, and verify that a certain voltage appears at the appropriate contact points.

SMT parts have many advantages over their older through hole ancestors, namely: smaller size, lower cost manufacturing costs, and less likelihood of obsolescence. However, an often overlooked advantage is the ease at which surface mount components can be soldered and desoldered. At first this might seem like a controversial subject, but it isn’t to engineers and technicians to have grown accustomed to working with both types of parts. Just try desoldering a 16 pin DIP from a PCB with a solder sucker without ripping a trace, and you’ll understand how hard reworking a through hole part can be. Compare this to a desoldering a 16 pin SOIC which can be removed in a matter of seconds with no special equipment.

Vacuum Desoldering

The vacuum based through-hole desoldering station consisted of a soldering iron with a hollow tip and body which leads to a glass tube capped by a filer at one end which is also the end the vacuum is applied to. The trick is to heat up the whole solder joint (I use an ample amount of flux to assist) and then start the vacuum by pulling the trigger. During this time I am also wiggling the soldering iron tip in order to break the component pin free from the wall of the hole or plate-through. Done correctly both the PCB and the component being removed are reusable.

Infrared Desoldering

The infrared based system, referred to as an Infrared Welder by the manufacturer, can ultimately heat a smaller area to a hotter temperature than hot air, or so I believe. To mask off the surrounding area for hot air you need to keep your airflow low and redirect it away from the rest of the PCB. To redirect Infrared you use the reflective properties of aluminum foil. It’s then mostly a matter of firing up the fume fan and having the patience to wait for the direct heat to do the job. Again a judicious use of flux helps.

Hot Air Desoldering

Hot Air is similar in that flux helps, fumes and smoke may be present and you have to have the patience to wait for the part to come fully loose — half loose doesn’t cut it. To this end I recommend a hot air holder, a fume fan and an egg timer. If you don’t have an egg timer I am sure there is an app for that somewhere.

Desoldering with Chip Quik and an iron

I have found The quickest way to desolder SMT without investing in any of this equipment is to use a product which lowers the melting point of the solder metal when mixed with it as it allows a soldering iron to melt the entire chip’s footprint simultaneously allowing it to be removed.

The China Printed Circuit Board (PCB) Industry 2016 Market Research Report is a professional and in-depth study on the current state of the Printed Circuit Board (PCB) industry.

The China Printed Circuit Board Industry provides a basic overview of the industry including definitions, classifications, applications and industry chain structure. The Printed Circuit Board market analysis is provided for the international markets including development trends, competitive landscape analysis, and key regions development status. Development policies and plans are discussed as well as manufacturing processes and cost structures are also analyzed. This report also states import/export consumption, supply and demand Figures, cost, price, revenue and gross margins.

Over the five years through 2016, revenue for the Printed Circuit Board Manufacturing industry has increased at an average annualized rate of 8.1% to $78.9 billion. As printed circuit boards are intermediate components, the majority of industry revenue is derived from sales to downstream wireless industries and consumer electronic manufacturing industries. Growing household income in China has led to increasing demand for electronic products, boosting demand for printed circuit boards.

Growth in the Printed Circuit Board Manufacturing industry in China has gradually slowed in recent years. In 2016 alone, industry revenue is expected to grow 6.5%.

The Printed Circuit Board Manufacturing industry has grown rapidly over the past five years. In 2016, industry revenue is expected to reach $78.9 billion. High growth has been driven by greater domestic and foreign demand.

As printed circuit boards are an intermediate product, the majority of industry revenue is derived from sales to downstream wireless industries and consumer electronic manufacturing industries. Growing household income in China has led to increasing demand for electronic products, creating demand for printed circuit boards. However, wireless and consumer electronics industries are subject to rapid technological change, which brings about intense competition, short product life cycles and significant fluctuations in product.