The electronics Printed Circuit Board industry is evolving as new production technologies become available at inexpensive. Direct digital printing is making inroads into the traditional photolithography and screen printing processes that were used to manufacture Fast PCB Produce for the last 20 years.

Here we shall focus on the utilization of direct digital printing to individualize PCBs just prior to their assembly. The goal is always to print an exclusive mark on each board that can be employed to identify the board. The mark should be permanent and can probably contain 1D or 2D machine readable codes in addition to alpha numeric characters. The marks will need to have a 600 DPI (dots per inch) resolution or better due to size constraints on the PCB. We shall also focus on applications that require more that one thousand,000 boards per year. At these volumes automated material handling actually starts to become extremely important to the overall success from the system.

High volume PCB fabricators use screen printing with thermally cured ink to print the legends which cover both sides from the board. At this time digital printing can not print the whole side of any board at a price that competes with screen printing. Even though many printers, like the PPS7000, could print all the nomenclature on the board, here we will give attention to using digital printing just to print the individualizing marks.

Several individualizing options exist including the following:

Preprinted Label Application

Many low volume products get started with labels printed on office equipment and hand put on each Instant PCB Quote prior to or after assembly. Since the product volumes ramp the reliability and cost of hand applying labels gets to be a problem. Automated systems that print and apply labels can be found. (check this out site ) As a result of PCB space constraints these systems must place labels very accurately, a huge problem for most label application systems. The labels are not permanent. At high volumes the labels are more expensive than other marking methods.

Advantages

* Low Initial Cost

* High Contrast Mark

Disadvantages

* Not Permanent

* Higher Incremental Cost

* Difficult to Change Label Size On The Fly

* Mechanical Complexity For Automated Application

Solvent Based Continuous Ink Jet Digital Printing. Continuous ink-jet technology has been adapted to mark on many industrial products including PCBs. By using these systems a continuous stream of ink droplets is steered towards the desired location using electromagnetic fields. Solvent based inks produce permanent marks on porous surfaces. The marks are less permanent on non-porous surfaces where smearing may become a problem for that short time its takes to dry.

Advantages

* Competitive Incremental Cost

* High Contrast Mark

* Many Colors Available

Disadvantages

* Complex Ink Viscosity Process Can Be Difficult To Control

* High Resolution (Greater Than 300 DPI) Difficult To Achieve?

* Solvents May Be Released Into Atmosphere, Most Companies Trying To Reduce Solvent Issues

* Mark Not Resistant Against Some Cleaning Solvents

Laser Ablated Ink Patches – Many industries use lasers to engrave marks onto many different parts. Lasers have been utilized to engrave marks onto PC boards with limited success because of the lack of contrast from the resulting mark. A more recent approach is to have the circuit boards printed with ink patches, the ink patch will then be selectively removed (ablated) by the laser creating the mark to be printed. (see here ) PPSI has the capabilities to build up a laser based marking system.

Advantages

* Competitive Incremental Cost

* High Contrast Mark If Ink Patch Is Used

* Very Fine, Highly Reliable Marks Provided By Laser Galvo Head

Disadvantages

* High Initial Cost

* Requires Preprinted Ink Patch

* Even At Low Power Laser heat May Damage (by Fracture) Traces, Causing Intermittent Reliability Problems

* Particle Generation May Demand A Cleaning Step

Piezoelectric Drop On Demand Digital Printing, Solvent Based Ink. For any concise description of drop at will digital printing see here [http://www.aellora.com/documents/whatisdodij.pdf]. In my view this alternative represents a small improvement over option 2.

Advantages

* Competitive Incremental Cost

* High Contrast Mark

* Many Colors Available

* Easier Process To Regulate Than Continuous Ink Jet

Disadvantages

* Standoff Distance less Than 2mm, Ideal For Unpopulated Boards Only

* Solvents May Be Released Into Atmosphere, Most Companies Trying To Reduce Solvent Emissions

* Mark Not Immune To Some Cleaning Solvents

Piezoelectric Drop At Will Digital Printing, Thermally Cured Ink. A startup company in Israel “Printar” has introduced a printer directed at low volume, fast turn PCB fabricators who need to lessen the fee and lead time connected with small lot screen printing. Interesting is their thermally cured ink that reportedly has better adhesion capability than other ink systems.

Advantages

* Good Ink Adhesion ?

Disadvantages

* Requires Large Oven For 350-400 deg F Heat Cure

* Fails To Include High Volume Material Handling

Piezoelectric Drop When Needed Digital Printing, UV Cured Ink. Markem Corporation has evolved an ink/print head system ( the Model 4000, see here ) that several OEMs and integrators are employing to print on PCBs. The program uses an ink which is less viscous at high temperature and almost solid at room temperature. Paper head operates at 68 deg C, the ink drops cool when they contact the PCB becoming almost solid. This permits the system to print fine detail on PCBs without ink running or smearing. When subjected to UV light the ink undergoes a chemical reaction being a solid plastic like substance. The cured ink is impervious to common solvents.

Advantages

* Competitive Incremental Cost

* High Contrast With Fine Detail (600 DPI)

* Before Cure, the Ink Can Be Wiped Off As well as the Board Reprinted

* After cure, The Ink Can Not Really Removed Except By Scraping

* High volume Material Handling Available

* Works Well With Inline Inspection (Inspect Before Cure, Cure Only Good Boards)

Disadvantages

* Ink Adhesion Can Be A Problem On Certain Substances

* Requires the PCB Be Clean (No Finger Oils)

* Standoff Distance Lower Than 2mm, Appropriate For Unpopulated Boards Only

The PPS7000 has become created to print individualizing marks on Ultrafast PCB Produce using option 6. The system works with a SMEMA compatible edge belt conveyor to move PCBs to the print area where they may be printed and optically inspected. After inspection they may be conveyed to the inline curing station and then out the back in the machine. When being automatically loaded with a board destacker, panels exit qhzwxo system about once every 10 seconds. Each panel usually contains multiple boards that each receives a unique serial number. The general throughput in the machine is highly dependent on the quantity of boards in each panel. The better boards in each panel the higher the throughput in boards each minute. A drag and drop WYSIWYG (Whatever You See Is Exactly What You Get) programming system has been developed that enables a brand new panel to become programmed in approximately 5 minutes. An offline programming system is also available.

We have been the only real PCB board marking system that creates a lasting (solvent resistant) high contrast mark, incorporates SMEMA compatible high volume material handling and incorporates inline inspection.

Special Offer For 2layers PCB – Visit This Outstanding Gaming Internet Site..

We are using cookies on our website

Please confirm, if you accept our tracking cookies. You can also decline the tracking, so you can continue to visit our website without any data sent to third party services.