Choosing a PCB Printing Solution

PCB

The electronic equipment Printed Circuit Board industry is evolving as new production technologies become available at low price. Direct digital printing is making inroads into the traditional photolithography and monitor printing procedures that were used to fabricate PCB for the last twenty years.

Here we’ll focus on using guide electronic printing to individualize PCBs just prior to their own meeting. The purpose is to publish a exceptional mark on each board that may be employed to identify the plank. The mark has to be durable and will most likely contain 1D or 2D machine readable codes along with alpha numeric characters. The symbols should have a 600 DPI (dots per inch) resolution or better thanks to size limitations about the PCB. We will also concentrate on software that require more that 1,000,000 boards per year. These volumes automated material handling starts to become very essential to the over all success of their system.

High volume PCB fabrication utilize screen printing using thermally treated ink to print the legends that cover each side of this board. Only at that time around digital printing can’t publish the whole aspect of a board at a price that competes with screen printing. Although many printers, for example, PPS7000, can print all the nomenclature on the plank, here we’ll focus on using digital printing only to print the individualizing marks.

Several individualizing choices exist for example the following:

Preprinted Label Application

Many low volume products focus on tags printed on office equipment and hands put on each PCB before or after assembly. As the item volumes ramp the reliability and cost of hands employing labels becomes a issue. Automated systems which publish and apply labels are all available. (visit this site ) Due to PCB distance limitations these systems must put labels very accurately, a major problem for most tag application methods. The tags aren’t permanent. At high volumes the labels are costlier than other indicating techniques.

Advantages

  • Low Preliminary Cost
  • Highcontrast Mark

Cons

  • Maybe Not Permanent
  • Greater Than Cost
  • Difficult to Modify Tag Size On Your Fly
  • Mechanical Complexity For Automated Application

Solvent Based Continuous Ink Jet Digital Printing

Continuous ink-jet technology was adapted to indicate on many industrial services and products including PCBs. With these systems a continuous stream of ink droplets is led into the desired location with electromagnetic fields. Solvent based inks produce permanent marks on porous surfaces. The marks are less permanent on non porous surfaces where smearing could possibly be a issue for the short period its ability to dry.

Advantages

  • Competitive Incremental Cost
  • High Contrast Mark
  • Many Colors Available

Cons

  • Complex Ink Viscosity Process Might Be Tough To Control
  • High Resolution (More than 300 DPI) Difficult To Attain?
  • Solvents Could Be Released in to Atmosphere, Many Companies Attempting to Cut Back Solvent Problems
  • Mark Maybe Not Resistant for Your Cleaning Solvents

Laser Ablated Ink Patches

Many businesses use lasers to engrave marks onto a variety of parts. Lasers are used to engrave marks onto PC boards with minimal success due to the lack of contrast of the consequent mark. A more recent approach is to get the circuit boards printed with ink stains the ink patch is then selectively removed (ablated) by the laser creating the mark to be published.

Advantages

  • Competitive Incremental Cost
  • Highcontrast Mark If Ink Patch Is Used
  • Very Fine, Highly Reliable Marks Available With Laser Galvo Head

Cons

  • High Initial Cost
  • Requires Preprinted Ink Patch
  • At Low Power Laser warmth Might harm (by Fracture) Traces, Causing Irregular Fasting Problems
  • Particle Generation Might Demand a Cleaning Measure

Piezoelectric Drop On Demand Digital Printing, Solvent Based Ink

For a succinct description of drop on demand digital printing see here [http://www.aellora.com/documents/whatisdodij.pdf]. In my opinion this choice reflects a small improvement over option 2.

Advantages

A startup company in Israel”Printar” has introduced a printer targeted at low volume, quick turn PCB fabricators who should lower the cost and lead time associated with little bit screen printing. Interesting is that their thermally treated ink which reportedly has better adhesion capability than some other ink systems.

Advantages Disadvantages

  • Requires Enormous Oven For 350-400 deg F Heating Cure
  • Does Not Include High Volume Material Handling

Piezoelectric Drop On Demand Digital Printing, UV Cured Ink

Markem Corporation has developed an ink/print head system ( that the Model 4000, visit here ) that several OEMs and integrators are using to publish on PCBs. The system utilizes a ink which is certainly less viscous at high temperature and almost solid at room temperature. The printing head works at 68 deg C, so the ink drops trendy when they get the PCB becoming nearly solid. This permits the platform to publish nice detail on PCBs without ink smearing. When exposed to UV light the ink expands a chemical reaction becoming a solid vinyl such as chemical. The treated ink is impervious to ordinary solvents.

Advantages

  • Competitive Incremental Cost
  • High Comparison With Nice Detail (600 DPI)
  • Before Cure, the Ink May Be Wiped Away As well as the Board Reprinted
  • After treatment, The Ink Cannot Be Removed Except By Scraping
  • High volume Material Handling Available
  • Works Well With in Line Inspection (Inspect Ahead Cure, Cure Only Excellent Boards)

Cons

  • Ink Adhesion Can Be an Issue On Specific Compounds
  • Demands the PCB Be Clean (No Finger components )
  • Standoff Distance Less Than 2mm, Proper For Unpopulated Boards Only

The PPS 7000

The system utilizes a SMEMA compatible border belt conveyor to go PCBs to the print area where they’re published and optically scrutinized. After review they are hauled into the inline curing station and out the back of this machine. When being mechanically loaded by means of a plank destacker, panels depart the system around once every 10 seconds. Each panel usually contains multiple boards which all receives a exceptional sequential number. The total throughput of this machine is extremely determined by the number of planks in each panel. The more boards in each panel that the higher the throughput in planks each minute. A drag and drop WYSIWYG (What You See Is What You Get) programming system has been developed which allows a brand new panel to be programmed in approximately five minutes. A offline programming system can be offered.

We’re the only PCB board marking system that creates a permanent (solvent-resistant ) high contrast mark, incorporates SMEMA compatible high degree material handling and incorporates inline review.

In case the PPS7000 looks like it could fulfill your requirements the next step is to publish samples to you in order to verify that the ink will stick nicely for your substrates.