Laser Marking
Realize long-lasting traceability with laser marking
In SMD production, a laser marker is used to apply codes or labels to the PCB (DPM, Direct Part Marking). These usually contain the unique serial number or other information with which the PCB can be clearly identified and are therefore an essential part of continuous traceability.
SmartRep offers the laser marker from YJ Link for the permanent marking of PCBs.
The advantages of the YJ LINK Laser Marker
Integrated Flip-Station
With the flip station integrated as standard, the YJ Link Laser Marker can be used to mark PCBs on both sides in just one process step.
Ghost Marking Function
The code can be projected onto the PCB in advance for precise placement of the marking, even on densely populated PCBs.
Readback-Function
Each lasered code is automatically checked by the system for readability and evaluated according to the criteria of ISO IEC TR 29158.
Secured traceability
With laser marking, the code is permanently applied to the PCB material, which has a number of advantages in terms of the legibility and durability of the code:
In contrast to a stick-on marking (label), a laser marking cannot peel off or fade. The marking proves to be extremely robust against mechanical influences such as scratching, which can make the code illegible.
Laser marking therefore ensures the permanent traceability of the PCB.
Fast, safe, clean
With an integrated turning station, ionizing and exhaust unit and a high-quality CO2 laser, the codes are applied quickly, reliably and cleanly. For full traceability right from the start, it is advisable to place the laser marker upstream of the line as a marking cell. This means that every process step can be tracked.
Frequently asked questions about laser marking
How does laser marking work and how small can a code be lasered? Do you need a laser safety officer to operate a laser marker?
We'll tell you!
How Laser Marking works
Material procesing with a laser follows a simple principle: The laser transfers energy into the material that is to be processed, which triggers a reaction based on the material. Therefore, a laser can ablate, engrave and oxidize metal, while plastics can be ablated, carbonized and foamed. A color shift is also possible. Because a color shift only needs a little energy, this method is most commonly used for marking PCBs.
Color shift in solder resist
In this process, the color pigments in the solder resist are deliberately destroyed by the laser, which becomes visible on the surface as discoloration (marking).
The color of the marking cannot be controlled by the intensity of the laser; the contrast between the marking and the background therefore varies with the color of the solder resist. In general, markings on green or blue PCBs result in a very good contrast, while markings on red PCBs have a lower contrast.
How small can the code be lasered?
With the ongoing miniaturization, PCBs are becoming smaller and increasingly more crowded –space for markings is thus getting scarce and the question "How small can I laser my codes?" arises.
Since a Data Matrix code requires less space than a QR code to display the same information, the Data Matrix code is predominantly used for marking printed circuit boards. However, how large or small the marking ultimately is depends on the structure of the code and the information encoded in it.
A Data Matrix Code basically consists of individual dots:
The dot is the basic element of the Data Matrix code
In order to be readable by standard scanners, a dot should not be smaller than 0.2 to 0.25mm. Since each Data Matrix code consists of at least 10 x 10 digits (dots), the recommended minimum size is 2mm x 2mm - even if smaller formats can be implemented with a laser marker.
10 x10 dots are the minimun size of a data matrix code
The final code size depends directly on the amount of coded information: A maximum of six-digit numbers or three alphanumeric characters can be stored in a 10 x 10 matrix. The more information to be contained, the larger the barcode.
More information can be stored in a larger code.
Which information can be coded?
To ensure continous traceability, the marking should contain information with which the PCB can be clearly identified. A unique ID, i.e. a unique serial number, is usually used for this purpose. In addition to the unique ID, other information such as the current date or the job number can also be encoded. The YJ LINK laser marker divides the information to be coded into two groups:
Rigidly defined information
The code contents stored here are lasered on each PCB. Information that is valid for each PCB, such as the name of the manufacturer or the name of the end product in a batch, can be stored here.
Variables
Variable Code contents like the current date or the unique ID can be realised as well with the YJ LINK laser marker. Individually definable variables such as various counters, e.g. a continuous PCB counter or one counter per program, can also be implemented.
Do I need a laser safety officer to operate a Laser Marker?
Whether or not a laser safety officer is required to operate a laser marker depends on the design of the system.
Since YJ LINK's laser marker is completely enclosed and equipped with additional safety measures such as a door interlock, the system has a laser class 1 rating. A laser safety officer is therefore not required to operate YJ LINK's laser marker.
Barcode Grading - Classification according to ISO IEC TR 29158
The quality of 2D codes directly embedded in the printed circuit board is regulated by the ISO IEC TR 29158 standard, also known as "AIM DPM". The standard specifies various evaluation criteria that can be used to classify the quality of a code on a scale from "A" (very good) to "F" (very poor).
The criteria specified by the standard include pattern errors, contrast ratios, distortions and aspect ratio errors. With the YJ LINK laser marker, all codes are automatically checked and evaluated according to the criteria of the ISO IEC TR 29158 standard.
