What is Laser scribing?

Laser scribing drawing

Definition

Laser scribing is a technique that allows for easy singulation of ceramic substrates/circuits from a manufacturing panel/sheet. As opposed to laser cutting, the laser beam does not go all the way through the material during a laser scribing process and the goal is to make a perforated line along which an easy and clean break out can be done.

In essence, small (<30um) blind holes are drilled next to each other in a straight line creating a weak spot in the material. Your design should not account for a spacing between the different design as the scribe lines will not affect the final dimensions of the part. The depth of the blind holes is less than half of the substrate.

Laser scribing is often used to prepare the substrate to be easily singled out after being printed or assembled. This way, no expensive equipment is needed by the party that assembles the ceramic substrate and you also avoid any difficulties with cutting ceramics later in the process by avoiding the risk to damage other components using high-power/temperature lasers.

When – how to use it (on your drawing)

Generally, we advise making straight lines on the outline of your design laser scribing and curved one’s laser cutting. Also inward corners we advise to laser cut instead of scribing. Furthermore, mounting holes and slots inside the material we also advise to cut (mill) and not to scribe. The thicker the material shorter the scribe lines need to be to ensure the design will stay properly inside the panel and will not break out because of handling or transport

If you want to indicate laser scribing lines on your drawing, please assign them to a separate layer (mechanical, fab or graphical). This way, we know where to cut and where to scribe. Make sure lines always run until the the edge of the panel. If you are unsure how to do this. Let us finish your panel design, we will be happy to assist.

Breaking out from a panel

Even though most panels can be singled out by hand, a little practice is required. Needless to say that the thicker the ceramic panel and the smaller the design, the harder it gets to break out by hand. Rule of thumb: below if panel thickness is equal or below 0.5mm / 0.02″ it can be done by hand. If above, we advise making a simple jig to ensure proper snap breaking.

Singling out by hand

Start by breaking the shorting lines first. If all scribe lines are more or less the same length, take the one where the longest edges of your design are scribed. Try to spread the force by holding the panel with multiple fingers (if possible) on both sides of the scribing line with one hand on each side. Make sure the scribing lines faces you and break away from you. Take your time.

Alternatively, place one side on a flat & clean surface (f.e. piece of glass or a mirror) the scribing line facing upwards, press it down with your full hand and with your other hand grasp the other side with as many fingers close to each other and gently push it down.

We advise using gloves doing this.

Laser scribing is the fastest and most cost effective way we use to cut ceramic circuits and substrates. If you would like to learn what other methods there are and how they affect edge quality and price, read the article we wrote about it here: Cutting ceramic pcbs and the influence on edge quality & cost.