For the laser circuit board industry cutting or drilling, only UV laser can be a few watts or more than 10 watts of laser power, no need kW level, in consumer electronics, automotive industry or robot manufacturing technology, the use of flexible circuit board becomes more and more important. UV laser processing system has become the first choice of flexible circuit board and thin PCB laser drilling and cutting because of its flexible processing method, high precision processing effect and flexible and controllable processing.

Today, the laser system configuration of the long life laser source is basically close to maintenance free, in the production process, the laser level is 1, safe, without other protective devices. The LPKF laser system is equipped with a vacuum cleaner, which will not cause harmful substances emission. Coupled with its intuitive, easy to operate software control, laser technology is replacing traditional mechanical processes, saving the cost of special tools.

CO2 laser or UV laser?
For example, a CO2 laser system with a wavelength of about 10.6 M can be selected when PCB is split or cut. The processing cost is relatively low, and the laser power provided can reach several kilowatts. But it will produce a lot of heat in the cutting process, resulting in severe carbonization of the edges. The UV laser wavelength is 355 nm. The laser beam of this wavelength is very easy to focus on. A UV laser with less than 20 watts of laser power focuses on only 20 m of light after focusing, and its energy density is even comparable to that of the solar surface.

Advantages of UV laser processing
UV laser is especially suitable for the combination of soft and hard cutting board, hard board, soft board and its accessories and marking. So what are the advantages of the laser process? In the SMT industry, the circuit board, sub board, as well as PCB industry micro drilling and other fields, UV laser cutting system shows great technological advantages. Depending on the thickness of the circuit board, the laser is cut one or more times along the desired contour. The thinner the material, the faster the cutting. If the laser pulse is lower than that of penetrating materials required for laser pulse accumulation, only scratches on the surface of the material; therefore, can be two-dimensional code or code in the material marking, in order to follow the process of tracking information.
The pulse energy of the UV laser is only in the microsecond time of the material, and there is no obvious thermal effect in the micron several microns beside the notch, so it is unnecessary to consider the damage caused by the heat generated by it. Near the edge of the line and solder joints intact, without burr.
In addition, LPKF UV laser system integrated with CAM software can directly import and export data from CAD, the laser cutting path for editing, laser cutting contour, select suitable processing parameters for different materials, can direct laser processing. The laser system is not only suitable for mass production, but also for sample production.

Drilling application
The through hole in the circuit board is used to connect the front and back of the double plate, or to connect any interlayer circuit between the multilayer plates. In order to conduct electrical conductivity, it is necessary to coat the hole wall with a metal layer after drilling. Now using the traditional mechanical method has been unable to meet the requirements of more and more small hole diameter: Despite the increased rotational speed of the spindle, but the radial velocity precision drilling tool can be reduced because the diameter is too small, even unable to complete the processing requirement. In addition, from the economic point of view, easy to wear tool materials is also a limiting factor.

Prepreg cutting
In the manufacture of electronic components, what are the requirements for cutting semi cured sheet materials? As early as possible, prepreg materials have been applied to multilayer printed circuit boards. Each circuit layer in the multilayer circuit board is pressed together by the function of the prepreg; according to the circuit design, the prepreg of some areas needs to be cut and opened in advance, and then pressed.
A similar process is also applicable to FPC overlay films. The covering film is usually composed of polyimide and a thickness of 25 m or 12.5 m. It is easy to deform. A single area (such as a pad) does not need to be covered with film to allow for later assembly and connection. This thin material is very sensitive to mechanical stresses - it can be easily accomplished by noncontact laser processing. At the same time, the vacuum adsorption table can well fix its position and maintain its flatness.

Hard and soft plate processing
In the hard and soft board, the rigid PCB and the flexible PCB are pressed together to form a multilayer plate. The pressing process, flexible and rigid PCB PCB above is not pressed bonded together by laser cutting deep cover over the rigid flexible PCB above the cut and separate, leaving a flexible portion formed flex board. Such deep processing can also be applied to blind groove machining of surfaces embedded in integrated plates. The UV laser will precisely cut the blind groove of the target layer separated from the multilayer circuit board. In this region, the target layer is not connected with the material it covers.

Efficient boards for PCB and FPC
The SMT rear sub plate is a circuit board that has been assembled with a wide range of electronic components. The process is already at the end of the production chain. For sub panels, you can choose different techniques: for the usual PCB, priority should be given to traditional cutting, stamping and contour milling processes. For more complex electronic circuits and thin substrates, especially for mechanical stress, dust, and dimensional deviations, UV laser cutting is more advantageous. The following three charts evaluate the three approaches from different factors.
For the cutting of the complete profile, LPKF will recommend cutting the material thickness of not more than 1.6mm depending on the different laser sources used. For some thicker materials and expensive assembly components, priority is given to safety and quality, while cutting length is secondary.
The cutting point divides the plate and the laser system cuts the connection point through a process described earlier. The cutting process can be carried out close to the edge of the components, and it is also very economical for thicker circuit boards.

Other application areas
Because the UV laser has a shorter wavelength, it can be applied to most material processing. For example, it can be used in the field of electronics:
• processing TCO/ITO glass with no damage to the substrate
• Drilling on flexible or thin materials
• solder resist or cover film window
• Flexible / flexible circuit board partition board
• Slotted
• rework of circuit boards that have been assembled or not assembled
• Cutting and sintering ceramics
• Precision cutting LTCC