Laser Drilling In The Ceramic Circuit Boards

Laser drilling is one of the earliest practical laser processing technologies and an important application area of laser processing. Laser drilling is mainly used for metal materials such as steel, platinum, molybdenum, tantalum, magnesium, germanium, silicon, light metal materials such as copper, zinc, aluminum, stainless steel, heat-resistant alloys, nickel matrix alloys, titanium gold, platinum, ordinary hard alloy magnetic materials, and non-metallic materials such as ceramic substrates, artificial gemstones, diamond films, ceramics, rubber, plastics, glass, etc.

1. Laser drilling only requires forming a certain angle between the beam and the material surface to achieve laser beam intake drilling, effectively avoiding the occurrence of impact and breakage events caused by structural interference during mechanical processing.

2. Short opening time.

3. Strong adaptability to automation.

4. Can be used for penetration processing of materials that are difficult to drill.

5. Compared with mechanical drilling, there is no form of mechanical wear between the drilling process and the workpiece.

During the drilling process, first use the drilling mode to prepare small holes of sufficient size, so that the subsequent cutting process can start from here. The drilling or penetration process requires a repeatable pulsed laser beam with high peak power, coupled with high air pressure to achieve cutting. After the workpiece is penetrated, the laser beam is reduced or even converted to a non pulse mode through peak power reduction.

Solid-state lasers have shorter wavelengths and can achieve high-intensity pulse output, so they are more suitable for laser drilling, such as Nd:YAG lasers, Nd:glass lasers, and Nd:ruby lasers.

CO2 lasers are commonly used to open holes in non-metallic materials such as ceramics, composites, plastics or rubber. Laser drilling of metal materials requires pulsed laser.

In this paper, the laser drilling in the production process of ceramic circuit board is taken as an example to elaborate.

In the production process of ceramic circuit board processing, laser processing mainly includes laser drilling and laser cutting.

Ceramic materials such as alumina and aluminum nitride have the advantages of high thermal conductivity, high insulation and high temperature resistance, and are widely used in the field of electronics and semiconductors. However, ceramic materials have high hardness and brittleness, and its molding processing is very difficult, especially the processing of micro-holes is particularly difficult. Due to the high power density and good directivity of laser, it is widely used to punch holes in ceramic plates.

Laser ceramic drilling is generally pulsed laser or quasi-continuous laser (fiber laser), laser beam through the optical system focused on the workpiece placed vertically with the laser axis, emit high energy density) laser beam to melt, gasification, a beam and beam coaxial flow by the laser cutting head ejecta, the melted material by the bottom of the incision blown out and gradually formed through the hole.

Because electronic devices and semiconductor components have the characteristics of small size and high density, the precision and speed of laser punching processing are required to have higher requirements, according to the different requirements of the application of components, the diameter of the micro-hole ranges from 0.05 to 0.2mm. For the laser used for ceramic precision processing, the laser focal spot diameter is generally ≤0.05mm, according to the thickness of the ceramic plate is different, generally can be controlled by the defocus amount to achieve different aperture through hole drilling, for the diameter of less than 0.15mm through hole, can be controlled by the defocus amount to achieve drilling.