Ceramic Substrate Cutting Technologies: Laser Cutting vs. Mechanical Dicing

Ceramic substrates, renowned for their excellent electrical insulation, high thermal conductivity, reliability, and low coefficient of thermal expansion, are fundamental materials in high-power electronic and interconnection technologies. However, due to the inherent hardness and brittleness of ceramic materials, achieving precise hole drilling and cutting poses significant challenges. Traditional mechanical methods are laborious, time-consuming, and can induce stress that may damage the substrate. With increasing demands for precision and efficiency in ceramic substrate processing, traditional mechanical methods are no longer adequate. Ceramic substrates are typically cut using laser cutting or blade cutting methods.

Laser Cutting of Ceramic Substrates

1. Principles of Laser Cutting

Laser processing technology offers advantages such as non-contact operation, flexibility, high efficiency, digital control capability, and high precision, making it one of the most ideal methods for ceramic processing today. Laser cutting, also known as scribing or controlled fracture cutting, works by focusing a laser beam through a guiding system onto the surface of the ceramic substrate. This generates heat through a photothermal reaction, resulting in ablation, melting, and vaporization of the ceramic along the scribed line, creating interconnected blind holes (grooves) on the ceramic surface. Applying stress along the scribed line causes the material to fracture precisely, completing the cutting process.

2. Technical Challenges in Laser Cutting of Ceramic Substrates

Laser cutting of ceramics faces two main technical challenges: "spatter accumulation" and "non-directional fracture."

• Spatter accumulation can roughen the surface of the scribed line.
• Non-directional fracture refers to irregular fractures or bursts that occur with minimal external force or high-temperature baking, posing difficulties and losses in thick film circuit manufacturing. Solutions include:
  - Using protective gases.
  - Opting for smaller laser pulse widths at the same frequency to increase vaporization proportionally, shorten heating time, and reduce the heat-affected zone.
  - Keeping the optical path unobstructed, using beam expanders to compress the beam divergence angle, minimizing aberrations, and ensuring even laser irradiation energy.
  

Laser scribing offers advantages such as fine scribing, high speed, smooth cross-sections, and minimal substrate damage.

Mechanical Cutting of Ceramic Substrates (Dicing)

Mechanical cutting involves using blades to physically cut ceramic substrates. These blades typically consist of synthetic resin combined with binders such as copper, tin, nickel, or synthetic diamonds. The cutting process is driven by a spindle that rotates the blade at high speed to achieve high rigidity, thereby removing material and achieving cutting.

Due to the thickness of the blades, mechanical cutting requires larger cutting line widths. Synthetic diamond blades can achieve a minimum cutting line width of 25-35 ?m. Cutting substrates of different materials and thicknesses necessitates changing different tools. During rotary grinding wheel cutting, deionized water is used for blade cooling and to carry away debris generated after cutting.

In conclusion, while both laser cutting and mechanical cutting methods have their specific advantages and challenges, laser cutting stands out for its precision, efficiency, and ability to handle the delicate nature of ceramic substrates effectively in advanced manufacturing processes.

The laser system is specifically designed to handle and process thick film ceramics. Powerful laser solutions for trimming, scribing, marking, and cutting ceramic substrates. With our advanced technology, we offer precise and efficient processing capabilities for a wide range of applications, from ohmic trimming arrays to active and functional trimming of hybrid, digital, and RF circuits.

Contact us for more information about our belt furnace offerings!