Production of DPC Ceramic Substrates
To ensure that the ceramic substrates are free of contaminants and have a smooth surface, pre-treatment cleaning and surface polishing are carried out after the ceramic materials are processed into sheets or plates of the desired size. Vacuum sputtering is used to deposit a Ti or Cu layer on the substrate surface (on either one or both sides) as a seed layer, and subsequently the circuit is manufactured by photolithography, development, and etching. Electroplating or electroless plating is then used to increase the thickness of the circuit. The substrate fabrication is finished after the photoresist is removed.
Characteristics of DPC Ceramic Substrate
High Thermal Conductivity
Ceramic materials used in DPC substrates, such as AlN, offer exceptional thermal characteristics and can effectively dissipate heat generated by electronic components. Direct copper bonding further improves the substrate's heat transfer capabilities.
Electrical Function
The electrical function is provided by the copper layer on the ceramic DPC substrate. It functions as a conductive layer to transfer power and electrical signals on the substrate. Typically, copper is patterned into circuits and interconnects via processes like plating or etching.
Low Thermal Expansion Coefficient
Particularly in applications where there are considerable temperature variations, the ceramic material used in DPC substrates has a low coefficient of thermal expansion, which helps lower thermal stress between the substrate and mounted components. Additionally, it allows for more dependable and stable performance of electronic equipment.
High Mechanical Strength
Ceramic DPC substrates exhibit great mechanical strength and rigidity. They are suited for situations where mechanical stability and resistance to bending or warping are essential thanks to their robustness.
Air Tightness
The hermetic seal provided by the direct bonding technique employed in ceramic DPC substrates ensures the formation of a protective barrier against moisture, contaminants, and other environmental factors. This characteristic is extremely vital for applications requiring high dependability and long service life.
Key Technologies of DPC Ceramic Substrate
Formation of Transition Layer
Due to the significant difference in thermal expansion coefficient between the metal and the ceramic, a transition layer should be added between the copper layer and the ceramic in order to reduce interface stress and increase interface bonding strength. Metals with high activity and good diffusivity, such as Ti, Cr, and Ni, are frequently chosen as the transition layer (and as the electroplating seed layer simultaneously) because the bonding forces between the transition layer and ceramics are primarily diffusion adhesion and chemical bonds.
Plating and Hole Filling
Another critical technology for the preparation of DPC ceramic substrates is electroplating and hole filling. Currently, pulse power supplies are mostly employed for electroplating and hole filling of DPC substrates. The technical advantages include: easy to fill through holes, reduce coating flaws in holes, dense surface coating structure, uniform thickness, and high current density for electroplating to increase deposition efficiency.
Uses for DPC Ceramic Substrates
Direct bonded copper ceramic substrates, or DPC ceramic substrates, are widely used in contemporary electronics production because of their many benefits. Because of their well-known outstanding thermal conductivity, these substrates can efficiently disperse the heat produced by electronic components. This characteristic not only increases electronic gadget longevity and dependability but also allows them to run at larger power densities without overheating.
DPC ceramic substrates also provide the important advantages of outstanding mechanical strength and dimensional stability. Under high temperatures and mechanical stress, conventional printed circuit boards (PCBs) may stretch or deteriorate; DPC substrates are robust and resilient. This stability lowers the possibility of mechanical fatigue failure and guarantees dependable operation in a variety of environmental circumstances.
Excellent electrical insulating qualities of DPC ceramic substrates are also necessary to guarantee signal integrity in high-frequency applications and avoid unforeseen electrical interference. For use in telecommunications, aerospace, and automobile electronics, their dielectric qualities assist sustain high-speed data transmission rates and minimize signal loss.
Apart from the thermal, mechanical, and electrical benefits, DPC ceramic substrates may be used with sophisticated production techniques like metallization and laser drilling, which enable accurate component placement and productive production cycles.