Kontaktfladen

Kontaktfladen, or contact pad, is a defined surface on an electronic substrate that is intended to establish an electrical connection to another component, probe, or interconnect. It is typically a metalized region on a printed circuit board, a semiconductor wafer, or a microfabricated device. The pad provides a reliable contact area for soldering, bonding, probing, or wire bonding, and is designed to minimize contact resistance, corrosion, and impedance while accommodating manufacturing tolerances.

In printed circuit boards, contact pads are the copper areas where components are soldered or where testing probes touch. They are often coated with a surface finish such as HASL, ENIG, immersion gold, or solderability-enhancing layers to improve solderability and longevity. Pad geometry, spacing, and the presence of solder mask influence manufacturability, solder fillets, impedance, and reliability, making careful design essential.

In semiconductor and microfabrication contexts, contact or bonding pads are exposed metal areas used for electrical testing, probe cards, or bonding processes (wire bonding, flip-chip). Common pad materials include aluminum and gold, sometimes with underlayers, and pads are kept free of insulating passivation at the contact site. Proper pad sizing, metallurgy, and surface cleanliness are crucial to ensure low contact resistance and robust interconnects under thermal and mechanical stress.

Applications extend from electronic PCBs and integrated circuits to MEMS devices and sensors. Pad design must balance electrical performance, manufacturability, and reliability, taking into account factors such as material, surface finish, protection, and how the pads will be contacted during assembly or testing.