Contact Material:

The bonding pads and back contacts of the chips are gold. The beamleads are solid gold. All packages except the E47, SOT23, SOD323 and 0805 are plated with nickel and gold. The E47 package is nickel plated only. SOT23 and SOD323 have lead tin solder coating.

Handling:

Aeroflex / Metelics chips are usually shipped in anti-static plastic chip trays containing up to 400 units. They may be removed using tweezers or a grounded vacuum pickup being careful not to damage the active junction area or metallization. Excessive removal force will cause cracks or chip outs.

Aeroflex / Metelics beamlead devices are designed to have exceptional lead strength, however they are very small and require special handling to assure that the devices are not mechanically or electrically damaged. Beamlead devices can be picked up with a very small vacuum pencil or a sharpened wooden stick such as a Q-tip dipped in isopropyl alcohol.

All devices require standard ESD handling precautions (grounded wrist strap, etc) to prevent static damage.

Die Attach:

• Conductive silver epoxy - cured at 100 to 125°C - (100 to 110°C recommended for Tunnels)
• Solder perform gold (80%) - tin (20%) at about 320°C - (too hot for Tunnels)
• Solder perform gold (90%) - germanium (10%) at about 380oC - (too hot for Tunnels and Schottkys)

Bonding:

• Use thermocompression bonding - pads are not designed for thermosonic bonding. The best settings for a specific application are determined by expermentation, starting with the typical value shown below.
• For all chips except Tunnels - Wire or Ribbon - base at 210°C, tip at 150°C, tip pressure between 15 and 50 grams
• For Tunnels - 0.7 mil wire - base at 150°C,  capillary at 150°C,  capillary pressure less than 20 grams. A thermocompression wedge bond is done on the offset bonding pad. Bonding should not be done directly over junction. The Tunnel diode can not be subjected to 150°C for more than 5 sec.
• For beamleads - Thermal compression bonding with a heated wedge or parallel gap welding can be used to bond beamlead devices to substrates. In either case the devices are positioned face down with the beamleads flat on the substrate's metalization and then the beams are bonded. Care must be taken not to damage the beam - glass interface with too much lateral stress or by bonding too close to the chip. Any cracking caused in the glass can put stress on the diode junction. This stress usually increases the junction resistance. It is not recommended that beamlead devices be mounted on a soft substrates (such as Duroid) as temperature variations can cause excessive expansion or contraction resulting in breakage of the beamlead device. For thermal compression: base at 180°C,  tip at 220°C,  tip pressure 150 grams.

Soldering:  all packaged devices (not chips or beamleads) - 230o C for 5 seconds.