Precaution for use

• Window

Care should be taken not to touch the window with bare hands, especially in the case of ultraviolet detection since foreign materials on the window can seriously affect transmittance in the ultraviolet range. (There have been occasions where contamination of the window by oil from hands reduced sensitivity at 250 nm by as much as 30 %.)If the window needs to be cleaned, use ethyl alcohol and wipe off the window gently. Avoid using any other organic solvents than ethyl alcohol as they may cause deterioration of the device's resin coating or filter.When using tweezers or other hard tools, be careful not to allow the tip or any sharp objects to touch the window surface. If the window is scratched or damaged, accurate measurement cannot be expected when detecting a small light spot. In particular, use sufficient care when handling resin-coated or resin-molded devices.

• Lead forming

When forming leads, care should be taken to keep the recommended mechanical stress limits: 5 N pull for 5 seconds maximum, two 90 degrees bends and two twists of the leads at 6 mm minimum away from the package base.To form the leads of plastic-molded package devices, use long-nose pliers to hold near by the root of the leads securely.

• Soldering

Since photodiodes are subject to damage by excessive heat, sufficient care must be given to soldering temperature and dwell time. As a guide, metal package devices should be soldered at 260 °C or below within 10 seconds, ceramic package devices at 260 °C within 5 seconds at 2 mm minimum away from the package base, and plastic package devices at 230 °C or below within 5 seconds at 1 mm minimum away from the package base.

• Recommended soldering condition

• Cleaning

Use alcohol to remove solder flux. Never use other type of solvent because, in particular, plastic packages may be damaged. It is recommended that the device be dipped into alcohol for cleaning. Ultrasonic cleaning and vapor cleaning may cause fatal damage to some types of devices (especially, hollow packages and devices with filters). Confirm in advance that there is no problem with such cleaning methods, then perform cleaning.Some caution may be needed when using the photodiode according to the particular structure. Cautions needed when using various products are listed on the next page.

Bare chip Si photodiode (S3590-19, S6337-01)

S3590-19 and S6337-01 have a windowless package and does not incorporate measures to protect the photodiode chip.

• Never touch the photodiode chip surface or wiring.
• Wear dust-proof gloves and a dust-proof mask.
• Use air-blow to remove foreign objects or objects attached to the surface.
• Do not attempt to wash.

Si photodiode with preamp

The Si photodiode with preamp is prone to damage or deterioration from static electricity in the human body, surge voltages from test equipment, leakage voltage from soldering irons, and packing materials, etc. To eliminate the risk of damage from static electricity, the device, worker, work location, and tool jig must all be at the same electrical potential. Take the following precautions during use.

• Use items such as a wrist strap to get a high resistance (1 MW) between the human body and ground to prevent damage to the device from static electricity that accumulates on the worker and the worker’s clothes.
• Lay a semi-conductive sheet (1 MΩ to 100 MΩ) on the floor and also on the workbench, and then connect them to ground.
• Use a soldering iron having an insulation resistance of 10 MW or more and connect it to ground.
• Conductive material or aluminum foil is recommended for use as a container for shipping or packing. To prevent accumulation of static charges, use material with a resistance of 0.1 MΩ/cm² to 1 GΩ/cm².

Surface mount type Si photodiode

Surface mount Si photodiodes come in ceramic or plastic package types. Sealing resin used for photodiodes was designed with light transmittance in mind and so has low resistance to moisture and heat compared to sealing resin for general-purpose IC. This means that special care is required during handling. Unexpected troubles can occur if the IC temperature profile is used in reflow soldering. Therefore keep the following points in mind.

1) Ceramic type (silicone resin coating type)

• The resin protecting the photodiode surface is soft so that applying an external force may damage the resin surface, warp the bonding wires, or break wires, so avoid touching the surface as much as possible.
• If stored for 3 months while unpacked or if more than 24 hours have elapsed after unpacking, bake for 3 to 5 hours at 150 °C in a nitrogen atmosphere, or for 12 to 15 hours at 120 °C in a nitrogen atmosphere.
  Note) Stick type shipping container material is vulnerable to heat, so do not try bakingwhile the photodiodes are still in a stick.

2) Plastic type (epoxy resin mold type)

• Trouble during reflow is due to moisture absorption in the epoxy resin forming the package material.During soldering, the amount of moisture increases suddenly due to the heat and trouble such as peeling on the chip surface and package cracks is prone to occur.
• The packing is not usually moisture-proof so baking for 3 to 5 hours at 150 °C or for 12 to 15 hours at 120 °C in a nitrogen atmosphere is necessary before reflow soldering.
  Note) Stick type shipping container material is vulnerable to heat, so do not try bakingwhile the photodiodes are still in a stick.
• When required, it is possible to bake photodiodes prior to shipping and pack them in a moisture-proof case.

3) Reflow soldering

• Reflow soldering conditions depend on factors such as the PC board, reflow oven and product being used. Please ask in advance, about recommended reflow conditions for a particular product.