Optical sensors are used for a wide variety of consumer,
automotive and industrial applications, such as smart phones, tablets, TVs, laptop
computers, self-driving cars, health monitors, and bar code scanners. For example, ambient light sensors help
manage the backlighting and power consumption of Liquid Crystal Displays (LCDs)
for energy efficiency and longer battery life.Infrared sensors measure invisible light to detect body heat in
proximity sensors, night vision camerasand hand gesture
controls. Pulse oximeters
continuously monitor the oxygen level in the blood in hospital and wearable
settings.
Sensors protected by miniature surface mount packages have enabled small and light weight devices
for handheld and wearable applications.Although
clear and light filtering epoxy encapsulants have been in volume use for
decades, robust packaging for surface mount devices (SMDs) continues to be a
challenge.Reflow soldering of these
components to printed circuit board at 260C for lead-free applications causes
extreme stress from thermal expansion and moisture absorption.
Unfortunately, the ingredients used to reduce stress for
traditional semiconductors in SMDs will seriously degrade the optical
properties of the encapsulant.This causes
the reliability of many optical devices, such as the Moisture Sensitivity Level
(MSL), to lag that of other semiconductors protected by black epoxy molding
compound.
The SolEpoxyTM factory in Olean New York has
supplied optical grade molding compoundsaround the world under the HYSOL and Henkel
brands since the 1970s.Under the
current management, there has been a renewed focus to upgrade the properties of
optical encapsulants and customize them for modern surface mount applications. As a result, we have refreshed our product pipeline
with a variety of new molding compounds and liquid encapsulants for sensors,
LEDs and other optical components.
In addition to surface mount requirements, often it’s best
for the device to only transmit selected wavelengths of light, and filter out
others that cause noise and reduce effectiveness.Although special grades of light filtering
glass are sometimes used for this purpose, they are expensive and not well
suited to miniature devices.
One recently launched commercialized product is OP70-2, designed to block visible light for
infrared devices. It features low moisture absorption and enhanced adhesion for
improved MSL performance, plus custom light filtering. It features high
transmittance at 840 nm and up, with a sharp cutoff at approximately 700nm,
depending upon encapsulant thickness. It has passed rigorous customer
qualification testing for surface mount packages. As a result of our focus on customized
materials, we can adjust the light cut-off for various package thicknesses, to
maintain consistent optical properties.OP70-2 is now in production and available for sampling.
In addition, we will soon be launching a similar surface
mount grade molding compound for ambient light sensors.NB1111-11 features similar physical and
mechanical properties, but light transmittance has been fine-tuned to mimic the
response of the human eye.
We also have the capability to modify light filtering
properties for various thicknesses or applications. Please contact
usdirectly or through your local
representative for more information.