OPF794 Optek, OPF794 Datasheet - Page 33

• Manufacturer Part Number: OPF794
• Description: Photodiodes Pin Photodiode
• Manufacturer: Optek

Specifications of OPF794

• Maximum Reverse Voltage: 100 V
• Maximum Rise Time: 6 ns
• Mounting Style: SMD/SMT
• Product: Photodiode
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Issue A.1 2005
OPTEK Technology Inc. www.optekinc.com
Surface Mount Chip Carriers
Introduction to SMCC
SMCC Construction
SMCC Advantages
Surface Mount Chip Carriers (SMCC) offer solutions to many applications that cannot be satisfied with standard or
conventional optoelectronic components. These devices are used where the desired function cannot be
accomplished with conventional through hole, leaded or individual surface mount components. SMCC devices
allow multiple LEDs and sensors to be packaged together to create compact sensing solutions. Space savings can be
as much as 80% as compared with discrete packaged components.
The polyimide chip carrier, an OPTEK standard packaging method, has four main parts: Substrate, Frame,
Components and Encapsulation.
The OPTEK standard chip carrier substrate and frame material thickness is 0.030” (0.76mm). Including the adhesive
and metal layers, this two layer, laminated package has a nominal thickness of 0.063” (1.60mm).
Polyimide is an excellent substrate because of its strength, high processing temperature, and close match with the
expansion coefficient of silicon devices. OPTEK uses a special opaque grade of 0.030” (0.76mm) polyamide which
can effectively shield sensors from stray light.
The substrate is fabricated from high temperature copper-clad laminate. Standard PC Board processing provides
the plated and non-plated holes, circuit patterns and chip mounting features. To make the substrate compatible
with die attach and wire bonding techniques, the copper surface is plated with a nickel barrier and gold.
Components used in SMCC designs can be any of OPTEK’s standard LED or sensor products.
The frame layer is made from the same polyimide laminate as the substrate and is used to protect the die and
contain the encapsulation material. After the chip components are mounted and bonded, the frame is screen
printed with a pattern of non-conductive epoxy, aligned with the matching substrate cells, and laminated to the
substrate under elevated temperature and pressure.
The encapsulant is a conformal coating which is applied to fill the component cavities. After curing the
encapsulant, the array is sawn into individual product elements and is ready for final test and packaging.
SMCC devices offer unique LED and sensor configurations to suit a special set of application requirements.
The standard materials and processes result in packages that accommodate extended temperatures beyond the
range of many commercial components.
Reduced part count, automated processes, and OPTEK’s commitment to quality results in robust, defect free
parts.
Chip carriers withstand the challenges of low cost automated handling, placement and reflow soldering.
In comparison to a custom IC solution, the development cost of a typical SMCC circuit is far less and
modifications are quicker and easier.
Array processing in SMCC fabrication minimizes cost and optimizes quality.
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