Manufacture Process For Frequency Control Devices

The principal components of frequency control products include Filters, Quartz oscillators and crystals.

Just about every machine and mobile wireless device from cell phones to remote controlled toys and games have quartz crystals built into them for precise timing and frequency regulation.

Typical Uses include:

Security cameras

Radio transmitters

Cell phones

Gps systems

Sensors

Computer disk drives

Desktops

Crystal Manufacturing

Crystal manufacturing occurs in two stages, optical and electrical:

Optical

Quartz crystal production commences with the selection of quartz crystal blanks in the suitable thickness and cut orientation from a comprehensive library of quartz blanks. Subsequent processes consist of lapping, polishing and contouring operations to produce quartz crystal blanks with exactly specified dimensions, shape, orientation and surface finish to ensure the exact electrical properties of the finished items.

Electrical

The optical processes of manufacture are followed by electrical stages including etching and cleaning, vacuum deposition of gold or silver electrodes, mounting and bonding, adjustment to final frequency, encapsulation, marking and final quality assurance inspection.

Crystal oscillator Manufacture

Oscillator devices are fabricated by using both thick film hybrid substrates and printed circuit board techniques. Depending upon the end application, the oscillator crystal can be incorporated as an independently sealed device or as an un-encapsulated crystal blank. With the latter scenario, the blank is mounted straight onto the oscillator substrate and the completed assembly is modified to final frequency ahead of hermetic sealing. Items produced by an oscillator department usually includes standard CMOS/TTL oscillators, ECL/PECL output oscillators, Voltage Controlled Crystal Oscillators (VCXOs), Temperature Controlled Crystal Oscillators(TCXOs), and Oven Controlled Crystal Oscillators (OCXOs), these latter products needing a considerable input by engineering and quality assurance departments.

Filter Production

Crystal filters consist of a number of discrete crystal or monolithic dual components put together on a printed circuit board (PCB) with other passive elements (inductors, transformers, capacitors etc.), the entire unit being hermetically sealed in a metal casing. The elementary production steps for filter production are crystal units, printed circuit board assembly, filter alignment, encapsulation and final test. Additionally to crystal filters other customized filters may also be manufactured; (e.g. LC filters,) for creation of these components numerous non-crystal elements for example wound coils are needed.