晶振详解(EPSON)
Do you know the Crystal Devices?
ECC
Engineering Sec.
What is a Crystal Device?
About Crystals
Process
for Growing Synthetic Quartz Crystals
for manufacturing tuning-fork crystals units Device Types and Features
Timing devices
Sensing devices
Optical devices
The crystal devices around us
What is a QMEMS?
What is a Crystal Device?
About Crystals
Process
for Growing Synthetic Quartz Crystals
for manufacturing tuning-fork crystals units Device Types and Features
Timing devices
Sensing devices
Optical devices
The crystal devices around us
What is a QMEMS?
What Is a Crystal Device?
The piezoelectric effect of crystals-the ability of crystals to generate electricity when subjected to mechanical stress, or the ability to generate stress in crystals subjected to an applied voltage-was discovered more than a century ago.
Over the ensuing years, researchers have taken advantage of both the piezoelectric and optical properties of crystals to develop a variety of crystal-based devices.
Today, such crystal devices are an indispensable component in the electronics that support our way of life
We in the modern age have become dependent on a variety of different conveniences.
We all have different needs, of course, but if asked what modern convenience they would have a hard time living without, many people would probably name some form of electronic device or system:
a cell phone, PC, TV, or watch, perhaps.
As home electronics and home appliances, as tools for work and play, and as means of communication, electronics are an integral, embedded part of our lives.
Though they come in all sorts of shapes and sizes, and perform myriad functions, the operations of these electronic devices and systems are orchestrated by a critical electronic components called "crystal devices."
If semiconductor chips are the brains of industry, then crystal devices are the heart and pulse.
< Contents >
What is a Crystal Device?
About Crystals
Process
for Growing Synthetic Quartz Crystals
for manufacturing tuning-fork crystals units Device Types and Features
Timing devices
Sensing devices
Optical devices
The crystal devices around us
What is a QMEMS?
The history of crystal devices traces back to France and the year 1880, when the Curie brothers discovered the piezo-electric effect that crystals exhibit.
Crystal device Timeline
Jacques Curie (1855-1941)
Pierre Curie (1859-1906)
Marie Curie (1867-1934)
Timeline
Piezo-electric effect
Pressure
Tension
+
++++
++++++++
--------
------+Reverse Piezo-electric effect
Stress
Voltage
Voltage
Displacement
Crystal properties
Electrical properties Piezo-electric effect
The application of mechanical pressure to a crystal Reverse piezo-electric effect
The application of electricity (voltage) causes a Crystal devices take advantage of crystal’s Electrical &Optical properties
Crystal properties
Optical properties
Crystals split light into two beams and
Example of Birefringence (Calcite) change the direction in which the light
oscillates.
Natural & Synthetic quartz crystals
Natural quartz crystals and synthetic quartz crystals
The crystals used in crystal devices are synthetic crystals grown especially for that purpose. Nearly all of the world's high-performance synthetic crystals are produced in Japan.
The major producers of natural quartz crystals are Brazil, America, China, Australia, Russia and Madagascar.
Source of Natural quartz crystal
Factory Tour: Process for Growing Synthetic Quartz Crystals
Natural quartz crystals were used in the manufacture of crystal devices during the early days of the industry.
Today, however, synthetic quartz crystals are favored for their consistent quality.
Synthetic crystals are grown over a period of months from fragments of natural quartz placed in a large ultra-high pressure chamber called an autoclave.
Source of Natural quartz crystals
Quality of Quartz ◎: Exellent ○: Good ●: Fair
◎：Brazil
◎: Madagascar ○：Angola ●：Russia
●：China
●：Australia
●：U.S.A.
Zimbabwe
○
South Africa ○
Natural & Synthetic quartz crystals
Natural & Synthetic quartz crystals Natural crystals Synthetic crystals
Disadvantages of natural crystals
1. Impurities
2. Cracks
3. Variations in size and shape
4. Twinning Advantages of synthetic crystals 1. Consistent quality
2. Efficiently yield crystal chips
< Contents >
What is a Crystal Device?
About Crystals
Process
for Growing Synthetic Quartz Crystals
for manufacturing tuning-fork crystals units Device Types and Features
Timing devices
Sensing devices
Optical devices
The crystal devices around us
What is a QMEMS?
Growing Synthetic Quartz Crystals
Synthetic crystals are grown over a period of months from fragments of natural quartz placed in a massive, ultra-high pressure chamber called an autoclave.
The natural quartz, the raw materials for synthetic quartz, is placed in an alkaline solution and heated to a temperature of about 360 deg. C, under a pressure ranging from 1100 to 1700 kg/cm2, for a period of 2 to 6 months.
Autoclave
Growing Synthetic Quartz Crystals 1.
Washing the natural quartz fragments >
2.
Seed crystal
processing
>
3.
Solvent
preparation
>
4.
Autoclave
preparation
>
5. Sealing>
6.
Autoclave
heating
>
7.
Growth>
8.
Completion
Growing Synthetic Quartz Crystals
1. Washing the natural quartz fragments
The fragments are washed and then dried.
The natural quartz fragments (lascas)
2. Seed crystal processing
Crystals are cut into the shape required
for seed crystals.
3. Solvent preparation
An alkaline aqueous solution is prepared.
Growing Synthetic Quartz Crystals 4. Autoclave preparation
Growing Synthetic Quartz Crystals
5. Sealing
The autoclave is sealed with a top cover and a clamp.
An alkaline aqueous solution is prepared.
Growing Synthetic Quartz Crystals
6. Autoclave heating
An alkaline aqueous solution is prepared.
The top half (growth chamber) is heated to a lower temperature than the bottom half (solution chamber) to produce natural convection.
Growing Synthetic Quartz Crystals
7. Growth
8. Completion
The elevated temperature and pressure of the autoclave are maintained, and the crystals are allowed to grow slowly.
The synthetic crystal growth process, from start to finish, takes about 2-6 months.