About the origin of silicon crystal oscillator

The author:admin Number of visits: Date:2020-12-28 13:50

With the rapid development of science and technology, the research and development of all kinds of new electronic products are also accelerated, and all kinds of novel electronic products are constantly emerging.

In the past circuit board, we are common is the diode, transistor, resistor, capacitor and other most low-level electronic components have gradually disappeared to now, a variety of integrated circuits, a variety of electronic modules gradually replaced these "antique" electronic components.

Now when it comes to the circuit, you will think of the transmission of all kinds of electronic signals, and the transmission of these electronic signals are also formed by the collocation of some kinds of electronic components.A complete circuit is just as complete as a human being.If the CPU in the computer is compared to the human brain to give instructions to various components, then there is no doubt that the crystal oscillator is the human heart, responsible for sending action signals to various components, ensuring that each component has sufficient energy, so that they can complete their work tasks stably and intact.One of the most important things is to ensure its stability.

So far, the raw material of crystal oscillator made by countries in the world is quartz crystal, because this quartz crystal has a certain piezoelectric effect, and now many circuits are completed through this piezoelectric effect.At present, the world produces the largest amount of artificially grown quartz crystals, second only to that other material, silicon.

Now the major manufacturers are also in the cost control, the pursuit of product integration, low cost, but for the original crystal oscillator cost is quite high, so many manufacturers are gradually transforming the direction of the development of silicon crystal oscillator!

For the original crystal oscillator, there are still the following problems:

1. Difference of high and low stability:

The temperature characteristic curve of quartz crystal is nonlinear.This shows that the relationship between frequency stability and temperature of each crystal oscillator is unique, so it is necessary to adjust each crystal oscillator one by one.If it is a small batch, it needs to be adjusted manually, which will increase the cost of labor.If it is a large number of production can certainly appear high and low temperature performance is inconsistent, or even often high or low temperature vibration phenomenon.

2, poor seismic performance:

Because the quartz crystal itself belongs to the fragile, afraid of falling products.It is because in the production process, the product will be polished very thin, which increases the damage of the product.

3. There is a risk of air leakage.

In order to increase the stability of quartz crystal oscillator, it is necessary to make a silver plating treatment on its wafer.Then, at the time of encapsulation, a nitrogen-filled seal is applied.Any vibration during the transportation of the product is likely to cause nitrogen leakage of the product, resulting in no vibration or stability deviation and other problems.The most serious problem is that it can not be detected, because this problem is like a bicycle belt, there is a small hole, generally not easy to be found, with the cycling, use of the car, the hole is bigger and bigger, finally causing the point of irreparable.But this problem will occur in many places, such as product packaging, transportation, production, use and many other places, is considered uncontrollable.

4. Difficult delivery time

The general manufacturer's product inventory is not too much, although the product will do a process with an aging rate, even if the military grade has finished the aging rate of the process, there is a certain time, if the time is too long, it can not fully guarantee that it can meet the original factory standards.And the delivery time should be at least 6 weeks or so.Unable to meet the customer's continuing needs.

5. Frequency point narrowing

General crystal oscillator can only achieve the conventional frequency point, but in the actual application of the frequency point is relatively biased, so this crystal oscillator can not reach, or can not make the frequency point, resulting in the loss of many customers.And because of some more deviant frequency points, only a few shippers can have inventory.This causes the shipper to exchange goods, and the product bumps in transit, may damage the product, so that it can not be caused in the circuit vibration, or frequency deviation and other consequences.

To sum up, Dr. Kurt Petersen, chairman, CEO, and co-founder of Sitime, Inc. began working on MEMS resonators at IBM in 1976.To date, Sitime has shipped more than 3 billion pieces of MEMS silicon crystal oscillator.It is widely used in all walks of life such as consumption, medical treatment, industrial control, communication and military industry.