How to avoid risks caused by cosmic radiation?

As introduced in a previous article, cosmic rays exist in space.

▶ Learn more about the space environment

Also called cosmic radiation, it literally refers to radiationin the space environment.

It is said that the radiation level in outer space is higher than that on the ground.

If this radiation enters a semiconductor device (semiconductor for space use) mounted on a satellite, the following events will occur.

• TID (Total Ionizing Dose effects)
• SEE (Singe Event Effects)

These problems can cause deterioration or damage to the functionality/performance of space semiconductors.

There is a risk of loss of functionality of some or all system components.

If the above problem occurs in the space environment, it is impossible to repair it from the ground.

It is necessary to select devices (space semiconductors) that are resistant to the space environment.

How to choose a semiconductor device package that is resistant to the space environment?

​Radiation is not the only consideration.

In an ultra-high vacuum environment, organic materials such as plastics may deteriorate and cause cracks.

In addition, the gas generated by evaporation may adhere to surrounding parts and cause problems.

To avoid these problems, ceramic, an inorganic material that is resistant to vacuum, has​ ​traditionally been used in packages.

However, in recent years, space development has progressed in various countries, and knowledge in outer space is expanding.
among them,

• Geostationary Orbit (GEO)
• Medium Earth Orbit (MEO)
• Low Earth Orbit (LEO)

This has led to differences in the specifications of semiconductor devices required for each orbit.

A new field called New Space?

recent years, A field called “New Space” In addition to ceramic packages, we also offer semiconductor devices in plastic packages.
The number of cases in which it is installed in satellite equipment is increasing.

When customers consider plastic packaging products, they often point to the ``price'' advantage.

However, all risks must be considered when considering plastic packaging products.

In addition to the "gas generation risk" mentioned above, the perspective of total cost is also important.

If you are concerned about the reliability of the device or if the end customer has specific requirements,
There may be cases where additional tests are required. Considering the “testing cost” and “yield” caused by additional testing,
The total cost will rise, and the unit price of the device may become "expensive" as a result.

 If you choose a plastic package product simply because of its "low price," testing costs will be added, and as a result,
This is not recommended as it may end up being expensive.
It is necessary to consider trade-offs based on both quality and price.
We recommend that you consider this after comparing it with the use of conventional ceramic products.

▶What kind of analysis and evaluation can be done with Macnica?


When selecting parts, it is necessary to carefully select compatible parts based on the following two points.

1. Expected orbit of your satellite
2. Estimated mission life (how many years should the satellite be active in space)

Have you understood the points to consider when selecting parts depending on the purpose of the explanation so far?

In the next and subsequent articles, we will provide an in-depth explanation of component selection focusing on the differences in the specifications and test content of space semiconductors. looking forward to.