What is the relationship between the space environment and ceramic packaging products?

First, let's review the "space environment" that we have introduced so far.

The space environment differs from the Earth we live in mainly in the following points.

• Vibration and shock from firing etc.
• ultra high vacuum
• Temperature cycle (100-150℃ in direct sunlight, around -100℃ in the shade)
• Zero gravity (floating if there is a foreign object inside the cavity of the part)
• Heat (cooling with air cannot be expected)
• Atomic oxygen (very strong oxidizing power)
• Radiation (unintended electric current occurs and destroys parts)

▶Click here for details on the space environment

Among the above, ceramics are considered particularly effective as a countermeasure for ultra-high vacuum conditions.

In ultra-high vacuum environments, organic materials such as plastics may develop cracks, etc.
Additionally, the gas generated by evaporation may adhere to surrounding parts and cause malfunctions.

To avoid these problems, ceramics, which are vacuum-resistant inorganic materials, have traditionally been chosen.

Ceramic is expensive! But why is it used?

Ceramic package products for space use are very expensive compared to consumer products. There is a price difference of several tens to hundreds of times.

There are multiple factors contributing to this price difference, but the characteristics of space components are screening and QCI (Quality Conformance Inspection).

• Screening: A 100% inspection conducted in the manufacturing department after the package is sealed, and is conducted in accordance with standards such as the U.S. government's MIL standard.
• QCI: Refers to an inspection performed on a sample after screening is completed for lot assurance, and is also conducted in accordance with MIL standards.

​Inspection costs and yield (reduced yield) are one of the reasons why ceramic packaged products for space are so expensive.
 

However, the reason why ceramic packaging products have long been the standard for space components is that

This can be said to be because it has been recognized to be highly effective in the harsh space environment, especially as a countermeasure against ultra-high vacuum.