JP2002166899A - Reinforced container for space environment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforced container for space environment shielding assuredly cosmic rays, which is light, low-cost, tolerable for a change in temperature and reliable. SOLUTION: This reinforced container for space environment 30 is formed with a closed aluminum container 11 and comprises a printed board 12 mounted on an inner surface of the closed container 11 and a household electronic component 13 mounted on the printed board 12 while a copper wire 14 allows electric connection of the electronic component 13 with outside. By setting a thickness of aluminum 3 mm the light and low-cost reinforced container 30 for pace environment can be obtained. By using the copper wire 14, the reinforced container 30 for space environment can be obtained prevented from cutting due to the change in temperature or an impact by vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container for enhancing space environment resistance, which protects and protects electronic components used in space, particularly for artificial satellites and spacecraft.

[0002]

2. Description of the Related Art FIG. 7 is a conceptual view showing a conventional radiation shielding container for protecting electronic components from radiation. In FIG. 7, a conventional radiation shielding container 1 is formed of a heavy metal container 2 (for example, a tungsten alloy) for shielding radiation from the outside, and a printed circuit board 3 is provided on the inner surface of the heavy metal container 2. A bare chip 4 which is an electronic component and has no package is provided on 3.

The heavy metal container 2 includes a base member 5 to which the printed board 3 is soldered or bonded with an adhesive, a side member 6 whose one side is brazed to the periphery of the base member 5 with Au or Ag braze, Au or A on the other side of the side material 6
g cover material 7 brazed with brazing. The heavy metal container 2 is added with iron, graphite, lead or the like in accordance with the irradiation ratio or dose in order to shield radiation.

A plurality of terminals 8 for electrically connecting the inside and the outside of the heavy metal container 2 are penetrated through the side member 6 via a glass sealing material 9, and the inner side end portion and the bare chip 4 are connected to each other. Are connected by a bonding wire 10.

[0005] With the above configuration, radiation, especially neutrons and γ-rays are shielded to protect electronic components (bare chips and the like) inside the container.

[0006]

As described above, the conventional radiation shielding container is provided with measures to enhance the resistance to radiation, and the electronic components used in electronic devices such as artificial satellites flying in outer space are also specially radiation-sensitive. Measures had been taken.
However, in recent years, the price of artificial satellites and the like has been reduced, and the use of the satellites for commercial activities such as a communication business has been performed worldwide. Under such circumstances, it is necessary to reduce the price of electronic components mounted on artificial satellites and the like, and therefore, general consumer electronic components used in cars, computers, telephones, etc. are used in space. Has been strongly demanded.

However, general consumer electronic components are formed of a plastic package, and have poor airtightness. Therefore, there are problems such as failure due to intrusion of moisture, degassing from the package, and susceptibility to radiation. Furthermore, in the case of a plastic package, it is designed on the assumption that it will be used on the ground, and since heat treatment is scheduled to release heat by air convection in addition to conduction, it is possible to use thermal convection due to vacuum and zero gravity. It is difficult to use it as it is in a space where it cannot.

If this electronic component is forcibly used in a space environment, only components that have undergone complicated and expensive evaluation tests and have been confirmed to be resistant to the space environment can be used, which has been an obstacle to cost reduction.

In addition, the above-mentioned measures for enhancing radiation resistance have a problem in that the heavy weight and large space are required because many heavy metals are used, which hinders downsizing and weight reduction of artificial satellites and the like.

[0010] Furthermore, although the electronic component and the terminal are connected by a bonding wire, there is a problem that the bonding wire is easily cut off due to a temperature change and is easily broken.

[0011] In order to solve the above-mentioned problems, a container for accommodating general consumer electronic parts used in outer space is supplied at a low price to reduce the weight and improve the reliability of electrical connection. The purpose is to obtain a container with enhanced space environment resistance.

[0012]

According to the present invention, means for solving the above-mentioned problems are as follows. (1) According to the first aspect of the present invention, electrons and protons among the cosmic rays are selected as main objects to be shielded in order to house the electronic components for consumer use and protect them from cosmic rays in a satellite orbit in outer space. The cosmic rays are shielded to such an extent that the electronic components are not adversely affected by using a metal material and a thickness dimension.

(2) In the invention according to claim 2, the metal material is aluminum.

(3) In the invention according to claim 3, the thickness dimension is 3 mm.

(4) According to a fourth aspect of the present invention, a cooling plate is provided on the surface of the container, and the electronic component is provided on the inner surface of the container.

(5) The invention according to claim 5, wherein the electronic component is connected to a copper wire inserted from the outside of the container, and the copper wire is interposed between the relay plates provided on the inner surface of the container. It is.

(6) The invention according to claim 6 is that the inside of the container is evacuated.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Generally, it is known that general consumer electronic components have a radiation absorption dose resistance of about 10,000 RAD. Therefore, by reducing the radiation absorption dose of this electronic component to 10,000 RAD or less, the consumer electronic components can be used in space. Can also be used in space. In order to reduce the radiation absorption dose to 10,000 RAD or less, a method has been adopted in which electronic components are housed in a sealed container that shields radiation.

Generally, it is known that cosmic rays in an orbit of an artificial satellite are mostly protons and electrons, and neutrons and γ-rays having high permeability are few. Therefore, in the case of cosmic rays, shielding the protons and electrons can protect the internal electronic components. Here, FIGS. 3 and 4 show graphs of the relationship between the particle energies and the particle densities of electrons and protons of cosmic rays, respectively. According to this graph, in both cases, particles having low particle energy, that is, particles that are easy to shield, are large, and particles having high particle energy, that is, particles that are difficult to shield are rapidly reduced. From this, it is understood that cosmic rays can be shielded relatively easily if the metal can shield particles having low particle energy.

FIG. 5 is a graph showing the relationship between the thickness of aluminum and the radiation absorption dose at this aluminum. In FIG. 5, it can be seen that when the thickness of the aluminum is about 3 mm or more, the radiation absorption dose is lower than 10,000 RAD, and the consumer electronic component can be sufficiently used in outer space.

Therefore, cosmic rays can be effectively shielded by the space environment resistance enhanced container according to the first embodiment as shown in FIGS. That is, the container 30 for strengthening space environment resistance is composed of a closed container 11, a printed circuit board 12 is provided on the inner surface of the closed container 11, and a consumer electronic component 13 in a plastic package is provided on the printed circuit board 12. ing. Also, a copper wire 1 for enabling electrical connection to the electronic component 13 from outside the sealed container 11
4 penetrates the side surface of the closed container 11.

The hermetically sealed container 11 is made of aluminum, and has a bottom plate 15 on which a printed board 12 is provided, a side wall 16 erected so as to surround the periphery of the bottom plate 15 and connected by welding, and covers the side wall 16. And a lid plate 17 which is connected by welding. The plate thickness of the closed container 11 is 3 mm. Also, the side wall 16
, A copper wire 14 penetrates through a glass sealing material 18 to enable electrical connection between the inside and the outside of the sealed container 11.

The printed circuit board 12 is in close contact with the bottom plate 15 of the closed casing 11.

The copper wire 14 is connected to an electronic component 13 packaged in a plastic via a relay plate 19 provided on the printed circuit board 12. The relay plate is a relay point on the electronic component 13 side 14a and the outer side 14b of the copper wire 14, and each is soldered.

As described above, it has been revealed that a light metal such as aluminum can efficiently shield cosmic rays with a thickness of 3 mm. By applying a shielding means suitable for this characteristic, it is possible to obtain a container with enhanced space environment resistance which is cheaper and easier to handle than conventional ones.

Space environment resistant container 3 having the above configuration
0 is a vacuum inside, so that stress such as thermal deformation is not applied to the copper wire 14 or the like, and care is taken to prevent the air from affecting the operation in the outer space.

The copper wire 14 is connected to the relay plate 19
Also, since the connection is reliably performed by soldering, there is no possibility that the copper wire 14 is cut due to a change in temperature or vibration, and the reliability is greatly improved.

In addition, through the relay plate 19, the production becomes easy and the strength is increased.
And it has an excellent effect in terms of heat conduction.

The relay plate 19 may be omitted if the copper wire 14 has a diameter enough to withstand a temperature change or vibration.

The aluminum sealed container 11 shields cosmic rays, and the cosmic rays are applied to the electronic components 13.
It is not necessary to limit the thickness to 3 mm if it does not affect the thickness. In addition, there are many metals such as Fe that are superior in price and weight to the conventional shielding container, but aluminum is the most suitable metal for the space environment resistant container 30 when comprehensively judged. Therefore, it is desirable to use aluminum.

As shown in FIG. 6, the provision of the cooling plate 20 on the outer surface of the closed casing 11, especially on the bottom plate 15, allows the heat generated by the electronic component 13 and the relay plate 19 to be efficiently conducted to the outside, This is desirable because the reliability can be improved by preventing the temperature of the electronic component 13 and the copper wire 14 from rising.

[0032]

As is clear from the above description, the effects of the present invention are as follows. (1) In the invention according to claim 1, in order to house consumer electronic components and protect them from cosmic rays on a satellite orbit in outer space, electrons and protons among the cosmic rays are selected as main shielding targets. Since the cosmic rays are shielded to such an extent that the electronic components are not adversely affected by using a metal material and a thickness dimension, the cosmic rays are effectively shielded, and the cosmic rays can be manufactured easily at a low cost and reliably. A space environment resistant container that protects components can be obtained.

(2) The invention according to claim 2 is that, since the metal material is aluminum, it can be manufactured at a low weight and at a low cost, and can reliably shield the cosmic rays so as to protect the electronic components. A reinforced container can be obtained.

(3) In the invention according to claim 3, the thickness dimension is 3 mm, so that the electronic parts are not damaged, and the lightest, inexpensive and easy-to-work space environment resistant. A reinforced container can be obtained.

(4) In the invention according to claim 4, since the cooling plate is provided on the surface of the container and the electronic component is provided on the inner surface of the container, the heat generated by the electronic component is effectively removed. A space environment resistant container that improves the reliability of the electronic component can be obtained.

(5) In the invention according to claim 5, the electronic component is connected to a copper wire inserted from the outside of the container, and the copper wire is interposed between the relay plates provided on the inner surface of the container. In addition, it is possible to obtain a container with enhanced space environment resistance, in which the connection strength of the copper wire is increased and the heat generated by the copper wire is prevented from being thermally cut by removing the heat to the outside.

(6) In the invention according to claim 6, since the inside of the container is evacuated, stress such as thermal deformation is not applied to the copper wire and the like, and air does not affect the operation in outer space. A space environment resistant container can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a configuration of a space environment resistance enhanced container according to Embodiment 1 of the present invention.

FIG. 2 is a schematic top view showing a configuration of a space environment resistance enhanced container according to Embodiment 1 of the present invention.

FIG. 3 is a graph showing the relationship between particle energy and particle density of electrons that are components of cosmic rays.

FIG. 4 is a graph showing a relationship between particle energy and particle density of protons, which are components of cosmic rays.

FIG. 5 is a graph showing the relationship between the thickness of aluminum with respect to cosmic rays and the radiation absorption dose.

FIG. 6 is a schematic side view showing a configuration of another space environment resistance enhanced container according to Embodiment 1 of the present invention.

FIG. 7 is a schematic side view showing a configuration of a conventional radiation shielding container.

[Explanation of symbols]

1 radiation shielding container, 2 container, 3 printed circuit board, 4
Bare chip, 8 terminals, 9 glass sealing material, 10 bonding wire, 11 hermetic container, 12 printed circuit board, 13 electronic components, 14 copper wire, 19 relay plate, 20 cooling plate, 30 container with enhanced space environment resistance.

Claims (6)

[Claims] 1. A metal material and a thickness dimension of a cosmic ray selected as a main shielding target in order to house a consumer electronic component and protect it from cosmic rays in a satellite orbit in outer space. Wherein the cosmic ray is shielded to such an extent that the electronic component is not adversely affected by using the above. 2. The container according to claim 1, wherein the metal material is aluminum. 3. The container according to claim 2, wherein the thickness dimension is 3 mm. 4. The container according to claim 1, further comprising a cooling plate on a surface of the container, wherein the electronic component is provided on an inner surface of the container.
The container for enhancing space environment resistance according to any one of claims 3 to 3. 5. The container according to claim 1, wherein the electronic component is connected to a copper wire inserted from outside the container, and the copper wire is provided via a relay plate provided on an inner surface of the container. Item 5. The container for enhancing space environment resistance according to any one of Items 4. 6. The space environment resistant container according to claim 1, wherein the inside of the container is evacuated.