Vacuum package and manufacturing process thereof

1. A vacuum package comprising:

a chamber in which pressure is reduced to less than the atmospheric pressure;

a functional component sealed in said chamber said functional component is an infrared receiving component;

a material forming at least a part of said chamber; wherein

said material has at least one through hole to evacuate said chamber;

in a cross section perpendicular to said material taken along said through hole, an edge portion of said material forming said through hole has an obtuse angle;

said through hole is sealed with a sealing material; and

a pad formed only on a part of the through hole.

2. The vacuum package according to claim 1 , wherein

an inner wall of said through hole has a first taper surface which reduces an opening area of said through hole in a direction from an outer surface side toward an inner surface side of said chamber and a second taper surface which reduces the opening area of said through hole in a direction from the inner surface side toward the outer surface side of said chamber; and

said first taper surface is formed on the outer surface side as compared with said second taper surface.

3. The vacuum package according to claim 2 ,

wherein the pad is formed on only said first taper surface in the inner wall of the through hole, said pad having a higher wetting property to said sealing material than said material.

4. The vacuum package according to claim 2 , wherein

said first taper surface and said second taper surface are formed continuously.

5. The vacuum package according to claim 1 , wherein said sealing material does not project from said through hole into said chamber.

6. The vacuum package according to claim 1 , wherein

said chamber comprises, at least, a light-receiving component substrate on which said infrared receiving component is mounted, an infrared transmission window transmitting infrared rays so that said infrared receiving component receives the infrared rays from the outside of said chamber, and a spacer forming a predetermined gap between said light-receiving component substrate and said infrared transmission window; and

said material forming said through hole makes up at least one of said light-receiving component substrate, said infrared transmission window and said spacer.

7. A process of manufacturing a vacuum package in which a functional component, said functional component is an infrared receiving component, is sealed in a chamber, pressure in said chamber being reduced to less than the atmospheric pressure, the process comprising:

a through hole forming step of forming a through hole to evacuate said chamber in a material forming at least a part of said chamber, an inner wall of said through hole having at least a tubular first taper surface and a tubular second taper surface, said first taper surface being formed from one surface of said material so as to reduce an opening area, said second taper surface being formed from the other surface of said material so as to reduce an opening area;

an evacuating step of evacuating said chamber accommodating said functional component through said through hole;

a sealing step of sealing said through hole with a sealing material; and

a forming step of forming a pad only on a part of the through hole, wherein

in said through hole forming step, said through hole is formed so that an edge portion of said material forming said through hole has an obtuse angle in a cross section perpendicular to said material taken along said through hole.

8. The process according to claim 7 , wherein

the forming step of forming the pad further comprising forming the pad on said first taper surface located on the outer side of said chamber as compared with said second taper surface, said pad having a higher wetting property to said sealing material than said material; wherein

said sealing material placed on said pad of said first taper surface or on the opening of said through hole formed on said one surface of said material is fused to seal said through hole.

9. The process according to claim 8 , wherein

in said evacuating step, before said chamber is evacuated, said sealing material is placed on said pad of said first taper surface or on said opening of said through hole formed on said one surface of said material;

said chamber is evacuated through a gap between said sealing material and said through hole; and

after evacuating said chamber, said sealing material is fused to seal said through hole.

10. The process according to claim 8 , wherein

in said sealing step, after said chamber is evacuated, said sealing material is placed on said pad of said first taper surface or on said opening of said through hole formed on said one surface of said material; and

said sealing material is fused to seal said through hole.