Ngk Insulators, Inc.

Toshio Ohashi

Michio Asai

Sugio Miyazawa

Takehiro Kajihara

Koichiro Maekawa

Masaki Wakayama

A passage tube including a ceramic tube body through which plasma producing gas passes and is irradiated from outside the ceramic tube body with ultraviolet rays, and a ceramic flange member joined to an outer peripheral surface of the ceramic tube body, is manufactured by forming calcined bodies for the passage tube body and flange member, machining the calcined body for the tube body so as to form a first portion and a second portion having an outer diameter larger than that of the first portion, joining the calcined body for the flange member to a stepped region between the first portion and the second portion and sintering them.

Method of manufacturing a passage tube for passing plasma producing gas

A gas tube for passing plasma generating gases, having high UV transmittance and corrosion resistance against corrosive gases is disclosed. The tube is composed of a longitudinally extended throughhole and a thin circumferential wall and is provided with a means for radiating UV rays directed to an upstream portion thereof from outside. The wall is formed of a light-pervious alumina ceramic, and has a center-line mean roughness (R.sub.a) of not more than 1.0 .mu.m in a portion exposed to gas plasma.

Gas tube for passing plasma generating gases

A method for producing a cylindrical ceramic body having a hollow portion and having an uneven thickness includes the steps of: granulating a ceramic material powder to obtain granules having an average diameter of 50-90 .mu.m and an apparent bulk density of 0.60-0.80 g/cm.sup.3 ; mixing a binder with the granules to obtain a molding material; subjecting the molding material to an injection molding under a pressure of 500 kg/cm.sup.2 or less to obtain a compact; removing a binder from the compact to obtain a binder-removed compact; and firing the binder-removed compact. The method can excellently mold and produce a cylindrical ceramic body which has a hollow portion therein, which is very thin, and which has an uneven thickness.

Method for producing cylindrical ceramic body

A ceramic package for a memory semiconductor accommodates therein the memory semiconductor and is sealingly closed by an ultraviolet ray transmissible ceramic lid. The ceramic lid is made of a polycrystalline alumina and formed with at least one groove in a sealing portion with the ceramic package. With the arrangement, the ceramic package is superior in sealing strength, air-tightness and ultraviolet ray transmission and can easily accommodate any increase of memory amount of semiconductor elements.

Ceramic package for memory semiconductor

A ceramic lid for sealing a semiconductor element and having a sealing surface which is to seal a semiconductor element within a recess of a ceramic package, by heating the recess with glass sealant and hermetically sealing the semiconductor element. The ceramic lid is made of alumina of high purity and to the sealing surface of the ceramic lid is applied a glass sealing aid which is pretreated at a higher temperature than the heating temperature for sealing the semiconductor element, before hermetically sealing the semiconductor element in the ceramic package. A method of manufacturing a ceramic lid for sealing a semiconductor element includes the steps of manufacturing the ceramic lid with alumina of high purity having a sealing surface with the recess of the ceramic package, wherein to the sealing surface of the ceramic lid is applied a glass sealing aid of 5-30 .mu.m in thickness onto a sealing surface of the ceramic lid with the ceramic package. The ceramic lid is heat-treated at a higher temperature than the sealing temperature of the semiconductor element. Thereafter a glass sealant is applied and dried on the glass sealing aid layer, and then calcined at a temperature lower than the airtight sealing temperature of the semiconductor element, thereby removing an organic binder contained in the glass sealant. A semiconductor element is then housed within a recess of the ceramic package and the ceramic lid and a glass sealant are heated to hermetically seal the ceramic lid with the semiconductor element in the recess to the ceramic package.

Growing community of inventors

Komaki, Japan

Toshio Ohashi