Glass and glass tube for encapsulating semiconductors

• US 6,534,346 B2
• Filed: 05/14/2001
• Issued: 03/18/2003
• Est. Priority Date: 05/16/2000
• Status: Expired due to Term

• Current Assignee: Nippon Electric Glass Company Limited
• Original Assignee: Nippon Electric Glass Company Limited
• Inventors: Kosokabe, Hiroyuki
• Primary Examiner(s): Sherry, Michael
• Assistant Examiner(s): GEYER, SCOTT B
• Application Number:
  US09/853,605
• Publication Number:
  US 20020001881A1
• Time in Patent Office: 673 Days
• Field of Search: 501/11, 501/15, 501/18, 501/53, 501/55, 438/127, 438/106, 438/112, 438/124, 438/126
• US Class Current: 438/127
• CPC Class Codes: C03C 3/089 containing boron
• CPC Class Codes: C03C 4/16 for dielectric glass

Abstract

Glass, for encapsulating a semiconductor, which is substantially free of lead or other harmful ingredients, but which exhibits a sealing temperature of not higher than 710° C., and which stably seals with Dumet. Further, when the glass has a viscosity of 10⁶ dPa·s, the temperature of said glass is not higher than 710° C., and includes two or more of Li₂O, Na₂O and K₂O and B₂O₃. Also, the glass may comprise: SiO₂, B₂O₃ and Al₂O₃ in an amount of from 40 to 70%, from 5 to 20% and from 0 to 15% by weight, respectively; MgO, CaO, SrO, BaO and ZnO in a total amount of from 0 to 45% by weight; and Li₂O, Na₂O and K₂O in a total amount of from 5 to 25% by weight.

Claims

1. An encapsulator, for encapsulating a semiconductor,

wherein the encapsulator is in the form of a glass tube and capable of hermetically encapsulating the semiconductor which is clamped by an electrode material in the glass tube, and

wherein the encapsulator comprises a glass tube including:

SiO₂ in an amount of from 40 to 70% by weight;

B₂O₃ in an amount of from 5 to 20% by weight;

Al₂O₃ in an amount of from 0 to 10% by weight;

MgO, CaO, SrO, BaO and ZnO in a total amount of from 0 to 45% by weight; and

at least two of Li₂O, Na₂O and K₂O in a total amount of from 5 to 25% by weight, each based on the total amount of said glass, wherein said glass tube is free of lead.

2. The encapsulator, for encapsulating a semiconductor, according to claim 1, wherein the glass tube is produced by:

melting a glass material to prepare molten glass;

forming the molten glass to be a glass tube;

cutting the glass tube to have a predetermined size,

wherein the glass material is prepared to give the glass tube including;

SiO₂ in an amount of from 40 to 70% by weight;

B₂O₃ in an amount of from 5 to 20% by weight;

Al₂O₃ in an amount of from 0 to 10% by weight;

MgO, CaO, SrO, BaO and ZnO in a total amount of from 0 to 45% b weight; and

at least two of Li₂O, Na₂O and K₂O in a total amount of from 5 to 25% b weight,

each based on the total amount of said glass, wherein said glass tube is free of lead.

3. The encapsulator, for encapsulating a semiconductor, according to claim 1, wherein the glass tube includes:

SiO₂ in an amount of from 40 to 70% by weight;

B₂O₃ in an amount of from 5 to 20% by weight;

Al₂O₃ in an amount of from 0 to 10% by weight;

MgO, CaO, SrO, BaO and ZnO in a total amount of from 0 to 45% by weight;

at least two of Li₂O, Na₂O and K₂O in a total amount of from 5 to 25% by weight; and

TiO₂ in an amount of from 0 to 1.5% by weight,

each based on the total amount of said glass, wherein said glass tube is free of lead.

4. The encapsulator, for encapsulating a semiconductor, according to claim 1, wherein the glass tube includes:

SiO₂ in an amount of from 50.7 to 70% by weight;

B₂O₃ in an amount of from 5 to 20% by weight;

Al₂O₃ in an amount of from 0 to 10% by weight;

MgO, CaO, SrO, BaO and ZnO in a total amount of from 0 to 45% by weight; and

at least two of Li₂O, Na₂O and K₂O in a total amount of from 5 to 25% by weight,

each based on the total amount of said glass, wherein said glass tube is free of lead.

5. The encapsulator, for encapsulating a semiconductor, according to claim 1, wherein the glass tube includes:

SiO₂ in an amount of from 40 to 70% by weight;

B₂O₃ in an amount of from 5 to 20% by weight;

Al₂O₃ in an amount of from 0 to 10% by weight;

MgO, CaO, SrO, BaO and ZnO in a total amount of from 0 to 45% by weight;

SrO in an amount of from 1 to 20% by weight; and

at least two of Li₂O, Na₂O and K₂O in a total amount of from 5 to 25% by weight,

each based on the total amount of said glass, wherein said glass tube is free of lead.