Glass for laser processing and method for producing perforated glass using same
The present invention provides a glass composition that allows holes with a circular contour and a smooth inner wall to be formed by a collective micro-hole-forming process using a combination of modified portion formation by ultraviolet laser irradiation and etching, the glass composition being adapted for practical continuous production. The present invention relates to a glass for laser processing, the glass including a metal oxide serving as a coloring component, the glass having a glass composition including, in mol %: 45.0%≤SiO 2 ≤68.0%; 2.0%≤B 2 O 3 ≤20.0%; 3.0%≤Al 2 O 3 ≤20.0%; 0.1%≤TiO 2 ≤5.0%; and 0%≤ZnO≤9.0%, wherein a relationship of 0≤Li 2 O+Na 2 O+K 2 O<2.0% is satisfied.
1. A glass for laser processing, the glass comprising a metal oxide serving as a coloring component, the glass having a glass composition comprising, in mol %:
45.0%≤SiO 2 ≤68.0%;
2.0%≤B 2 O 3 ≤20.0%;
3.0%≤Al 2 O 3 ≤20.0%;
1.0%≤TiO 2 ≤5.0%;
1.0%≤ZnO≤8.0%; and
3.0%≤MgO≤10.0%;
wherein the metal oxide serving as a coloring component comprises, in mol % relative to the glass composition:
0.01%≤Fe 2 O 3 ≤0.4%; and
the following relationships are satisfied:
6.0%≤MgO+CaO+SrO+BaO≤25.0%; and
0≤Li 2 O+Na 2 O+K 2 O<0.1%.
2. The glass for laser processing according to claim 1 , wherein the metal oxide serving as a coloring component comprises, in mol % relative to the glass composition:
0.02%≤Fe 2 O 3 ≤0.4%.
3. The glass for laser processing according to claim 1 , wherein the metal oxide serving as a coloring component further comprises, in mol % relative to the glass composition:
0.1%≤CeO 2 ≤2.0%.
4. The glass for laser processing according to claim 1 , wherein the glass composition comprises, in mol %:
45.0%≤SiO 2 ≤63.0%.
5. The glass for laser processing according to claim 1 , wherein the following relationship is satisfied:
55.0%≤SiO 2 +B 2 O 3 ≤72.0%.
6. The glass for laser processing according to claim 1 , wherein the glass composition further comprises at least one component selected from the group consisting of ZrO 2 , Ta 2 O 5 , and Nb 2 O 5 , and
contents of ZrO 2 , Ta 2 O 5 , and Nb 2 O 5 are in the following range, in mol %:
0.1%≤ZrO 2 ≤7.0%;
0.1%≤Ta 2 O 5 ≤7.0%;
0.1%≤Nb 2 O 5 ≤7.0%.
7. The glass for laser processing according to claim 1 , further comprising a refractive index modifying component.
8. The glass for laser processing according to claim 7 , wherein the refractive index modifying component comprises at least one component selected from the group consisting of La 2 O 3 and Bi 2 O 3 , and
contents of La 2 O 3 and Bi 2 O 3 are in the following range, in mol % relative to the glass composition:
0.1%≤La 2 O 3 ≤7.0%; or
0.1%≤Bi 2 O 3 ≤7.0%.
9. The glass for laser processing according to claim 1 , having a coefficient of thermal expansion of 60×10 −7 /° C. or less.
10. The glass for laser processing according to claim 1 , having an absorption coefficient α of 3 to 40/cm.
11. A method for producing a perforated glass, comprising:
(i) irradiating an area of the glass for laser processing according to claim 1 with a laser pulse focused by a lens, thereby forming a modified portion in the irradiated area; and
(ii) etching at least the modified portion using an etchant, thereby forming a hole in the glass for laser processing.
12. The glass for laser processing according to claim 1 , wherein the glass composition comprises, in mol %:
45.0%≤SiO 2 ≤66.0%;
7.0%≤B 2 O 3 ≤17.0%;
7.0%≤Al 2 O 3 ≤13.0%;
1.0%≤TiO 2 ≤4.0%;
1.0%≤ZnO≤8.0%; and
3.0%≤MgO≤10.0%;
wherein the metal oxide serving as a coloring component comprises, in mol % relative to the glass composition:
0.01%≤Fe 2 O 3 ≤0.4%; and
the following relationships are satisfied:
58.0%≤SiO 2 +B 2 O 3 ≤76.0%;
6.0%≤MgO+CaO+SrO+BaO≤25.0%; and
0≤Li 2 O+Na 2 O+K 2 O≤0.1%.
13. The glass for laser processing according to claim 12 , wherein the glass composition further comprises, in mol %:
0%≤BaO≤6.0%.
14. The glass for laser processing according to claim 12 , wherein the glass composition further comprises, in mol %:
2.0%≤CaO≤10.0%;
2.0%≤SrO≤10.0%; and
0%≤BaO≤6.0%.
15. A glass for laser processing, the glass comprising a metal oxide serving as a coloring component, the glass having a glass composition comprising, in mol %:
45.0%≤SiO 2 ≤68.0%;
2.0%≤B 2 O 3 ≤20.0%;
3.0%≤Al 2 O 3 ≤20.0%;
1.0%≤TiO 2 ≤5.0%;
1.0%≤ZnO≤8.0%; and
3.0%≤MgO≤10.0%,
wherein the metal oxide serving as a coloring component comprises, in mol % relative to the glass composition:
0.1%≤CeO 2 ≤2.0%; and
the following relationships are satisfied:
6.0%≤MgO+CaO+SrO+BaO≤25.0%; and
0<Li 2 O+Na 2 O+K 2 O<0.1%.