Layered unit provided with piezoelectric ceramics, method for producing the same, and ink jet printing head employing the same

• US 20020036679A1
• Filed: 07/27/2001
• Published: 03/28/2002
• Est. Priority Date: 07/27/2000
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Tateyama, Yasuharu, Ueki, Chitoshi
• Granted Patent: US 6,626,526 B2
• Time in Patent Office: Days
• US Class Current: 347/72
• CPC Class Codes: B41J 2/14209 of finger type, chamber walls consisting integrally of piezoelectric material
• CPC Class Codes: H10N 30/073 by fusion of metals or by adhesives

Abstract

Provided are a layered unit provided with piezoelectric ceramics having an increased adhesive strength while lowering cell content in an adhesive layer, a method for producing the layered unit, and an ink jet printing head incorporated with such layered unit having improved ink emission precision and durability as well as suppressing occurrence of assembly failure at the time of producing the ink jet printing head. The layered unit has a first member made of piezoelectric ceramics, a second member which is placed over the first member, and an adhesive layer which is formed between the first member and the second member to adhere the first member and the second member. A joint surface of the first member to be jointed to the second member is formed with a multitude of recesses. A sum of opening areas of the recesses occupies 50% or more relative to a total surface area of the joint surface of the first member. Alternatively, a crystalline part comprising the joint surface of the first member is formed with a multitude of microprotrusions.

Claims

1. A layered unit provided with piezoelectric ceramics comprising:

a first member made of piezoelectric ceramics;

a second member which is placed on the first member; and

an adhesive layer which in formed between the first member and the second member to adhere the first member and the second member, wherein

a joint surface of the first member to be jointed to the second member is formed with a multitude of recesses, a surface area ratio of the recesses relative to a total surface area of the joint surface being 50% or more.

2. The layered unit according to claim 1, wherein the recesses are formed by shedding crystalline grains on the joint surface of the first member.

3. The layered unit according to claim 1, wherein the recesses include voids in the joint surface of the first member.

4. The layered unit according to claim 1, wherein the piezoelectric ceramics composing the first member includes alumina (Al₂O₃) and silicon oxide (SiO₂) in such an amount that a content thereof relative to the piezoelectric ceramics composing the first member is 0.08 mass % or less.

5. The layered unit according to claim 4, wherein the piezoelectric ceramics composing the first member includes lead zirconate titanate as a main component.

6. A method of producing a layered unit provided with piezoelectric ceramics having an improved adhesive strength comprising steps in the order of:

lapping a surface of a first member made of piezoelectric ceramics including lead zirconate titanate in which a total content of alumina (Al₂O₃) and silicon oxide (SiO₂) relative to the piezoelectric ceramics is 0.08 mass % or less, with abrasive grains of silicon carbide having a grain diameter ranging from 5 to 10 μ

m as free abrasive grains to form a joint surface to be jointed to a second member;

applying an adhesive agent to at least one of the joint surface of the first member and a surface of the second member to form a joint unit of the first member and the second member; and

curing the adhesive agent while pressurizing the joint unit.

7. A method of producing a layered unit provided with piezoelectric ceramics having an improved adhesive strength comprising steps in the order of:

machining a surface of a first member made of piezoelectric comprising including lead zirconate titanate in which a total content of alumina (Al₂O₃) and silicon oxide (SiO₂) relative to the piezoelectric ceramics is 0.08 mass % or less, with a diamond wheel to which diamond grains having a grain diameter ranging from 5 to 10 μ

m are attached to form a joint surface of the first member to be jointed to a second member;

applying an adhesive agent to at least one of the joint surface of the first member and a surface of the second member to form a joint unit of the first member and the second member; and

curing the adhesive agent while pressurizing the joint unit.

8. A layered unit provided with piezoelectric ceramics comprising;

a first member made of piezoelectric ceramics;

a second member which is placed an the first member; and

an adhesive layer which is formed between the first member and the second member to adhere the first member and the second member, wherein

a joint surface of the first member to be jointed to the second member is formed with a multitude of microprotrusions on a crystalline part thereof.

9. The layered unit according to claim 8, wherein a surface area ratio of the microprotrusions relative to a measured surface area of the joint surface from 10⁻

6 to 10⁵ mm² ranges from 5 to 40%.

10. A method of producing a layered unit provided with piezoelectric ceramics having an improved adhesive strength comprising steps in the order of:

treating a surface of the first member with plasma to form a multitude of microprotrusions thereon so as to form a joint surface of the first member to be jointed to a second member;

applying an adhesive agent to at least one of the joint surface of the first member and a surface of the second member to form a joint unit of the first member and the second member; and

curing the adhesive agent while pressurizing the joint unit.

11. The method according to claim 10, wherein the surface treatment with plasma is performed after a step of machining or polishing the surface of the first member.

13. The ink jet printing head according to claim 12, further comprising a top plate attached to upper surfaced of the partition walls, wherein a joint surface of the partition wall to be jointed to the top plate is formed with a multitude of recesses having a surface area ratio of thereof relative to a total surface area of the joint surface at 50% or more.

14. The ink jet printing head according to claim 12, further comprising a top plate attached to upper surfaces of the partition walls, wherein a joint surface of the partition wall to be jointed to the top plate is formed with a multitude of microprotrusions on a crystalline part thereof.

15. The ink jet printing head according to claim 12, wherein

the partition wall comprises:

a first member made of piezoelectric ceramics;

a second member which is placed on the first member; and

an adhesive layer which is formed between the first member and the second member to adhere the first member and the second member,

a joint surface of the first member to be jointed to the second member being formed with a multitude of recesses having a surface area ratio thereof relative to a total surface area of the joint surface of 50% or more.

16. The ink jet printing head according to claim 12, wherein

the partition wall comprises:

a first member made of piezoelectric ceramics;

a second member which is placed on the first member; and

an adhesive layer which is formed between the first member and the second member to adhere the first member and the second member,

a joint surface of the first member to be jointed to the second member being formed with a multitude of microprotrusions on a crystalline part thereof.

17. The ink jet printing head according to claim 12, wherein the partition wall is polarized in a direction perpendicular to a direction of applying a voltage thereto.

18. The ink jet printing head according to claim 12, wherein the partition wall is constructed by forming at least one cutaway having a certain length in a piezoelectric plate adhered to the base plate.

20. The ink jot printing head according to claim 19, further comprising a top plate attached to upper surfaces of the partition walls, wherein a joint surface of the partition wall to be jointed to the top plate is formed with a multitude of recesses having a surface area ratio of thereof relative to a total surface area of the joint surface at 50% or more.

21. The ink jot printing head according to claim 19, further comprising a top plate attached to upper surfaces of the partition walls, wherein a joint surface of the partition wall to be jointed to the top plate is formed with a multitude of microprotrusions on a crystalline part thereof.

22. The ink jet printing head according to claim 19, wherein

the partition wall comprises:

a first member made of piezoelectric ceramics;

a second member which is placed on the first member; and

an adhesive layer which is formed between the first member and the second member to adhere the first member and the second member,

a joint surface of the first member to be jointed to the second member being formed with a multitude of recesses having a surface area ratio thereof relative to a total surface area of the joint surface at 50% or more.

23. The ink jet printing head according to claim 19, wherein

the partition wall comprises:

a first member made of piezoelectric ceramics;

a second member which is placed on the first member; and

an adhesive layer which is formed between the first member and the second member to adhere the first member and the second member,

a joint surface of the first member to be jointed to the second member being formed with a multitude of microprotrusions on a crystalline part thereof.

24. The ink jet printing head according to claim 19, wherein the partition wall is polarized in a direction perpendicular to a direction of applying a voltage thereto.

25. The ink jet printing head according to claim 19, wherein the partition wall is constructed by forming at least one cutaway having a certain length in a piezoelectric plate adhered to the base plate.

12. An ink jet printing head comprising:

a base plate;

an array of ink flow channels each defined by a pair of partition walls constituting a piezoelectric member, the ink flow channel being arrayed on the base plate in a widthwise direction of the ink jet printing head at a certain interval; and

pairs of electrodes each provided at opposing sides of each partition wall to apply a voltage to deform the partition wall, wherein

a multitude of recesses are formed in a joint surface of the partition wall to be jointed to the base plate in such a manner that a surface area ratio of the recesses relative to a total surface area of the joint surface is set at 50% or more, and the partition wall and the base plate are jointed by the adhesive agent.

19. An ink jet printing head comprising:

a base plate;

an array of ink flow channels each defined by a pair of partition walls constituting a piezoelectric member, the ink flow channels being arrayed on the base plate in a widthwise direction of the ink jet printing head at a certain interval; and

pairs of electrodes each provided at opposing sides of each partition wall to apply a voltage to deform the partition wall, wherein

a multitude of microprotrusions are formed on a joint surface of the partition wall to be jointed to the base plate, and the partition wall and the base plate are jointed by the adhesive agent.