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CN-122002714-A - Substrate bonding method, substrate assembly, and inkjet printhead

CN122002714ACN 122002714 ACN122002714 ACN 122002714ACN-122002714-A

Abstract

Substrate bonding methods, substrate assemblies, and inkjet printheads are disclosed. A bonding method includes the steps of applying a first adhesive to a bonding region of a first substrate in a line shape, applying a second adhesive to the bonding region of the first substrate in a dotted line shape at a predetermined interval from the first adhesive layer in the line shape to form a plurality of second adhesive layers having gaps formed due to the dotted line shape, bonding the second substrate to the first substrate with the first adhesive layer and the plurality of second adhesive layers and bonding the second substrate to the first substrate, curing the plurality of second adhesive layers between the bonded first substrate and second substrate, and curing the first adhesive layer after the plurality of second adhesive layers are cured.

Inventors

  • KATANO KAORU

Assignees

  • 佳能株式会社

Dates

Publication Date
20260508
Application Date
20251107
Priority Date
20241107

Claims (16)

  1. 1. A joining method comprising the steps of: applying a first adhesive to the bonding region of the first substrate in a line shape to form a first adhesive layer; Applying a second adhesive to the bonding region of the first substrate in a dotted line shape at a predetermined interval from the first adhesive layer in a line shape to form a plurality of second adhesive layers having gaps formed due to the dotted line shape; Bonding a second substrate to the first substrate with the first adhesive layer and the plurality of second adhesive layers and pressing the second substrate to the first substrate; Curing the plurality of second adhesive layers between the first substrate and the second substrate which are pressure bonded, and The first adhesive layer is cured after the plurality of second adhesive layers are cured.
  2. 2. The bonding method according to claim 1, wherein a length of each of the plurality of second adhesive layers is longer than a length of the gap.
  3. 3. The bonding method according to claim 1, wherein the plurality of second adhesive layers are arranged along two opposite sides in the outer periphery of the bonding region.
  4. 4. The joining method according to claim 1, wherein The first substrate is a semiconductor substrate, and The second substrate is a metal substrate.
  5. 5. The joining method according to claim 1, wherein The second substrate has an opening, and The inner periphery of the engagement region corresponds to the outer periphery of the opening.
  6. 6. The joining method according to claim 1, wherein The plurality of second adhesive layers have a length equal to or longer than two-thirds of a length of an edge of the first substrate adjacent to the plurality of second adhesive layers.
  7. 7. The bonding method according to claim 1, wherein the first adhesive layer is formed of a thermosetting adhesive.
  8. 8. The bonding method according to claim 7, wherein the plurality of second adhesive layers are formed of a material that cures at a lower temperature than the first adhesive layer.
  9. 9. An assembly, comprising: a first substrate and a second substrate bonded together; A first adhesive layer formed in a linear shape from a first adhesive between the first substrate and the second substrate, and A plurality of second adhesive layers formed of a second adhesive in a dotted line shape and disposed adjacent to the first adhesive layer in a line shape, the plurality of second adhesive layers having gaps due to the dotted line shape.
  10. 10. An inkjet printhead, comprising: a first substrate and a second substrate bonded together; A first adhesive layer formed in a linear shape from a first adhesive between the first substrate and the second substrate; a plurality of second adhesive layers formed in a dotted line shape from a second adhesive and disposed adjacent to the first adhesive layer in a line shape, the plurality of second adhesive layers having a gap due to the dotted line shape, and And a spray chip mounted on the first substrate, covered by the second substrate, and having spray nozzles surrounded by and exposed from the openings of the second substrate.
  11. 11. The inkjet printhead of claim 10, wherein the plurality of second adhesive layers have lengths longer than the length of the gap.
  12. 12. The inkjet printhead of claim 10 or 11, wherein the plurality of second adhesive layers are formed of a material that cures at a lower temperature than the first adhesive layer.
  13. 13. The inkjet printhead of claim 10, wherein the plurality of second adhesive layers are disposed along two opposite sides of the first substrate.
  14. 14. The inkjet printhead of claim 10, wherein The first substrate is a semiconductor substrate, and The second substrate is a metal substrate.
  15. 15. The inkjet printhead of claim 10, wherein The plurality of second adhesive layers have a length equal to or longer than two-thirds of a length of an edge of the first substrate adjacent to the plurality of second adhesive layers.
  16. 16. The inkjet printhead of claim 10, wherein the first adhesive layer is formed from a thermoset adhesive.

Description

Substrate bonding method, substrate assembly, and inkjet printhead Technical Field The present disclosure relates to a substrate joining method, a substrate assembly, and an inkjet printhead, and more particularly to a technique of bonding substrates together by using temporary fixation with a thermosetting adhesive. Background Japanese patent laid-open No. 2010-82537 (hereinafter referred to as patent document 1) describes a technique of bonding substrates together by using a main adhesive that is thermosetting and has a relatively high adhesive strength and a temporary adhesive that is also thermosetting. In patent document 1, a temporary adhesive is spot-coated to the joining surfaces of the substrates and cured in a step before the main adhesive is cured to temporarily bond the substrates together. However, in the case of bonding a substrate of low wettability such as a semiconductor substrate used in an inkjet head to another substrate using spot coating, it is difficult to control the amount of adhesive applied, resulting in unstable amount of adhesive applied. Furthermore, even if an adhesive is applied, it is difficult to obtain a desired adhesive strength. In contrast, in the case where the adhesive is coated in a line shape, the amount of the coated adhesive can be stably controlled, and thus the adhesive strength of the adhesive can also be ensured. However, in the case where the line-shaped main adhesive and the line-shaped temporary adhesive are applied close to each other, air bubbles may be trapped between the two adhesives. Then, in the process of thermally curing the main adhesive, the trapped bubbles expand and create leakage paths through the main adhesive, which may cause defects in the product manufactured using the bonded substrate. Disclosure of Invention The present disclosure is directed to a substrate bonding method, substrate assembly, and inkjet printhead that bond substrates together without creating a leakage path. The present disclosure relates to a bonding method including the steps of applying a first adhesive to a bonding region of a first substrate in a line shape, applying a second adhesive to the bonding region of the first substrate in a dotted line shape at a predetermined interval from the first adhesive layer in the line shape to form a plurality of second adhesive layers having gaps formed due to the dotted line shape, bonding the second substrate to the first substrate with the first adhesive layer and the plurality of second adhesive layers and pressing the second substrate to the first substrate, curing the plurality of second adhesive layers between the pressed first substrate and the second substrate, and curing the first adhesive layer after the plurality of second adhesive layers are cured. Features of the present disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings. The following description of the embodiments is by way of example. Drawings Fig. 1A is a top view illustrating a state in which a temporary adhesive and a main adhesive according to a comparative example are applied to a bonding surface of a substrate to be bonded; fig. 1B is a top view illustrating a state in which a temporary adhesive and a main adhesive according to a comparative example are applied to a bonding surface of a substrate to be bonded; fig. 1C is a top view illustrating a state in which a temporary adhesive and a main adhesive according to a comparative example are applied to a bonding surface of a substrate to be bonded; fig. 1D is a top view illustrating a state in which a temporary adhesive and a main adhesive according to a comparative example are applied to a bonding surface of a substrate to be bonded; Fig. 1E is a top view illustrating a state in which a temporary adhesive and a main adhesive according to a comparative example are applied to a bonding surface of a substrate to be bonded; FIG. 2A is a cross-sectional view taken along line A-A in FIG. 1A; FIG. 2B is a cross-sectional view taken along line A-A in FIG. 1B; FIG. 2C is a cross-sectional view taken along line A-A in FIG. 1C; FIG. 2D is a cross-sectional view taken along line A-A in FIG. 1D; FIG. 2E is a cross-sectional view taken along line A-A in FIG. 1E; fig. 3A and 3B are plan views illustrating two substrates to be bonded and a bonding region according to an embodiment; FIG. 4 is a flowchart presenting a process of bonding a first substrate and a second substrate together according to an embodiment; fig. 5A is a view for explaining the application of the main adhesive to the first substrate in step 401 in fig. 4; fig. 5B is an enlarged view illustrating a portion of the first substrate shown in fig. 5A; fig. 6A is a view for applying a temporary adhesive to a first substrate in step 402 of fig. 4; fig. 6B is an enlarged view illustrating a portion of the first substrate shown in fig. 6A; fig. 7 is a view for explaining an operation of pressin