Laser welding methods and structures and control therefor including welded inkjet printheads

• US 7,354,137 B2
• Filed: 08/16/2004
• Issued: 04/08/2008
• Est. Priority Date: 11/19/2002
• Status: Expired due to Fees

• Current Assignee: Funai Electric Co., Ltd.
• Original Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Inventors: Drummond, James Paul, Kwan, Kin-Ming, Whitney, Jon Brock, Phatak, Ganesh Vinayak
• Primary Examiner(s): FEGGINS, KRISTAL J
• Application Number:
  US10/918,940
• Publication Number:
  US 20050024455A1
• Time in Patent Office: 1,331 Days
• Field of Search: 347/49, 347/86, 347/108, 219/121.63, 219/121.64, 219/121.66, 219/121.6, 156/272.8, 298/901, 298/40, 298/32, 295/93, 228/180.22, 228/279
• US Class Current: 347/49
• CPC Class Codes: B29C 65/1606 Ultraviolet [UV] radiation, e.g. by ultraviolet excimer lasers
• CPC Class Codes: B29C 65/1616 Near infrared radiation [NIR], e.g. by YAG lasers
• CPC Class Codes: B29C 65/1635 at least passing through one of the parts to be joined, i.e. laser transmission welding
• CPC Class Codes: B29C 65/1654 scanning at least one of the parts to be joined
• CPC Class Codes: B29C 65/1664 making use of several radiators
• CPC Class Codes: B29C 65/1667 at the same time, i.e. simultaneous laser welding
• CPC Class Codes: B29C 65/1674 making use of laser diodes B29C65/167 takes precedence
• CPC Class Codes: B29C 65/1687 making use of light guides
• CPC Class Codes: B29C 65/48 using adhesives , i.e. using supplementary joining material; solvent bonding
• CPC Class Codes: B29C 65/542 by injection
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/114 Single butt joints
• CPC Class Codes: B29C 66/1222 comprising at least a lapped joint-segment
• CPC Class Codes: B29C 66/1224 comprising at least a butt joint-segment
• CPC Class Codes: B29C 66/12449 being asymmetric B29C66/12445 takes precedence
• CPC Class Codes: B29C 66/1282 comprising at least one overlap joint-segment
• CPC Class Codes: B29C 66/12841 comprising at least two butt joint-segments
• CPC Class Codes: B29C 66/21 said joint lines being formed by a single dot or dash or by several dots or dashes, i.e. spot joining or spot welding
• CPC Class Codes: B29C 66/24244 forming a rectangle
• CPC Class Codes: B29C 66/30223 said melt initiators being rib-like
• CPC Class Codes: B29C 66/322 : Providing cavities in the joined article to collect the burr
• CPC Class Codes: B29C 66/53461 : joining substantially flat covers and/or substantially flat bottoms to open ends of container bodies
• CPC Class Codes: B29C 66/542 : joining hollow covers or hollow bottoms to open ends of container bodies
• CPC Class Codes: B29C 66/61 : Joining from or joining on the inside for making tubes by bending sheets and joining from the inside B29C53/387
• CPC Class Codes: B29C 66/71 : characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/73161 : Roughness or rugosity
• CPC Class Codes: B29C 66/73321 : both parts to be joined being coloured
• CPC Class Codes: B29C 66/7352 : Thickness, e.g. very thin
• CPC Class Codes: B29C 66/73921 : characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/8322 : Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29K 2009/00 : Use of rubber derived from conjugated dienes, as moulding material
• CPC Class Codes: B29K 2009/06 : SB polymers, i.e. butadiene-styrene polymers
• CPC Class Codes: B29K 2025/06 : PS, i.e. polystyrene
• CPC Class Codes: B29K 2025/08 : Copolymers of styrene, e.g. AS or SAN, i.e. acrylonitrile styrene B29K2055/02 takes precedence
• CPC Class Codes: B29K 2055/02 : ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2067/003 : PET, i.e. poylethylene terephthalate
• CPC Class Codes: B29K 2067/006 : PBT, i.e. polybutylene terephthalate
• CPC Class Codes: B29K 2067/04 : Polyesters derived from hydroxycarboxylic acids
• CPC Class Codes: B29K 2069/00 : Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2071/12 : PPO, i.e. polyphenylene oxide; PPE, i.e. polyphenylene ether
• CPC Class Codes: B29K 2995/0025 : Opaque
• CPC Class Codes: B29K 2995/0027 : for light outside the visible spectrum
• CPC Class Codes: B29K 2995/0072 : Roughness, e.g. anti-slip
• CPC Class Codes: B29L 2031/767 : Printing equipment or accessories therefor
• CPC Class Codes: B41J 2/17513 : Inner structure
• CPC Class Codes: B41J 2/17559 : Cartridge manufacturing

Abstract

In a system for laser welding work pieces along a collapsing weld interface, methods and apparatus include providing welding pads and/or stop projections on either or both of the work pieces to control the manner or amount of collapse. Preferably, the stop projections exist a separation distance from the weld interface while the welding pads exist at and form a portion of the weld interface. Buffers are taught between the weld interface and stop projection. The work pieces may comprise inkjet printhead lids and bodies. In another aspect, the invention teaches methods of laser welding inkjet printhead lids and bodies according to whether the inkjet printhead body embodies a mono or color ink body type and especially includes selective control of one or more laser light sources to illuminate the inkjet printhead lid in a specific pattern of light.

Claims

1. An inkjet printhead, comprising:

a lid transparent to laser light;

a body that is laser light absorbent; and

a welding pad having a volume prior to welding located on one of the lid and body,

whereby said welding pad is laser welded at a weld interface to a surface of the other of the lid and body to substantially prevent bowing of a weld joint at the weld interface.

2. The inkjet printhead of claim 1, wherein the welding pad is integrally formed on one of the lid and body.

3. The inkjet printhead of claim 1, wherein prior to welding the welding pad has a height, width, and length, such that the height is less than the width and the length is substantially equal to a length of one of the lid and body.

4. The inkjet printhead of claim 1, wherein more than one welding pad exists on one of the lid and body.

5. The inkjet printhead of claim 4, wherein a horizontal distance exists between at least one of the more than one welding pad and another one of the more than one welding pad.

6. The inkjet printhead of claim 1, wherein the lid has a first welding pad and the body has a second welding pad.

7. The inkjet printhead of claim 6, wherein the first and second welding pad each have a side surface that exist adjacent to one another when contacted.

8. The inkjet printhead of claim 6, wherein the second welding pad has a surface that exists substantially flush with a surface of the body.

9. The inkjet printhead of claim 6, wherein the first welding pad exists at a terminal end of the lid.

10. The inkjet printhead of claim 6, wherein the first welding pad does not exist at a terminal end of the lid.

11. The inkjet printhead of claim 1, wherein the lid is configured to transmit laser light at a rate of above 50%.

12. The inkjet printhead of claim 1, wherein the lid comprises a material selected from the group consisting of polyphenylene ether, polystyrene, copolyesters, polyethylene terephthalate, glycol modified polyethylene terephthalate, glycol modified polycyclohexylenemethylene terephthalate, polybutylene terephthalate, acid modified polycyclohexylenemethylene terephthalate, styrene methyl methacrylate, styrene acrylonitrile, acrylonitrile butadiene styrene, methacrylate acrylonitrile butadiene styrene, and compositions thereof.

13. The inkjet printhead of claim 1, wherein the body comprises a material selected from the group consisting of polystyrene, styrene-butadiene copolymers, styrene-acrylic copolymers, polyesters, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, acrylonitrile styrene acrylic, and compositions thereof.

14. An inkjet printhead, comprising:

a lid transparent to laser light;

a body that is laser light absorbent;

a welding pad having a volume prior to welding located on one of the lid and body; and

a stop projection located on one of the lid and body contacting a surface of the other of the lid and body,

whereby said welding pad is laser welded at a weld interface to a surface of the other of the lid and body to substantially prevent bowing of a weld joint at the weld interface and said stop projection existing at a separation distance from the weld interface to control a distance of collapse at the weld interface between said lid and said body.

15. The inkjet printhead of claim 14, wherein a buffer exists between the weld interface and the stop projection.