Fabrication Method of Microfluidic Circuit, and Microfluidic Circuit Fabricated by Method Thereof

• US 20110244559A1
• Filed: 06/13/2011
• Published: 10/06/2011
• Est. Priority Date: 05/16/2006
• Status: Active Grant

• Current Assignee: Horiba Limited
• Original Assignee: ROHM Co., Ltd.
• Inventors: MOMOSE, Shun
• Granted Patent: US 8,377,391 B2
• Time in Patent Office: Days
• US Class Current: 435/287.3
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B29C 2035/0827 using UV radiation
• CPC Class Codes: B29C 65/14 using wave energy , i.e. electromagnetic radiation, or particle radiation using mechanical waves B29C65/06; using ultrasonic waves B29C65/08; pressing means transparent to electromagnetic radiation B29C66/81267
• CPC Class Codes: B29C 65/1406 Ultraviolet [UV] radiation
• CPC Class Codes: B29C 65/1435 at least passing through one of the parts to be joined, i.e. transmission welding
• CPC Class Codes: B29C 65/149 being a part of the joined article
• CPC Class Codes: B29C 65/1493 in the form of a cavity
• CPC Class Codes: B29C 65/1496 making use of masks B29C65/1696 takes precedence
• 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 65/169 being a part of the joined article
• CPC Class Codes: B29C 65/1693 in the form of a cavity
• CPC Class Codes: B29C 65/1696 making use of masks
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/114 Single butt joints
• CPC Class Codes: B29C 66/5346 said single elements being substantially flat
• 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 66/71 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 66/73341 : at least one of the parts to be joined being glossy or reflective
• CPC Class Codes: B29C 66/73343 : at least one of the parts to be joined being matt or refractive
• CPC Class Codes: B29C 66/73365 : at least one of the parts to be joined being transparent or translucent to visible light
• CPC Class Codes: B29C 66/73521 : of different thickness, i.e. the thickness of one of the parts to be joined being different from the thickness of the other part
• CPC Class Codes: B29C 66/73921 : characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/836 : Moving relative to and tangentially to the parts to be joined, e.g. transversely to the displacement of the parts to be joined, e.g. using a X-Y table B29C66/65 takes precedence
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2023/38 : Polymers of cycloalkenes, e.g. norbornene or cyclopentene
• CPC Class Codes: B29K 2025/00 : Use of polymers of vinyl-aromatic compounds or derivatives thereof as moulding material
• CPC Class Codes: B29K 2025/06 : PS, i.e. polystyrene
• CPC Class Codes: B29K 2027/06 : PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2033/12 : Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• 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 2069/00 : Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• 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 2031/756 : Microarticles, nanoarticles
• CPC Class Codes: B81B 2201/058 : Microfluidics not provided for in B81B2201/051 - B81B2201/054
• CPC Class Codes: B81C 3/001 : Bonding of two components
• CPC Class Codes: Y10T 29/49826 : Assembling or joining
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

A fabrication method of a microfluidic circuit is provided, dispensable of mask registration, absent of deviation in mask positioning, and inexpensive in fabrication cost. The fabrication method of a microfluidic circuit has a light transmissive substrate stacked on a light absorptive substrate, and the light transmissive substrate welded with the light absorptive substrate for bonding by directing light through the light transmissive substrate. The microfluidic circuit includes a microchannel at the bottom face of the light transmissive substrate and/or at the top face of the light absorptive substrate. The method includes the step of forming, at the light transmissive substrate, a light attenuation region attenuating transmittance of light towards the microchannel when light is directed through the light transmissive substrate.

Claims

1. A fabrication method of a microfluidic circuit having a light transmissive substrate stacked on a light absorptive substrate, and said light transmissive substrate welded with said light absorptive substrate for bonding by directing light through said light transmissive substrate,

said microfluidic circuit including a microchannel at a bottom face of said light transmissive substrate and/or at a top face of said light absorptive substrate, said method comprising the step of:

forming, at said light transmissive substrate, a light attenuation region attenuating an amount of transmitted light towards said microchannel when light is directed through said light transmissive substrate.

2. The fabrication method of a microfluidic circuit according to claim 1, wherein the amount of transmitted light at said microchannel is attenuated, by said light attenuation region, to not more than 80% of an amount of directed light to said light transmissive substrate.

3. The fabrication method of a microfluidic circuit according to claim 1, wherein said light attenuation region at said light transmissive substrate includes a surface having an arithmetical mean roughness Ra of 1 μ

m to 50 μ

m.

4. The fabrication method of a microfluidic circuit according to claim 1, wherein said light attenuation region at said light transmissive substrate includes a cavity having a face to which directed light does not enter perpendicularly.

5. The fabrication method of a microfluidic circuit according to claim 4, wherein said light transmissive substrate has a thickness d and a refraction index n, and includes a microchannel of a width w at a bottom face, and a value of (d/w) tan [90−

θ

−

sin<sup>−

1</sup>{(sin(90−

θ

))/n}] is at least 0.1, where θ

is an incident angle of directed light transmitted to said microchannel.

6. The fabrication method of a microfluidic circuit according to claim 1, wherein said light attenuation region at said light transmissive substrate contains a light blocking material.

14. A microfluidic circuit fabricated by the method of claim 1.

7-13. -13. (canceled)