Microchip and method of manufacturing the same

1. A microchip, comprising a fluid circuit consisting of a space formed therein, moving a liquid present in said fluid circuit to a desired position in said fluid circuit,

including a light-absorbing first substrate and a light-transmitting second substrate bonded onto said first substrate, and

further including a groove, having a V-shaped section, extending parallelly to said fluid circuit on a surface of said second substrate opposite to said first substrate on a position immediately above at least part of said fluid circuit.

2. The microchip according to claim 1 , wherein

both end portions of said groove in the width direction are positioned immediately above bonded portions where said first substrate and said second substrate are in contact with each other.

3. The microchip according to claim 1 , wherein

said V-shaped section of said groove is in the form of an isosceles triangle, and satisfies the following expression (1):

L=[a ·tan(θ−θ′)]/[1+tan θ·tan(θ−θ′)]  (1)

where L represents ½ of the distance between both end portions of said groove in the width direction, a represents the distance from a surface of said second substrate provided with said groove to said fluid circuit, and θ represents an angle formed by a straight line connecting said both end portions of said groove in the width direction with each other and inclined surfaces constituting said groove. θ′ represents an angle satisfying the following expression (2):

sin θ/sin θ′= n/ 1  (2)

where n represents the refractive index of said second substrate.

4. A method of manufacturing the microchip according to claim 1 , comprising the steps of:

arranging said second substrate on said first substrate;

welding said first substrate and said second substrate to each other by applying light to the side of said second substrate from a direction perpendicular to said surface of said second substrate opposite to said first substrate.

5. A microchip, comprising a fluid circuit consisting of a space formed therein, moving a liquid present in said fluid circuit to a desired position in said fluid circuit,

including a light-absorbing first substrate and a light-transmitting second substrate bonded onto said first substrate, wherein

said fluid circuit consists of a space formed by a groove provided on a surface of said second substrate closer to said first substrate and said first substrate, and

the microchip further comprises a tapered structure portion including a protrusion having a sectional shape of an isosceles triangle and an apical angle of 90°.

6. The microchip according to claim 5 , wherein

said tapered structure portion is formed by parallelly arraying a plurality of protrusions in the form of triangular prisms having sectional shapes of isosceles triangles and apical angles of 90°.

7. The microchip according to claim 5 , wherein

said tapered structure portion is formed by adjacently arraying a plurality of protrusions in the form of quadrangular pyramids having sectional shapes of isosceles triangles and apical angles of 90°.

8. The microchip according to claim 5 , further including a groove, having a V-shaped section, extending parallelly to said fluid circuit on another surface of said second substrate opposite to said first substrate on a position immediately above at least part of said fluid circuit.

9. A method of manufacturing the microchip according to claim 5 , comprising the steps of:

arranging said second substrate on said first substrate; and

welding said first substrate and said second substrate to each other by applying light to the side of said second substrate from a direction perpendicular to said surface of said second substrate opposite to said first substrate.

10. A microchip comprising a first substrate having a recess portion divided by a partition on at least a first surface and a second substrate bonded onto at least said first surface of said first substrate, and

including a fluid circuit constituted of said recess portion and a surface of said second substrate, wherein

at least part of a forward end of said partition of said first substrate dividing said recess portion is welded to said second substrate through a welding rib.

11. The microchip according to claim 10 , wherein

said welding rib partially has a liquid movement preventing stopper longer than the remaining portion in the thickness direction of said partition.