Microchip

1. A microchip comprising a first substrate bonded to a second substrate and including a groove on its surface, the microchip further comprising:

a fluid circuit defined by said groove and a surface of said second substrate closer to said first substrate therein, wherein

said fluid circuit includes a separation portion for separating a first component from a fluid containing at least said first component and a second component,

said separation portion includes a substantially V-shaped region surrounded by points P 1 , P 2 , P 3 , P 4 , P 5 and P 6 arranged clockwise as viewed from the thickness direction of said first substrate,

said substantially V-shaped region is a region formed by a flow channel wall W 2 having a wall surface passing through the point P 2 and the point P 3 , a flow channel wall W 3 having a wall surface passing through the point P 3 and the point P 4 , a flow channel wall W 4 having a wall surface passing through the point P 4 and the point P 5 , a flow channel wall W 5 having a wall surface passing through the point PS and the point P 6 , and a flow channel wall W 6 having a wall surface passing through the point P 6 and the point P 1 , and

an external angle formed by the wall surface of said flow channel wall W 2 passing through the point P 2 and the point P 3 and the wall surface of the flow channel wall W 3 passing through the point P 3 and the point P 4 and an internal angle formed by the wall surface of said flow channel wall W 5 passing through the point P 5 and the point P 6 and the wall surface of the flow channel wall W 6 passing through the point P 6 and the point P 1 are less than 180 degrees respectively.

2. The microchip according to claim 1 , wherein

a portion having no flow channel wall reaching said point P 2 from said point P 1 is an opening for introducing said fluid.

3. The microchip according to claim 2 , wherein

the depth of the groove in said opening is smaller than the depth of the groove in a region B surrounded by said point P 3 , the point P 4 , the point P 5 and the point P 6 , and

the groove bottom surface in a region forming a part of a region A surrounded by said point P 1 , the point P 2 , the point P 3 and the point P 6 and including a straight line passing through said point P 3 and the point P 6 has an is inclined structure changing from the depth of the groove in said opening to the depth of the groove in said region B.

4. The microchip according to claim 2 , wherein

said fluid circuit further has a flow rate limiting portion for limiting the flow rate of said fluid introduced into said separation portion above said opening as viewed from the thickness direction of said first substrate, and

a groove constituting said flow rate limiting portion is constituted of a linearly extending flow channel wall W 7 and a flow channel wall W 8 formed to be opposed to said flow channel wall W 7 .

5. The microchip according to claim 4 , wherein

the groove constituting said flow rate limiting portion is formed by a linear wall surface belonging to said flow channel wall W 7 and another linear wall surface belonging to said flow channel wall W 8 , and

the linear wall surface belonging to said flow channel wall W 7 and the linear wall surface belonging to said flow channel wall W 8 are substantially parallel to each other.

6. The microchip according to claim 5 , wherein

the distance from said point P 1 to said point P 2 is three to 10 times as large as the distance between the linear wall surface belonging to said flow channel wall W 7 and the linear wall surface belonging to said flow channel wall W 8 .

7. The microchip according to claim 4 , wherein said flow channel wall W 7 extends to said point P 2 .

8. The microchip according to claim 7 , wherein

an external angle formed by the linear wall surface belonging to said flow channel wall W 7 and the wall surface of said flow channel wall W 2 passing through the point P 2 and the point P 3 is larger than 180 degrees and smaller than 240 degrees.

9. A microchip comprising a first substrate bonded to a second substrate and including a groove on its surface, the microchip further comprising:

a fluid circuit defined by said groove and a surface of said second substrate closer to said first substrate therein, wherein

said fluid circuit includes a separation portion for separating a first component from a fluid, having an opening for introducing said fluid containing at least said first component and a second component, and a flow rate limiting portion arranged above said opening for limiting the flow rate of said fluid introduced into said separation portion,

said flow rate limiting portion in said first substrate is formed by a flow channel wall W 7 having a linearly extending wall surface a and a flow channel wall W 8 having a linearly extending wall surface b substantially parallel to said wall surface a,

an angle θ 4 formed by a wall surface c, belonging to said flow channel wall W 8 , on a side of said opening and said wall surface a satisfies 90 degrees<θ4<180 degrees, and

the following expression (1) is satisfied assuming that L 1 represents the distance between said wall surface a and said wall surface b, L 2 represents the width of said opening and R represents the radius of curvature of a corner portion of said flow channel wall W 8 formed by said wall surface b and said wall surface c:

2×( L 1+ R )< L 2  (1).