Abstract:
A microfluidic device includes a processing layer and a temperature control layer. The processing layer applies a predetermined process to a subject fluid. The temperature control layer is disposed adjacent to the processing layer to give a predetermined temperature environment to the processing layer.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a microfluidic device produced by a layer manufacturing technology and particularly relates to a microfluidic device, which can be produced easily and can give an optimum processing environment to a process such as reaction of subject fluid. 
     2. Description of the Related Art 
     In the field of parts manufacture, a layer manufacturing technology has been recently spread rapidly as a method for forming a computer-designed complex three-dimensional object in a short time. In most cases, the layer manufacturing technology has been applied to relatively large parts with a size not smaller than the order of cm. In recent years, this method has been also applied to microstructures formed by high-precision processing, such as micro-gears, micro-optical parts, microfluidic devices, etc. 
     Microfluidic device is a generic terms of “microreactor”, “lab-on a chip” or “micro total analytical systems (μ-TAS)”. A microfluidic device can be integrated with another microfluidic device having another function such as synthesis, physicochemical treatment, detection to construct a microchemical system. Because the microfluidic devices are excellent in uniformity of reaction solution temperature and good in temperature response, it is possible to shorten reaction time and save the amount of a sample and the amount of a solvent used. Accordingly, because resources and energy required for production of a device can be saved, the microfluidic devices have merits in energy conservation in operation, reduction in the amount of waste, etc. There is expectation that the microfluidic devices will contribute to many industries in the future. 
     A microreactor provided as a kind of microfluidic device is a device having a micro reaction field smaller by several orders than that of an conventional reactor. In most cases, the microreactor uses a channel having a diameter of from 1 mm to the order of micros as the reaction field. Accordingly, the microreactor is also referred to as “micro channel reactor”. It is conceived that temperature control can be performed accurately on the basis of reduction in heat capacity because the device surface area per unit volume of such a microreactor is large. Researches into the microreactor have been advanced in various countries because the microreactor is a device particularly having an appeal for catalytic reaction sensitive to temperature and having a reaction rate dependent on the contact area (e.g. see US2005/106078 A). 
       FIG. 17  shows a microreactor described in US 2005/106078 A. This microreactor  100  is a microstructure provided as a laminate of a first pattern layer  110  serving as a top surface, a plurality of second pattern layers  120  each having a reaction portion  123  in which two source fluids L 1  and L 2  meet (merge into) and react with each other, and a third pattern layer  130  serving as a bottom portion. 
     The first pattern layer  110  has: first and second inlets  111   a  and  111   b  for inletting the two source fluids L 1  and L 2  in respectively; and an outlet  120  from which a reaction liquid M obtained as a product of reaction of the source fluids L 1  and L 2  is drained. 
     Each of the second pattern layers  120  defines: through-holes  121   a ,  121   b  and  121   d  defined so as to correspond to the inlets  111   a  and  111   b  and the outlet  112 ; a junction  122  in which the two source fluids L 1  and L 2  led in meet with (merge into) each other; and a reaction portion  123  in which the two source fluids L 1  and L 2  react with each other. 
     The microreactor  100  is produced in such a manner that the first to third pattern layers  110  to  130  formed from a glass substrate are pressurized and laminated by thermal fusion. When a plurality of pattern layers each having the same structure as the second pattern layer  120  are laminated, a plurality of reactions can be performed by parallel processing. 
     SUMMARY OF THE INVENTION 
     In the microreactor  100  according to US 2005/106078 A, the source fluids L 1  and L 2  are merged to flow together and react each other in the second pattern layer  120 , which is a micro pattern layer. Therefore, in most cases, the reaction environment represented by the temperature condition can be hardly kept optimal. 
     The invention provides a microfluidic device, which can be produced easily and can give an optimum processing environment to a process such as reaction of subject fluid. 
     According to one embodiment of the invention, a microfluidic device includes a processing layer and a temperature control layer. The processing layer applies a predetermined process to a subject fluid. The temperature control layer is disposed adjacent to the processing layer to give a predetermined temperature environment to the processing layer. 
     According to this structure, an optimum process can be applied to subject fluid because the temperature control layer gives a predetermined temperature environment to the processing layer. 
     The processing layer may perform as the predetermined process one process selected from making the subject fluid a laminar flow, dividing flow of the subject fluid, merging the subject fluid and another fluid flow together, mixing the subject fluid and another fluid, making the subject fluid react, synthesizing another material from the subject fluid, diluting the subject fluid, washing the subject fluid and concentrating the subject fluid. The term “predetermined temperature environment” means a temperature environment for optimizing a process such as merging the subject fluid and another fluid to flow together and making the subject fluid react, and includes processing temperature such as reaction temperature, junction temperature, etc. 
     Here, the expression “merging fluid A and fluid B to flow together” means making the fluid A and the fluid B flow laminarly. Also, the expression “mixing fluid A and fluid B” means mixing the fluid A and the fluid B completely. 
     The processing layer and the temperature control layer may be laminated by room-temperature bonding. The term “room-temperature bonding” means direct bonding of atoms at room temperature. According to the room-temperature bonding, variations in shape and thickness of the constituent layers are so little that a high-precision microfluidic device can be obtained. A metal such as Al, Ni or Cu or a non-metal such as ceramics or silicon can be used as the material of the constituent layers. Before bonding of the constituent layers, the surfaces of the constituent layers may be irradiated with natural atom beams, ion beams or the like so that the surfaces of the constituent layers are washed. The surfaces are activated by washing, so that firm bonding can be obtained. 
     Each of the processing layer and the temperature control layer may be formed by electroforming or a semiconductor patterning process. In the case of electroforming, a metal substrate is used as the substrate. In the case where a semiconductor patterning process, such as photolithography and etching process for making fine patterns for the integrated semiconductor devices, is used, an Si wafer, a glass substrate, a quartz substrate or the like is used as the substrate. 
     According to one embodiment of the invention, a microfluidic device includes a first processing layer, a second processing layer, and a pair of temperature control layers. The first processing layer makes a plurality of subject fluids react with each other. In the second processing layer, a reaction fluid obtained as a product of reaction of the subject fluids is washed. One of the temperature control layers is disposed on one side of the first processing layer opposite to the second processing layer. The other of the temperature control layers is disposed between the first and second processing layers. The temperature control layers give a predetermined temperature environment to the first processing layer. 
     According to this structure, an optimum process can be applied to a plurality of subject fluids because the pair of temperature control layers gives a predetermined temperature environment to the first processing layer. 
     According to one embodiment of the invention, a microfluidic device includes a first processing layer, a second processing layer, a third processing layer, a pair of first temperature control layers, a pair of second temperature control layers, and a heat-insulating layer. The first processing layer makes a plurality of subject fluids to perform a first reaction in a first temperature region to produce a reaction fluid. The second processing layer makes a reaction fluid obtained as a product of the first reaction or the reaction fluid and another subject fluid to perform a second reaction in a second temperature region. In the third processing layer, a reaction fluid obtained as a product of the second reaction is washed. One of the first temperature control layers is disposed on a side of the first processing layer opposite to the second processing layer. The other of the first temperature control layers is disposed between the first and second processing layers. The first temperature control layers give a predetermined temperature environment to the first processing layer. One of the second temperature control layers is disposed on a side of the second processing layer opposite to the third processing layer. The other of the second temperature control layers is disposed between the second and third processing layers. The second temperature control layers give a predetermined temperature environment to the second processing layer. The heat-insulating layer is provided between the one of the first temperature control layers and the one of the second temperature control layers. The heat-insulating layer includes a closed space that shields heat conduction between the first and second processing layers. 
     According to this structure, an optimum process can be applied to a plurality of subject fluids even if the reaction temperature of the first processing layer is different from the reaction temperature of the second processing layer because the pair of first temperature control layers give a predetermined temperature environment to the first processing layer, the pair of second temperature control layers give a predetermined temperature environment to the second processing layer and the heat-insulating layer thermally insulates the first and second processing layers from each other. 
     According to the invention, an optimum processing environment can be given to a process such as reaction of subject fluid. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will be described in detail based on the following figures, wherein: 
         FIG. 1A  is a perspective view showing a microreactor according to a first embodiment of the invention; and  FIG. 1B  is a plan view of respective pattern layers in the microreactor; 
         FIG. 2A  is a plan view showing a donor substrate having pattern layers for forming the microreactor depicted in  FIGS. 1A and 1B ; and  FIG. 2B  is a sectional view taken along the line A-A in  FIG. 2A ; 
         FIG. 3A  is a plan view showing a pattern layer on the donor substrate;  FIG. 3B  is a sectional view taken along the line B-B in  FIG. 3A ; and  FIGS. 3C to 3F  are sectional views showing a process of producing the pattern layer by a two-stage electroforming method; 
         FIGS. 4A to 4C  are typical views showing a transfer process using a bonding apparatus,  FIG. 4A  being a view showing an FAB processing step,  FIG. 4B  being a view showing the step of bonding pattern layers,  FIG. 4C  being a view showing the step of removing the pattern layers; 
         FIG. 5A  is a fluid circuit diagram showing the operation of the microreactor according to the first embodiment of the invention; and  FIG. 5B  is a perspective view showing a flow of fluid in the microreactor; 
         FIG. 6A  is a perspective view showing a microreactor according to a second embodiment of the invention; and  FIG. 6B  is a plan view of respective pattern layers in the microreactor; 
         FIG. 7A  is a fluid circuit diagram showing the operation of the microreactor according to the second embodiment of the invention; and  FIG. 7B  is a perspective view showing a flow of fluid in the microreactor; 
         FIG. 8A  is a perspective view showing a microreactor according to a third embodiment of the invention; and  FIG. 8B  is a plan view of respective pattern layers in the microreactor; 
         FIG. 9  is an exploded perspective view showing a flow of fluid in the microreactor according to the third embodiment of the invention; 
         FIG. 10A  is a perspective view showing a microreactor according to a fourth embodiment of the invention; and  FIG. 10B  is a plan view of respective pattern layers in the microreactor; 
         FIG. 11  is an exploded perspective view showing a flow of fluid in the microreactor according to the fourth embodiment of the invention; 
         FIG. 12A  is a perspective view showing a microreactor according to a fifth embodiment of the invention; and  FIG. 12B  is a plan view of respective pattern layers in the microreactor; 
         FIG. 13  is an exploded perspective view showing a flow of fluid in the microreactor according to the fifth embodiment of the invention; 
         FIG. 14  is a perspective view of a microreactor according to a sixth embodiment of the invention; 
         FIGS. 15A and 15B  are exploded perspective views of the microreactor according to the sixth embodiment of the invention,  FIG. 15A  showing pattern layers having respective functions,  FIG. 15B  showing pattern layers laminated between the pattern layers having the respective functions; 
         FIGS. 16A to 16F  show pattern layers according to the sixth embodiment of the invention,  FIG. 16A  being a plan view of the first pattern layer,  FIG. 16B  being a sectional view taken along the line A-A in  FIG. 16A ,  FIG. 16C  being a plan view of the second pattern layer,  FIG. 16D  being a sectional view taken along the line D-D in  FIG. 16C ,  FIGS. 16E and 16F  being sectional views showing a method for producing a donor substrate by a one-stage electroforming method; and 
         FIG. 17  is an exploded perspective view of a microreactor according to the background art. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     First Embodiment 
       FIG. 1A  is a perspective view showing a microreactor  1  according to a first embodiment of the invention.  FIG. 1B  is a plan view showing respective pattern layers in the microreactor. This microreactor  1  operates so that a reaction liquid as a product of reaction of two source fluids L 1  and L 2  under a predetermined temperature is washed and ejected. This microreactor  1  is provided as a laminate of six pattern layers  13 A to  13 F. The first pattern layer  13 A leads the two source fluids L 1  and L 2  in. The second pattern layer  13 B serves as a processing layer having a junction at which the source fluids L 1  and L 2  meet with (merge into) each other. The fourth pattern layer  13 D serves as a processing layer having a reaction portion in which the source fluids L 1  and L 2  react with each other to produce a reaction liquid M. The third and fifth pattern layers  13 C and  13 E serve as temperature control layers in which constant-temperature water W 1 , which serves as a heat exchange medium controlled to be kept at a predetermined temperature, flows to keep the temperature of the reaction portion of the fourth pattern layer  13 D constant. The sixth pattern layer  13 F has a washing portion for washing the reaction liquid M. 
     The first pattern layer  13 A defines: first and second inlets  2   a  and  2   b  for leading the two source fluids L 1  and L 2  in, respectively; a constant-temperature water inlet  3  for leading the constant-temperature water W 1  in; and a constant-temperature water outlet  4  for ejecting used constant-temperature water W 1 ′. 
     The second pattern layer  13 B defines: inlet holes  5   a  and  5   b  and through-holes  6   a  and  6   b  defined so as to correspond to the inlets  2   a  and  2   b , constant-temperature water inlet  3  and constant-temperature water outlet  4  of the first pattern layer  13 A; channels  7   a  and  7   b  through which the source fluids L 1  and L 2  flow laminarly and meet with (merge into) each other at a junction  8 ; and a through-hole  9   a  through which the source fluids L 1  and L 2  merged at the junction  8  flow down to the third pattern layer  13 C under the second pattern layer  13 B. 
     The third pattern layer  13 C defines: a constant-temperature water inlet hole  15   a , a constant-water ejection hole  16   a  and a through-hole  9   b  defined so as to correspond to the through-holes  6   a ,  6   b  and  9   a  of the second pattern layer  13 B, respectively; and a plurality of groove portions  17   a  for connecting the constant-temperature water inlet hole  15   a  and the constant-water ejection hole  16   a  to each other. 
     The fourth pattern layer  13 D defines: through-holes  6   c  and  6   d  and a inlet hole  5   c  defined so as to correspond to the constant-temperature water inlet hole  15   a , constant-water ejection hole  16   a  and through-hole  9   b  of the third pattern layer  13 C, respectively; a reaction portion  30  in which the source fluids L 1  and L 2  led in through the inlet hole  5   c  react with each other; and a through-hole  9   c  through which the reaction liquid M as a product of reaction of the source fluids L 1  and L 2  flows down to the fifth pattern layer  13 E under the fourth pattern layer  13 D. 
     The fifth pattern layer  13 E defines: a constant-temperature water inlet hole  15   b , a constant-temperature water ejection hole  16   b  and a through-hole  9   d  defined so as to correspond to the through-holes  6   c ,  6   d  and  9   c  of the fourth pattern layer  13 D, respectively; and a plurality of groove portions  17   b  for connecting the constant-temperature water inlet hole  15   b  and the constant-temperature water ejection hole  16   b  to each other. 
     The sixth pattern layer  13 F defines: a reaction liquid M inlet hole  5   d  defined so as to correspond to the through-hole  9   d  of the fifth pattern layer  13 E; a washing water inlet  18  provided as a through-hole for leading washing water such as distilled water in upward; washing water channels  32   a  and  32   b  for flowing the washing water from the washing water inlet  18  to a junction  34 ; a channel  7   c  for flowing the reaction liquid M from the inlet hole  5   d  to a washing channel  31 ; the washing channel  31  for leading the washing water from the junction  34  and flowing the washing water as a laminar flow while bringing the washing water into contact with the reaction liquid M from the inlet hole  5   d ; a through-hole  9   e  from which the washed reaction liquid M separated at a flow-dividing portion  35  is ejected to the outside of the microreactor  1  through a channel  7   d ; and a washing water outlet  19  from which waste water after washing is ejected to the outside of the microreactor  1  through washing water channels  32   c  and  32   d.    
     (Production Method According to the First Embodiment) 
     Next, a method for producing the microreactor  1  according to the first embodiment will be described with reference to  FIGS. 2A and 2B ,  FIGS. 3A to 3F  and  FIGS. 4A to 4C .  FIG. 2A  is a plan view showing a donor substrate having pattern layers making up the microreactor depicted in  FIGS. 1A and 1B .  FIG. 2B  is a sectional view taken along the line A-A in  FIG. 2A .  FIGS. 3A to 3F  show a pattern layer on the donor substrate.  FIG. 3A  is a plan view of the pattern layer.  FIG. 3B  is a sectional view taken along the line B-B in  FIG. 3A .  FIGS. 3C to 3F  are sectional views showing a process for producing the pattern layer by a two-stage electroforming method.  FIGS. 4A to 4C  are typical views showing a transfer process using a bonding apparatus.  FIG. 4A  is a view showing an FAB (Fast Atom Beam) processing step.  FIG. 4B  is a view showing the step of bonding the pattern layers.  FIG. 4C  is a view showing the step of removing the pattern layers. 
     (Producing of Donor Substrate) 
     The donor substrate  10  shown in  FIGS. 2A and 2B  is prepared. A method for producing the donor substrate by a two-stage electroforming method will be described here with reference to  FIGS. 3A to 3F . First, a substrate  11  of a metal is prepared. A first photo resist is applied on the substrate  11  and exposed to light while a first photomask corresponding to the respective pattern layers of the microreactor  1  to be produced is used. Then, the photo resist is developed to form a first resist pattern  38 , which is reversal of each sectional pattern. 
     Then, as shown in  FIG. 3C , electroforming is applied to the substrate  11  having the resist pattern  38  formed thereon, so that a nickel plating layer  41   a  is grown on a surface of the substrate  11 , which is not covered with the photo resist. Then, as shown in  FIG. 3D , the first resist pattern  38  is removed. 
     Then, a second photo resist is applied on the substrate  11  and exposed to light while a second photomask corresponding to the respective pattern layers of the microreactor  1  to be produced is used. Then, as shown in  FIG. 3E , the photo resist is developed to form a second resist pattern  39 , which is reversal of each sectional pattern. Then, as shown in  FIG. 3F , electroforming is applied to the substrate  11  having the resist pattern  39  formed thereon, so that a nickel plating layer  41   b  is further formed on a surface of the nickel plating layer  41   a  in a portion of the substrate  11 , which is not covered with the photo resist. Then, the second resist pattern  39  is removed. Thus, the pattern layer  13 B shown in  FIG. 3B  is obtained. 
     (Transfer Process) 
     Then, a transfer process based on room-temperature bonding is carried out. First, as shown in  FIG. 4A , the donor substrate  10  is fixed to a planar stage  25  in a vacuum chamber  21  while a target substrate  27  is fixed to a counter stage  26 . The vacuum chamber  21  is evacuated through an air outlet  22  to form a vacuum of 10 −6  Pa. Then, FABs (Fast Atom Bombardments) made of Ar neutral beams emitted from FAB sources  24 A and  24 B are applied on the target substrate  27  and the pattern layer  13 A of the donor substrate  10 , respectively to clean their surfaces to thereby activate their surfaces. 
     Then, as shown in  FIG. 4B , while a vertical stage  28  is moved down, the planar stage  25  is moved in x and y directions horizontally and in a θ direction around a z axis vertically to thereby align the first pattern layer  13 A with the target substrate  27 . Then, the target substrate  27  and the first pattern layer  13 A are brought into contact with each other and pressed against each other under a load of 50 kgf/cm 2  for 5 minutes, so that the target substrate  27  and the first pattern layer  13 A are bonded to each other. The bonding strength on this occasion is from 50 to 100 MPa. 
     When the vertical stage  28  is then moved up as shown in  FIG. 4C , the first pattern layer  13 A is transferred onto the target substrate  27 . The reason why the pattern layer  13 A can be transferred from the donor substrate  10  side onto the target substrate  27  side is that adhesive force between the pattern layer  13 A and the target substrate  27  is larger than that between the pattern layer  13 A and the substrate  11 . Then, the planar stage  25  is moved in order to apply FABs on the first and second pattern layers  13 A and  13 B. FABs are applied on a rear surface (which was in contact with the substrate  11 ) of the first pattern layer  13 A and applied on a front surface of the second pattern layer  13 B. After the first pattern layer  13 A and the second pattern layer  13 B are aligned with each other, the first pattern layer  13 A and the second pattern layer  13 B are bonded to each other in the aforementioned manner. The same operation as described above is carried out for the third to sixth pattern layers  13 C to  13 F. When transferring is performed six times, the microreactor  1  shown in  FIGS. 1A and 1B  is obtained. 
     (Operation of the First Embodiment) 
     Next, the operation of the microreactor  1  according to the first embodiment will be described with reference to  FIGS. 5A and 5B .  FIG. 5A  is a fluid circuit diagram showing the operation of the microreactor  1 .  FIG. 5B  is a perspective view showing a flow of fluid in the microreactor  1 . 
     (Merging and Reaction of First and Second Source fluids) 
     When the first source fluid L 1  is led through the first inlet  2   a  of the first pattern layer  13 A while the second source fluid L 2  is led through the second inlet  2   b  of the first pattern layer  13 A, the two source fluids L 1  and L 2  flow laminarly in the channels  7   a  and  7   b  through the inlet holes  5   a  and  5   b  of the second pattern layer  13 B and meet with (merge into) each other at the junction  8 . The merged source fluids L 1  and L 2  are led into the inlet hole  5   c  of the fourth pattern layer  13 D through the through-hole  9   a  of the second pattern layer  13 B and the through-hole  9   b  of the third pattern layer  13 C. The source fluids L 1  and L 2  led into the inlet hole  5   c  flow laminarly in the reaction portion  30  and advance while reacting with each other in liquid interfaces between the source fluids L 1  and L 2 . The reaction liquid M as a product of reaction is ejected from the through-hole  9   c  and led into the inlet hole  5   d  of the sixth pattern layer  13 F through the through-hole  9   d  of the fifth pattern layer  13 E. 
     (Washing of Reaction Liquid) 
     The reaction liquid M led into the inlet hole  5   d  flows in the washing channel  31  through the channel  7   c . On the other hand, the washing water led in through the washing water inlet  18  is led into the washing channel  31  through the washing water channels  32   a  and  32   b  from both sides of the reaction liquid M at the junction  34 . The reaction liquid M comes into contact with the washing water and flows laminarly in the form of a three-layer structure in which the reaction liquid M is sandwiched between two layers of washing water. Unnecessary solvent components of the reaction liquid M diffuse into the washing water. The washed reaction liquid M flows only in the center portion of the washing channel  31 . Accordingly, at the flow-dividing portion  35 , the reaction liquid M flowing in the center portion is separated from the washing water flowing in the left and right of the reaction liquid M. The separated reaction liquid M is ejected from the through-hole  9   e  to the outside of the microreactor  1  through the channel  7   d . Waste water after washing is ejected from the washing water outlet  19  to the outside of the microreactor  1  through the washing water channels  32   c  and  32   d.    
     (Temperature Control of Reaction Portion) 
     On the other hand, the constant-temperature water W 1  led through the constant-temperature water inlet  3  of the first pattern layer  13 A reaches the constant-temperature water inlet hole  15   a  of the third pattern layer  13 C through the through-hole  6   a  of the second pattern layer  13 B. The constant-temperature water W 1  flows in the groove portions  17   a  from the constant-temperature water inlet hole  15   a  and is drained upward from the constant-temperature water ejection hole  16   a . On the other hand, the constant-temperature water W 1 , which has reached the constant-temperature water inlet hole  15   b  of the fifth pattern layer  13 E through the through-hole  6   c  of the fourth pattern layer  13 D from the constant-temperature inlet hole  15   a , flows in the groove portions  17   b  and is drained upward from the constant-temperature water ejection hole  16   b . The constant-temperature water W 1 ′ drained from the constant-temperature water ejection hole  16   b  reaches the constant-temperature water ejection hole  16   a  through the through-hole  6   d  of the fourth pattern layer  13 D and meets with (merges into) the constant-temperature water W 1 ′ drained from the constant-temperature water ejection hole  16   a , so that the confluent water W 1 ′ is drained from the constant-temperature water outlet  4  through the through-hole  6   b  of the second pattern layer  13 B. On this occasion, the third and fifth pattern layers  13 C and  13 E are arranged so that the fourth pattern layer  13 D is sandwiched between the third and fifth pattern layers  13 C and  13 E. Thus, the constant-temperature water W 1  at the temperature kept constant circulates to keep the reaction temperature at a desired temperature even if there is an exothermic or endothermic change caused by the reaction in the reaction portion  30 . The reaction advances after the temperature of the source fluids L 1  and L 2  reaches a suitable temperature in the reaction portion  30 . 
     (Effects of the First Embodiment) 
     According to the first embodiment as described above, the following effects can be obtained. 
     (i) Because the pattern layers  13 C and  13 E in which constant-temperature water flows sandwich therebetween the pattern layer  13 D having the reaction portion  30 , the temperature of the reaction portion  30  can be controlled efficiently. 
     (ii) Because one pattern layer has one function, it is possible to perform temperature control for each layer by sandwiching each layer having each function between the temperature-controllable pattern layers  13 C and  13 E. 
     (iii) Because unnecessary solvent components of the reaction liquid M diffuse into the washing water by washing, the purity of the reaction liquid M flowing in the center portion can be improved. 
     (iv) Because multiple stacking of channel plates (pattern layers) having different functions is possible, optimization of the reaction can be attained to improve the yield of the reaction liquid. 
     (v) Because each pattern layer is formed by a two-stage electroforming method, it is possible form a channel and a pattern layer having a portion serving as a bottom of the channel in one thin film. Accordingly, because no member (e.g., membrane) is required for covering the channel or the like, reduction in size of the microreactor  1  can be achieved by reduction in number of layers. 
     Second Embodiment 
       FIG. 6A  is a perspective view showing a microreactor  1  according to a second embodiment of the invention.  FIG. 6B  is a plan view showing respective pattern layers in the microreactor  1 . Numerals the same as in  FIGS. 1A and 1B ,  FIGS. 2A and 2B ,  FIGS. 3A to 3F ,  FIGS. 4A to 4C  and  FIGS. 5A and 5B  have functions the same as in these drawings. Accordingly, the description of these parts will be omitted. 
     This microreactor  1  is formed in the same manner as the microreactor  1  in the first embodiment except that the number of source fluids is changed from 2 to 3. Accordingly, a third inlet  2   c  for inletting a third source fluid L 3  in is additionally provided in the first pattern layer  33 A and a third inlet hole  5   c  corresponding to the inlet  2   c  is additionally provided in the second pattern layer  33 B. A channel  7   c  for the source fluid L 3  is defined so as to start at the inlet hole  5   c . The channel  7   c  is defined so that the third source fluid L 3  meets with (merges into) the second source fluid L 2  at a junction  8   a.    
     (Operation of the Second Embodiment) 
     Next, the operation of the microreactor  1  according to the second embodiment will be described with reference to  FIGS. 7A and 7B .  FIG. 7A  is a fluid circuit diagram showing the operation of the microreactor  1 .  FIG. 7B  is a perspective view showing a flow of fluid in the microreactor  1 . 
     (Merging and Reaction of the First to Third Source fluids) 
     When the first source fluid L 1  is led in through the first inlet  2   a  of the first pattern layer  33 A, the second source fluid L 2  is led in through the second inlet  2   b  of the first pattern layer  33 A and the third source fluid L 3  is led in through the third inlet  2   c  of the first pattern layer  33 A, these source fluids L 1 , L 2  and L 3  flow laminarly in the channels  7   a ,  7   b  and  7   c  through the inlet holes  5   a ,  5   b  and  5   c  of the second pattern layer  33 B and meet with (merge into) one another at the junctions  8   a  and  8   b . The source fluids L 1 , L 2  and L 3  are drained from the through-hole  9   a  and led into the inlet hole  5   d  of the fourth pattern layer  33 D through the through-hole  9   b  of the third pattern layer  33 C. The source fluids L 1 , L 2  and L 3  led into the inlet hole  5   d  flow laminarly in the reaction portion  30  and advance while reacting with one another at liquid interfaces between the first and second source fluids L 1  and L 2  and between the second and third source fluids L 2  and L 3 . The reaction liquid N obtained as a product of reaction of the source fluids L 1  to L 3  is drained from the through-hole  9   c  and led into the inlet hole  5   e  of the sixth pattern layer  33 F through the through-hole  9   d  of the fifth pattern layer  33 E. 
     (Washing of the Reaction Liquid) 
     The reaction liquid N led into the inlet hole  5   e  is washed with washing water led in through the washing water inlet  18  of the sixth pattern layer  33 F in the same manner as in the first embodiment. The washed reaction liquid N is drained from the through-hole  9   e  to the outside of the microreactor  1 . On the other hand, waste water after washing is drained from the washing water outlet  19  to the outside of the microreactor  1 . 
     (Temperature Control of the Reaction Portion) 
     On the other hand, the constant-temperature water W 1  led in through the constant-temperature water inlet  3  of the first pattern layer  33 A flows in the groove portions  17   a  and  17   b  of the third and fifth pattern layers  33 C and  33 E and is drained from the constant-temperature water outlet  4  of the first pattern layer  33 A in the same manner as in the first embodiment. The reaction portion  30  of the fourth pattern layer  33 D sandwiched between the third and fifth pattern layers  33 C and  33 E is kept at a desired reaction temperature even if there is an exothermic or endothermic change caused by the reaction. 
     (Effect of the Second Embodiment) 
     According to the microreactor  1  according to the second embodiment as described above, the temperature of the reaction portion  30  can be controlled to improve the yield of the product of reaction even if increasing amounts of source fluids react with each other because the pattern layer  33 D having the reaction portion  30  is sandwiched between the third and fifth pattern layers  33 C and  33 E, which serve as heat exchange portions. 
     Third Embodiment 
       FIG. 8A  is a perspective view showing a microreactor  1  according to a third embodiment of the invention.  FIG. 8B  is a plan view showing respective pattern layers in the microreactor  1 . This microreactor  1  is composed of nine layers. Reactions different in reaction temperature are performed in two different pattern layers  43 C and  43 G. The pattern layer  43 C provided for a reaction is sandwiched between pattern layers  43 B and  43 D, which serve as heat exchange portions. The pattern layer  43 G provided for a reaction is sandwiched between pattern layers  43 F and  43 H, which serve as heat exchange portions. A pattern layer  43 E, which serves as a heat-insulating layer, is provided between the pattern layers  43 C and  43 G provided for the reactions. A pattern layer  43 I for washing the reaction liquid is provided as a lowermost layer. Incidentally, each of the pattern layers  43 A to  43 I is formed by a two-stage electroforming method. 
     The first pattern layer  43 A defines: first to third inlets  2   a ,  2   b  and  2   c  for leading three source fluids L 1 , L 2  and L 3  in; a constant-temperature water inlet  3   a  for leading constant-temperature water W 1  in; and a constant-temperature water outlet  4   a  for draining used constant-temperature water W 1 ′. 
     The second pattern layer  43 B defines: through-holes  9   a ,  9   b  and  9   c , a constant-temperature water inlet hole  15   a  and a constant-temperature water ejection hole  16   a  defined so as to correspond to the inlets  2   a ,  2   b  and  2   c , the constant-temperature water inlet  3  and the constant-temperature water outlet  4  of the first pattern layer  43 A; and a plurality of groove portions  17   a  for connecting the constant-temperature water inlet hole  15   a  and the constant-temperature water ejection hole  16   a  to each other. 
     The third pattern layer  43 C defines: inlet holes  5   a  and  5   b  and through-holes  9   d ,  6   a  and  6   b  defined so as to correspond to the through-holes  9   a ,  9   b  and  9   c , the constant-temperature water inlet hole  15   a  and the constant-temperature ejection hole  16   a  of the second pattern layer  43 B; channels  7   a  and  7   b  in which the source fluids L 1  and L 2  flow laminarly and meet with (merge into) each other at a junction  8   a ; a first reaction portion  30   a  in which the source fluids L 1  and L 2  merged at the junction  8   a  react with each other in a laminar flow state; and a through-hole  9   e  through which the reaction liquid M obtained as a product of reaction of the source fluids L 1  and L 2  is led to the lower layer. 
     The fourth pattern layer  43 D defines: through-holes  9   f  and  9   g , a constant-temperature water inlet hole  15   b  and a constant-temperature water ejection hole  16   b  defined so as to correspond to the through-holes  9   d ,  9   e ,  6   a  and  6   b  of the third pattern layer  43 C; and a plurality of groove portions  17   b  for connecting the constant-temperature water inlet hole  15   b  and the constant-temperature water ejection hole  16   b  to each other. 
     The fifth pattern layer  43 E defines: through-holes  9   h  and  9   i  defined so as to correspond to the through-holes  9   f  and  9   g  of the fourth pattern layer  43 D; and a recess  40  forming a closed space when the fourth pattern layer  43 D is laminated on the fifth pattern layer  43 E. 
     The sixth pattern layer  43 F defines: through-holes  9   j  and  9   k  defined so as to correspond to the through-holes  9   h  and  9   i  of the fifth pattern layer  43 E; a constant-temperature water inlet hole  15   c  into which constant-temperature water is led from the lowermost layer; a constant-temperature water ejection hole  16   c  for draining the constant-temperature water; and a plurality of groove portions  17   c  for flowing the constant-temperature water horizontally. 
     The seventh pattern layer  43 G defines: inlet holes  5   c  and  5   d  and through-holes  6   c  and  6   d  defined so as to correspond to the through-holes  9   j  and  9   k , the constant-temperature water inlet hole  15   c  and the constant-temperature water ejection hole  16   c  of the sixth pattern layer  43 F; channels  7   c  and  7   d  in which the reaction liquid M led in and the third source fluid L 3  flow laminarly and meet with (merge into) each other at a junction  8   b ; a second reaction portion  30   b  in which the reaction liquid M and the third source fluid L 3  merged at the junction  8   b  react with each other in a laminar flow state; and a through-hole  9   l  through which the reaction liquid P obtained as a product of reaction of the reaction liquid M and the third source fluid L 3  is led to the lower layer. 
     The eighth pattern layer  43 H defines: a through-hole  9   m , a constant-temperature water inlet hole  15   d  and a constant-temperature water ejection hole  16   d  defined so as to correspond to the through-holes  9   l ,  6   c  and  6   d  of the seventh pattern layer  43 G; and a plurality of groove portions  17   d  for flowing the constant-temperature water horizontally. 
     The ninth pattern layer  43 I defines: a reaction liquid P inlet hole  5   e  defined so as to correspond to the through-hole  9   m  of the eighth pattern layer  43 H; a washing water inlet  18  provided as a through-hole for leading washing water such as distilled water in; washing water channels  32   a  and  32   b  for flowing the washing water from the washing water inlet  18  to a junction  34 ; a channel  7   f  for flowing the reaction liquid P to a washing channel  3   l ; a washing channel  31  for leading the washing water in from the junction  34  and flowing the washing water as a laminar flow while bringing the washing water into contact with the reaction liquid P from the inlet hole  5   e ; a through-hole  9   n  for separating the washed reaction liquid P after washed at a flow-dividing portion  35  and draining the reaction liquid P to the outside of the microreactor  1  through a channel  7   g ; and a washing water outlet  19  from which waste water after washing is drained to the outside of the microreactor  1  through washing water channels  32   c  and  32   d.    
     (Operation of the Third Embodiment) 
     Next, the operation of the microreactor  1  according to the third embodiment will be described with reference to  FIG. 9 .  FIG. 9  is an exploded perspective view showing a flow of fluid in the microreactor  1 . 
     (Merging and Reaction of the First and Second Source Fluids) 
     When the first source fluid L 1  is led in through the first inlet  2   a  of the first pattern layer  43 A while the second source fluid L 2  is led in through the second inlet  2   b  of the first pattern layer  43 A, these source fluids L 1  and L 2  are led into the inlet holes  5   a  and  5   b  of the third pattern layer  43 C through the through-holes  9   a  and  9   b  of the second pattern layer  43 B. The source fluids L 1  and L 2  led into the inlet holes  5   a  and  5   b  flow laminarly in the channels  7   a  and  7   b  and meet with (merge into) each other at the junction  8   a . The merged source fluids L 1  and L 2  flow laminarly in the first reaction portion  30   a  and advance while reacting with each other at liquid interfaces between the source fluids L 1  and L 2 . The reaction liquid M obtained as a product of reaction is drained from the through-hole  9   e  and led into the inlet hole  5   d  of the seventh pattern layer  43 G via the through-hole  9   g  of the fourth pattern layer  43 D, the through-hole  9   i  of the fifth pattern layer  43 E and the through-hole  9   k  of the sixth pattern layer  43 F. 
     (Merging and Reaction of the First Reaction Liquid and the Third Source Fluid) 
     On the other hand, the third source fluid L 3  led into the inlet  2   c  is led into the inlet hole  5   c  of the seventh pattern layer  43 G via the through-hole  9   c  of the second pattern layer  43 B, the through-hole  9   d  of the third pattern layer  43 C, the through-hole  9   f  of the fourth pattern layer  43 D, the through-hole  9   h  of the fifth pattern layer  43 E and the through-hole  9   j  of the sixth pattern layer  43 F. Then, the reaction liquid M led into the inlet hole  5   c  and the third source fluid L 3  led into the inlet hole  5   d  meet with (merge into) each other at the second junction  8   b  and flow laminarly in the second reaction portion  30   b . In the second reaction portion  30   b , the reaction liquid M and the third source fluid L 3  advance while reacting with each other at liquid interfaces between the reaction liquid M and the third source fluid L 3 . The reaction liquid P obtained as a product of reaction is drained from the through-hole  9   l  and led into the inlet hole  5   e  of the ninth pattern layer  43 I via the through-hole  9   m  of the eighth pattern layer  43 H. 
     (Washing of the Last Reaction Liquid) 
     The reaction liquid P led into the inlet hole Se flows in the washing channel  3   l  through the channel  7   f . On the other hand, the washing water led in from the washing water inlet  18  is led into the washing channel  3   l  from both sides of the reaction liquid P at the junction  34  through the washing water channels  32   a  ad  32   b . The reaction liquid P comes into contact with the washing water and flows as a laminar flow having a three-layer structure in which the reaction liquid P is sandwiched between two layers of the washing water. Unnecessary solvent components of the reaction liquid P diffuse into the washing water. At the flow-dividing portion  35 , the reaction liquid P flowing in the center is separated from the washing water flowing in the left and right of the reaction liquid P because the washed reaction liquid P flows only in the center portion of the washing channel  31 . The separated reaction liquid P is drained from the through-hole  9   n  to the outside of the microreactor  1  through the channel  7   g . The washing water is drained from the washing water outlet  19  to the outside of the microreactor  1  through the washing water channels  32   c  and  32   d.    
     (Temperature Control of the First Reaction Portion) 
     On the other hand, the constant-temperature water W 1  kept at a controlled temperature T 1  and led in from the constant-temperature water inlet  3   a  of the first pattern layer  43 A reaches the constant-temperature water inlet hole  15   a  of the second pattern layer  43 B. The constant-temperature water W 1  flows in the groove portions  17   a  and is drained upward from the constant-temperature water ejection hole  16   a . On the other hand, the constant-temperature water W 1 , which has reached the constant-temperature water inlet hole  15   b  of the fourth pattern layer  43 D from the constant-temperature water inlet hole  15   a  via the through-hole  6   a  of the third pattern layer  43 C, flows in the groove portions  17   b  and is drained upward from the constant-temperature water ejection hole  16   b . The constant-temperature water W 1 ′ drained from the constant-temperature water ejection hole  16   b  reaches the constant-temperature water ejection hole  16   a  via the through-hole  6   b  of the third pattern layer  43 C and meets with (merges into) the constant-temperature water W 1 ′ drained from the constant-temperature water ejection hole  16   a . The merged constant-temperature water W 1 ′ is drained from the constant-temperature water outlet  4   a  of the first pattern layer  43 A. 
     (Temperature Control of the Second Reaction Portion) 
     On the other hand, the constant-temperature water W 2  kept at a controlled temperature T 2  and led in from the constant-temperature water inlet  3   b  of the ninth pattern layer  43 I reaches the constant-temperature water inlet hole  15   d  of the eighth pattern layer  43 H. The constant-temperature water W 2  flows in the groove portions  17   d  and is drained downward from the constant-temperature water ejection hole  16   d . On the other hand, the constant-temperature water W 2 , which has reached the constant-temperature water inlet hole  15   c  of the sixth pattern layer  43 F from the constant-temperature water inlet hole  15   d  via the through-hole  6   c  of the seventh pattern layer  43 G, flows in the groove portions  17   c  and is drained downward from the constant-temperature water ejection hole  16   c . The constant-temperature water W 2 ′ drained from the constant-temperature water ejection hole  16   c  reaches the constant-temperature water ejection hole  16   d  via the through-hole  6   d  of the seventh pattern layer  43 G and meets with the constant-temperature water W 2 ′ drained from the constant-temperature water ejection hole  16   d . The merged constant-temperature water W 2 ′ is drained from the constant-temperature water outlet  4   b  of the ninth pattern layer  43 I. 
     (Heat Insulation Between the First and Second Reaction Portions) 
     Heat conduction between the first and second reaction portions  30   a  and  30   b  is shielded by the fifth pattern layer  43 E having the recess  40 , which is kept vacuum and is located between the third and seventh pattern layers  43 C and  43 G having the first and second reaction portions  30   a  and  30   b.    
     (Effects of the Third Embodiment) 
     According to the third embodiment, the following effects can be obtained in addition to the effects of the microreactor  1  according to the second embodiment. 
     (i) Because configuration is made so that the pattern layer  43 C having the first reaction portion  30   a  is sandwiched between the second and fourth pattern layers  43 B and  43 D serving as heat exchange portions while the pattern layer  43 G having the second reaction portion  30   b  is sandwiched between the sixth and eighth pattern layers  43 F and  43 H serving as heat exchange portions, reaction can advance at an optimum temperature in each reaction portion to improve the yield of the product of reaction.
 
(ii) Because a heat-insulating layer is provided between the pattern layer  43 C having the first reaction portion  30   a  and the pattern layer  43 G having the second reaction portion  30   b , heat transfer between the first and second reaction portions  30   a  and  30   b  can be reduced to make it easy to control the reaction temperatures of the first and second reaction portions  30   a  and  30   b  even if the difference between the reaction temperatures of the first and second reaction portions  30   a  and  30   b  is large.
 
     Fourth Embodiment 
       FIG. 10A  is a perspective view showing a microreactor according to a fourth embodiment of the invention.  FIG. 10B  is a plan view showing respective layers in the microreactor. This microreactor  1  is formed in the same manner as in the first embodiment except that both merging and reaction of source fluids can be performed in one pattern layer. Incidentally, each of pattern layers  53 A to  53 E constituting the microreactor  1  is formed by a two-stage electroforming method. 
     The first pattern layer  53 A has: first and second inlets  2   a  and  2   b  for leading source fluids L 1  and L 2  in; a constant-temperature water inlet  3  for leading constant-temperature water W 1  in; and a constant-temperature water outlet  4  for draining used constant-temperature water W 1 ′. 
     The second pattern layer  53 B defines: through-holes  9   a  and  9   b , a constant-temperature water inlet hole  15   a  and a constant-temperature water ejection hole  16   a  defined so as to correspond to the inlets  2   a  and  2   b , the constant-temperature water inlet  3  and the constant-temperature water outlet  4  of the first pattern layer  53 A; and a plurality of groove portions  17   a  for connecting the constant-temperature water inlet hole  15   a  and the constant-temperature water ejection hole  16   a  to each other. 
     The third pattern layer  53 C defines: inlet holes  5   a  and  5   b  and through-holes  6   a  and  6   b  defined so as to correspond to the through-holes  9   a  and  9   b , the constant-temperature water inlet hole  15   a  and the constant-temperature water ejection hole  16   a  of the second pattern layer  53 B; channels  7   a  and  7   b  in which the source fluids L 1  and L 2  flow laminarly and meet with (merge into) each other at a junction  8 ; a reaction portion  30  in which the merged source fluids L 1  and L 2  react with each other while flowing laminarly; and a through-hole  9   c  through which the reaction liquid M obtained as a product of reaction of the source fluids L 1  and L 2  is fed to the lower layer. 
     The fourth pattern layer  53 D defines: a through-hole  9   d , a constant-temperature water inlet hole  15   b  and a constant-temperature water ejection hole  16   b  defined so as to correspond to the through-holes  9   c ,  6   a  and  6   b  of the third pattern layer  53 C; and a plurality of groove portions  17   b  for connecting the constant-temperature water inlet hole  15   b  and the constant-temperature water ejection hole  16   b  to each other. 
     The fifth pattern layer  53 E defines: a reaction liquid M inlet hole  5   c  defined so as to correspond to the through-hole  9   d  of the fourth pattern layer  53 D; a washing water inlet  18  provided as a through-hole for leading washing water such as distilled water in; washing water channels  32   a  and  32   b  for pouring the washing water from the washing water inlet  18  to a junction  34 ; a channel  7   c  for pouring the reaction liquid M to a washing channel  3   l ; the washing channel  3   l  for leading the washing water in from the junction  34  and pouring the washing water as a laminar flow while bringing the washing water into contact with the reaction liquid M from the inlet hole  5   c ; a through-hole  9   e  for separating the washed reaction liquid M at a flow-dividing portion  35  and draining the reaction liquid M to the outside of the microreactor  1  through a channel  7   d ; and a washing water outlet  19  from which waste water after washing is drained to the outside of the microreactor  1  through washing water channels  32   c  and  32   d.    
     (Operation of the Fourth Embodiment) 
     Next, the operation of the microreactor  1  according to the fourth embodiment will be described with reference to  FIG. 11 .  FIG. 11  is an exploded perspective view showing a flow of fluid in the microreactor  1 . 
     (Merging and Reaction of the First and Second Source Fluids) 
     When the first source fluid L 1  is led in through the first inlet  2   a  of the first pattern layer  53 A while the second source fluid L 2  is led in through the second inlet  2   b  of the first pattern layer  53 A, these source fluids L 1  and L 2  are led into the inlet holes  5   a  and  5   b  of the third pattern layer  53 C through the through-holes  9   a  and  9   b  of the second pattern layer  53 B. The source fluids L 1  and L 2  led into the inlet holes  5   a  and  5   b  flow laminarly in the channels  7   a  and  7   b  and meet with (merge into) each other at the junction  8   a . The confluent source fluids L 1  and L 2  flow laminarly in the reaction portion  30  and advance while reacting with each other at liquid interfaces between the source fluids L 1  and L 2 . The reaction liquid M obtained as a product of reaction is drained from the through-hole  9   c  and led into the inlet hole  5   c  of the fifth pattern layer  53 E via the through-hole  9   d  of the fourth pattern layer  43 D. 
     (Washing of the Reaction Liquid) 
     The reaction liquid M led into the inlet hole  5   c  is washed with washing water led in through the washing water inlet  18  of the fifth pattern layer  53 E in the same manner as in the first embodiment. The washed reaction liquid M is drained from the through-hole  9   e  to the outside of the microreactor  1 . On the other hand, waste water after washing is drained from the washing water outlet  19  to the outside of the microreactor  1 . 
     (Temperature Control of the Reaction Portion) 
     On the other hand, the constant-temperature water W 1  led in through the constant-temperature water inlet  3  of the first pattern layer  53 A flows in the groove portions  17   a  and  17   b  of the second and fourth pattern layers  53 B and  53 D and is drained from the constant-temperature water outlet  4  of the first pattern layer  53 A in the same manner as in the first embodiment. The reaction portion  30  of the third pattern layer  53 C sandwiched between the second and fourth pattern layers  53 B and  53 D is kept at a desired reaction temperature even if there is an exothermic or endothermic change caused by the reaction. 
     (Effects of the Fourth Embodiment) 
     According to the fourth embodiment, the following effects can be obtained in addition to the effects of the microreactor  1  according to the first embodiment. 
     (i) Because both merging and reaction of source fluids can be performed in one pattern layer, reduction in size of the microreactor can be attained. 
     (ii) Because the reaction temperature can be controlled just after merging, optimization of reaction can be attained to improve the yield of the product of reaction. 
     Fifth Embodiment 
       FIG. 12A  is a perspective view showing a microreactor according to a fifth embodiment of the invention.  FIG. 12B  is a plan view showing respective pattern layers in the microreactor. This microreactor  1  is formed in the same manner as in the first embodiment except that the pattern layers having heat exchange functions are replaced by pattern layers constituting heat-insulating layers. Incidentally, each of pattern layers  63 A to  63 F constituting the microreactor  1  is formed by a two-stage electroforming method. 
     The first pattern layer  63 A defines first and second inlets  2   a  and  2   b  for leading source fluids L 1  and L 2  in. 
     The second pattern layer  63 B defines: inlet holes  5   a  and  5   b  defined so as to correspond to the inlets  2   a  and  2   b  of the first pattern layer  63 A; channels  7   a  and  7   b  in which the source fluids L 1  and L 2  thus led in flow laminarly and meet with (merge into) each other at a junction  8 ; and a through-hole  9   a  through which the merged source fluids L 1  and L 2  are fed to the lower layer. 
     The third pattern layer  63 C defines: a through-hole  9   b  defined so as to correspond to the through-hole  9   a  of the second pattern layer  63 B; and a recess  40   a  for forming a heat-insulating layer when the second pattern layer  63 B is laminated on the third pattern layer  63 C. 
     The fourth pattern layer  63 D defines: a inlet hole  5   c  defined so as to correspond to the through-hole  9   b  of the third pattern layer  63 C; a reaction portion  30  in which the source fluids L 1  and L 2  led in react with each other while flowing laminarly; and a through-hole  9   c  through which the reaction liquid M obtained as a product of reaction of the source fluids L 1  and L 2  is fed to the lower layer. 
     The fifth pattern layer  63 E defines: a though-hole  9   d  defined so as to correspond to the through-hole  9   c  of the fourth pattern layer  63 D; and a recess  40   b  for forming a heat-insulating layer when the fifth pattern layer  63 E is laminated on the fourth pattern layer  63 D. 
     The sixth pattern layer  63 F defines: a reaction liquid M inlet hole  5   d  defined so as to correspond to the through-hole  9   d  of the fifth pattern layer  63 E; a washing water inlet  18  provided as a through-hole for leading washing water such as distilled water in; washing water channels  32   a  and  32   b  for pouring the washing water from the washing water inlet  18  to a junction  34 ; a channel  7   c  for pouring the reaction liquid M from the inlet hole  5   d  to a washing channel  3   l ; the washing channel  3   l  for leading the washing water in from the junction  34  and pouring the washing water as a laminar flow while bringing the washing water into contact with the reaction liquid M; a through-hole  9   e  for separating the washed reaction liquid M at a flow-dividing portion  35  and draining the reaction liquid M to the outside of the microreactor  1  through a channel  7   d ; and a washing water outlet  19  from which waste water after washing is drained to the outside of the microreactor  1  through washing water channels  32   c  and  32   d.    
     On this occasion, the fourth pattern layer  63 D having the reaction portion  30  is sandwiched between the third and fifth pattern layer  63 C and  63 E having the recesses  40   a  and  40   b  so that the fourth pattern layer  63 D is thermally insulated by the laminated recesses  40   a  and  40   b.    
     (Operation of the Fifth Embodiment) 
     Next, the operation of the microreactor  1  according to the fifth embodiment will be described with reference to  FIG. 13 .  FIG. 13  is an exploded perspective view showing a flow of fluid in the microreactor  1 . 
     (Merging and Reaction of the First and Second Source Fluids) 
     When the first source fluid L 1  is led in through the first inlet  2   a  of the first pattern layer  63 A while the second source fluid L 2  is led in through the second inlet  2   b  of the first pattern layer  63 A, these source fluids L 1  and L 2  flow laminarly in the channels  7   a  and  7   b  through the inlet holes  5   a  and  5   b  of the second pattern layer  63 B and meet with (merge into) each other at the junction  8 . The merged source fluids L 1  and L 2  are led into the inlet hole  5   c  of the fourth pattern layer  63 D via the through-hole  9   a  of the second pattern layer  63 B and the through-hole  9   b  of the third pattern layer  63 C. The source fluids L 1  and L 2  led into the inlet hole  5   c  flow laminarly in the reaction portion  30  and advance while reacting with each other at liquid interfaces between the source fluids L 1  and L 2 . The reaction liquid M obtained as a product of reaction is led into the inlet hole  5   d  of the sixth pattern layer  63 F via the through-hole  9   d  of the fifth pattern layer  63 E from the through-hole  9   c  of the fourth pattern layer  63 D. 
     (Washing of the Reaction Liquid) 
     The reaction liquid M led into the inlet hole  5   d  is washed with washing water led in through the washing water inlet  18  of the sixth pattern layer  63 F in the same manner as in the first embodiment. The washed reaction liquid M is drained from the through-hole  9   e  to the outside of the microreactor  1 . On the other hand, waste water after washing is drained from the washing water outlet  19  to the outside of the microreactor  1 . 
     (Temperature Control of the Reaction Portion) 
     Heat conduction from the reaction portion  30  is shielded by the third and fifth pattern layers  63 C and  63 E having the recesses  40   a  and  40   b  which are kept vacuum and which are located on opposite sides of the fourth pattern layer  63 D having the reaction portion  30 , so that the temperature of the reaction portion  30  is controlled. 
     (Effect of the Fifth Embodiment) 
     According to the fifth embodiment, the temperature of the reaction portion  30  can be controlled by the heat-insulating layers without use of any fluid such as constant-temperature water. 
     Sixth Embodiment 
       FIG. 14  is a perspective view of a microreactor according to a sixth embodiment.  FIGS. 15A and 15B  are exploded perspective views of the microreactor.  FIG. 15A  shows pattern layers having respective functions.  FIG. 15B  shows pattern layers laminated between the pattern layers having the respective functions. 
     The microreactor  1  has the same structure as in the first embodiment and is composed of eleven pattern layers  73 A to  73 K, that is, first to eleventh pattern layers each formed by a one-stage electroforming method. That is, there are provided the first, second, fourth, sixth, eighth and tenth pattern layers  73 A,  73 B,  73 D,  73 F,  73 H and  73 J formed in the same manner as the first to sixth pattern layers  13 A to  13 F in the first embodiment and the third, fifth, seventh, ninth and eleventh pattern layers  73 C,  73 E,  73 G,  73 I and  73 K disposed under the second, fourth, sixth, eighth and tenth pattern layers  73 B,  73 D,  73 F,  73 H and  73 J respectively. 
       FIGS. 16A to 16F  show the first and second pattern layers  73 A and  73 B for explaining the one-stage electroforming method.  FIG. 16A  is a plan view of the first pattern layer  73 A.  FIG. 16B  is a sectional view taken along the line C-C in  FIG. 16A .  FIG. 16C  is a plan view of the second pattern layer  73 B.  FIG. 16D  is a sectional view taken along the line D-D in  FIG. 16C .  FIGS. 16E and 16F  are sectional views showing a process of producing a donor substrate. The first and second pattern layers  73 A and  73 B are pierced by the one-stage electroforming method as described above so that the first and second inlets  2   a  and  2   b , the constant-temperature water inlet  3 , the constant-temperature water outlet  4 , the inlet holes  5   a  and  5   b , the through-holes  6   a ,  6   b  and  9   a  and the channels  7   a  and  7   b  are formed. 
     Next, the newly added third, fifth, seventh, ninth and eleventh pattern layers  73 C,  73 E,  73 G,  73 I and  73 K will be described. 
     The third pattern layer  73 C defines through-holes  6   d ,  6   e  and  9   f  defined so as to correspond to the through-holes  6   a ,  6   b  and  9   a  of the second pattern layer  73 B. 
     The fifth pattern layer  73 E defines through-holes  6   f ,  6   g  and  9   g  defined so as to correspond to the constant-temperature water inlet hole  15   a , the constant-temperature water ejection hole  16   a  and the through-hole  9   b  of the fourth pattern layer  73 D. 
     The seventh pattern layer  73 G defines through-holes  6   h ,  6   i  and  9   h  defined so as to correspond to the through-holes  6   c ,  6   d  and  9   c  of the sixth pattern layer  73 F. 
     The ninth pattern layer  73 I defines a through-hole  9   i  defined so as to correspond to the through-hole  9   d  of the eighth pattern layer  73 H. 
     The eleventh pattern layer  73 K defines through-holes  9   k ,  37   a  and  37   b  defined so as to correspond to the through-hole  9   e , the washing water inlet  18  and the washing water outlet  19  of the tenth pattern layer  73 I. 
     (Production Method according to the Sixth Embodiment) 
     Next, a method for producing the microreactor  1  according to the sixth embodiment will be described with reference to  FIG. 14 ,  FIGS. 15A and 15B  and  FIGS. 16A to 16F . First, a substrate  11  of a metal is prepared. A thick-film photo resist is applied on the substrate  11  and exposed to light with use of a photomask corresponding to the respective patterns  73 A to  73 K of the microreactor  1  to be produced. The photo resist is developed to form a resist pattern  74  which is reversal of the respective pattern layers  73 A to  73 K. 
     Then, the substrate  11  having the resist pattern  74  deposited thereon is immersed in a plating bath so that nickel plating is grown on a surface of the substrate  11  not covered with the resist pattern. Then, the resist pattern  74  is removed to produce a donor substrate  10  having the respective pattern layers  73 A to  73 K which are formed by batch processing and which constitute the microreactor  1 . 
     Then, the donor substrate  10  is set in the bonding apparatus  20  shown in  FIGS. 4A to 4C . The respective pattern layers are bonded to the target substrate  27  successively as described in the first embodiment. Thus, the microreactor  1  is produced. 
     (Effects of the Sixth Embodiment) 
     According to the sixth embodiment, the following effects can be obtained in addition to the effects of the microreactor  1  according to the first embodiment. 
     (i) Because it is unnecessary to strictly control a process such as stopping etching at an etching depth corresponding to the middle of the depth of each pattern layer, it is easy to produce the pattern layer. 
     (ii) Because pattern layers as top and bottom surfaces of pattern layers having respective functions are interposed between the pattern layers having the respective functions, it is easy to produce the pattern layers though the number of pattern layers increases. Accordingly, the microreactor can be produced easily. Incidentally, the two kinds of pattern layers may be used wisely in accordance with necessity so that reduction in cost can be attained. 
     Example 1 
     Example 1 of the invention will be described below. Example 1 corresponds to the first embodiment. A polymethacrylate particle emulsion is a subject of the reaction liquid. 
     A mixture of 10 g of methacrylic acid and 0.1 g of divinylbenzene as monomers is used as the first source fluid. The first source fluid is led in through the first inlet  2   a  shown in  FIGS. 1A and 1B  at a flow rate of 0.1 ml/min. A solution prepared by dissolving 0.5 g of a surface-active agent EMULGEN MS-110 (made by KAO CORPORATION) and 0.01 g of ammonium persulfate in 120 ml of distilled water is used as the second source fluid. The second source fluid is led in through the second inlet  2   b  at a flow rate of 0.1 ml/min. The two source fluids thus led in flow laminarly in the channels  7   a  and  7   b  and meet with (merge into) each other at the junction  8 . Then, the confluent source fluids are led into the inlet hole Sc via the through-hole  9   b  from the through-hole  9   a . The two source fluids led into the inlet hole  5   c  react with each other in the reaction portion  30 . Thus, a polymethacrylate particle emulsion is produced as the reaction liquid. The reaction liquid is led into the inlet hole  5   d  of the sixth pattern layer  13 F via the through-hole  9   d  from the through-hole  9   c.    
     On the other hand, cooling water kept at a controlled temperature of 20° C. is led in through the constant-temperature water inlet  3 . The cooling water is led into the third and fifth pattern layers  13 C and  13 E, so that the reaction portion  30  of the fourth pattern layer  13 D is kept at 20° C. 
     In the sixth pattern layer  13 F, the reaction liquid is led into the washing channel  31  while distilled water is led in from the washing water inlet  18  through the channels  32   a  and  32   b  at a flow rate of 0.1 ml/min at the junction  34 . At the junction of the reaction liquid and the distilled water, a laminar flow is generated so that two flows of distilled water flow on opposite sides of the reaction liquid. Accordingly, the polymethacrylate particle emulsion as a product of reaction continuously flows in the center of the laminar flow but unnecessary solvent components diffuse into the two flows of distilled water on the both sides of the channel. 
     At the flow-dividing portion  35 , the reaction liquid is separated from the washing water. Thus, the washed polymethacrylate particle emulsion is obtained from the center of the channel. 
     Incidentally, the same emulsion can be produced when methacrylic acid is replaced by acrylic acid, methacrylic alkyl ester, acrylic alkyl ester, styrene, methacrylic acid amide, acrylic acid amide, methacrylic alkyl amide, or acrylic alkyl amide. 
     Any pigment may be dispersed in the aforementioned monomers. The pigment is not particularly limited but carbon black or phthalocyanine pigment can be used as the pigment. 
     Example 2 
     Example 2 of the invention will be described below. Example 2 corresponds to the sixth embodiment. A method for producing the donor substrate  10  by a one-stage electroforming method will be described. 
     (Method for Producing the Donor Substrate) 
     Next, a method for producing the microreactor  1  will be described with reference to  FIGS. 4A to 4C  and  FIG. 14 . First, a substrate  11  of mirror-polished stainless steel is prepared. A photo resist film about 30 μm thick is applied on the substrate  11  and exposed to light with use of a photomask corresponding to the respective pattern layers of the microreactor  1  to be produced. The photo resist is developed to form a resist pattern which is reversal of the respective pattern layers. The size of each pattern layer is generally from the order of millimeter square to the order of centimeter square. The pattern layers are arranged in the form of a matrix at regular intervals of from the order of hundreds of microns to the order of millimeter. Incidentally, the film thickness of the photo resist may be selected arbitrarily if the film thickness of the photo resist is not smaller than the film thickness of plating formed in the next process. 
     Then, the substrate  11  having the resist pattern deposited thereon is immersed in a plating bath so that nickel plating 25 μm thick is grown on a surface of the substrate  11  not covered with the photo resist. The film thickness of plating is decided in accordance with the design of the microreactor to be produced but the film thickness of plating is generally from the order of microns to the order of hundreds of microns, preferably from 10 μm to 50 μm. Then, the resist pattern is removed. Thus, the donor substrate  10  is produced in such a manner that the respective pattern layers constituting the microreactor are formed by batch processing. 
     Other Embodiments 
     The invention is not limited to the aforementioned embodiments and various changes may be made without departing from the gist of the invention. For example, constituent members in the respective embodiments may be combined at option without departing from the gist of the invention. 
     Although all the embodiments except the fifth embodiment have been described on the case where constant-temperature water is used for controlling the reaction temperature, the constant-temperature water may be replaced by a suitable material such as gas or oil in accordance with the subject of temperature control. Although description has been made on the case where two heat exchange portions are provided on opposite sides of a pattern layer having a reaction portion, one heat exchange portion may be disposed on a single side of the pattern layer. 
     Although description has been made on the case where nickel is used as a plating material when the donor substrate  10  is produced, copper or gold capable of being formed by plating may be used like nickel. Because nickel is excellent in chemical resistance and heat resistance, nickel is suitable to a microreactor used for synthesis caused by acid or alkali reaction or high-temperature reaction. Because copper has a very high heat conductivity, copper is suitable to a microreactor used for synthesis severe in terms of temperature control. 
     For production of each pattern layer, the groove portions  17 , the inlet holes  5 , etc. may be formed by cutting without etching of the plating layer. 
     A releasable layer may be provided between the substrate and the pattern layer so that the pattern layer can be removed easily.