JP2007003276A - Measuring plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting method of a sensor for measuring temperature at many points in the vicinity of a minute reaction field, and to provide a device with a built-in thermal conduction circuit equipped with a temperature measuring function with a flow-path plate and a measuring plate docked together. <P>SOLUTION: This measuring plate constitutes a flow-path ceiling surface. A plurality of minute heat transmissive parts (Cu) excelling in thermal conductivity are provided on the exterior of the surface while heat insulating materials (resin) are layered in portions other than the transmissive parts. This device comprises minute sensors mounted on the transmissive parts and electrodes built in its surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reaction method and a reaction apparatus. In particular, a microreactor that controls chemical reactions with high precision by utilizing micro-effects in a small field.

  The microreactor that has been actively researched in recent years controls the fluid in a minute space, so heat exchange is efficient, and it can be applied to reactions with rapid exotherm, and is thermally unstable. This is advantageous for the synthesis of compounds and the like. Further, it has various features such as a small amount of reagent, a reduced reagent cost, a small amount of waste liquid generated, a reduction in environmental burden, and a space saving. Moreover, when the same reaction is performed in a large-scale plant and when it is performed locally, the latter has an advantage that the reaction yield is higher.

  In general, the conventional method using a flask or the like, when a chemical reaction is performed while controlling the temperature, for example, even if most of the endothermic reaction is performed in the reaction tank, an exothermic reaction occurs locally, or a reaction by-product is generated. Locally different phenomena are often seen, such as the generation of objects. As described above, since the chemical reaction changes with time depending on the residence time and the residence location, in order to control the reaction, it is important to measure and control the temperature of the minute field strictly and many times. On the other hand, the microreactor can control the chemical reaction with high accuracy by utilizing the micro effect in a micro field from the above characteristics. Accurate temperature measurement in a micro reaction field is expected to control the temperature uniformly, prevent the generation of reaction by-products, and build a database on the relationship between temperature and reaction products. . This makes it possible to improve the yield of the reaction product, control the reaction, and provide data necessary for the optimal design of the microreactor. Further, by using a microreactor, it becomes a clue to discover a chemical reaction process that has not been discovered by a conventional method.

  The description of Patent Document 1 aims to control the temperature and promote the chemical reaction in the micro reaction field. The configuration of the microreactor includes a flow path plate through which two kinds of mixed liquids pass and a heating plate for heating the flow path plate as a whole. The flow path plate has a width of about 100 μm and forms a meandering flow path. The heating plate has a conductor meandering wider than the flow path, sends an electrical signal from the transmitter, and uses a thermal resistor or Peltier to control the temperature. The temperature is controlled by arranging the heating plate adjacent to the flow path plate.

  In the description of Patent Document 2, a contact-type surface temperature sensor head that can measure the temperature of a minute region with high accuracy in a nondestructive manner is proposed. A temperature sensor head that is in direct contact with an object to be measured or indirectly through another substance, and is formed of a metal plate having a thermal conductivity of 100 W / mK or more from the side close to the object to be measured. It is characterized by comprising a first layer, a thermocouple tip crossover on the first layer, a second layer including a brazing material, and a third layer of a metal plate on the second layer. That is, it has a structure in which the thermocouple cross-joining portion is sandwiched between metal plates and hardened with a brazing material. The plate material provides a high heat conductivity and a considerable heat capacity, and quickly brings a stable equilibrium with the object. The minute head portion has a structure in which plate members are stacked and the tip of the thermocouple is pressed down, so that the manufacture is easy. Further, since the head has a circular shape and a diameter as small as φ0.8 mm, a plurality of microregions of φ0.8 mm or less can be simultaneously measured with high accuracy. Furthermore, the temperature can be measured even for a very small region of 0.3 mmφ by a device. By using this surface temperature sensor head, it is possible to inspect LD and LSI with high precision in a short time.

US Patent Publication No. 20040066118 JP 2001-159568 A

In order to study the reaction state in the micro reaction field, it is important to improve the spatial resolution of temperature measurement in the reactor. In order to improve the spatial resolution of temperature measurement, how to realize a sensor device directly under the micro reaction is an issue. Currently, (1) it is difficult to measure the temperature of the minute field.
(2) Condensation occurs inside and outside the reactor when the temperature is below the zero point. (3) The measurement location is narrow and the type of sensor (material, heat resistance, size) is limited. (4) The sensor mounting method (how to make space) is mainly cited.

  In US Patent Publication No. 20040066118, when measuring the temperature of a minute field in a microreactor, several temperature sensors such as a thermocouple of a conventional method are installed on the reactor surface cover or on the side wall. For this reason, the temperature of the whole chip is measured, the spatial resolution is low, and the temperature of the minute field is not accurately measured. In addition, since the temperature is not measured at many points, even if there is a sudden temperature change at a part of the flow path in the microreactor, it is not possible to follow and measure over time. Not done.

  In Japanese Patent Laid-Open No. 2001-159568, the problem is that countermeasures when condensation occurs are insufficient. Since the sensor is affixed to the surface of the measurement object as it is, when the temperature of the reactor is cooled below the freezing point, it is cooled to the outside air around the sensor, so that condensation occurs around the sensor and adversely affects temperature measurement. If the opposite side of the sensor attachment surface is not coated with an insulator, the ambient temperature will also be measured. The sensor fixing method involves fixing the sensor by joining with a soldering material such as solder, so that it is not easy to detach, and if it is removed, there is a problem that marks are likely to remain. Also, if minute sensors are mounted on the chip surface at many points, the number of wires increases, making it difficult to attach the wires.

  Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

  The measurement plate of the present invention is equipped with a sensor capable of measuring the temperature in the vicinity of the minute reaction field at multiple points. A device with a built-in heat transfer circuit having a temperature measurement function is provided by docking a measurement plate to a flow path plate. The measurement plate forms a ceiling surface of the flow path, and a plurality of minute heat transfer portions made of a material having a thermal conductivity of 100 W / (mK) or more are provided outside the surface, and the heat conductivity other than the heat transfer portion is 10 W / (MK) A heat insulating material made of the following is laminated. This is a device in which a minute sensor is attached to the heat transfer section, and a conductor or electrode is incorporated on the surface.

  A material having strong chemical resistance such as SUS is used for the flow path ceiling surface of the measurement plate. The measurement plate is plated with a heat transfer portion (Cu) having good thermal conductivity on the upper surface of a thin SUS. The unplated part is formed by resin injection molding. Spatial resolution of temperature measurement in the reactor can be improved by manufacturing a large number of heat transfer parts on the surface of the measurement plate by micromachining. As a result, the responsiveness is fast and the temperature of the micro field can be measured at multiple points. Since the heat insulating portion is provided by the resin structure, the thickness can be increased and the strength can be increased.

  According to the present invention, it is possible to mount a sensor capable of measuring temperature in the vicinity of a minute reaction field at multiple points. It is possible to provide a device with a built-in heat transfer circuit, which has a temperature measurement function by docking a measurement plate with a flow path plate and can save space.

  As shown in FIG. 1, the measurement plate 1 of the present invention is a chip with a built-in heat transfer circuit that is sandwiched between a flow path plate 2 and a pressure plate 3 and docked, and has a temperature measurement function. The flow path plate 1 has a flow path cross section of □ 100 μm × 100 μm and is composed of an A liquid storage tank 8, a B liquid storage tank 9, a mixing section 27, and a lead-out section 26, mainly made of SUS. It is. The flow path has a meandering shape from the mixing section 27 to the outlet section 26 and is called a reaction time control section 29. In this section, the reaction is controlled by heating from the bottom side of the plate.

  The channel plate 1 has a generally well-known microreactor structure. The pressure plate 3 is mainly made of SUS, and includes a liquid A introduction part 24, a liquid B introduction part 25, a lead-out part 26, and an electrode part 5. For example, salicylic acid is supplied to the A liquid and methanol is supplied to the B liquid at a flow rate of 2 ml / min, respectively, and after mixing, the chemical reaction is promoted by heating 28 at about 80 ° C. from the bottom side of the flow path plate 1. When concentrated sulfuric acid is used as a catalyst for this, esterification is performed and methyl salicylate is produced. In order to improve the yield of the reaction product and control the temperature with high accuracy, the temperature measurement in the reactor has high spatial resolution, quick response, and accurate temperature measurement is required.

  However, the temperature cannot be measured by bringing the thermocouple directly into contact with the solvent liquid in the minute reaction field. This is because the thermocouple material is weak in chemical resistance and may corrode. Therefore, it is effective to measure the temperature of the channel wall surface near the minute reaction field. For this reason, SUS with strong chemical resistance is used because it directly contacts the solvent solution on the ceiling surface, wall surface, and bottom surface of the channel. Thus, various solvent liquids can be flowed through the flow path as long as the solvent liquid is other than strongly acidic.

  However, since the thermal conductivity of SUS is 16 W / (mK) and the thermal conductivity is not so good, when using SUS for the measurement plate, the thickness should be as thick as possible for accurate temperature measurement and responsiveness. It needs to be thin. The thickness of SUS can be processed for mass production up to about 500 μm to 1 mm. However, when sealing the flow path so as not to leak, the measurement plate and flow path plate need to be sufficiently pressurized and pressure bonded, so there is a problem that the strength will be weakened if it is too thin. Occurs.

  Therefore, in the present invention, Cu having good thermal conductivity is used for the heat transfer section 10 only in a minute region where the sensor 4 is mounted on the surface of the SUS of the measurement plate which is also the ceiling surface of the flow path. The thermal conductivity of Cu is 390 W / (mK), which is more than about 20 times the thermal conductivity of SUS, and is an optimal material for use in the heat transfer section. A heat insulating material (resin) is laminated on the surface of SUS other than the heat transfer section (Cu). Polycarbonate resin is effective for the heat insulating material, and its thermal conductivity is as low as 0.23 W / (mK). As a result, since the sensor measures only the temperature of only the heat transfer section arranged minutely, the spatial resolution is high and more accurate temperature measurement can be expected.

  FIG. 2 shows an enlarged view of the measurement plate. A large number of minute sensors 4 are arranged in a matrix in the heat transfer section. Moreover, an electrode such as Al and a conductor part are incorporated on the surface, and temperature measurement in a minute field is possible at multiple points. It is possible to cope with a change with time of a chemical reaction in the flow path.

  FIG. 3 shows an enlarged view of the cross section of the channel of the thermoelectric circuit built-in chip. The measuring plate 1 is plated with a heat transfer portion (Cu) 10 having good thermal conductivity on the upper surface of SUS. A polycarbonate resin 11 is formed on the portion not plated. Mainly by injection molding. A sensor 4 is mounted on the surface of the heat transfer section, and an electrode section 5 such as Al is plated on a part of the resin surface.

  The manufacturing method will be described in detail in Examples. The feature is that it is possible to measure the temperature in a small field at multiple points, and in order to see the change over time, it is also possible to measure according to the residence time and location. When assembled, the sensor is not in direct contact with the external atmosphere, so that condensation does not occur around the sensor even if the reactor is cooled. It has the advantage that the mounting space of the sensor can be reduced. The temperature change of the chemical reaction in a minute field is known, and the user can easily design the flow path according to the purpose of use based on the measured data. In addition, for example, by taking measurement data every 10 msec, it is also possible to measure the temperature by narrowing down to a place to be measured. In addition, it is possible to grasp the temperature distribution in a specific place at a certain time interval. The measurement plate has a noun size (50 mm × 80 mm) and a thickness of 3 to 5 mm, and is preferably as compact as possible. This is because in the case of mass production using the MEMS processing technique, there is a restriction on the size that can be processed. The shape of the chip may not be square but circular.

  A unit system of thermal conductivity and thermal resistance will be described here. There are objects 1 and 2 which are kept at constant temperatures T1 and T2 (T1> T2). If a bar having a cross-sectional area A and a length L is connected between the two, a heat energy is transferred from the object 1 to the object 2 through the bar. Assuming that heat does not escape from the surroundings of the rod, the temperature distribution along the rod will be linear when sufficient time elapses and a steady state is reached.

The heat flow Q [W] means the amount of heat that passes through the cross section of the bar per unit time, and is proportional to the cross sectional area A and the temperature gradient (T1-T2) / L. That is, if the proportionality constant is k,
Q = kA (T1-T2) / L (1.1)
Or q = Q / A = k (T1-T2) / L (1.2)
It is expressed as q [W / m ^2] is referred to as the heat flux in the amount of heat passing through a unit sectional area of the rod in a unit time.

In general, the magnitude of the heat flow rate or the heat flow rate is proportional to the temperature gradient dT / dx [W / m] in the direction of heat flow (this is the x direction)
Q = −kA dT / dx (1.3),
Or q = −k dT / dx (1.4)
Can be expressed as This is called Fourier law. When heat flows by heat conduction, the heat flows from higher to lower, so the temperature gradient dT / dx in the heat flow direction is always negative. k is a proportionality constant and is called thermal conductivity, and its value is determined by the type and state of the substance. The thermal conductivity k represents the magnitude of the heat flow rate per unit temperature gradient [1 K / m]. The larger the value of k, the better the conductor of heat. For example, when the value of k at room temperature [W / (mK)] is shown, Teflon (registered trademark), glass, SUS304, polycarbonate resin, Cu, and Al are 0.4, 1.4, 16, 0.23, 390, 200.

From (1.1), Q = kA (T1-T2) / L = 1 / (L / kA) * (T1-T2) = T1-T2 / Rc (1.5)
Rc = L / kA, which is referred to as thermal resistance of heat conduction.

In general, when the number of stacked plates is n,
Q = T1-Tn + 1 / Σ ⁿ Rc (1.6)
It becomes.

  Here, in order to explain the effect of the present invention, as shown in FIG. 4, the temperature of the front and back surfaces of the measurement plate is different when only SUS14 is used as the material of the measurement plate and when SUS14 and Cu15 are used in combination. Compare how much it changes.

  As shown in FIG. 4 (a), the SUS thickness L is 0.003 m, the SUS thermal conductivity k1 is 20 W / (mK), and the front and back surface temperatures are T1 and T2 (= ΔTa−T1), respectively. To do. ΔTa represents a temperature change of T2−T1.

In the case of FIG. 4B, the SUS thickness L1 is 0.001 m, the Cu thickness L2 (= L−L1) is 0.002 m, the Cu thermal conductivity k2 is 400 W / (mK), and the front and back surfaces. Are T1 and T3 (= ΔTb−T1), respectively. ΔTb represents a temperature change of T3-T1. In both plates, the cross-sectional area A is a unit cross-section [m ² ], and the heat flow rate q across the plate from the front to the back of this plate is 100 kW / m ² .

  Using the above formulas (1.1) to (1.6), ΔTa and ΔTb are obtained, and ΔTa = 15K and ΔTb = 5.5K. Even when the thickness of the plate is the same, it is clear that the combination of SUS and Cu has better responsiveness and can accurately measure the temperature.

  As shown in FIG. 5, the electrode part 19 of the measurement plate and the electrode part 18 of the pressure plate can be jointed with one touch. A hemispherical contact portion 16 having a diameter of 30 to 50 μm exists at the tip of the electrode portion of the measurement plate, and when docked with the pressure plate, it is crushed when the slightly projecting contact portion is pressed and can conduct. It has become. Thereby, attachment and detachment are easy, a flow path can be wash | cleaned after use, and it can be used many times.

  FIG. 6 is a diagram showing a method for manufacturing a measurement plate. The measurement plate is plated with a heat transfer portion (Cu) having good thermal conductivity on the upper surface of SUS. In addition, since heat conductivity of Ag, Al, etc. which are heat-transfer materials is as high as 420 and 200 W / (mK), respectively, it is effective for a heat-transfer part. Before plating, a resist (made of resin) is applied to the upper surface of SUS, and baked and hardened. After that, patterning is performed with photolithography or the like to form a mold in which the heat transfer portion is cut out, and the molten Cu is poured into the portion, and the temperature is lowered and solidified.

  Subsequently, after removing the resist with an organic solvent such as acetone, a polycarbonate resin 11 is formed as a heat insulating material in a portion not plated. Mainly by injection molding.

  In addition, since the heat conductivity of Teflon, glass, etc. is as low as 0.4 and 1.4 W / (mK), respectively, a heat insulating material is effective for a heat insulating part. A sensor is mounted on the surface of the heat transfer portion, and an electrode portion such as an electrode Al is plated on a part of the resin surface. In the plating method, as in the case of Cu, only the conductor portion is plated with a resist. A polycarbonate resin is injection-molded at the joint part to give an annular projection structure (φ300 μm, thickness 100 μm). The electrode part such as Al is plated again in the ring, and deep drilling is performed to make the hemispherical contact part of FIG. As a sensor, a conventional thermocouple made finer (within φ0.1 mm) is used. Alternatively, using a MEMS technique, a structure in which a voltage difference is produced with a metal plating on the surface of SUS and a sensor for measuring a voltage is used. By arranging a plurality of sensors (for example, 10 to 1000) in a matrix, the temperature distribution in the plate can be grasped. The sensor may be arranged not only around the reaction channel but also on the entire plate surface. The molded surface of the measurement plate is polished by CMP to make the surface shape uniform and clean so that there is no gap between the contact surface of the measurement plate and the pressure plate.

  FIG. 7 shows an overall assembly diagram of the measurement plate when the wireless device 20 is added to the upper part of the pressure plate. When a wireless device is used, it is possible to exchange data measured by the measurement plate wirelessly with a PC. As a result, the state of the apparatus can be managed for a long time without a person present in the vicinity of the apparatus, and a sensor network can be realized. For example, if an abnormal situation such as a sudden rise in temperature in the reactor or an irregular temperature change occurs during the experiment, the sensor immediately detects and sends a signal to stop the reaction from the PC. The danger can be avoided. Sensor networks can be expected to reduce the burden of hazard prediction, accident prevention measures, and human maintenance. Further, in the case of a wireless device, no extra wiring is required, and the working space for mounting and experiments is reduced. As shown in FIG. 5, the wireless device and the measurement plate are provided with a joint portion having a shape that can be easily joined to each other. In addition to temperature, a conventional sensor such as a pressure sensor may be incorporated in the measurement plate to form an integrated microreactor. Also, the flow rate in the flow path may be measured by measuring the minute temperature of the fluid. The power consumption is very small, such as mV, and is suitable for multipoint measurement.

  As another effect that can be expected, the microreactor can also be arranged in the order of heat transfer, heating / cooling plate on the outer wall of the flow path (reaction tank) on the opposite side of the measurement plate, and as an integrated microreactor where the liquid in the flow path is thermally controlled Good. Also, an integrated microreactor in which a heat insulating plate is arranged on the outer peripheral portion of the heating / cooling plate to block the release of heat may be used. Although a metal material having strong chemical resistance such as SUS is used on the surface of the measurement plate and the flow path plate that contact the liquid, a glass film may be formed on the outer wall surface of the SUS flow path. In this case, an effect of chemical resistance can be obtained even with a strongly acidic solvent solution. Other than SUS, if the material has strong chemical resistance, glass, Teflon or the like may be used for the plate material.

  Although the invention made by the present inventor has been specifically described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Of course.

Schematic when a measurement plate is assembled by being sandwiched between a pressure plate and a flow path plate. The enlarged view of a measurement plate. The enlarged view of the flow-path cross section of the chip | tip with a built-in thermoelectric circuit. The cross-sectional enlarged view of the model which used only SUS for the material of a measurement plate. The cross-sectional enlarged view of the model which used SUS and Cu combination for the material of a measurement plate. The cross-sectional enlarged view of the electrode part of a measurement plate and the electrode part of a pressurization plate. Schematic showing the manufacturing method of the measurement plate. Assembly drawing of the measurement plate when the wireless device is added to the upper part of the pressure plate.

Explanation of symbols

1 ... Measurement plate, 2 ... Channel plate, 3 ... Pressure plate, 4 ... Sensor,
5 ... Electrode (Al), 6 ... Electrode joint part, 7 ... Sensor mounting desired location,
8 ... A liquid storage tank, 9 ... B liquid storage tank, 10 ... Heat transfer part, 11 ... Resin,
12 ... Flow path, 13 ... Direction of heat transfer, 14 ... SUS, 15 ... Cu,
16 ... contact part, 17 ... joint, 18 ... pressure plate side joint part 19 ... measurement plate side joint part, 20 ... wireless device,
21 ... Radio antenna, 22 ... Radio wave, 23 ... Screw, 24 ... A liquid introduction part,
25 ... B liquid introduction part, 26 ... Derivation part, 27 ... Mixing part, 28 ... Heating,
29 ... Reaction time control section

Claims (7)

  A measuring plate that is equipped with sensors that can measure temperature near the micro reaction field at multiple points.   The measurement plate according to claim 1, wherein the measurement plate is docked with the flow path plate to provide a device with a built-in heat transfer circuit having a temperature measurement function.   The measurement plate forms a ceiling surface of the flow path, and a plurality of minute heat transfer portions made of a material having a thermal conductivity of 100 W / (mK) or more are provided outside the surface, and the heat conductivity other than the heat transfer portion is 10 W / The measurement plate according to claim 1 or 2, wherein a heat insulating material made of (mK) or less is laminated.   The measurement plate according to claim 1, wherein a minute sensor is attached to the heat transfer unit, and a conductor or an electrode is incorporated on the surface.   The measurement plate according to any one of claims 1 to 4, wherein a material having strong chemical resistance such as SUS is used for a flow path ceiling surface of the measurement plate.   By producing a large number of heat transfer parts on the surface of the measurement plate by microfabrication, the spatial resolution of temperature measurement in the reactor is improved, the responsiveness is fast, and the temperature of the micro field can be measured at multiple points. The measurement plate according to claim 1, wherein The measurement plate according to any one of claims 1 to 6, wherein the heat insulating portion is provided by a resin structure, so that the thickness can be increased and the strength can be increased.

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