JP4480608B2 - Wiring board - Google Patents

Description

  The present invention relates to a wiring board used for analysis, verification, synthesis, amplification, and the like of biological substances (specimens) such as DNA (deoxyribonucleic acid) and proteins.

  Conventionally, a wiring substrate having a predetermined flow path (also referred to as a channel or a capillary) has been used to collate, synthesize, and amplify biological substances (analytes) such as DNA and proteins. being called.

  As such a conventional wiring substrate, a substrate having a structure in which a wiring conductor is formed on the surface of an insulating base made of ceramics and a groove for forming a flow path is provided.

  Such a wiring board is manufactured as follows by a conventionally known ceramic green sheet (ceramic raw sheet, hereinafter also referred to as green sheet) lamination method.

  That is, first, glass powder, organic binder, solvent, plasticizer, etc. are added to and mixed with ceramic raw material powder made of alumina or the like to form a mud, which is formed into a sheet by the doctor blade method or calendar roll method. A green sheet is obtained, and grooves and holes that become flow paths and migration paths are formed by a press punching method or the like. Furthermore, a fine hole for forming a through conductor penetrating the ceramic layer is formed by a press punching method or the like, and a metal powder such as tungsten (W), molybdenum (Mo) or the like, desired glass powder, organic A metal paste obtained by adding and mixing a binder, solvent, plasticizer, etc. is embedded. After that, a metal paste obtained by adding and mixing desired glass powder, organic binder, solvent, plasticizer, etc. to metal powder such as tungsten (W), molybdenum (Mo), etc. on the green sheet surface is predetermined by screen printing. A pattern is printed and applied to form a thermocouple. Thereafter, a plurality of the green sheets are laminated to form a laminated body, and the laminated body is fired at a temperature of about 800 to 1650 ° C. to complete a wiring board as a product.

  In addition, such a wiring board used for DNA analysis, verification, etc., allows the sample in the flow path to be about 70 to 100 ° C. when performing a splitting operation to decompose two strands of DNA into one strand. Since it is necessary to heat, a heating function and a temperature measurement function are separately required.

  The heating function is generally formed by a heater conductor made of a platinum-rhenium (Pt-Re) alloy or tungsten-rhenium (W-Re) alloy, which is a high resistance material, inside the wiring board, and is formed by printing or the like. The heater is heated by passing an electric current through the heater conductor and generating Joule heat. In this method, the position of the heater conductor is close to the object to be heated, and the amount of heat taken away by the surroundings is small, so that the object to be heated can be efficiently heated. Further, since the heater conductor is close to the object to be heated, there is an advantage that temperature control can be performed with high accuracy. As another heating method, a method is known in which a wiring board with a flow path is placed on a heating source of hot water washing or a desktop heater conductor to indirectly heat an object to be heated.

  On the other hand, the temperature measuring function can be used for the thermocouple element such as an alumel-chromel thermocouple, iron (Fe) -constantan thermocouple, chromel-constantan thermocouple, platinum-platinum rhodium alloy thermocouple, etc. A method of measuring the temperature by inserting a linear thermocouple into the hole, and joining a thermocouple mounting jig on the wiring board using a brazing material or a heat-resistant adhesive, etc. A method of measuring temperature by fixing a linear thermocouple to a tool, or a method of measuring temperature by directly fixing to a wiring board using a low softening point glass having a softening point of about 350 to 500 ° C. or a heat resistant adhesive Etc. are known.

  However, in the method of directly attaching these thermocouples to the wiring board, it is necessary to secure a wide space for attaching the thermocouple on the wiring board, so that the thermocouple is attached to the wiring board that is becoming smaller and higher in density. Therefore, it is becoming difficult to secure a large area. In particular, in a wiring board having a channel for collating, synthesizing, and amplifying a sample such as DNA, the channel width for migrating the sample in a liquid reagent is becoming smaller year by year. Under such circumstances, it is extremely difficult to secure a large area for mounting the thermocouple element wire on the surface of the wiring board.

  Further, in the process of collating, synthesizing, and amplifying the specimen, treatment with a strong acidic or strong alkaline chemical is performed, so that the use of a metal brazing material and a mounting bracket that are eroded by the chemical is limited.

Therefore, in recent years, as a method of forming a thermocouple inside a wiring board, a metal sheet such as tungsten (W) or molybdenum (Mo) is used as a wiring conductor on a green sheet made of alumina or the like, and platinum and platinum- A method has been proposed in which a metal paste with a rhodium alloy is formed by printing, a green sheet is laminated, and fired at about 1650 ° C.
JP 54-137141 A JP-A-11-214127

  However, in the conventional wiring board described above, when a thermocouple made of a platinum-platinum rhodium alloy is formed therein, the decomposition temperature of the specimen in DNA analysis, the self-heating temperature of the IC chip or the use environment temperature is 300. At temperatures below ℃, the generated electromotive force is as small as about 100 to 2400 μV. Therefore, the measurement accuracy is not stable due to noise generated by wiring and connection lines of voltage measurement equipment and drift due to the operating atmosphere. There is a problem that it is necessary to use the power after correcting it.

  Therefore, in order to solve such problems, an electromotive force at 300 ° C. is as large as 12209 μV, and stable measurement accuracy can be obtained without correction, an alumel-chromel thermocouple or an iron (Fe) -constantan thermocouple. It is conceivable to use a thermocouple made of a relatively low melting point metal such as a chromel-constantan thermocouple.

  However, the thermocouple made of such a low melting point metal has a low use limit temperature of about 800 to 1000 ° C. because the melting point of the metal constituting the thermocouple is about 900 to 1700 ° C. Therefore, a green sheet made of alumina or the like is laminated on a green sheet by printing a metal paste such as tungsten (W) or molybdenum (Mo) as a wiring conductor and a platinum and platinum rhodium alloy metal paste as a thermocouple. However, in the method of firing at about 1650 ° C., the metal interdiffusion proceeds at the metal contact of the thermocouple, thereby inducing the disadvantage that the function as the thermocouple is lost.

  In addition, when performing electrophoretic analysis of samples such as DNA and proteins, the intermolecular force of the strands is reduced to facilitate separation, better chemical solution adhesion, and good chemical reaction with the chemical solution. Therefore, the specimen accommodated in the flow path is usually heated to about 70 to 100 ° C. This is because the molecular vibration is increased by raising the temperature of the specimen, and the strand train is separated by breaking the intermolecular force. In recent years, the accuracy of electrophoretic analysis of specimens such as DNA and proteins has been improved. Therefore, temperature control within ± 1.0 ° C. is required.

  When such temperature control is required, the method of heating the flow path with a hot water wash or a table heater conductor, etc., can not heat the object to be heated efficiently because the amount of heat taken away is large. Because the distance between the flow path and the heating source is far away, it is difficult to accurately control the sample temperature in the flow path, and it is not possible to sufficiently perform the separation of DNA or protein or the reaction with the chemical solution, The accuracy of electrophoretic analysis cannot be improved.

  On the other hand, in the method of incorporating the heater conductor in the wiring board, in recent electrophoretic analysis of DNA or protein, the mass of DNA or protein is as wide as several tens to several thousand ng in order to improve work efficiency and work throughput. Electrophoretic analysis is performed in the range. DNA and protein are composed of adenine, thymine, cytosine, and guanine sequences, and each has a different electronegativity, and therefore has a polarity as a DNA chain. When an electric current flows through the heater conductor in electrophoretic analysis, an electric field is generated around the heater conductor. Therefore, if the heater conductor and the flow path are close to each other, the electric field lines of the electric field affect DNA and protein, and the framing Power will be applied according to the law. For this reason, DNA and proteins do not flow accurately through the flow path, and it takes time for migration, and small DNA and protein fragments with a mass of several tens of ng do not flow through the flow path, resulting in a decrease in analysis accuracy. Be triggered.

  Further, since the monitored temperature and the set temperature are the temperature of the specimen flowing through the flow path, it is necessary to install the temperature measuring unit of the alumel-chromel thermocouple element as close to the flow path as possible. For this reason, in the ceramic wiring board, a method is adopted in which the layer thickness of the ceramic layer on the lower side of the flow path is made as thin as possible and a thermocouple is installed close to the flow path.

  In addition, as a method of forming the flow path, when forming with a green sheet single layer, a method of forming a concave groove by pressing and pressing a convex flow path pattern formed on a mold against the green sheet is used. It has been.

  However, when the flow path is formed by such a method, the pressure applied to the green sheet when the convex flow path pattern is pressurized and bites into the green sheet differs between the flow path portion and its peripheral portion. Cracks and cracks occur in the green sheet, or there is a partial difference in the specific gravity in the green sheet, which causes a difference in the amount of sintering shrinkage when firing the wiring board, causing cracks and cracks in the wiring board. May occur.

  Therefore, a penetrating pattern shape to be a flow path is formed in the first layer green sheet by punching with a mold, and another first layer is formed on the lower layer of the first layer green sheet subjected to the flow path processing. A method of forming a bottom of the flow path by laminating and pressing the second green sheet with a press or the like to form a flow path is conceivable.

  However, when the flow path is formed by such a method, the second layer green sheet in which the third green sheet on which the thermocouple element is placed is laminated with the first green sheet that has been punched is stacked. Positioned on the lower surface of the sheet and pressure laminated with a press or the like, but due to the shrinkage of the thickness of the glass ceramics during subsequent firing, the second layer green sheet or thermocouple wire is placed at the location where the flow path is formed The density is lower than that of the third-layer green sheet. Therefore, the bottom of the flow path is pushed into the flow path to form a convex shape. As a result, when the sample is migrated into the flow path and analyzed, the convex portion at the bottom of the flow path prevents the sample from migrating and cannot be detected correctly. There is a problem.

  Therefore, in order to prevent the bottom of the flow path from being pushed into the flow path and forming a convex shape, the first layer of the green sheet was formed by punching a pattern shape penetrating the flow path with a mold. After that, by filling this punched hole with high-sintering non-sinterable powder such as alumina powder alone, the bottom of the channel is prevented from being pushed into the channel and deformed into a convex shape. Can be considered.

  However, even when this method is used, the bottom of the flow path and the non-sinterable powder for preventing deformation such as alumina powder are pressed against each other at the time of firing the wiring substrate. Since the indentation of the cohesive powder is attached, the bottom of the flow channel does not become a flat surface, and the unevenness of the bottom of the flow channel prevents the migration of the specimen, thus causing a problem that correct detection cannot be performed.

  The present invention has been devised to solve the above-described problems, and an object of the present invention is to provide a wiring board capable of stable measurement and improving analysis accuracy.

The wiring board of the present invention is formed by laminating a plurality of insulating layers made of glass ceramics , wiring conductors formed between the insulating layers and on the surface of the insulating layers, and penetrating the insulating layers. A through conductor, a flow path for accommodating a fluid to be processed containing a biological material , formed in an insulating layer, and a heater formed in the interlayer of the insulating layer and on the surface of the insulating layer and arranged close to the flow path a conductor, and the conductor and / or electrically connected to the through conductors, low melting point metal formed Ru thermocouples, disposed between the channel and the heater conductor, a ground conductor connected to the reference potential, including It is characterized by comprising.

  Furthermore, the wiring board of the present invention is characterized in that the heater conductor and the flow path are arranged so as to face each other with the ground conductor interposed therebetween.

  Furthermore, the wiring board of the present invention is characterized in that the wiring conductor and the through conductor are made of a conductor mainly composed of at least one of silver, copper, palladium and platinum.

  Furthermore, in the wiring board of the present invention, the connection wiring portion made of a conductive material mainly composed of at least one of silver, palladium, platinum and gold is formed in the connection portion between the wiring conductor and the thermocouple. It is a feature.

  In the wiring board of the present invention, preferably, the heater conductor is disposed below the bottom surface of the flow path, and a part of the ground conductor faces the side of the flow path with the flow path therebetween. It arrange | positions so that it may do.

  The wiring board of the present invention is preferably characterized by comprising a plurality of through conductors in which ground conductors located on the side of the flow path are arranged in a line.

  The wiring board of the present invention is preferably formed such that the flow path is exposed on the surface of the insulating substrate, and the exposed surface of the flow path is covered with a conductive shield cover. And

According to the wiring board of the present invention, the insulating board formed by laminating a plurality of insulating layers made of glass ceramics , the wiring conductor formed between the insulating layers and on the surface of the insulating layer, and the insulating layer are formed so as to penetrate therethrough. Formed in the insulating layer, the flow path for containing the fluid to be treated containing biological material , formed between the insulating layer and the surface of the insulating layer, and disposed close to the flow path and a heater conductor, and a thermocouple Ru formed of a low-melting-point metal which is electrically connected to the wiring conductor and / or through conductor, disposed between the channel and the heater conductor, a ground conductor connected to the reference potential, the Therefore , the electric field generated by the current flowing when the heater conductor is heated is blocked by the ground conductor connected to the reference potential, so that the electric field can be effectively prevented from reaching the flow path, and thus has polarity. DNA and protein Is as migrating the flow path hardly affected lines of electric force. Thus, it can stop DNA and protein in the electrophoresis, or become faster migration speed, often a useful led to slow is reduced, it becomes possible to improve the accuracy of analysis. In this case, since the ground conductor has higher thermal conductivity than the insulating layer made of glass ceramics or the like, the heat of the fluid to be treated is diffused by the ground conductor when the temperature of the fluid to be treated flowing through the flow path is measured. Can be transmitted to the thermocouple without any problem, and more accurate temperature measurement is possible. In addition, a low melting point and low resistance metal that does not melt and does not form a wiring conductor when fired at 1000 ° C. or higher can be formed as a wiring conductor. -A thermocouple having a large electromotive force made of a metal having a relatively low melting point such as a constantan thermocouple can be used. As a result, it is possible to stabilize the measurement accuracy without correcting the measurement electromotive force. In addition, when the wiring board is applied to a microchemical chip or the like for analyzing a biological material such as DNA or protein, a microchemical chip capable of analyzing the biological material with high accuracy can be obtained.

In the wiring board of the present invention, preferably , a ground conductor made of silver, copper, palladium and platinum having a higher thermal conductivity than the insulating layer made of glass ceramics is formed between the flow path and the thermocouple, When measuring the temperature of the specimen flowing through the flow path, the temperature to be measured can be more accurately transmitted to the thermocouple.

Also, the wiring board is preferably of the present invention, the heater conductor and the flow path is provided so that face each other across the ground conductor between the ground conductor an electric field generated from the heater conductors which are connected to a reference potential In this case, since it is grounded as an eddy current in the ground conductor, it hardly reaches the flow path. This also makes it possible to obtain a wiring board with excellent measurement accuracy.

Also, the wiring board is preferably of the present invention, the wiring conductor and the through conductor, silver, copper, by forming a conductive material mainly composed of at least one of palladium and platinum, of the wiring conductor and the through conductor The resistivity is as low as 1.59 to 1.67 μΩcm, so that the electromotive force of the thermocouple can be transmitted to the measuring instrument without loss, and highly accurate measurement can be performed.

Also, the wiring board is preferably of the present invention, is formed in the connecting portion of the wiring conductor and the thermocouple, silver, palladium, a connection wiring portion made of a conductive material mainly containing at least one of platinum and gold it makes without nickel oxide between the nickel metal constituting the basic composition of the thermocouple wire conductor or through hole conductor is formed and a wiring conductor and the thermocouple can be satisfactorily connected .

  In the wiring board of the present invention, the heater conductor is preferably disposed below the bottom surface of the flow path, and a part of the ground conductor is disposed so as to face the side of the flow path with the flow path therebetween. Therefore, the electric field generated from the heater conductor and the surrounding measuring equipment, heating equipment, and stirring equipment hits the ground conductor arranged between the flow path and the heater conductor and the ground conductor located on the side of the flow path. These eddy currents are grounded in the ground conductor. For this reason, the flow path can be shielded more effectively by surrounding the flow path with the ground conductor and the ground conductor located on the side of the flow path, and generated from the heater conductor and the surrounding measuring, heating, and stirring equipment. It is possible to effectively suppress the electric field that affects the migration of the fluid to be processed flowing through the flow path. As a result, even when the mass of DNA or protein is extremely small, such as several ng, it is possible to obtain a wiring board with excellent measurement accuracy.

  Further, when the ground conductor is formed of a material having high thermal conductivity mainly composed of at least one of silver, copper, palladium, and platinum, the heat from the heater conductor is also transferred from the ground conductor to flow. It is also possible to heat the path uniformly.

  In addition, the wiring board of the present invention is preferably composed of a plurality of through conductors in which the ground conductors located on the side of the flow path are arranged in a row, so that by surrounding the flow path with the ground conductor and the through conductor, The flow path can be shielded more effectively, and the thermal expansion of the ground conductor located on the side of the flow path can be effectively restrained from being restrained by the insulating substrate. As a result, it is possible to effectively suppress the influence of the electric field generated from the heater conductor and the surrounding measuring device, heating device, and stirring device on the migration of the fluid to be processed flowing through the flow path, and to crack the insulating substrate. It is possible to effectively prevent migration of the fluid to be processed flowing through the flow path by effectively preventing the occurrence of breakage.

  Furthermore, if the ground conductors located on the side of the flow path are formed of a plurality of through conductors arranged in a row, the conductors are manufactured in the same process as the signal transmission through conductors, and there is no need to increase the number of processes. .

  According to the wiring board of the present invention, preferably, in the above configuration, the flow path is formed to be exposed on the surface of the insulating substrate, and the exposed surface of the flow path is covered with a conductive shield lid. Therefore, when the liquid flowing in the flow path is migrated, the electric field generated by the heater conductor, surrounding measuring equipment, heating equipment, stirring equipment, etc. is grounded as eddy current in the conductive shield lid. It is possible to more effectively suppress the generated electric field from affecting the migration of the fluid to be processed flowing through the flow path. As a result, even when the mass of DNA or protein is extremely small, such as several ng, it is possible to obtain a wiring board with excellent measurement accuracy.

  Furthermore, since the exposed surface of the flow path is covered with the electric field shield cover, the heat of the liquid flowing through the flow path is prevented from escaping, so that the liquid temperature of the liquid flowing through the flow path can be kept constant. It becomes possible.

  As described above, according to the wiring board of the present invention, for example, when used as a microchemical chip for analyzing, collating, synthesizing, and amplifying biological substances (analytes) such as DNA and proteins, various reaction temperatures on the wiring board. Can be accurately and stably measured, and can effectively prevent sample verification failure, synthesis failure, and amplification rate reduction, and improve the reliability of DNA analysis and shorten verification time. It becomes possible.

  The wiring board of the present invention will be described below. 1 and 2 show an example of an embodiment of a wiring board according to the present invention. FIG. 1 (a) is a partially cutaway perspective view partially showing the configuration of an inner layer of the wiring board, and FIG. 1 (b) is a perspective view of the wiring board. 2 is a cross-sectional view of the wiring board of FIG. 1 and 2, reference numeral 1 is an insulating layer (insulating base), 2 is a ground conductor (electrically grounded metal layer, etc., hereinafter simply referred to as a ground conductor) connected to a reference potential, 3 is a wiring conductor, 4 Is a through conductor, and 5 is a linear thermocouple wire. Further, 6 is joined to a thermocouple, an inner-layer wiring conductor (hereinafter also referred to as lead-out wiring) that draws the electromotive force of the thermocouple to the outside, 7 is a connection wiring portion between the thermocouple and the lead-out wiring 6, and 8 is An IC chip having a chemical-resistant protective film, 9 is a groove-like flow path for migrating a fluid to be treated (specimen) such as DNA or protein, and 10 is a fluid to be treated containing a biological substance or the like flowing through the flow path. This is a heater conductor.

  The insulating layer 1 is made of glass ceramics, a ceramic sintered body, a composite material of ceramic powder and resin, etc., and an insulating substrate is formed by laminating a plurality of such insulating layers 1. FIG. 2 shows an example in which an insulating substrate is formed by the first insulating layer 11, the second insulating layer 12, the third insulating layer 13, and the fourth insulating layer 14. It is a thing. A flow path 9 for accommodating the fluid to be processed is formed in the first insulating layer 11.

The fluid to be processed accommodated in the flow path 9 is heated to a predetermined temperature controlled by the heater conductor 10 and the thermocouple, and subjected to processing such as chemical analysis such as electrophoresis analysis. The processing result is analyzed by the IC chip 8 and transmitted to the outside as an electric signal.

In this embodiment, the insulating layer 1 is formed of a glass ceramic sintered body, and the glass ceramic sintered body is composed of a glass component and a filler component. Examples of the glass component include SiO ₂ -B _2. O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —MO system (where M represents Ca, Sr, Mg, Ba or Zn) , SiO ₂ —Al ₂ O ₃ —M ¹ O—M ² O (wherein M ¹ and M ² are the same or different and represent Ca, Sr, Mg, Ba or Zn), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —M ¹ O—M ² O system (where M ¹ and M ² are the same as above), SiO ₂ —B ₂ O ₃ —M ³ ₂ O system (where M ³ Represents Li, Na or K), SiO ₂ − B ₂ O ₃ —Al ₂ O ₃ —M ³ ₂ O (where M ³ is the same as above), Pb glass, Bi glass, and the like can be given.

On the other hand, examples of the filler component include a composite oxide of Al ₂ O ₃ , SiO ₂ , ZrO ₂ and an alkaline earth metal oxide, a composite oxide of TiO ₂ and an alkaline earth metal oxide, and Al ₂ O _3. And composite oxides containing at least one selected from SiO ₂ (for example, spinel, mullite, cordierite) and the like.

  The ground conductor 2 is made of a metallized layer mainly composed of a metal powder such as silver (Ag), copper (Cu), palladium (Pd), platinum (Pt). The metallized layer is obtained by sintering a conductor paste containing the metal powder. The ground conductor 2 blocks the electric field generated by the current that flows when the heater conductor 10 is heated, and prevents the electric field from being generated in the flow path 9. For this reason, polar DNA and protein are hardly affected by the lines of electric force, and the flow path 9 can be migrated. As a result, the analysis accuracy can be improved because the DNA or protein being migrated is not stopped, and the migration speed is neither increased nor decreased.

  The ground conductor 2 connected to the reference potential is made of, for example, a grounded metal layer such as the metallized layer. The ground conductor 2 is grounded from the outer edge portion of the ground conductor 2 to the surface of the insulating substrate 1 or the inside. A ground wiring (not shown) is formed by being led to the outer surface of the side surface, bottom surface, top surface, etc., and this ground wiring is connected to the ground terminal of the external electric circuit board by soldering or screwing. It is performed by such means.

  The ground wiring is composed of a metallized layer mainly composed of a metal powder such as silver (Ag), copper (Cu), palladium (Pd), or platinum (Pt). For example, a conductor paste containing the metal powder is baked. It is obtained by ligating. In this case, glass powder or ceramic powder may be added to the conductor paste in order to match the firing shrinkage of the conductor paste and the firing shrinkage of the glass ceramic, or to ensure the bonding strength with the insulating layer 1.

  Further, when the insulating layer 1 is formed of glass ceramics, the sintering temperature depends on the average particle size of the main component glass powder or alumina powder contained therein, but the sintering temperature of the ground conductor 2 is included in it. Generally, the starting temperature of solid phase sintering of metal is 45 to 65% of the melting point K (Kelvin) depending on the melting point of the main component metal powder. From this, by adjusting the average particle size of the glass powder and alumina powder contained in the glass ceramics to a desired sintering temperature, and then selecting a metal composition with an appropriate melting point of the metal powder contained in the ground conductor 2 The sintering temperature of the ground conductor 2 can be made lower than that of the insulating layer 1.

As described above, when the insulating layer 1 is made of a sintered body such as glass ceramics and the thermocouple is formed by simultaneous firing with the insulating layer 1, the insulating layer 1 is sintered between the flow path 9 and the thermocouple. since the ground conductor 2 made of a low temperature metal is formed, during the firing of the wiring board, first, it hardens the ground conductor 2 by sintering, then, since the insulating layer 1 is sintering shrinkage, the metal surface Even if the thermocouple formed on the other main surface of the layer tries to bite into the metal surface layer, since the ground conductor 2 is sintered and shrinks and the density is high, the thermocouple does not bite, and the metal surface layer does not flow There is no convex to the 9 side. For this reason, it is effectively prevented that the bottom portion of the flow channel 9 is pushed into the inside of the flow channel 9 to form a convex shape, and the flow channel 9 having a flat bottom portion can be obtained. Thereby, the roughness of the surface of the bottom surface of the flow path 9 can be reduced, and the sample can be migrated smoothly.

  Further, when selecting the material of the ground conductor 2, it is preferable to sinter and shrink the ground conductor 2 earlier than the insulating layer 1. Therefore, first, the green sheet to be the insulating layer 1 is fired in a firing furnace to obtain Tg (glass transition). Point) and shrinkage behavior curve data. Since the sintering temperature of the material such as glass ceramics that becomes the insulating layer 1 can be confirmed from this, the material of the grounding conductor 2 connected to the reference potential is a sintering temperature lower than the sintering temperature of the desired glass ceramics. A certain metal material can be selected.

In this embodiment, the _SiO 2 _-B 2 _{O 3} -based the glass powder contained in the insulating layer 1, average particle size (D50) was applied ones 1.2～5.0Myuemu. As a result, since the sintering start temperature was 700 ° C. and the sintering end temperature was 850 ° C. , silver (Ag) having a melting point of 962 ° C. was selected as the material of the ground conductor 2 connected to the reference potential. Thus, the sintering temperature of the ground conductor 2 is set lower than that of the insulating layer 1. In addition , silver (Ag) having a thermal conductivity of 427 W / m · K was selected in order to transmit the temperature of the specimen flowing through the flow channel 9 more accurately to the thermocouple.

  Here, “D50” is an index representing the particle size distribution of the powder, and means a particle size at a position of 50% integrated from a powder having a small particle size in the distribution.

In this embodiment, a ground conductor 2 made of silver, copper, palladium and platinum having a higher thermal conductivity than the insulating layer 1 made of glass ceramics is formed between the flow path 9 of the wiring board and the thermocouple . ing. Therefore, when measuring the temperature of the sample flowing through the duct 9, it is possible to tell the temperature of the sample more accurately thermocouple. The thermal conductivity of glass ceramics is 1.5 to 10.0 W / m · K, whereas the thermal conductivities of silver, copper, palladium and platinum are 427, 398, 75.5, 71. 4 W / m · K.

  Further, in this case, since the thermal conductivity of the ground conductor 2 is higher than that of the insulating layer 1 made of glass ceramics, the heater conductor 10 emits when the specimen flowing through the flow path 9 is heated by the heater conductor 10. The heat is hardly diffused by the ground conductor 2, and is efficiently conducted to the lower part of the flow path 9, so that the heat can be more uniformly transmitted to the specimen.

  In addition, it is preferable that the wiring conductor 3 and the through conductor 4 are formed of a conductive material mainly containing at least one of silver (Ag), copper (Cu), palladium (Pd), and platinum (Pt). In this case, the resistivity of the wiring conductor 3 and the through conductor 4 is as low as 1.59 to 1.67 μΩcm, so that the electromotive force of the thermocouple can be transmitted to the measuring device without losing a large amount, and the measurement is performed with high accuracy. be able to. The metal material such as silver (Ag) is used as a main component because the metal material such as silver (Ag) is used so that the resistivity of the wiring conductor 3 and the through conductor 4 becomes low as described above. Is contained in a large proportion.

  Also, the lead-out wiring 6 is preferably formed of the same conductive material as that of the wiring conductor 3.

  The wiring conductor 3 and the lead-out wiring 6 are made of, for example, a metallized layer containing a metal powder such as silver (Ag), copper (Cu), palladium (Pd), platinum (Pt) as a main component. This metallized layer can be obtained by sintering a conductor paste containing the above metal powder. The metal paste can be combined with the firing shrinkage of the conductor paste and the firing shrinkage of the glass ceramic, or the bonding strength with the insulating layer 1 can be ensured. In order to do this, glass powder or ceramic powder may be added to the conductor paste. Further, the wiring conductor 3 and the lead-out wiring 6 may be different in the kind and amount of glass powder or ceramic powder added.

  The through conductor 4 is made of, for example, a metallized layer mainly composed of metal powder such as silver (Ag), copper (Cu), palladium (Pd), platinum (Pt). This metallized layer can be obtained by sintering a conductor paste containing the above metal powder. The metal paste can be combined with the firing shrinkage of the conductor paste and the firing shrinkage of the glass ceramic, or the bonding strength with the insulating layer 1 can be ensured. In order to do this, glass powder or ceramic powder may be added to the conductor paste. Further, the wiring conductor 3 and the lead-out wiring 6 may be different in the kind and amount of glass powder or ceramic powder added.

  The linear thermocouple element 5 is composed of, for example, an alumel-chromel thermocouple, an iron (Fe) -constantan thermocouple, a chromel-constantan thermocouple, etc., and particularly an alumel-chromel thermocouple most frequently used for industrial use. The best results were obtained.

  For example, silver (Ag), copper (Cu), palladium (Pd), platinum (Pt) or the like is used as the lead-out wiring 6 that is joined to the linear thermocouple wire 5 and draws the electromotive force of the thermocouple to the outside. It consists of a metallized layer composed mainly of a metal powder. This metallized layer is obtained by sintering a conductor paste containing the above metal powder, and combines the firing shrinkage of the conductor paste with the firing shrinkage of the glass ceramic, or ensures the bonding strength with the insulating layer 1. For example, glass powder or ceramic powder may be added to the conductor paste.

  The connection wiring portion 7 between the linear thermocouple element 5 and the lead wiring 6 is made of, for example, silver (Ag), palladium (Pd), platinum (Pt), gold (Au), or at least one of them. It consists of an alloy containing. The connection wiring portion 7 is formed around the thermocouple by plating, vapor deposition, printing, or the like. The connection wiring part 7 must not be formed at the temperature sensitive part of the thermocouple, that is, at the joint between alumel and chromel. This is because, for example, when a conductive substance contacts across alumel and chromel, the potential difference between alumel and chromel disappears, no electromotive force is generated, and the thermocouple does not function.

  The heater conductor 10 is made of, for example, a metallized layer mainly composed of a metal powder such as platinum-rhenium (Pt-Re) or tungsten-rhenium (W-Re). The metallized layer is obtained by sintering a conductor paste containing the metal powder.

Here, with respect to the wiring board of this embodiment, the measurement results of the electromotive force curve in the temperature range of −40 ° C. to 300 ° C. when an alumel-chromel thermocouple is used are shown in the graph of Table 1 and FIG.

  According to Table 1 and FIG. 3, it can be seen that the characteristic almost coincident with the theoretical value of electromotive force is obtained.

  In the wiring board of the present invention, preferably, as shown in FIG. 4, the heater conductor 10 is disposed below the bottom surface of the flow path 9, and a part of the ground conductor 2 is disposed on the side of the flow path 9. It is good to arrange | position so that the flow path 9 may be pinched | interposed. Thereby, the electric field generated from the heater conductor 10 and the surrounding measuring device, heating device, and stirring device is located on the side of the ground conductor 2 and the flow channel 9 disposed between the flow channel 9 and the heater conductor 10. It hits the ground conductor 15 and is grounded as an eddy current in these ground conductors 2 and 15. Therefore, the flow path 9 can be shielded more effectively by surrounding the flow path 9 with the ground conductor 2 and the ground conductor 15 located on the side of the flow path 9, and the heater conductor 10 and the surrounding measuring equipment and heating It is possible to effectively suppress the electric field generated from the device or the stirring device from affecting the migration of the fluid to be processed flowing through the flow path 9. As a result, even when the mass of DNA or protein is extremely small, such as several ng, it is possible to obtain a wiring board with excellent measurement accuracy.

  Furthermore, when the ground conductor 2 is formed of a material having a high thermal conductivity mainly composed of at least one of silver, copper, palladium, and platinum, heat from the heater conductor 10 is also transferred from the ground conductor 2. In addition, the flow path 9 can be heated uniformly.

  The ground conductor 15 disposed so as to face the side of the flow channel 9 with the flow channel 9 interposed therebetween may be a wall-shaped conductor formed along the flow channel 9. A plurality of through conductors arranged in a line on the side of the path 9 may be used.

Next, a manufacturing method of the wiring substrate described above will be described with the insulating layer 1 is formed of glass ceramics.

  First, a desired organic binder, plasticizer, organic solvent, etc. are added to the raw material powder such as ceramic powder and glass powder to form a slurry, which is then formed into a sheet by a conventionally known doctor blade method or calendar roll method. A glass ceramic green sheet (hereinafter also referred to as a green sheet) is prepared. Further, a conductor paste is prepared by adding and mixing a desired organic solvent and solvent to a powder of a low melting point metal such as copper or silver. Here, each green sheet is manufactured by setting the average particle diameter (D50) of the glass powder and alumina powder contained in the green sheet to be the insulating layer 1 to a desired size.

  Next, in order to form the groove 9 as a channel for migrating DNA or protein to the green sheet to be the first insulating layer 11, using a mold or the like in which the groove pattern is formed in a convex shape, The green sheet is pressed and punched at a temperature of 50 to 150 ° C. and a pressure of 3 to 200 MPa to form grooves 9 having a predetermined pattern on the surface of the green sheet.

  Next, a plurality of through conductors 15 arranged in a row on the side of the through conductors 4 and the flow paths 9 are formed on the green sheet to be the first insulating layer 11 having the grooves 9 by, for example, a punching method. A through hole is formed, and a conductive paste is filled in the through hole by, for example, a screen printing method. Subsequently, the wiring conductor 3 and the lead wiring 6 are printed and applied in a predetermined pattern on the surface of each green sheet.

  Next, the green sheet to be the second insulating layer 12 that is the lower layer of the green sheet to be the first insulating layer 11 in which the grooves 9 are formed is formed on the side of the through conductor 4 channel 9 by, for example, a punching method. Through holes for forming a plurality of through conductors 15 arranged in a row are formed, and the paste is filled in the through holes by, for example, screen printing. Subsequently, the wiring conductor 3 is printed and applied in a predetermined pattern on the surface of the green sheet serving as the second insulating layer 12.

  Next, a through hole for forming the through conductor 4 is formed in the green sheet to be the third insulating layer 13 which is the lower layer of the green sheet to be the second insulating layer 12, for example, by a punching method, For example, the through-hole is filled with a conductive paste by a screen printing method. Subsequently, the ground conductor 2 and the wiring conductor 3 are printed and applied in a predetermined pattern on the surface of the green sheet to be the third insulating layer 13.

  Next, a through hole for forming the through conductor 4 is formed in the green sheet to be the fourth insulating layer 14 which is the lower layer of the green sheet to be the third insulating layer 13 by, for example, a punching method, For example, the through-hole is filled with a conductive paste by a screen printing method. Subsequently, the wiring conductor 3, the lead-out wiring 6, and the heater conductor 10 are printed and applied in a predetermined pattern on the surface of the green sheet to be the fourth insulating layer.

  Next, in order to form the connection wiring portion 7 at a predetermined position of the thermocouple element 5, a palladium film is formed by a plating method, a printing method, or the like. Thereafter, the thermocouple element 5 on which the palladium film is formed is positioned and placed at a predetermined position of the lead-out wiring 6 on the green sheet to be the fourth insulating layer 14, and then the groove 9 is formed. The green sheet 11 that is the fourth insulating layer is overlapped with the green sheet 11 that is the first insulating layer, and is pressed with a pressure of 3 to 200 MPa to fix the thermocouple in the green sheet. At this time, the plurality of through conductors 15 arranged in a row on the side of the flow path 9 are connected to the ground conductor 2 on the third insulating layer 13. In addition, you may form the film | membrane which consists not only of a palladium film but silver, platinum, and gold | metal | money.

  Next, a desired green sheet is laminated on the laminate of the green sheet 11 serving as the first insulating layer in which the grooves 9 are formed to the green sheet 14 serving as the fourth insulating layer. Accordingly, pressure bonding is performed at a temperature of 50 to 100 ° C. at a pressure of 3 to 200 MPa, and firing is performed at a temperature of about 800 to 950 ° C.

  Finally, nickel plating, palladium plating, gold plating, or the like is applied to the surfaces of the wiring conductor 3 and the lead-out wiring 6 exposed on the main surface of the wiring board in order to prevent corrosion.

The wiring board of the present embodiment manufactured as described above includes an insulating board formed by laminating a plurality of insulating layers made of glass ceramics, a wiring conductor formed between the insulating layers and on the surface of the insulating layer, and an insulating layer. and through conductor formed through the, and comprises a channel formed in the surface of the layer and in the insulating layer of the insulating layer, and a thermocouple is electrically connected to the wiring conductor or through hole conductor, grounding conductors are formed consisting of metal having a low sintering temperature Ri by an insulating layer between the flow path and the thermocouple. That is, between the groove and the thermocouple as the channel, the deformation preventing layer made of low ground conductors or et of sintering temperature Ri by an insulating layer is formed.

  As a result, in a wiring board with a channel for collating, synthesizing, and amplifying a sample such as DNA, the bottom of the channel is not deformed into a convex shape by a thermocouple, and the sample migrates smoothly through the channel. The reaction temperatures on the wiring board can be measured accurately and stably. As a result, it is possible to effectively prevent sample verification failure, synthesis failure, and amplification factor reduction, thereby improving the reliability of DNA analysis and shortening the verification time.

  The present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the scope of the present invention.

  For example, in the above-described embodiment, the case where the ground conductor 2 is configured up to the end of the wiring board as illustrated in FIG. 2 has been described, but the ground conductor 2 may be configured to be configured inside the insulating layer 1. I do not care. Further, the treatment applied to the fluid to be treated is not limited to chemical analysis such as electrophoresis using the IC chip 8, but may be based on various chemical reactions such as synthesis and decomposition. Also in this case, the reaction temperature can be controlled with high accuracy, the action of an unnecessary electric field is prevented, and the flow of the fluid to be treated is smooth, so that it is easy to control chemical reactions and improve accuracy. it can.

(A), (b) shows an example of the embodiment of the wiring board of the present invention, (a) is a partially cutaway perspective view partially showing the configuration of the inner layer of the wiring board, (b) is a perspective view of the wiring board. It is. It is sectional drawing of the wiring board of FIG. It is a graph which shows the measurement result of the electromotive force curve at the time of using an alumel-chromel thermocouple about the wiring board of FIG. It is sectional drawing which shows the other example of embodiment of the wiring board of this invention.

Explanation of symbols

1: Insulating layer (insulating base)
2: Grounding conductor connected to the reference potential 3: Wiring conductor 4: Through conductor 5: Thermocouple element 6: Lead-out wiring 7: Connection wiring portion 8: IC chip 9: Channel (groove)
10: Heater conductor 11: First layer insulating layer 12: Second layer insulating layer 13: Third layer insulating layer 14: Fourth layer insulating layer 15: On the side of the flow path Part of the ground conductor that is placed so as to face each other across the flow path

Claims (7)

An insulating substrate formed by laminating a plurality of insulating layers made of glass ceramic, a wiring conductor formed in said interlayer and the surface of the insulating layer of the insulating layer, and a through conductor formed through the insulating layer, the insulating layer formed, a flow path for containing the fluid to be treated containing biological material, is formed on the surface of the insulating layer of the interlayer and the insulating layer, a heater which is disposed close to the flow path a conductor, the wiring conductor and / or said through-conductors electrically connected to the low melting point metal formed Ru thermocouple from being disposed between the passage and the heater conductor, a ground conductor connected to the reference potential A wiring board comprising:   The wiring board according to claim 1, wherein the heater conductor and the flow path are disposed so as to face each other with the ground conductor interposed therebetween. The wiring conductor and the through conductor, silver, copper, a wiring board according to claim 1 or claim 2, characterized in that it comprises at least one of palladium and platinum from the conductive material mainly. The connection wiring part which consists of a conductor material which has at least 1 type as a main component among silver, palladium, platinum, and gold | metal | money is formed in the connection part of the said wiring conductor and the said thermocouple. The wiring board according to claim 3 . The heater conductor is disposed below the bottom surface of the flow path, and a part of the ground conductor is disposed so as to be opposed to the side of the flow path with the flow path therebetween. wiring board according to any one of claims 1 to 4, characterized. 6. The wiring board according to claim 5, wherein the grounding conductor located on the side of the flow path is composed of a plurality of through conductors arranged in a row. The channel is formed by exposing the surface of the insulating substrate, wherein the flow path preceding claims, characterized in that exposed surface is covered with a conductive shield lid 6 A wiring board according to any one of the above.

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