JP2005244057A - Substrate manufacturing method, and forming apparatus of continuity layer for substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate manufacturing method and a forming apparatus of a continuity layer for substrates, whereby in forming a continuity layer in a through hole of a substrate, the occurrence of the wiring faults of the substrate are made hard, while improving the working efficiency in the manufacturing work of the substrate. <P>SOLUTION: In the forming apparatus 1 of a continuity layer for substrates, its evacuation flow rate generated by a vacuum pump 17 is set large and its vacuum drawing force generated by a chamber portion 21 for fastening is set large so that it can chuck and fasten the substrate to a substrate disposing jig. At this time, the flow rate generated in a printing vacuum system portion 15 is reduced by using a flow-rate adjusting gate valve 57. Thereby, conductive paste can be so prevented from scattering as to be able to set to a proper state the printing state of the conductive paste on the inside of a through hole 63. Also, since the forming apparatus 1 of continuity for substrates has a structure for chucking and fastening the substrate to the substrate disposing jig 11, a substrate-fastening work and a substrate-detaching work can be readily executed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a substrate manufacturing method for printing a conductive paste on an inner wall surface of a through hole on a substrate having a through hole penetrating in the thickness direction, and forming the conductive paste as a conductive layer in the through hole, and the substrate The present invention relates to a conductive layer forming apparatus.

  Conventionally, as a substrate on which electrical wiring and electrodes are formed, there is a through hole penetrating in the thickness direction, and a conductive layer for electrically connecting the front surface and the back surface of the substrate to the inner wall surface of the through hole There are known substrates comprising: In addition, as an application of such a substrate, for example, there is a stacked sensor element formed by stacking a plurality of substrates and performing a baking process.

  In such a substrate manufacturing process, a conductive layer is formed on the inner wall surface of the through hole by applying a paste made of a conductive material (conductive paste) from one opening of the through hole and the other. There is a method of printing the conductive paste on the inner wall surface of the through hole by depressurizing the chamber in contact with the opening and sucking the conductive paste into the through hole. The conductive paste thus printed forms a conductive layer on the inner wall surface of the through hole after drying (see Patent Document 1).

  In such a conductive paste printing operation, the substrate is fixed so that the through hole is located on the chamber with respect to the substrate placement jig having the chamber for forming the vacuum region, and the degree of vacuum inside the chamber is increased. This can be realized by reducing the internal atmospheric pressure and sucking and applying the conductive paste to the inner wall surface of the through-hole with a negative pressure.

As a method for fixing the substrate to the substrate placement jig, for example, a fixing projection is provided on either the substrate placement jig or the substrate, and a fixing hole is provided on the other side. There is a method of fixing the substrate to the substrate placement jig by fitting the protrusion and the fixing hole.
JP 2001-242129 A (paragraph numbers [0030], [0031])

  However, in the fixing method in which the substrate is fixed to the substrate placement jig using the fixing protrusion and the fixing hole as described above, the movement direction of the substrate for placing the substrate placement jig at the chamber position There are cases where the (movement direction for alignment) and the movement direction (fixing movement direction) of the substrate for engaging the fixing protrusion and the fixing hole are different. In this case, when placing the substrate on the substrate placement jig, it is necessary to move the substrate in two directions (the movement direction for alignment and the movement direction for fixation), and the movement of the substrate becomes complicated.

  In addition, since the work for fixing and removing the substrate accompanied by such complicated work becomes longer, there arises a problem that work efficiency is lowered in an automated manufacturing process for mass production of substrates.

  Further, when printing is repeatedly performed on both the front and back surfaces of the substrate, the fixing protrusion and the fixing hole are engaged a plurality of times, so that the fixing hole of the substrate may be deformed. If the fixing hole is deformed, the alignment cannot be performed with high accuracy, resulting in an increase in the defect rate.

  On the other hand, as a substrate fixing method capable of performing work in a relatively short time, for example, a suction fixing method by evacuation can be considered. The suction fixing method by evacuation is a method of fixing a substrate by forming a vacuum region in a substrate placement jig and sucking the substrate into the vacuum region.

  Such a suction fixing method eliminates the need to move the substrate in the fixing movement direction, and moves the substrate in one direction (positioning movement direction) when placing the substrate on the substrate placement jig. Therefore, the substrate fixing operation and the substrate removing operation are simple operations, and the fixing operation time and the removal operation time can be shortened.

  Further, the substrate placement jig used for forming the conductive layer of the through hole should originally include a vacuuming means (printing vacuuming means) for forming a vacuum region for printing the conductive paste on the through hole. Therefore, by using this printing vacuuming means also as a vacuuming means for suction fixing of the substrate, there is an advantage that a suction fixing method can be realized relatively easily.

  However, when using the suction fixing method, in order to firmly fix the substrate, it is necessary to set the suction force large (high vacuum), but if the suction force is too large (the vacuum degree is too high). The conductive paste may be scattered in the vacuum region, and there is a possibility that the conductive layer cannot be formed properly. In some cases, the scattered conductive paste adheres to the surface of the substrate, causing a short circuit of the wiring pattern printed on the substrate, resulting in poor wiring on the substrate.

  On the other hand, if the suction force is reduced (the degree of vacuum is reduced) so that the printed state (application state) of the conductive paste in the through hole is good, the suction fixing force of the substrate is insufficient. During the printing operation, the relative position of the substrate relative to the substrate placement jig may move, causing printing displacement of the conductive paste, which may result in defective wiring on the substrate.

  Therefore, the present invention has been made in view of such problems, and in forming a conductive layer in a through hole of a substrate, it is difficult to cause a wiring defect on the substrate while improving work efficiency in a substrate manufacturing operation. It is an object of the present invention to provide a substrate manufacturing method and a substrate conductive layer forming apparatus.

  In order to achieve this object, the method of the present invention according to claim 1, wherein a conductive paste is printed on the inner wall surface of a through-hole on a substrate having a through-hole penetrating in the thickness direction. Is formed as a conductive layer extending from one open end to the other open end of the through hole, and includes a fixing chamber for forming a vacuum region for sucking and fixing the substrate, and a through hole Using a substrate placement jig comprising a printing chamber for forming a vacuum region for suction printing the conductive paste on the wall surface, at least the through hole of the first portion of the substrate where the through hole is formed is printed. The substrate is placed on the substrate placement jig so that at least a part of the second portion of the substrate excluding the first portion is located on the fixing chamber. In the state where the first step and the vacuuming flow rate for the fixing chamber and the vacuuming flow rate for the printing chamber are different, vacuuming is performed on the fixing chamber and the printing chamber to fix the substrate and to fix the inside of the through hole. And a second step of printing a conductive paste on the wall surface.

  In this substrate manufacturing method, after a substrate is placed on the substrate placement jig in the first step using a substrate placement jig having a fixing chamber and a printing chamber separately, a vacuum is drawn in the second step. The suction chamber is set in a negative pressure state and the substrate is sucked and fixed to the substrate placement jig, and the printing chamber is set in a negative pressure state by vacuuming and the conductive paste is drawn into the printing chamber side through the through hole. The conductive paste is printed on the inner wall surface of the through hole.

  In the first step, when placing the substrate on the substrate placement jig, at least the through hole of the first portion of the substrate where the through hole is formed is positioned on the printing chamber, thereby printing for the second step. In the vacuuming operation by the chamber, the conductive paste can be reliably sucked into the through hole. In the first step, when the substrate is placed on the substrate placement jig, at least a part of the second portion of the substrate excluding the first portion is positioned on the fixing chamber. In the vacuuming operation by the fixing chamber in the process, it is possible to prevent the vacuum pulling force from being lowered due to the gas flowing into the fixing chamber through the through hole, and the substrate can be reliably sucked and fixed.

  In the second step, vacuuming is performed on the fixing chamber and the printing chamber in a state in which the vacuuming flow rates for the fixing chamber and the printing chamber are different from each other. The pull-in force and the vacuum pull-in force by the printing chamber can be set individually.

  In other words, the vacuum pulling force by the fixing chamber is set large, and the substrate is firmly sucked and fixed to the substrate placement jig, while the vacuum pulling force by the printing chamber is suitable for printing the conductive paste. The conductive paste can be printed on the inner wall surface of the through hole in a favorable state.

  By fixing the substrate to the substrate placement jig by suction in this way, the work for fixing and removing the substrate from the substrate placement jig can be performed in a short time, thus improving the work efficiency in the substrate manufacturing work. Can be planned. In addition, since the substrate can be firmly fixed, it is possible to prevent a printing error of the conductive layer (conductive paste) caused by the displacement of the substrate.

  Furthermore, since the printed state of the conductive paste in the through hole becomes good, the conductive layer formed by drying the conductive paste is surely from one open end of the through hole to the other open end. Electrical conduction can be achieved.

  Therefore, according to the method of the present invention, when forming a conductive layer in a through hole of a substrate, it is possible to realize a substrate manufacturing method in which wiring efficiency of a substrate is unlikely to occur while improving work efficiency in the substrate manufacturing operation. Can do.

  In the above-described invention method, as described in claim 2, in the second step, the fixing chamber and the printing chamber are used in a state where the vacuum drawing flow rate for the printing chamber is smaller than the vacuum drawing flow rate for the fixing chamber. Vacuuming the chamber may be performed.

  By adjusting the evacuation flow rate in this way and executing the evacuation, the vacuum pulling force in the fixing chamber is increased, and the fixing force of the substrate with respect to the substrate placement jig can be set large. It can be surely prevented.

  In addition, by reducing the vacuum drawing flow rate for the printing chamber, it is possible to prevent the vacuum drawing force in the printing chamber from becoming excessive, to prevent the conductive paste from being scattered, and to cause poor wiring on the substrate. It can be surely prevented.

  Next, the invention according to claim 3, which has been made to achieve the above object, prints a conductive paste on the inner wall surface of the through hole on a substrate having a through hole penetrating in the thickness direction. A conductive layer forming apparatus for a substrate that forms a conductive paste as a conductive layer from one open end to the other open end of a through hole, the first portion excluding the first portion of the substrate where the through hole is formed At least part of the two parts are arranged, a fixing chamber that forms a vacuum region for sucking and fixing the second part, and a through hole of the first part of the substrate is arranged, and the inner wall surface of the through hole is electrically conductive A substrate placement jig having a printing chamber for forming a vacuum region for sucking and printing paste, and a fixing vacuum for evacuating the fixing chamber to suck and fix the substrate And a evacuating means for evacuating the printing chamber in order to print the conductive paste on the inner wall surface of the through hole. A conductive layer forming apparatus for a substrate, characterized by: a flow rate adjusting means for setting the vacuuming flow rate by the means to a different flow rate value.

  This conductive layer forming apparatus for a substrate includes a substrate placement jig having a fixing chamber and a printing chamber, respectively, and the fixing evacuation means places the fixing chamber in a negative pressure state (vacuum region). The substrate is sucked and fixed to the substrate placement jig, and the vacuuming means for printing places the printing chamber in a negative pressure state (vacuum region) and draws the conductive paste through the through-hole to the printing chamber side, thereby making it conductive. The paste is printed on the inner wall surface of the through hole.

  The vacuuming flow rate of the fixing vacuuming unit and the printing vacuuming unit can be set to different flow rate values by the flow rate adjusting unit, and the vacuum pulling force by the fixing chamber and the vacuum pulling force by the printing chamber are: Different values can be set by the flow rate adjusting means.

  In other words, the vacuum pulling force by the fixing chamber is set large, and the substrate is firmly sucked and fixed to the substrate placement jig, while the vacuum pulling force by the printing chamber is suitable for printing the conductive paste. It is possible to make the printed state of the conductive paste in the through hole favorable.

  By fixing the substrate to the substrate placement jig by suction in this way, the work for fixing and removing the substrate from the substrate placement jig can be performed in a short time, thus improving the work efficiency in the substrate manufacturing work. Can be planned. In addition, since the substrate can be firmly fixed, it is possible to prevent a printing error of the conductive layer (conductive paste) caused by the displacement of the substrate.

Therefore, according to the present invention, when the conductive layer is formed in the through hole of the substrate, it is possible to improve the work efficiency in the manufacturing process of the substrate and suppress the occurrence of wiring defects on the substrate.
In the above invention, as described in claim 4, the flow rate adjusting means controls the flow rate so that the vacuuming flow rate by the printing vacuuming means is smaller than the vacuuming flow rate by the fixing vacuuming means. Adjust it.

  Since the flow rate adjusting means adjusts the vacuum drawing flow rate and executes the vacuum drawing in this way, the vacuum drawing force in the fixing chamber is increased, and the fixing force of the substrate to the substrate placement jig can be set large. Can be reliably prevented.

  In addition, by reducing the vacuum drawing flow rate for the printing chamber, it is possible to prevent the vacuum drawing force in the printing chamber from becoming excessive, to prevent the conductive paste from being scattered, and to cause poor wiring on the substrate. It can be surely prevented.

Embodiments to which the present invention is applied will be described below with reference to the drawings.
FIG. 1 shows a schematic configuration diagram of a conductive layer forming apparatus for a substrate for forming a conductive layer on the inner wall surface of the through hole of the substrate.

This substrate can be used, for example, as one member constituting a stacked sensor element.
The multilayer sensor element is configured by laminating a plurality of substrates together with electrodes, wiring patterns (lead portions), and the like, and through holes formed in the substrates are formed on the front surface and the back surface of each substrate. It is formed in order to dispose a conductive layer serving as a current conduction path between the wiring patterns.

  In addition, as the multilayer sensor element, there is a multilayer sensor element for gas detection whose electrical characteristics change depending on the presence or absence of a specific gas (for example, oxygen, NOx, etc.) or according to a specific gas concentration. Such a laminated sensor element that can be used for detecting a specific gas constitutes a gas sensor together with other sensor constituent members (a metal shell, an outer cylinder, a lead frame, etc.).

  In addition, as a gas sensor provided with a laminated sensor element, for the purpose of detecting a specific gas (oxygen) in exhaust gas to be measured, for example, for use in air-fuel ratio feedback control in automobiles and various internal combustion engines, There is an oxygen sensor (also simply referred to as an air-fuel ratio sensor) attached to an exhaust pipe of an internal combustion engine.

  As shown in FIG. 1, the substrate conductive layer forming apparatus 1 includes a substrate placement jig 11 having a fixing chamber portion 21 and a printing chamber portion 23, and a fixing vacuum system connected to the fixing chamber portion 21. A vacuum for the fixing chamber part 21 and the printing chamber part 23 via the fixing part 13, the printing vacuum part 15 connected to the printing chamber part 23, the fixing vacuum part 13 and the printing vacuum part 15. And a vacuum pump 17 for drawing.

  The substrate placement jig 11 includes a base member 25 having an internal space serving as a fixing chamber portion 21 and a printing chamber portion 23, a paint plate member 27 attached to the base member 25 so as to cover the internal space, It is configured with.

  The base member 25 is configured to divide the internal space into one fixing chamber portion 21 and two printing chamber portions 23 by including a partition wall 26 that partitions the internal space. In addition, the base member 25 includes four fixing chamber connection ports 31 that communicate with the fixing chamber portion 21 and four printing chamber connection ports 33 that communicate with the printing chamber portion 23. The two printing chamber connecting ports 33 are configured to communicate with one printing chamber portion 23.

  The paint plate member 27 includes a plurality of fixing air holes 35 formed at positions corresponding to the fixing chamber portion 21, a plurality of printing air holes 37 formed at positions corresponding to the printing chamber portion 23, It has. Only one fixing vent 35 may be formed, and a plurality of fixing vents 35 are preferably formed, and can be more firmly fixed. The paint plate member 27 is fixed to the base member 25 with four fixing screws 28.

  The paint plate member 27 has one fixing vent hole 35 that does not communicate with both the fixing chamber portion 21 and the printing chamber portion 23, and one printing vent hole 37 has the fixing chamber. It is formed so as not to communicate with both the portion 21 and the printing chamber portion 23. Thereby, it is possible to prevent the gas from moving between the fixing chamber portion 21 and the printing chamber portion 23, and the vacuum drawing force by the fixing chamber portion 21 and the vacuum drawing force by the printing chamber portion 23 are It can be set to a different value.

  The fixing vacuum system unit 13 includes four fixed system chamber side connection parts 41 connected to the fixing chamber connection port 31 in a one-to-one relationship, a fixed system pump side connection part 43 connected to the vacuum pump 17, and And four fixed system chamber side connection parts 41 and one fixed system pump side connection part 43. The fixed system sealed pipe 45 branches from the fixed system pump side connection part 43 to the fixed system chamber side connection part 41 at three points to connect the vacuum pump 17 and the four fixing chamber connection ports 31. It is configured as follows.

  The printing vacuum system unit 15 includes four printing system chamber side connection parts 51 connected to the printing chamber connection port 33 in a one-to-one relationship, a printing system pump side connection part 53 connected to the vacuum pump 17, and A printing system sealing pipe 55 that connects four printing system chamber side connection parts 51 and one printing system pump side connection part 53 is provided. Note that the printing system sealed pipe 55, like the fixed system sealed pipe 45, is branched from the printing system pump side connection portion 53 to the printing system chamber side connection portion 51 at three locations, so that the vacuum pump 17 and the four prints are printed. It is comprised so that the chamber connection port 33 may be connected.

  Further, the printing vacuum system unit 15 includes a flow rate adjustment gate valve 57 for adjusting the flow rate of the gas flowing through the printing system sealed pipe 55 and a flow rate for measuring the flow rate value of the gas flowing through the printing system sealed pipe 55. 59 in total.

  The vacuum pump 17 has a function of lowering the atmospheric pressure in the specific region and bringing it closer to a vacuum state by a vacuuming operation for forcibly transporting (removing) gas from the specific region. A vacuuming operation for removing gas from the fixing chamber unit 21 and the printing chamber unit 23 is executed via the vacuum system unit 13 and the printing vacuum system unit 15.

  The flow rate in the printing vacuum system unit 15 can be set to a flow rate value different from the flow rate in the fixing vacuum system unit 13 by adjusting the flow rate adjusting gate valve 57. Accordingly, the suction flow rate in the printing vent hole 37 of the substrate placement jig 11 can be set to a value different from the suction flow rate in the fixing vent hole 35 of the substrate placement jig 11. That is, by adjusting the flow rate adjusting gate valve 57, the printing vacuum pulling force and the fixing vacuum pulling force in the substrate placement jig 11 can be set to different magnitudes.

  For example, by adjusting the flow rate adjusting gate valve 57, the flow rate in the printing vacuum system unit 15 is set smaller than the flow rate in the fixing vacuum system unit 13, so that the vacuum drawing force for printing in the substrate placement jig 11 is set. Can be set smaller than the vacuum pull-in force for fixing.

Needless to say, the fixed system sealed pipe 45 may be provided with a flow rate adjusting gate valve, and the fixed system sealed pipe 45 and the printing system sealed pipe 55 may be separately used.
Next, the laminated sensor element will be described with reference to an exploded perspective view shown in FIG.

  FIG. 3 is an exploded perspective view of a stacked sensor element 131 provided in an oxygen sensor that is one of the gas sensors. The stacked sensor element 131 includes an oxygen concentration battery unit 125 and a heater unit 126. It is an oxygen sensor element.

  As shown in FIG. 3, the laminated sensor element 131 constitutes a first ceramic substrate 121 made of a plate-like oxygen ion conductive solid electrolyte (such as zirconia) that constitutes the oxygen concentration battery portion 125, and a heater portion 126. A second ceramic substrate 123 and a third ceramic substrate 124 made of insulating ceramics (such as alumina) are laminated in this order.

  A detection electrode 135 is provided on the outer side surface (upper side surface in the drawing) of the first ceramic substrate 121 at a position near the front end in the longitudinal direction, and on the surface of the first ceramic substrate 121 facing the second ceramic substrate 123. Is provided with a reference electrode 137 at a position near the front end in the longitudinal direction. In the detection electrode 135 and the reference electrode 137, wiring portions 136 and 138 extending from the respective rear end portions toward the rear end portion in the longitudinal direction of the first ceramic substrate 121 are extended.

  A through hole 143 is provided at the rear end portion of the first ceramic substrate 121 from the surface on which the detection electrode 135 is provided to the surface on which the reference electrode 137 is provided, and the wiring portion 138 and one output electrode 133 are provided. Are electrically connected through a through hole 143. Further, with respect to the other output electrode 134, an end portion of the wiring portion 136 extending from the detection electrode 135 is provided as the output electrode 134.

  The third ceramic substrate 124 is provided with two heater electrodes 141 on the outer side surface (lower side surface in the drawing) of the rear end portion in the longitudinal direction, and the outer surface from the surface facing the second ceramic substrate 123 in the rear end portion in the longitudinal direction. Two through holes 147 penetrating through are provided.

Further, a heater 139 is sandwiched between the second ceramic substrate 123 and the third ceramic substrate 124.
Two wiring portions 148 extending from the rear end portion of the heater 139 toward the rear end portion in the longitudinal direction of the multilayer sensor element 131 are extended. The end portions 149 of the two wiring portions 148 are respectively through holes 147. It is electrically connected to the heater electrode 141 through a conductive layer formed on the inner wall surface.

Next, a procedure for printing the conductive paste on the inner wall surface of the through hole using the substrate conductive layer forming apparatus 1 on the substrate having the through hole will be described.
FIG. 2 is an explanatory diagram showing a procedure for printing the conductive paste 65 on the inner wall surface of the through hole 63 formed in the print target substrate 61.

  In FIG. 2, the substrate placement jig 11 of the substrate conductive layer forming apparatus 1 is shown, and the vacuum pump 17, the fixing vacuum system unit 13, and the printing vacuum system unit 15 are not shown. . The print target substrate 61 is an unfired ceramic sheet (green sheet), and is cut and processed with a predetermined size to stack and fire the first ceramic substrate 121 in the multilayer sensor element 131. Alternatively, the third ceramic substrate 124 can be formed.

  When the conductive paste 65 is printed on the inner wall surface of the through hole 63 in the substrate to be printed 61, first, as a first step, the first portion of the substrate to be printed 61 where the through hole 63 is formed is a printing chamber. The second part excluding the first part of the print target substrate 61 is located in the fixing part 23 (see FIG. 1) via the paint plate member 27. The operation of placing the print target substrate 61 on the substrate placement jig 11 is performed.

  That is, in the first step, at least the through hole 63 of the first part of the substrate to be printed 61 communicates with the printing vent 37, and at least a part of the second part of the substrate to be printed 61 is the fixing vent. An operation of placing the print target substrate 61 on the substrate placement jig 11 so as to abut on the substrate 35 is executed.

  Next, in the second step, the vacuum pump 17 is driven, and the fixing chamber portion 21 and the printing chamber of the substrate placement jig 11 are connected via the fixing vacuum system portion 13 and the printing vacuum system portion 15. While performing the vacuuming operation | movement which removes gas from the part 23, the operation | work which apply | coats the electrically conductive paste 65 with respect to the printing target board | substrate 61 by screen printing is performed.

  In FIG. 2, as a printing form of the conductive paste 65, a printing form of the conductive paste constituting the conductive layer formed on the inner wall surface of the through hole 63 and the heater formed on the substrate surface is shown. .

  By this evacuation operation, the fixing chamber portion 21 is brought into a negative pressure state, the printing target substrate 61 is sucked and fixed through the fixing vent hole 35, and the printing chamber portion 23 is brought into a negative pressure state to set the printing vent hole 37 and The conductive paste 65 is printed on the inner wall surface of the through hole 63 by sucking the conductive paste 65 into the printing chamber portion 23 through the through hole 63.

  At this time, by adjusting the flow rate adjusting gate valve 57, the flow rate in the printing vacuum system unit 15 is set smaller than the flow rate in the fixing vacuum system unit 13, and the vacuum pulling force for printing in the substrate placement jig 11 is set. Is set smaller than the vacuum pull-in force for fixing.

  Then, by setting the vacuum drawing flow rate by the vacuum pump 17 to be large, the vacuum drawing force by the fixing chamber portion 21 is set to be large, and the substrate to be printed 61 is firmly sucked and fixed to the substrate placement jig 11. On the other hand, by adjusting the flow rate adjusting gate valve 57, the vacuum drawing force by the printing chamber portion 23 is set to a size suitable for printing the conductive paste 65, and the conductive paste 65 is printed in the through hole 63. Can be set in a good state.

  At this time, for example, the internal pressure of the fixing chamber portion 21 is set to be 70 [kPa] lower than the atmospheric pressure (gauge pressure: −70 [kPa]), and the internal pressure of the printing chamber portion 23 is set. Can be set to be 40 [kPa] lower than the atmospheric pressure (gauge pressure: −40 [kPa]).

  Immediately after the conductive paste 65 is screen-printed on the print target substrate 61, the through hole 63 is sealed with the conductive paste 65, but the conductive paste 65 is removed from the through hole 63 by evacuation. When applied to the inner wall surface, the through hole 63 penetrates from one opening end to the other opening end. As described above, since the through-hole 63 is penetrated, the outside air is supplied to the printing chamber portion 23 through the through-hole 63 and the printing air hole 37. Therefore, the printing chamber portion 23 is not sealed in the sealed space. Disappear.

  If the printing chamber portion 23 is a sealed space, the degree of vacuum will rise slowly but surely even if the flow rate is reduced by the flow rate adjusting gate valve 57, so the degree of vacuum is constant. Difficult to adjust.

  On the other hand, since the printing chamber section 23 is not a sealed space, the degree of vacuum inside the printing chamber section 23 increases to a certain value, but the degree of vacuum does not increase further. In other words, the internal air pressure of the printing chamber unit 23 is the same as the evacuation flow rate through the printing vacuum system unit 15 and the outside air supply amount through the through hole 63 and the printing vent hole 37. (Until the equilibrium state is reached), but does not decrease to an internal pressure value that is lower than the internal pressure value in the equilibrium state.

  Thus, since the printing chamber portion 23 is not a sealed space, it is possible to prevent an excessive increase in the degree of vacuum, and the degree of vacuum inside the printing chamber portion 23 is adjusted by the flow rate adjusting gate valve 57. I can do it.

  Then, after the printing of the conductive paste 65 to the through hole 63 is completed, the vacuum pump 17 is stopped, and the suction fixing of the substrate to be printed 61 by the fixing chamber portion 21 (fixing air hole 35) is released, By removing the printed print target substrate 61 from the substrate placement jig 11, a series of printing operations using the substrate conductive layer forming apparatus 1 is completed.

  The conductive paste 65 printed on the inner wall surface of the through hole 63 in this manner is then subjected to a drying process to form a conductive layer from one opening end to the other opening end in the through hole 63. To do. The conductive layer functions as an energization path for electrically connecting the wiring pattern and the like on the front side plate surface and the wiring pattern and the like on the back side plate surface in the print target substrate 61.

  Then, as described above, the substrate to be printed 61 on which the conductive layer is formed is cut at a predetermined dimension corresponding to the dimension of the multilayer sensor element, thereby forming the first ceramic substrate 121 or the third ceramic substrate 124. it can.

  Of the conductive members constituting the sensor element, conductive members other than the conductive layer inside the through hole (wiring pattern, detection electrode, reference electrode, heater electrode, heater, etc.) are also applied to the substrate with a conductive paste. After printing, it can be formed through a drying process. For this reason, when printing the conductive paste that becomes the conductive layer inside the through-hole on the substrate, it is also possible to simultaneously perform the printing work of the conductive paste that becomes another conductive member constituting the sensor element. is there.

  In this way, the substrates (first ceramic substrate 121 and third ceramic substrate 124) on which the conductive layer and other conductive members are formed and the substrate (second ceramic substrate 123) on which the conductive layer is not formed are stacked. Then, the laminated sensor element 131 can be manufactured through a firing process and the like.

An oxygen sensor can be configured by using the laminated sensor element 131 and other sensor constituent members (such as a metal shell and a lead frame).
As described above, the substrate conductive layer forming apparatus 1 according to the present embodiment sets the vacuum drawing flow rate by the vacuum pump 17 and sets the vacuum drawing force by the fixing chamber portion 21 to be large. The substrate can be firmly sucked and fixed to the jig.

  At this time, by reducing the flow rate in the printing vacuum system 15 using the flow rate adjusting gate valve 57, it is possible to prevent the conductive paste from splashing when the conductive paste is sucked into the through hole. . That is, by setting the vacuum pulling force by the printing chamber portion 23 to a size suitable for printing of the conductive paste by the flow rate adjusting gate valve 57, the state of printing of the conductive paste in the through hole 63 is improved. Can be set to state.

  Further, the substrate conductive layer forming apparatus 1 does not have a structure in which the substrate is fixed to the substrate arrangement jig using the fixing protrusions and the fixing holes, but the substrate is sucked and fixed to the substrate arrangement jig 11. Because of this structure, it is possible to easily perform the fixing operation and the removing operation of the substrate with respect to the substrate arrangement jig 11, and the fixing operation and the removing operation can be performed in a short time.

  Therefore, by using the substrate conductive layer forming apparatus 1, it is possible to perform the work for fixing and removing the substrate with respect to the substrate placement jig 11 in a short time, and it is possible to improve the work efficiency in the substrate manufacturing work.

  Further, since the substrate can be firmly sucked and fixed to the substrate placement jig 11 by setting the vacuum pulling force by the fixing chamber portion 21 large, the pressure of the squeegee in screen printing (press the paste against the substrate) Even when the pressure is increased, the movement of the substrate can be suppressed, and printing errors of the conductive layer (conductive paste 65) due to the positional deviation of the substrate can be prevented.

  Further, since the printed state of the conductive paste 65 in the through hole 63 becomes good, the conductive layer formed by drying the conductive paste is formed from one open end of the through hole 63 to the other open end. Thus, electrical continuity can be reliably achieved, and the occurrence rate of wiring defects on the substrate can be reduced.

  Therefore, according to the board | substrate conductive layer forming apparatus 1, when forming a conductive layer in the through-hole of a board | substrate, generation | occurrence | production of the wiring defect of a board | substrate can be suppressed, aiming at the improvement of the working efficiency in the manufacture operation | work of a board | substrate. .

  In this embodiment, the vacuum pump 17 and the fixing vacuum system unit 13 correspond to the fixing vacuum evacuation means described in the claims, and the vacuum pump 17 and the printing vacuum system unit 15 are used for printing. The flow rate adjusting gate valve 57 corresponds to the flow rate adjusting means.

  Moreover, the board | substrate used for a 1st process and a 2nd process means the board | substrate which was not baked instead of the board | substrate after baking, and in this specification, the board | substrate used in the 1st process and the 2nd process is the unbaked board | substrate. For convenience, it is referred to as a “substrate”.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various aspect can be taken.
For example, the substrate to be printed may be an element used for a plate-type full-range air-fuel ratio sensor or an element of a NOx sensor. The heater is not limited to the detection element, and may be a heater used for the sensor or the like. Of course, the substrate is not limited to the substrate used for the laminated sensor element, and the substrate including a conductive layer for electrically connecting the front side plate surface and the back side plate surface is also a target.

  The stacked sensor element is highly demanded of miniaturization due to the limitation of the sensor installation space, and the outer dimensions are formed to be small in order to meet the demand, and accordingly the inner diameter of the through hole is also made small. ing. In such a through hole having a small inner diameter, the flow rate at the time of evacuation operation increases at the through hole portion, so that the vacuum drawing force for printing tends to increase.

  For this reason, in the printing operation for the through hole of the substrate constituting the multilayer sensor element, by using the method of the present invention or the apparatus according to the present invention, the vacuum pulling force for suction fixing is sufficiently secured and the printing The vacuum pulling force can be set to an appropriate magnitude.

  Therefore, in the conductive layer printing work inside the through-hole on the substrate of the multilayer sensor element, by using the method of the present invention or the apparatus of the present invention, the wiring efficiency of the substrate is improved while improving the work efficiency in the substrate manufacturing work. The effect that generation | occurrence | production of can be suppressed can be exhibited more effectively.

  For a substrate made of a conductive material, an insulating layer made of an insulating material such as alumina may be formed on the substrate surface and the inner wall surface of the through hole, and then a conductive paste (for example, platinum paste) may be applied. Is possible.

  Furthermore, the printing operation into the through hole of the substrate to be printed can be performed from both the front side plate surface and the back side plate surface. In other words, after performing the printing operation from one plate surface for one printing target substrate, the printing target substrate is reversed and placed on the substrate placement jig, and the printing operation is also performed from the other plate surface. .

  At this time, in the case of adopting the fixing method using the fixing protrusion and the fixing hole as the fixing method of the substrate to be printed, in both cases before and after the substrate to be printed is inverted, In order to fix the substrate to be printed, it is necessary to consider the formation positions and shapes of the fixing protrusions and fixing holes.

  On the other hand, the substrate conductive layer forming apparatus of the present invention has a structure in which the substrate to be printed is sucked and fixed to the substrate arrangement jig. However, there is an advantage that the substrate to be printed can be fixed to the substrate placement jig.

  The flow rate adjusting gate valve may be provided not only in the printing vacuum system section but also in the fixing vacuum system section. As a result, the vacuum pulling force by the fixing chamber can be set smaller than the vacuum pulling force by the printing chamber, and the vacuum pulling force for printing can be reduced as in the case of printing using a highly viscous conductive paste. It is possible to cope with a case where a large setting is required.

It is a schematic block diagram of the board | substrate conductive layer formation apparatus for forming a conductive layer in the through-hole inner wall surface of a board | substrate. It is explanatory drawing showing the procedure which prints an electrically conductive paste on the inner wall face of the through hole formed in the printing object board | substrate. It is a disassembled perspective view of the lamination type sensor element with which an oxygen sensor is equipped.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Substrate conductive layer forming apparatus, 11 ... Substrate placement jig, 13 ... Fixing vacuum system part, 15 ... Printing vacuum system part, 17 ... Vacuum pump, 21 ... Fixing chamber part, 23 ... Printing chamber 35, fixing vent, 37 ... printing vent, 57 ... flow control gate valve, 59 ... flow meter, 61 ... substrate to be printed, 63 ... through hole, 65 ... conductive paste, 131 ... laminated type Sensor element.

Claims (4)

For a substrate having a through hole penetrating in the thickness direction, a conductive paste is printed on the inner wall surface of the through hole, and the conductive paste is applied from one open end to the other open end of the through hole. A substrate manufacturing method for forming as a conductive layer,
A substrate arrangement comprising: a fixing chamber for forming a vacuum region for sucking and fixing the substrate; and a printing chamber for forming a vacuum region for sucking and printing the conductive paste on the inner wall surface of the through hole. Using a jig
At least the through hole of the first portion of the substrate where the through hole is formed is positioned on the printing chamber, and at least a part of the second portion of the substrate excluding the first portion is for fixing. A first step of placing the substrate on the substrate placement jig so as to be positioned on the chamber;
With the evacuation flow rate for the fixing chamber and the evacuation flow rate for the printing chamber different, evacuation is performed on the fixing chamber and the printing chamber to fix the substrate and to fix the through hole. A second step of printing the conductive paste on the inner wall surface;
A substrate manufacturing method comprising: Performing the evacuation for the fixing chamber and the printing chamber in a state where the evacuation flow rate for the printing chamber is smaller than the evacuation flow rate for the fixing chamber in the second step;
The substrate manufacturing method according to claim 1. For a substrate having a through hole penetrating in the thickness direction, a conductive paste is printed on the inner wall surface of the through hole, and the conductive paste is applied from one open end to the other open end of the through hole. A conductive layer forming apparatus for a substrate that forms a conductive layer to reach,
A fixing chamber for forming a vacuum region for sucking and fixing the second portion, wherein at least a part of the second portion of the substrate excluding the first portion where the through hole is formed is disposed; A substrate placement jig having a printing chamber in which the through hole of the first part is disposed and forming a vacuum region for suction printing the conductive paste on an inner wall surface of the through hole;
A fixing evacuation means for evacuating the fixing chamber to suck and fix the substrate;
A evacuation means for printing that evacuates the printing chamber in order to print the conductive paste on the inner wall surface of the through hole;
A flow rate adjusting means for setting the vacuuming flow rate by the fixing vacuuming unit and the vacuuming flow rate by the printing vacuuming unit to different flow rate values;
A conductive layer forming apparatus for a substrate, comprising: The flow rate adjusting means adjusts the flow rate so that the vacuuming flow rate by the printing vacuuming unit is smaller than the vacuuming flow rate by the fixing vacuuming unit;
The conductive layer forming apparatus for a substrate according to claim 3.

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