JP2009117735A - Antistatic component, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antistatic component whose mounting quality and strength are stabilized by securing the smoothness of a protecting film on the upper face of the component. <P>SOLUTION: The antistatic component includes drawing out electrodes provided at both ends on the upper face of a ceramic base material 11, an overvoltage protecting material layer 14 provided for covering a gap 13 between a part of the drawing out electrode 12 and a drawing out electrode 12, and the protecting film provided for covering the overvoltage protecting material layer 14. The protecting film consists of a first protecting film 15 formed encircling the overvoltage protecting material layer 14 to reduce a level difference from the overvoltage protecting material layer 14, and a second protecting film 16 formed covering the overvoltage protecting material layer 14 and the first protecting film 15 to smooth their surfaces. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an anti-static component for protecting an electronic device from static electricity and a method for manufacturing the same.

  In recent years, electronic devices such as mobile phones have been rapidly reduced in size and performance, and accordingly, electronic components used in electronic devices have also been rapidly reduced in size. However, with this miniaturization, the withstand voltage of electronic equipment and electronic components decreases, and this causes the electrical circuit inside the equipment to be destroyed by electrostatic pulses generated when the human body contacts the terminals of the electronic equipment. Increasingly. This is because a high voltage of several hundreds to several kilovolts is applied to the electric circuit inside the device at a rising speed of 1 nanosecond or less by electrostatic pulses.

  Conventionally, as a countermeasure against such an electrostatic pulse, a method of providing a countermeasure component between a line where static electricity enters and a ground has been taken, but in recent years, the transmission speed of a signal line has been increased to several hundred Mbps or more. In the case where the stray capacitance of the countermeasure component described above is large, the signal quality is inferior, so the smaller one is preferable. Therefore, a countermeasure component having a low capacitance of 1 pF or less is required at a transmission speed of several hundred Mbps or more. It will become.

  Conventionally, as a countermeasure against static electricity in such a high-speed transmission line, a type of countermeasure against static electricity in which an overvoltage protection material is filled between opposing gap electrodes has been proposed.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
Special table 2002-538601 gazette

  The mechanism of characteristic development in the antistatic component of the type in which an overvoltage protection material is filled between the gaps between the opposing extraction electrodes described above is that when the overvoltage due to static electricity is applied between the gaps between the opposing extraction electrodes, the opposing extraction electrodes Such a discharge current flows between conductive particles or semiconductor particles scattered in the overvoltage protection material between the gaps, and bypasses it to the ground as a current. In the conventional anti-static component described in Patent Document 1, a method for forming a protective film that covers an overvoltage protective material layer located in a gap between opposing extraction electrodes is not defined, and as shown in FIG. When the film thickness of the overvoltage protection material layer 1 is thick, as shown in FIG. 5B, when the protection film 2 is printed so as to cover the overvoltage protection material layer 1, the overvoltage protection material layer in the protection film 2 The thickness of the portion overlapping 1 becomes different from the thickness of the other portions, and as a result, the smoothness of the surface of the protective film 2 is hindered, which may lead to a decrease in mounting quality and a decrease in component strength. . This tendency is not particularly changed even when the protective film 2 is printed twice at the same location as shown in FIG. 5 (c), and the effect becomes more noticeable as the size of the component becomes smaller. .

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and provides a static electricity countermeasure component that can secure the smoothness of the protective film on the upper surface of the component, and that has stable mounting quality and strength, and a method for manufacturing the same. It is for the purpose.

  In order to achieve the above object, the present invention has the following configuration.

  The invention according to claim 1 of the present invention is an extraction electrode provided at both ends of the upper surface of the ceramic substrate, and an overvoltage protection material provided so as to cover a gap between the extraction electrode and a portion of the extraction electrode. And a protective film provided so as to cover the overvoltage protection material layer, and the protective film is formed so as to surround the overvoltage protection material layer, and a step difference from the overvoltage protection material layer is reduced. The first protective film is provided with a second protective film that covers the overvoltage protective material layer and the first protective film, and is formed so that the surface thereof is smooth. According to this configuration, As the protective film provided so as to cover the overvoltage protective material layer, a first protective film is formed so as to surround the overvoltage protective material layer, and the step difference from the overvoltage protective material layer is reduced, and the overvoltage protective material layer And the second protective film which covers the first protective film and is formed so that the surface thereof is smooth, the surface of the second protective film located on the upper surface of the antistatic component is smooth. As a result, the load applied when attracted to the mounting nozzle is dispersed without concentrating on one point, so that it is possible to obtain an anti-static component with stable mounting quality and strength. It is what has.

  According to the second aspect of the present invention, in particular, the maximum value of the thickness of the first protective film is substantially equal to the maximum value of the thickness of the overvoltage protective material layer. Since the maximum value of the thickness of the protective film is substantially equal to the maximum value of the thickness of the overvoltage protective material layer, the step difference between the overvoltage protective material layer and the first protective film is reduced, whereby the overvoltage protective material layer When the second protective film is formed so as to cover the first protective film, the surface of the second protective film positioned on the upper surface of the antistatic component can be formed smoothly. Since the top surface of the surface is smooth, the load applied when attracted to the mounting nozzle is dispersed without being concentrated on one point. It has the effect of being obtained

  In the invention according to claim 3 of the present invention, in particular, the viscosity of the resin constituting the first protective film is made higher than the viscosity of the resin constituting the second protective film. Since the viscosity of the resin constituting the first protective film is high, the first protective film formed so as to surround the periphery of the overvoltage protective material layer does not spread greatly. The level difference between the first protective film and the first protective film can be easily reduced, and since the viscosity of the resin constituting the second protective film is low, the surface of the second protective film located on the upper surface of the anti-static component can be easily As a result, the upper surface of the anti-static component is also smoothed, and the load applied when being attracted to the mounting nozzle is distributed without being concentrated on one point. And antistatic parts with stable strength And it has a effect that is.

  The invention according to claim 4 of the present invention is a step of forming an extraction electrode having a gap on the upper surface of the ceramic substrate, and a step of forming an overvoltage protection material layer so as to cover the gap and a part of the extraction electrode. And a step of forming a protective film so as to cover the overvoltage protective material layer, and as the step of forming the protective film, a step difference from the overvoltage protective material layer is reduced so as to surround the overvoltage protective material layer. A first protective film forming step formed so as to cover the overvoltage protective material layer and the first protective film, and a second protective film forming step formed so as to have a smooth surface. Therefore, according to this manufacturing method, as a step of forming a protective film so as to cover the overvoltage protection material layer, a step with the overvoltage protection material layer is formed so as to surround the overvoltage protection material layer. A first protective film forming step formed so as to cover, and a second protective film forming step formed so as to cover the overvoltage protective material layer and the first protective film and to have a smooth surface. Therefore, the surface of the second protective film located on the upper surface of the anti-static component is smooth, so that the load applied when being attracted to the mounting nozzle is dispersed without being concentrated on one point. Therefore, it has an operational effect that an anti-static component having stable mounting quality and strength can be obtained.

  The invention according to claim 5 of the present invention is an extraction electrode provided at both ends of the upper surface of the ceramic substrate, and an overvoltage protection material provided so as to cover a gap between the extraction electrode and a part of the extraction electrode. A layer, an intermediate layer provided to cover the overvoltage protection material layer, and a protective film provided to cover the intermediate layer, and the protective film is formed so as to surround the periphery of the intermediate layer. And a first protective film for reducing the level difference from the intermediate layer, and a second protective film that covers the intermediate layer and the first protective film and that has a smooth surface. Thus, according to this configuration, the protective film provided so as to cover the intermediate layer is formed so as to surround the intermediate layer, and the first protective film that reduces the step with the intermediate layer, and the intermediate layer And covering the layer and the first protective film In addition, since the second protective film formed so as to have a smooth surface is provided, the surface of the second protective film located on the upper surface of the anti-static component becomes smooth. Since the load applied when attracted to the surface is dispersed without concentrating on one point, an anti-static component having stable mounting quality and strength can be obtained. Moreover, since the intermediate layer is provided between the overvoltage protective material layer and the second protective film, the discharge protective spark generated between the metal powders contained in the overvoltage protective material when applying the electrostatic pulse causes the second protective film. The phenomenon that the carbon compound in the resin component is carbonized and causes deterioration of insulation can be prevented by the presence of the intermediate layer, and this has the effect of being able to obtain an anti-static component with excellent electrostatic pulse resistance. It is.

  In the invention according to claim 6 of the present invention, in particular, the maximum value of the thickness of the first protective film is substantially equal to the maximum value of the sum of the thickness of the overvoltage protective material layer and the thickness of the intermediate layer. Since the maximum value of the thickness of the first protective film is substantially equal to the maximum value of the sum of the thickness of the overvoltage protective material layer and the thickness of the intermediate layer, the level difference between the intermediate layer and the first protective film Accordingly, when the second protective film is formed so as to cover the intermediate layer and the first protective film, the surface of the second protective film located on the upper surface of the antistatic component is smoothed. Since the upper surface of the anti-static component can be formed smoothly, the load applied when attracted to the mounting nozzle is dispersed without being concentrated on one point. The effect of obtaining anti-static parts with stable strength It is intended to.

  In the invention according to claim 7 of the present invention, in particular, the viscosity of the resin constituting the first protective film is made higher than the viscosity of the resin constituting the second protective film. Since the viscosity of the resin constituting the first protective film is high, the first protective film formed so as to surround the periphery of the intermediate layer does not spread greatly, and thereby the intermediate layer and the first protective film Since the resin constituting the second protective film has a low viscosity, the surface of the second protective film located on the upper surface of the anti-static component can be easily kept smooth. As a result, the top surface of the anti-static component is also smoothed, and the load applied when attracted to the mounting nozzle is dispersed without being concentrated on one point, so that the mounting quality and strength are stable. The effect of being able to obtain the static electricity countermeasure parts Those having.

  The invention according to claim 8 of the present invention is the step of forming an extraction electrode having a gap on the upper surface of the ceramic substrate, and the step of forming an overvoltage protection material layer so as to cover the gap and a part of the extraction electrode. A step of forming an intermediate layer so as to cover the overvoltage protection material layer, and a step of forming a protective film so as to cover the intermediate layer. Forming a first protective film forming step so as to reduce the level difference with the intermediate layer, covering the intermediate layer and the first protective film, and forming the surface to be smooth According to this manufacturing method, as the step of forming the protective film so as to cover the intermediate layer, the step with the intermediate layer is reduced so as to surround the periphery of the intermediate layer. To do Since it includes a first protective film forming step to be formed, and a second protective film forming step that covers the intermediate layer and the first protective film and that has a surface that is smoothed. Since the surface of the second protective film located on the upper surface of the countermeasure component is smooth, the load applied when attracted to the mounting nozzle is dispersed without being concentrated on one point. It is possible to obtain antistatic parts with stable quality and strength. Moreover, since the intermediate layer is provided between the overvoltage protective material layer and the second protective film, the discharge protective spark generated between the metal powders contained in the overvoltage protective material when applying the electrostatic pulse causes the second protective film. The phenomenon that carbon compounds in the resin component are carbonized and cause deterioration of insulation can also be prevented by the presence of the intermediate layer, and this has the effect of being able to obtain an anti-static component with excellent electrostatic pulse resistance It is.

  As described above, the anti-static component of the present invention is formed as a protective film provided so as to cover the overvoltage protection material layer so as to surround the overvoltage protection material layer, and has a small step with the overvoltage protection material layer. And a second protective film that covers the overvoltage protective material layer and the first protective film and that has a smooth surface. Since the surface of the second protective film located at the surface is smooth, the load applied when attracted to the mounting nozzle is dispersed without concentrating on one point, so that the mounting quality and strength are improved. It has an excellent effect that a stable anti-static component can be obtained.

(Embodiment 1)
Hereinafter, the invention described in the first to fourth aspects of the present invention will be described using the first embodiment.

  FIGS. 1A to 1F are cross-sectional views showing a method for manufacturing an antistatic component in Embodiment 1 of the present invention, and FIGS. 2A to 2F are top views showing a method for manufacturing the antistatic component. It is.

  First, as shown in FIGS. 1 (a) and 2 (a), a ceramic substrate obtained by firing a low dielectric constant material such as alumina at a temperature of 900 to 1300 ° C. having a dielectric constant of 50 or less, preferably 10 or less. The lead electrode 12 is formed by disposing a conductive material mainly composed of gold on the upper surface of the material 11. It is possible to form the extraction electrode 12 by printing and baking using a gold-based organic paste (resinate paste) as a material mainly composed of gold used for forming the extraction electrode 12, other gold-based materials, For example, it is more preferable in terms of productivity and cost than selecting gold-based sputtering. The thickness of the extraction electrode 12 after firing is as thin as 0.2 to 2.0 μm. FIG. 2A shows a rectangular ceramic substrate 11 having a long side of L (mm) and a short side of W (mm), which is an individual size of an antistatic component, and the following manufacturing process is shown. In the description of, the ceramic substrate 11 of this individual size is used for explanation. However, in the actual manufacturing process, a sheet-like ceramic substrate from which a large number of ceramic substrates 11 can be obtained vertically and horizontally is used. A sheet-like ceramic substrate is divided into strips or individual pieces before a terminal electrode forming step described later. Here, the extraction electrode 12 is printed leaving a blank on the long side of the ceramic substrate 11, but may be printed leaving a blank on the short side of the ceramic substrate 11.

  Next, as shown in FIG. 1B and FIG. 2B, a gap 13 having a width of about 10 μm is formed by cutting a substantially central portion of the extraction electrode 12 using a UV laser. Here, since the extraction electrode 12 is formed by printing and baking a gold-based organic paste, its thickness is as thin as 0.2 to 2.0 μm. Therefore, the gap 13 is formed by using a relatively low output UV laser. It is possible to reliably form with high accuracy. The method of forming the gap 13 is not limited to the method of cutting the extraction electrode 12 using a UV laser, and the gap 13 may be formed by etching the extraction electrode 12 by a photolithography process. Here, the gap 13 is formed substantially parallel to the short side of the ceramic substrate 11, but may be formed substantially parallel to the long side of the ceramic substrate 11. In this case, when the extraction electrode 12 is formed, it is preferable to print with leaving a blank on the short side of the ceramic substrate 11. Moreover, although the shape of the gap 13 is linear in FIGS. 1B and 2B, it may be stepped or meandered.

  Next, an appropriate organic solvent is added to a mixture of metal powder composed of any one of Ni, Al, Ag, Pd, Cu, and the like having a mean particle size of 0.3 to 10 μm and silicone resin such as methyl silicone, These were kneaded and dispersed by a three-roll mill to prepare an overvoltage protection material paste. Then, as shown in FIGS. 1C and 2C, this overvoltage protection material paste is printed using a screen printing method and dried at 150 ° C. for 5 to 15 minutes, thereby overvoltage protection material layer 14. Formed. In this case, as shown in FIGS. 1C and 2C, the overvoltage protection material layer 14 is patterned so as to cover a part of the two opposing extraction electrodes 12 and the gap 13. .

  Here, the thickness of the overvoltage protection material layer 14 after drying is set to 5 μm or more and 50 μm or less. If the thickness of the overvoltage protection material layer 14 is less than 5 μm, for example, when a high voltage electrostatic pulse of 8 kV or higher is applied, the discharge in the gap 13 becomes intense, which causes the overvoltage protection material layer 14 to deteriorate. On the other hand, when the thickness of the overvoltage protection material layer 14 exceeds 50 μm, the size reduction of the anti-static component is hindered, and it is difficult to finish the surface of the protective film described later smoothly. It will be. Therefore, the thickness of the overvoltage protection material layer 14 after drying is set in the range of 5 μm or more and 50 μm or less depending on the required level of electrostatic withstand capability, which increases the reliability against high voltage electrostatic pulses and the miniaturized shape of the product. It is preferable in terms of achieving both.

  Next, as shown in FIG. 1D and FIG. 2D, the overvoltage protection material layer 14 is not covered completely, that is, surrounding the overvoltage protection material layer 14. A first protective film 15 is formed so as to cover the extraction electrode 12 positioned around the periphery of the ceramic substrate 11 and leave the end portions of the extraction electrode 12 at both ends of the ceramic substrate 11. And a first protective film forming step for reducing the step between the overvoltage protective material layer 14. Then, after the first protective film formation step, as shown in FIGS. 1E and 2E, the overvoltage protection material layer 14 and the first protection located around the overvoltage protection material layer 14 are provided. A second protective film 16 was formed so as to cover the film 15, and a second protective film forming step for smoothing the surface was performed. In addition, the 1st protective film 15 and the 2nd protective film 16 printed the protective resin paste which consists of an epoxy resin, a phenol resin, etc. using the screen printing method, and made it dry for 5 to 15 minutes at 150 degreeC, Then, It is formed by curing at 150 to 200 ° C. for 15 to 60 minutes.

  Here, the maximum thickness of the first protective film 15 after curing is substantially equal to the maximum thickness of the overvoltage protection material layer 14 after drying. By doing so, overvoltage protection is achieved. The level difference between the material layer 14 and the first protective film 15 is reduced, whereby the second protective film 16 is formed so as to cover the overvoltage protective material layer 14 and the first protective film 15 located around the overvoltage protective material layer 14. In this case, since the surface of the second protective film 16 positioned on the upper surface of the antistatic component can be formed smoothly, the upper surface of the antistatic component becomes smooth, and is thereby attracted to the mounting nozzle. Since the load applied at that time is not concentrated on one point but is dispersed, an anti-static component having stable mounting quality and strength can be obtained. Further, the thickness of the portion of the second protective film 16 positioned on the overvoltage protective material layer 14 after curing is 10 μm or more and 40 μm or less in order to achieve both high voltage electrostatic pulse reliability and a compact product shape. It is what you are trying.

  Further, since the place where the first protective film 15 is printed and the place where the second protective film 16 is printed are different, the mask used in the first protective film forming process and the mask used in the second protective film forming process are also used. The thing of a different pattern is used. In particular, in the mask used in the first protective film forming step, the portion corresponding to the overvoltage protective material layer 14 is shielded so that the protective resin paste does not penetrate so that the protective resin paste is not printed on the overvoltage protective material layer 14 as much as possible. It is the composition.

  In addition, the same material is preferably used for the protective resin paste constituting the first protective film 15 and the protective resin paste constituting the second protective film 16, but different types of protective resin pastes are used. It may be used. In particular, when the viscosity of the protective resin paste constituting the first protective film 15 is higher than that of the protective resin paste constituting the second protective film 16, the protective resin constituting the first protective film 15 is used. Since the viscosity of the paste is high, the first protective film 15 formed so as to surround the periphery of the overvoltage protective material layer 14 does not spread greatly toward the end of the individual region of the ceramic substrate 11. Thus, the thickness of the first protective film 15 can be easily controlled. For this reason, the level difference between the overvoltage protection material layer 14 and the first protective film 15 can be easily reduced, and the viscosity of the protective resin paste constituting the second protective film 16 is low. The surface of the second protective film located on the upper surface of the substrate can be kept smooth, thereby smoothing the upper surface of the anti-static component, and the load applied when being attracted to the mounting nozzle can be concentrated on one point. Therefore, it is possible to obtain an anti-static component with stable mounting quality and strength.

  In the first embodiment of the present invention, the example in which the process of forming the protective film is performed in two steps has been described. However, if the protective film is formed in at least two steps, the surface of the protective film is formed. Since it can be made smooth, the protective film may be formed in three or more steps according to the thickness of the protective film required by the withstand voltage standard of the antistatic component.

  After the second protective film 16 is formed, the sheet-shaped ceramic substrate is divided into strips, and sputtering is performed from the top and back surfaces of the strip-shaped ceramic substrate, so that FIG. As shown in FIG. 2 (f), terminal electrodes 17 were formed on both ends of the ceramic substrate 11 so as to be electrically connected to the ends of the extraction electrode 12. Then, after the strip-shaped ceramic substrate is divided into individual pieces, nickel plating (not shown) and tin plating (not shown) are formed on the surface of the terminal electrode 17 by barrel plating. The antistatic component in Embodiment 1 of the invention was obtained.

  The antistatic component in the first embodiment of the present invention manufactured by the above manufacturing method is a silicone of the overvoltage protection material layer 14 present in the gap 13 between the opposing extraction electrodes 12 during normal use (under rated voltage). Since the resin is insulating, it is electrically open. However, when a high voltage such as an electrostatic pulse is applied, a discharge current is generated between the metal particles existing through the silicone resin in the overvoltage protection material layer 14 and the impedance is remarkably reduced. The anti-static component in the first embodiment uses this phenomenon to bypass abnormal voltages such as electrostatic pulses and surges to the ground.

  Here, in the conventional antistatic component and the antistatic component in the first embodiment of the present invention, a strength test was performed in which a load was applied horizontally from the upper surface of the antistatic component. In the conventional anti-static component, the average value (n = 20) of the breaking strength is 10.3 N, but in the anti-static component in the first embodiment of the present invention, the average value of the breaking strength (n = 20). ) Was 25.7N. As is clear from this result, in the anti-static component in the first embodiment of the present invention, the overvoltage protection material layer 14 is formed as a protection film covering the overvoltage protection material layer 14 and surrounds the overvoltage protection material layer 14. A first protective film 15 for reducing the level difference from the layer 14, and a second protective film 16 that covers the overvoltage protective material layer 14 and the first protective film 15 and has a smooth surface. Therefore, the surface of the second protective film 16 located on the upper surface of the anti-static component becomes smooth, so that the load applied when being attracted to the mounting nozzle is dispersed without concentrating on one point. As a result, an anti-static component with stable mounting quality and strength can be obtained.

(Embodiment 2)
Hereinafter, the invention according to the fifth to eighth aspects of the present invention will be described using the second embodiment.

  FIGS. 3A to 3G are cross-sectional views showing a method for manufacturing an antistatic component in Embodiment 2 of the present invention, and FIGS. 4A to 4G are top views showing the method for manufacturing the antistatic component. It is.

  First, as shown in FIG. 3 (a) and FIG. 4 (a), a ceramic substrate obtained by firing a low dielectric constant material such as alumina at a temperature of 900 to 1300 ° C. of 50 or less, preferably 10 or less. The lead electrode 22 is formed by disposing a conductive material mainly composed of gold on the upper surface of the material 21. Forming the extraction electrode 22 by printing and baking using a gold-based organic paste (resinate paste) as a material mainly composed of gold used for the formation of the extraction electrode 22, other gold-based materials, For example, it is more preferable in terms of productivity and cost than selecting gold-based sputtering. The thickness of the extraction electrode 22 after firing is as thin as 0.2 to 2.0 μm. FIG. 4A shows a rectangular ceramic base material 21 having a long side of L (mm) and a short side of W (mm), which is an individual size of an antistatic component, and the following manufacturing process is shown. In the description, the individual-sized ceramic base material 21 is used for explanation, but in the actual manufacturing process, a sheet-like ceramic substrate that can obtain a large number of the ceramic base materials 21 vertically and horizontally is used. A sheet-like ceramic substrate is divided into strips or individual pieces before a terminal electrode forming step described later. Here, the extraction electrode 22 is printed leaving a blank on the long side of the ceramic substrate 21, but may be printed leaving a blank on the short side of the ceramic substrate 21.

  Next, as shown in FIGS. 3B and 4B, a gap 23 having a width of about 10 μm is formed by cutting a substantially central portion of the extraction electrode 22 using a UV laser. Here, since the extraction electrode 22 is formed by printing and baking a gold-based organic paste, its thickness is as thin as 0.2 to 2.0 μm. Therefore, the gap 23 is formed by using a relatively low output UV laser. It is possible to reliably form with high accuracy. The method of forming the gap 23 is not limited to the method of cutting the extraction electrode 22 using a UV laser, and the gap 23 may be formed by etching the extraction electrode 22 by a photolithography process. Here, the gap 23 is formed substantially parallel to the short side of the ceramic base material 21, but may be formed substantially parallel to the long side of the ceramic base material 21. In this case, when forming the extraction electrode 22, it is preferable to print with leaving a blank on the short side of the ceramic substrate 21. 3B and 4B, the shape of the gap 23 is a straight line, but may be a stepped shape or a meandering shape.

  Next, an appropriate organic solvent is added to a mixture of metal powder composed of any one of Ni, Al, Ag, Pd, Cu, and the like having a mean particle size of 0.3 to 10 μm and silicone resin such as methyl silicone, These were kneaded and dispersed by a three-roll mill to prepare an overvoltage protection material paste. Then, as shown in FIGS. 3 (c) and 4 (c), this overvoltage protection material paste is printed using a screen printing method and dried at 150 ° C. for 5 to 15 minutes, thereby overvoltage protection material layer 24. Formed. In this case, as shown in FIGS. 3C and 4C, the overvoltage protection material layer 24 is patterned so as to cover a part of the two opposing extraction electrodes 22 and the gap 23. .

  Here, the thickness of the overvoltage protection material layer 24 after drying is set to 5 μm or more and 50 μm or less. If the thickness of the overvoltage protection material layer 24 is less than 5 μm, for example, when a high voltage electrostatic pulse of 8 kV or more is applied, the discharge in the gap 23 becomes intense, which causes the overvoltage protection material layer 24 to deteriorate. On the other hand, if the thickness of the overvoltage protection material layer 24 exceeds 50 μm, the miniaturization of the antistatic component is hindered, and it is difficult to finish the surface of the protective film described later smoothly. It will be. Therefore, the thickness of the overvoltage protection material layer 24 after drying is set in the range of 5 μm or more and 50 μm or less in accordance with the required level of static electricity resistance. It is preferable in terms of achieving both.

Next, an appropriate organic solvent is added to a mixture of insulator powder made of Al ₂ O ₃ , SiO ₂ , MgO or a composite oxide thereof having an average particle size of 0.3 to 10 μm and silicone resin such as methyl silicone. In addition, the intermediate layer paste prepared by kneading and dispersing them with a three-roll mill was subjected to overvoltage with a thickness of 5 to 50 μm using a screen printing method as shown in FIGS. 3 (d) and 4 (d). The intermediate layer 25 was formed by printing so as to almost completely cover the protective material layer 24 and drying at 150 ° C. for 5 to 15 minutes. Here, the intermediate layer 25 is preferably formed in substantially the same shape as the overvoltage protection material layer 24. If the same shape is used in this way, the same mask as that used when the overvoltage protection material layer 24 is printed can be used when the intermediate layer 25 is printed. Further, complication of the manufacturing process and cost increase due to the formation of the intermediate layer 25 on the overvoltage protection material layer 24 can be minimized.

  Next, as shown in FIG. 3 (e) and FIG. 4 (e), the drawers positioned around the intermediate layer 25 so as not to completely cover the intermediate layer 25, that is, surrounding the periphery of the intermediate layer 25. A first protective film 26 is formed so as to cover the electrode 22 and leave the end portions of the extraction electrode 22 at both ends of the ceramic substrate 21, so that the first protective film 26 and the intermediate layer 25 A first protective film forming step for reducing the level difference was performed. After the first protective film forming step, the intermediate layer 25 and the first protective film 26 located around the intermediate layer 25 are covered as shown in FIGS. 1 (f) and 2 (f). Thus, the second protective film 27 was formed, and the second protective film forming step for smoothing the surface was performed. In addition, the 1st protective film 26 and the 2nd protective film 27 print the protective resin paste which consists of an epoxy resin, a phenol resin, etc. using a screen printing method, and are dried for 5 to 15 minutes at 150 degreeC, Then, It is formed by curing at 150 to 200 ° C. for 15 to 60 minutes.

  Here, the maximum thickness after curing of the first protective film 16 is substantially equal to the maximum sum of the thickness after drying of the overvoltage protection material layer 24 and the thickness after drying of the intermediate layer 25. By doing so, the level difference between the intermediate layer 25 and the first protective film 26 is reduced, whereby the second protective layer 26 covers the intermediate layer 25 and the first protective film 26 located around the intermediate layer 25. When the protective film 27 is formed, the surface of the second protective film 27 located on the upper surface of the anti-static component can be formed smoothly, so that the upper surface of the anti-static component becomes smooth. Since the load applied when attracted to the mounting nozzle is dispersed without concentrating on one point, an anti-static component with stable mounting quality and strength can be obtained. In addition, the thickness after curing of the portion of the second protective film 27 located on the intermediate layer 25 is set to 10 μm or more and 40 μm or less in order to achieve both high reliability of high-voltage electrostatic pulses and a compact size of the product. Is.

  Further, since the place where the first protective film 26 is printed and the place where the second protective film 27 is printed are different, the mask used in the first protective film forming process and the mask used in the second protective film forming process are also used. The thing of a different pattern is used. In particular, the mask used in the first protective film forming step has a structure in which the protective resin paste is not permeated so that the portion corresponding to the intermediate layer 25 is shielded so that the protective resin paste is not printed on the intermediate layer 25 as much as possible. It is what.

  The protective resin paste constituting the first protective film 26 and the protective resin paste constituting the second protective film 27 preferably use the same material for process control, but different types of protective resin pastes are used. It may be used. In particular, when the viscosity of the protective resin paste constituting the first protective film 26 is higher than the viscosity of the protective resin paste constituting the second protective film 27, the protective resin constituting the first protective film 26 is used. Since the viscosity of the paste is high, the first protective film 26 formed so as to surround the periphery of the intermediate layer 25 does not spread greatly toward the end of the individual region of the ceramic base material 21. The thickness of the first protective film 26 can be easily controlled. For this reason, the level difference between the intermediate layer 25 and the first protective film 26 can be easily reduced, and the viscosity of the protective resin paste constituting the second protective film 27 is low. The surface of the second protective film located on the surface can be kept smooth, thereby smoothing the top surface of the anti-static component, and the load applied when being attracted to the mounting nozzle is not concentrated on one point. As a result, it is possible to obtain an anti-static component with stable mounting quality and strength.

  In the second embodiment of the present invention, the example in which the process of forming the protective film is performed in two steps has been described. However, if the protective film is formed in at least two steps, the surface of the protective film is formed. Since it can be made smooth, the protective film may be formed in three or more steps according to the thickness of the protective film required by the withstand voltage standard of the antistatic component.

  After the second protective film 27 is formed, the sheet-shaped ceramic substrate is divided into strips, and sputtering is performed from the top and back surfaces of the strip-shaped ceramic substrate, so that FIG. As shown in FIG. 4G, terminal electrodes 28 were formed on both ends of the ceramic substrate 21 so as to be electrically connected to the ends of the extraction electrode 22. Then, after the strip-shaped ceramic substrate is divided into individual pieces, nickel plating (not shown) and tin plating (not shown) are formed on the surface of the terminal electrode 28 by barrel plating. The antistatic component in Embodiment 2 of invention was obtained.

  The antistatic component in the second embodiment of the present invention manufactured by the above manufacturing method is a silicone of the overvoltage protection material layer 24 existing in the gap 23 between the opposing extraction electrodes 22 during normal use (under rated voltage). Since the resin is insulating, it is electrically open. However, when a high voltage such as an electrostatic pulse is applied, a discharge current is generated between the metal particles existing through the silicone resin in the overvoltage protection material layer 24, and the impedance is significantly reduced. The antistatic component in the second embodiment uses this phenomenon to bypass abnormal voltages such as electrostatic pulses and surges to the ground. In this case, when the applied voltage of static electricity increases, for example, exceeding 15 kV, a spark starts to occur in the discharge between the metal particles, and the overvoltage protection material layer 24 and the second voltage are not generated in the state where the intermediate layer 25 is not present. In the case of the structure in which the protective film 27 is in direct contact, a carbon compound such as a hydrocarbon group in the resin of the second protective film 27 may be carbonized due to a spark of discharge, and the insulating performance of the second protective film 27 may be deteriorated. However, in the second embodiment of the present invention, since the intermediate layer 25 exists between the overvoltage protective material layer 24 and the second protective film 27, such insulation deterioration can be prevented. Since the resin contained in the intermediate layer 25 is desired to have a small hydrocarbon content, among the silicone resins, a resin having a small side chain hydrocarbon group such as methyl silicone is preferable.

  Here, in the conventional antistatic component and the antistatic component in the second embodiment of the present invention, a strength test was performed in which a load was applied horizontally from the upper surface of the antistatic component. In the conventional anti-static component, the average value (n = 20) of the breaking strength is 10.3 N. However, in the anti-static component in the second embodiment of the present invention, the average value (n = 20) ) Was 26.8N. As is clear from this result, in the antistatic component in Embodiment 2 of the present invention, a protective film covering the intermediate layer 25 is formed so as to surround the periphery of the intermediate layer 25, and a step with the intermediate layer 25 is formed. Since the first protective film 26 to be reduced and the second protective film 27 formed so as to cover the intermediate layer 25 and the first protective film 26 and have a smooth surface are provided. Since the surface of the second protective film 27 located on the upper surface of the component is smooth, the load applied when attracted to the mounting nozzle is dispersed without being concentrated on one point. It is possible to obtain an anti-static component with stable quality and strength.

  The antistatic component according to the present invention ensures the smoothness of the upper surface of the protective film by carrying out the protective film formation process at least twice, and thus the load applied when adsorbed to the mounting nozzle is also reduced. Distributing without concentrating on a single point has the effect of stabilizing the mounting quality and strength, and is particularly useful when applied to anti-static parts that are small and require high static electricity resistance. It will be.

(A)-(f) Sectional drawing which shows the manufacturing method of the antistatic component in Embodiment 1 of this invention (A)-(f) Top view which shows the manufacturing method of the static electricity countermeasure components (A)-(g) Sectional drawing which shows the manufacturing method of the antistatic component in Embodiment 2 of this invention (A)-(g) Top view which shows the manufacturing method of the static electricity countermeasure components (A)-(c) Sectional drawing which shows the manufacturing method of the conventional antistatic component

Explanation of symbols

11, 21 Ceramic substrate 12, 22 Extraction electrode 13, 23 Gap 14, 24 Overvoltage protection material layer 25 Intermediate layer 15, 26 First protection film 16, 27 Second protection film

Claims (8)

An extraction electrode provided at both ends of the upper surface of the ceramic substrate, an overvoltage protection material layer provided so as to cover a gap between a part of the extraction electrode and the extraction electrode, and so as to cover the overvoltage protection material layer A first protective film that is formed so as to surround the overvoltage protective material layer and that reduces a step difference from the overvoltage protective material layer, and the overvoltage protective material layer. And an anti-static component comprising a second protective film that covers the first protective film and that has a smooth surface. The antistatic component according to claim 1, wherein the maximum thickness of the first protective film is substantially equal to the maximum thickness of the overvoltage protective material layer. The antistatic component according to claim 1, wherein the viscosity of the resin constituting the first protective film is higher than the viscosity of the resin constituting the second protective film. Forming an extraction electrode having a gap on the upper surface of the ceramic substrate, forming an overvoltage protection material layer so as to cover part of the gap and the extraction electrode, and protecting so as to cover the overvoltage protection material layer Forming a protective film, and forming the protective film includes forming a first protective film that surrounds the overvoltage protective material layer so as to reduce a step difference from the overvoltage protective material layer. A method for manufacturing an anti-static component, comprising: a step; and a second protective film forming step of covering the overvoltage protective material layer and the first protective film and forming a surface thereof to be smooth. An extraction electrode provided at both ends of the upper surface of the ceramic substrate, an overvoltage protection material layer provided so as to cover a gap between a part of the extraction electrode and the extraction electrode, and so as to cover the overvoltage protection material layer A first intermediate layer, and a protective film provided so as to cover the intermediate layer. The protective film is formed so as to surround the periphery of the intermediate layer and reduces a step difference from the intermediate layer. And a second protective film formed to cover the intermediate layer and the first protective film and to have a smooth surface. The antistatic component according to claim 5, wherein the maximum value of the thickness of the first protective film is substantially equal to the maximum value of the sum of the thickness of the overvoltage protective material layer and the thickness of the intermediate layer. The antistatic component according to claim 5, wherein the viscosity of the resin constituting the first protective film is higher than the viscosity of the resin constituting the second protective film. Forming an extraction electrode having a gap on the upper surface of the ceramic substrate, forming an overvoltage protection material layer so as to cover part of the gap and the extraction electrode, and intermediate so as to cover the overvoltage protection material layer A step of forming a layer and a step of forming a protective film so as to cover the intermediate layer. As the step of forming the protective film, a step difference from the intermediate layer is reduced so as to surround the periphery of the intermediate layer. The first protective film forming step formed as described above and the second protective film forming step formed so as to cover the intermediate layer and the first protective film and to have a smooth surface. A manufacturing method for parts.

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