JP2009289839A - Anti-static electricity measure material, method of manufacturing the same, and anti-static electricity measure component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-static electricity measure material which has a stable electrostatic breakdown voltage and a low limited voltage, and to provide a method of manufacturing the anti-static electricity measure material, and an anti-static electricity measure component. <P>SOLUTION: The anti-static electricity measure component 10 has portions of internal electrodes 14A and 14B disposed on an insulating cover layer 12 opposite each other, and a film made of a material 16 for dealing with static electricity is provided between those internal electrodes 14A and 14B. The material 16 for dealing with static electricity has a structure such that conductive particles 18 each having an insulating film 20 formed on a surface are dispersed in an insulating resin matrix 22. The insulating film 20 is formed by performing a conversion treatment on surfaces of the metal particles 18 using an alcohol amine-based reaction accelerator. The metal particles 18 having the insulating films 20 formed on the surfaces are dispersed in the insulating resin matrix 22 to obtain the material 16 for dealing with static electricity which has the stable electrostatic breakdown voltage and low limited voltage. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antistatic material used in various electronic devices, a manufacturing method thereof, and an antistatic component.

  In multilayer varistors for static electricity countermeasures, capacitance and electrostatic withstand voltage are in a trade-off relationship. When the required electrostatic withstand voltage is maintained, a few pF is the limit due to the intrinsic dielectric constant of the material, and it should be used for high-speed transmission lines. I can't. Even if a low dielectric constant material is used for the cover portion, the capacitance is still reduced to about 1 pF.

A low dielectric constant electrostatic absorbing material in which conductive particles are dispersed in a resin has been reported as an electrostatic absorbing material having a capacitance that is small enough to be used for a high-speed transmission line and a necessary electrostatic withstand voltage. For example, Patent Document 1 below discloses an overvoltage protection polymer composition comprising an insulating binder, conductive particles, and semiconductor particles. Patent Document 2 below discloses a composition that provides protection against electrical overstress including an insulating binder, conductive particles composed of an inner core and an outer shell, and semiconductive particles.
Special table 2001-523040 gazette JP-A-11-317113

  However, the background art as described above has the following problems. First, in the technique described in Patent Document 1, when conductive particles whose surfaces are not coated are used, when the conductive particles are in contact with each other, it acts like a single particle. It tends to cause a decrease in electrostatic withstand voltage. For this reason, there is a problem that precise control of the conductive particle distribution is required. In the technique described in Patent Document 2, when the entire surface of the particle is coated with various materials, and is composed of a conductive core and an insulating shell, the limiting voltage is increased due to the energy barrier of the insulating layer. The problem arises.

  The present invention focuses on the above points, and an object of the present invention is to provide an antistatic material having a stable electrostatic withstand voltage and a low limiting voltage, a manufacturing method thereof, and an antistatic component.

  In order to achieve the above object, the method for producing an antistatic material of the present invention comprises a step of forming an insulating film on the surface of metal particles by chemical conversion treatment using a reaction accelerator, and the metal on which the insulating film is formed. Dispersing the particles in a curable insulating resin. One of the main forms is characterized in that the metal particles are Al particles, and a chemical conversion treatment by a boehmite method is performed using an alcoholamine-based reaction accelerator.

  The antistatic material of the present invention is characterized in that conductive metal particles having an insulating film formed on the surface thereof are dispersed in a curable insulating resin by chemical conversion treatment using a reaction accelerator. One of the main forms is characterized in that the metal particles are Al particles, and the insulating film is formed by chemical conversion treatment by a boehmite method using an alcoholamine-based reaction accelerator. Another aspect is characterized in that the hardness of the insulating resin after curing is 20 to 40 ° in the durometer type A.

  The antistatic component of the present invention has a pair of electrodes opposed to each other at a predetermined interval on a substrate, and the antistatic material described above is provided between the pair of electrodes. The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

  In the present invention, an insulating film is formed on the surface of the metal particles by chemical conversion treatment, and the metal particles are dispersed in the insulating resin. For this reason, it is possible to obtain a stable electrostatic withstand voltage, and to obtain an antistatic material (electrostatic absorption material) having a low limiting voltage and an antistatic component using the same.

  Hereinafter, the best mode for carrying out the present invention will be described in detail based on examples.

  First, Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1A is a main cross-sectional view of the anti-static component of this embodiment, FIG. 1B is a partially enlarged portion of FIG. 1A, and FIG. It is sectional drawing cut | disconnected along the line and seeing in the arrow direction. FIG. 2 is a diagram showing the relationship between the resin hardness, ESD withstand voltage (electrostatic withstand voltage), and limit voltage of the antistatic material of this example. As shown in FIG. 1A, the antistatic component 10 of the present embodiment is disposed on an insulating cover layer 12 so that part of the internal electrodes 14A and 14B face each other. A film made of an antistatic material (or ESD absorbing material) 16 is provided between the electrodes 14A and 14B. A protective film 24 is provided on the internal electrode 14A so as to cover the other internal electrode 14B. The internal electrodes 14A and 14B are connected to external electrodes 26A and 26B, respectively, and Ni platings 28A and 28B and Sn platings 30A and 30B are provided outside the external electrodes 26A and 26B.

  As shown in FIG. 1B, the antistatic material 16 has a structure in which conductive metal particles 18 having an insulating film 20 formed on the surface thereof are dispersed in an insulating resin matrix 22. For example, various metal particles such as Al, steel, Cu, Zn, Mg, Ni, and stainless steel are used as the metal particles 18, and the shape thereof is substantially spherical. Further, as the insulating resin matrix 22, various known curable insulating resins such as epoxy resin, silicone resin, and polyimide resin can be used. Here, the insulating film 20 is formed by subjecting the surface of the metal particles 18 to chemical conversion, and the metal particles 18 having the insulating film 20 formed on the surface thereof are converted into the insulating resin matrix 22. By dispersing in, a stable electrostatic withstand voltage (ESD withstand voltage) can be obtained, and an antistatic material 16 having a low limit voltage can be obtained.

  Here, an example of a manufacturing method of the antistatic material 16 will be described by taking as an example a case where Al particles are used as the metal particles 18. First, pure water is added to Al powder, TEA (triethanolamine) is added as a reaction accelerator, and a chemical conversion treatment is performed at a predetermined temperature and time. And a chemical conversion treatment Al powder is obtained through filtration, pure water washing | cleaning, methanol substitution, and drying. Then, an insulating boehmite layer (hydrated oxide layer) is generated on the surface of the Al particles. Next, when heat treatment dehydration is performed, crystal water in the boehmite layer on the surface is desorbed to become an oxide. This oxide layer corresponds to the insulating film 20. In this state, it is mixed with a resin (for example, epoxy resin) to obtain a paste of antistatic material. The obtained pace is applied to the resin substrate by an appropriate technique such as printing and is thermally cured. Here, although the crystal water of the boehmite layer (hydrated oxide layer) was removed by heat dehydration and then kneaded with the resin, it was mixed in the state of the hydrated oxide layer without performing heat dehydration. You may make it knead. In this case, the hydrated oxide layer corresponds to the insulating film 20.

  In the case of an insulating film obtained by a conventional film formation method by air oxidation (in the air or in oxygen-rich), only an nm order thickness can be obtained. However, as in this example, an alcoholamine-based reaction accelerator The insulating film 20 formed by chemical conversion treatment using a film becomes a uniform film with a thickness on the order of μm. The thickness, structure, and denseness of the insulating film 20 can be arbitrarily controlled by chemical conversion treatment conditions such as treatment liquid, temperature, and time.

  In the antistatic material 16 obtained as described above, the conductive portion of the metal particle 18 is shielded by the insulating film 20 and does not come into contact with the conductive portion of the adjacent metal particle 18, so that precise dispersion control is performed. Stable electrostatic withstand voltage is developed without performing. Further, since the thickness, structure, and denseness of the insulating film 20 can be arbitrarily controlled, a desired interparticle distance and energy barrier between particle conductive portions can be selected, and an arbitrary electrostatic withstand voltage and limit voltage can be designed. . It is desirable that the insulating film 20 has a dense structure.

FIG. 2 shows the relationship between the resin hardness after curing of the insulating resin matrix 22, the ESD withstand voltage (electrostatic withstand voltage), and the limiting voltage. The results are summarized in Table 1 below. Has been. In FIG. 2, the horizontal axis represents the resin hardness [°], the left vertical axis represents the ESD withstand voltage [kV], and the right vertical axis represents the limit voltage [V] (8 kV). In addition, resin hardness is a result at the time of using a durometer (type A). As shown in FIG. 2 and Table 1, when the resin hardness after curing is 20 to 40 ° with a durometer (type A), it can be seen that a stable ESD withstand voltage of 30 kV or more and a low limiting voltage can be obtained. .

Table 2 below shows the Al particle diameter, the thickness and density of the hydrated film (insulating film), the type of the insulating resin matrix 22, the blending ratio of the Al particles and the insulating resin, and the uncoated conductive particles. The measurement results of the limiting voltage [V] (8 kV) and the ESD withstand voltage [kV] when the addition amount and the addition amount of the insulating particles are changed are shown. The uncoated conductive particles are conductive particles whose surfaces are not insulated and are added to improve the contact frequency between the particles on which the insulating film 20 is formed. The insulating particles are generally added to adjust the rheology (viscosity) of the paste. From this result, by controlling the thickness, structure, denseness, etc. of the insulating film 20, it is possible to select a desired interparticle distance and energy barrier between conductive parts between particles and to design an arbitrary ESD withstand voltage and limiting voltage. It turns out that it is.

  As described above, according to Example 1, the insulating film 20 having a desired thickness, structure, and density is formed on the surface of the conductive metal particles 18 by chemical conversion treatment, and the metal particles 18 are formed into the insulating resin matrix 22. It was decided to be dispersed inside. For this reason, it is possible to obtain a stable electrostatic withstand voltage (ESD withstand voltage), an antistatic material 16 having a low limiting voltage, and an antistatic component 10 using the same.

In addition, this invention is not limited to the Example mentioned above, A various change can be added in the range which does not deviate from the summary of this invention. For example, the following are also included.
(1) The shape, dimensions, and materials shown in the above-described embodiments are examples, and may be appropriately changed as necessary. For example, the Al particles and triethanolamine shown in the above examples are also examples, and a combination of Zn particles and an alcoholamine-based reaction accelerator may be used, or iron-based particles may be subjected to chemical conversion treatment using phosphoric acid. Of course, these are also examples, and other known metal particles and reaction accelerators may be combined as long as the same effects can be obtained.

  (2) The static electricity countermeasure component 10 shown in the above embodiment is also an example, and the design may be changed as needed. For example, the anti-static component 10A shown in FIG. 3A is arranged on the cover layer 12 so that the end portions of the internal electrodes 14A and 14B face each other with a predetermined gap, and fill the gap. The antistatic material 16 is provided. 3B has a structure in which internal electrodes 14A to 14D are stacked at a predetermined interval, and the antistatic material 16 is provided between them, and the internal electrode 14A. And the bottom surface of the internal electrode 14D are covered with the cover layers 12A and 12B. Of course, it is not limited to these examples, What is necessary is just to provide the said antistatic material 16 between the electrodes which oppose.

  (3) In addition to the metal particles 18 provided with the insulating film 20 on the surface, conductive particles (metal particles) that do not form an insulating film on the surface, insulating particles, and semiconductor particles are added to the insulating resin matrix 22. The contact frequency between the particles on which the insulating film 20 is formed may be improved, or the viscosity may be adjusted.

  (4) In the above-described embodiment, by controlling the thickness, structure, denseness, etc. of the insulating film 20, a desired interparticle distance and energy barrier between particle conductive portions are selected, and an arbitrary ESD withstand voltage and limit voltage can be selected. In addition to this, the desired electrical characteristics depend on the dispersed particle size, dispersion particle surface coating presence / absence, dispersion particle / resin blending ratio, electrode shape, and presence / absence of addition of conductive particles or insulating particles. It is possible to control this.

  (5) The antistatic material of the present invention can be applied to single or multiple antistatic components, composite electronic components such as capacitors, inductors and resistors (for example, EMI filter arrays with antistatic functions). Is possible. Further, by embedding in a resin substrate, application as a resin substrate or a module with an anti-static function is also possible.

  According to the present invention, an insulating film having a desired thickness, structure, and density is formed on the surface of metal particles by chemical conversion treatment, and the metal particles are dispersed in the insulating resin, so that stable electrostatic withstand voltage and low Since the voltage limit is obtained, it can be applied to the use of antistatic materials and antistatic components that protect electrical equipment from static electricity.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Example 1 of this invention, (A) is principal sectional drawing of an antistatic component, (B) is the elements on larger scale of said (A), (C) is said (B) # A- # It is sectional drawing cut | disconnected along A line and seeing in the arrow direction. It is a figure which shows the relationship between the resin hardness of the antistatic material of the said Example 1, ESD withstand pressure | voltage, and a limiting voltage. It is principal sectional drawing which shows the other Example of this invention.

Explanation of symbols

10, 10A, 10B: Antistatic components 12, 12A, 12B: Cover layers 14A to 14D: Internal electrodes 16: Antistatic material (ESD absorbing material)
18: Metal particle 20: Insulating film 22: Insulating resin matrix 24: Protective film 26A, 26B: External electrodes 28A, 28B: Ni plating 30A, 30B: Sn plating

Claims (6)

Forming an insulating film on the surface of the metal particles by chemical conversion treatment using a reaction accelerator;
Dispersing the metal particles having an insulating film formed on the surface thereof in a curable insulating resin;
A method for producing an anti-static material, characterized by comprising:   The method for producing an antistatic material according to claim 1, wherein the metal particles are Al particles, and a chemical conversion treatment by a boehmite method is performed using an alcoholamine-based reaction accelerator.   An anti-static material, wherein metal particles having an insulating film formed on a surface are dispersed in a curable insulating resin by chemical conversion treatment using a reaction accelerator.   4. The antistatic material according to claim 3, wherein the metal particles are Al particles, and the insulating film is formed by chemical conversion treatment by a boehmite method using an alcoholamine-based reaction accelerator.   The antistatic material according to claim 3 or 4, wherein the hardness of the insulating resin after curing is 20 to 40 ° in durometer type A.   A pair of electrodes facing each other at a predetermined interval are provided on a substrate, and the antistatic material according to any one of claims 3 to 5 is provided between the pair of electrodes. The antistatic component as described in any one of 5 above.

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