KR20070050321A - A bead-varistor integrated device with different materials - Google Patents

Abstract

The present invention serves as a high-frequency noise filter in general by unifying components of beads and varistor heterogeneous materials, and bead-varistors using heterogeneous materials that can protect circuit components by effectively blocking electrostatic discharge or surge when electrostatic discharge or surge occurs. It relates to a composite device.

In the composite multiple type bead-varistor composite device using a heterogeneous material according to the present invention, in a composite device that blocks electrostatic discharge or surge, one or more varistor sheets and one or more bead sheets are laminated, but the varistor sheet is a varistor. A capacitor electrode having varistor characteristics is formed on a sheet surface made of a material having a characteristic property, and the bead sheet is formed by forming a bead electrode having inductor bead characteristics on a sheet surface made of a ferrite-based material having a high permeability. Each sheet is composed of adhesive glue,

The capacitor electrode and the bead electrode formed on the varistor sheet and the bead sheet are formed by printing any one of electrode materials such as Cu, Ni, Pd, Pt, Ag, Au, etc. by a thick film printing method at a temperature lower than the firing temperature of each sheet. The adhesive for adhering each varistor sheet and the bead sheet may be made of either epoxy or polymer, and an insulating sheet may be further disposed between the bead sheet and the varistor sheets, and the bead electrode implementing the inductor may be linear. Alternatively, the winding meander structure may be formed, and the inductor bead electrode and the capacitor electrode may be formed of a metal paste including a glass frit or a conductive epoxy paste including a polymer component.

Varistor, noise filter, composite device, zinc oxide, ferrite, bead inductor, heterogeneous composite material

Description

 Bead-varistor integrated device with different materials

1 is an example of a circuit diagram for implementing a high frequency noise cancellation and electrostatic discharge prevention using conventional ferrite beads and varistors,

2 is an example of a circuit diagram of a bead-varistor simplified by manufacturing a ferrite bead and a varistor according to the present invention in one body,

3 is an assembled perspective view illustrating a sheet stack structure of an example of a 3-terminal bead-varistor composite device among the bead-varistor composite devices using different materials according to the present invention;

Figure 4 is a perspective view showing an example of a three-terminal bead-varistor composite device of the multiple-type bead-varistor composite device using a heterogeneous material according to the present invention,

5 is a plan view of a sheet electrode of the varistor portion of the bead-varistor composite device using a dissimilar material according to the present invention,

6 is a plan view of the sheet electrode of the bead portion of the bead-varistor composite device using a dissimilar material according to the present invention,

7 is an assembled perspective view illustrating an example sheet lamination structure of a double bead-varistor composite device using a dissimilar material according to the present invention;

8 is an external perspective view of a double-type bead-varistor composite device using heterogeneous materials according to the present invention shown in FIG.

9 is an assembled perspective view illustrating an example sheet lamination structure of a quadruple bead-varistor composite device using a dissimilar material according to the present invention;

FIG. 10 is an external perspective view of a quadruple bead-varistor composite device using heterogeneous materials according to the present invention shown in FIG. 9;

11 is an assembled perspective view illustrating an example sheet lamination structure of a quadruple bead-varistor composite device using a dissimilar material according to the present invention;

12 is an assembled perspective view showing another example of the sheet stack structure of the quadruple bead-varistor composite device using a dissimilar material according to the present invention.

The present invention relates to a bead-varistor composite device, and more particularly, by unifying the parts of the ferrite bead and the varistor heterogeneous material to act as a high-frequency noise filter, and in the event of static electricity or surge, circuit components by effectively blocking static electricity or surge. It relates to a bead-varistor composite device using a heterogeneous material to protect the.

With the development of electric and electronic technology, many kinds of electric and electronic equipment are provided. Among these electric and electronic devices, there are electronic devices such as mobile phones, home appliances, personal computers (PCs), personal digital assistants (PDAs), liquid crystal displays (LCDs), and the like. Increasingly, digitalization is becoming faster. As a result, abnormal voltages and high frequency noises are introduced into the internal circuits of electronic devices, resulting in breakage of circuits or distortion of signals.

The causes of the abnormal voltage and noise are various, such as lightning strikes, electrostatic discharge (ESD) discharge to the human body, switching voltage generated in the circuit, power supply noise included in the power supply voltage, unnecessary electromagnetic signals or electromagnetic noise. The filter is used to prevent such abnormal voltage and high frequency noise from entering the circuit.

For mobile devices, board to board connector, camera module connector, I / O port, side key, microphone, speaker, receiver In particular, such abnormal voltages and noise are particularly generated, and a filter circuit is provided to protect the circuit from such noise and abnormal voltages.

However, as the technology of the mobile device develops, the transmission / reception and the signal inside the device become high speed and high frequency, and the noise attenuation effect through these filter circuits gradually decreases, causing many problems due to signal distortion or inflow of unnecessary high frequency noise into the circuit. Cause.

Therefore, various noise countermeasures are needed to improve the communication quality and high frequency noise is blocked by using LC filter or RC filter.

In general, one bead or inductor and one or two varistors are used on a circuit to block high frequency noise and electrostatic discharge.

This example is shown in FIG. A ferrite bead B1 was connected between the input terminal 1a and the output terminal 1b of the signal, and two varistors C1 and C2 were connected to both ends thereof, respectively, to each ground (G1, G2). . As described above, a circuit for removing noise and preventing electrostatic discharge may be configured using a plurality of devices, and in this case, a large mounting space and a lot of components need to be installed.

One thing that has been developed to eliminate this hassle is that the characteristics of the three components listed above are focused on one component.

In order to manufacture such components, green tapes made of ferrite and varistor raw materials are manufactured, laminated, and fired at the same time, but in this case, the characteristics of the materials are deteriorated by mutual diffusion between the two materials.

In addition, when the sintering temperature and shrinkage ratio between the two materials are different, the bonding between the two materials is not made, so it is difficult to properly implement the desired properties because only materials having limited properties that meet these characteristics can be used.

The present invention was developed to solve the problems of the prior art as described above, and the two products completed by firing the inductor layer made of a magnetic material such as a capacitor layer and a ferrite made of a semiconducting material having varistor properties, respectively, such as epoxy By bonding together, that is, by bonding two ceramic elements after sintering, it is possible not only to prevent the deterioration of properties due to the interdiffusion generally occurring in the simultaneous firing of two materials, but also to separate them due to the difference in shrinkage of the two materials. The purpose of the present invention is to provide a multi-layered bead-varistor composite device using high-performance heterogeneous materials capable of preventing the phenomenon and thus fully expressing the unique performance of each material.

In addition, since the electrode is formed after firing the ceramic, the Ag electrode can be used at low cost regardless of the firing temperature of the ceramic and has a high electrical conductivity. The purpose.

An object of the present invention is a composite device for preventing electrostatic discharge or surge, comprising at least one varistor sheet and at least one bead sheet laminated, wherein the varistor sheet has a varistor characteristic on the surface of the sheet made of a material having varistor properties Wherein the bead sheet is formed by forming a bead electrode having inductor bead characteristics on a sheet surface made of a ferrite-based material having a high permeability, and each sheet is formed by adhering with an adhesive. It is made by a composite multiple type bead-varistor composite device using heterogeneous materials.

In addition, an object of the present invention is the capacitor electrode and the bead electrode formed on the varistor sheet and the bead sheet is a thick film of any one electrode material such as Cu, Ni, Pd, Pt, Ag, Au at a temperature lower than the firing temperature of each sheet The adhesive is formed by printing by printing, and the adhesive for adhering each varistor sheet and the bead sheet is made of either epoxy or polymer, and an insulating sheet is further provided between the bead sheet and the varistor sheets.

In addition, the bead electrode for implementing the inductor is formed in a straight or twisted meander structure, the inductor bead electrode and the capacitor electrode is formed of a metal paste containing a glass frit or a conductive epoxy paste containing a polymer component Is made by

Hereinafter, with reference to the accompanying drawings, an embodiment of a composite multiple beads-varistor composite device using a heterogeneous material according to the present invention will be described in detail.

Composite multi-layered bead-varistor composite device using a heterogeneous material according to the present invention is to produce a hetero material of ferrite and zinc oxide-based oxide, respectively, and beaded using an adhesive such as epoxy to perform both functions simultaneously- Varistor single or multiple bead-varistor composite devices are provided.

2 is an example of a circuit diagram of a bead-varistor simplified by manufacturing the ferrite beads and the varistor according to the present invention in one body.

As shown, it consists of a ferrite 101 comprising an inductor or bead circuit 102 and a varistor 103 comprising two capacitors 104 and 105. In the present invention, unlike the co-firing technique used in the prior art, Two heterogeneous materials were fired and then bonded using an adhesive to realize a composite device.

After firing in this manner, adhesion at low temperatures of 300 to 400 degrees or less can prevent the deterioration of properties due to mutual diffusion between the two ceramics, and the bead-varistor composite device that can prevent the separation phenomenon caused by the plastic shrinkage rate of the two materials. To provide.

Example 1

3 is an assembled perspective view showing an example of a sheet stack structure of a three-terminal bead-varistor composite device among the bead-varistor composite device using a heterogeneous material according to the present invention, as shown in the ferrite beads to produce an inductor or a ferrite bead The ferrite slurry was prepared by mixing the powder and the organic binder component, and the prepared slurry was made of green tape by using a tape casting method. The green tape was laminated to a desired thickness and then calcined flat at 850 ° C to 1300 ° C. Ceramic bead sheets (hereinafter referred to as 'ferrite sheets') were produced.

The thickness was calcined to suit the desired properties, and the calcined ferrite sheet was cut to a predetermined size.

The metal oxides used to fabricate the varistor sheet forming the varistor layer in the present invention are zinc oxide (ZnO), bismuth oxide (Bi ₂ O ₃ ), antimony oxide (Sb ₂ O ₃ ), manganese oxide (Mn ₂ O ₄ ) , Cobalt oxide (Co ₃ O ₄ ), chromium oxide (Cr ₂ O ₃ ) and the like are added.

Specifically, zinc oxide (ZbO) 90 mol% or more, bismuth oxide (Bi ₂ O ₃ ) 0.25-2 mol%, antimony oxide (Sb ₂ O ₃ ) 0.25-2 mol%, manganese oxide (Mn ₃ O ₄ ) 0.1- 1 mol%, cobalt oxide (Co ₃ O ₄ ) 0.1-1 mol%, chromium oxide (Cr ₂ O ₃ ) It is controlled in the range of 0.1-1 mol%.

The mixture having the above components was mixed by a ball mill method, changed to a compound form through a calcination process at a temperature of 600 ℃ to 800 ℃, the calcined powder is ground through a fine grinding process The organic binder is mixed with alcohol, toluene and the like to prepare a slurry. The manufactured slurry can be obtained by forming a sheet in the form of a tape using a tape casting method.

The zinc oxide-based ceramic green sheet was laminated to a desired thickness and calcined flat to produce a zinc oxide-based ceramic sheet (hereinafter, referred to as a “varistor sheet”), and cut and prepared to the same size as the ferrite sheet.

Silver (Ag) paste is printed on the prepared ferrite sheet 120 using a thick film printing method, and the bead electrode 121 is formed by heat treatment at a temperature of 600 ° C. to 850 ° C., and another ferrite The bead electrode 161 was formed in the sheet 160 similarly.

Capacitor electrodes 131, 132, 141, and 142, which are capacitor electrodes, were formed on the top and back surfaces of the varistor sheets 130 and 140 cut to the same size. At this time, each varistor is formed by the capacitor electrode 131, the back ground electrode 132, the capacitor electrode 141, and the back ground electrode 142 formed on both surfaces of the varistor sheets 130 and 140.

The capacitor electrodes 131 and 141 become electrodes at the input and output ends, and the capacitor electrodes 132 and 142 become electrodes at the ground ends.

As the material of the electrodes, not only a silver paste used as an electrode by firing at 600 ° C. to 850 ° C., but also a conductive epoxy that can obtain electrical conductivity by heat treatment at a low temperature of 300 degrees or less can be used.

The sheets 120, 130, 140 and 160 on which the electrodes are formed and the sheets 110 and 160 on which the electrodes are not formed are sequentially bonded with an epoxy or an adhesive and heat treated to form a body.

In this case, only four sheets (110, 120, 130, 140) can be glued to produce a product with similar performance. Similar performance characteristics could be achieved.

The external electrode was formed using a conductive epoxy containing a conductive material such as silver (Ag) in the body manufactured as described above, and the shape of the manufactured product is shown in FIG. 4.

After the external electrode was formed, Ni and Sn plating were performed to complete the composite device having the shape as shown in FIG. 4.

The bead-varistor composite device configured as described above exists in the upper sheet 210 and the lower sheet 220 formed of the ferrite sheets 110 and 160 formed of the ferrite ceramic, and the center sheet 230 formed of the varistor sheet formed of the varistor ceramic. ) Is provided in the form of a sandwich.

The input terminal 212 of the bead-varistor composite device is connected to the output terminal 221 through the bead electrodes 121 and 161 between the ferrite sheets 120.

In addition, the input terminal 212 of the device is connected to the capacitor electrode 131 formed on one surface of the varistor sheet, the capacitor electrode 131 facing the ground electrode 132 formed on the opposite side of the varistor sheet 130 watching.

The ground electrode 132 is connected to the ground terminals 214 and 215 to ground on a circuit.

Therefore, as shown in FIG. 2, the capacitor electrodes formed on the varistor sheet have a structure connecting the signal line and the ground.

The capacitor electrode 142 formed on the another varistor sheet 140 is connected to the output terminal 221, and the ground electrode 141 opposed thereto is connected to the ground terminals 214 and 215 to connect the signal line. It acts as a capacitor connecting the ground line.

Looking at the circuit, it has the form of FIG. 2 and forms a typical LC noise filter in the form of one inductor bead on the signal line and two capacitors connected to ground lines at both ends thereof.

Therefore, when a high frequency noise comes along with the signal, the noise passes through the noise filter and is discharged through the ground, and the signal is transmitted to the next stage through the output terminal, thereby exhibiting a noise removing effect.

When a high voltage noise such as an electrostatic discharge or surge occurs, the varistor, which acted as a capacitor in the LC noise filter described above, returns to the varistor's original position and becomes a short circuit state with a very low resistance. The paper is discharged to ground through the varistor, which protects the rear part from electrostatic discharge or surge.

That is, a composite bead-varistor device is usually provided that serves as a high frequency noise filter and serves as a circuit protection device in the event of electrostatic discharge or surge.

In this process, each ceramic sheet is manufactured through its own sintering process without reacting with other materials, and is bonded at a temperature much lower than the sintering temperature, so that there is no material exchange between the two foreign matters. High performance bead-varistor composite devices are constructed that fully realize their respective characteristics compared to the parts manufactured by

In addition, since the adhesion is performed after the sintering is completed, it is possible to prevent the occurrence of cracking at the boundary between two materials and the separation between the two materials due to the difference in shrinkage that occurs during co-firing.

 When manufacturing the above devices in the manufacturing process, it is almost impossible to cut or print or bond the ceramic sheet to the size of the device, and accordingly, in the present invention, a ceramic sheet having a shape much larger than the size of the device is manufactured and bonded with an adhesive. After cutting is configured.

FIG. 5 illustrates a form in which capacitor electrodes 311, 312, 321, and 322 of the varistor sheets 310 and 320 and cutting lines 300 are printed, and FIG. 6 illustrates bead electrodes formed on the ferrite sheet 410. 411 and the cut line 400 are shown.

The ceramic sheets 310, 320, and 410 manufactured as described above are bonded in the order of FIG. 3 using an adhesive such as epoxy, cut along the cutting lines 300 and 400 to form a body of the device, and then polished. The corners are smoothed through.

As described above, an external electrode was formed on the composite ceramic body manufactured by lamination using conductive epoxy, and Ni plating and Sn plating were performed to fabricate a three-terminal bead varistor composite device as shown in FIG. 4.

Example 2

7 is an assembled perspective view showing an example sheet lamination structure of a double bead-varistor composite device using a dissimilar material according to the present invention.

As illustrated, the multiple bead-varistor composite device according to the present invention uses two inductor bead electrodes 521, 522, 561, and 562 in the ferrite sheets 520 and 560 fabricated as described above. It formed using the silver paste.

In addition, capacitor electrodes 531, 532, 542, and 543 and ground electrodes 533 and 541 were formed on the two varistor sheets 530 and 540 using the same method.

The sheets 510, 520, 530, 540, 550, and 560 are sequentially bonded and cured using an epoxy and an adhesive, and then cut to prepare a body of two bead-varistor composite elements.

Each of the sheets 510, 520, 530, 540, 550, and 560 is printed and laminated to print several electrodes at the same time by printing electrodes on a wide sheet as shown in FIGS. One element is formed by cutting.

After polishing the manufactured body was formed according to the method of the embodiment described above the electrode terminal on the outside of the shape as shown in FIG.

In the two composite devices, the varistor sheet layer 630 is stacked between two ferrite sheet layers 610 and 620.

As shown, two ground terminals having two signal input terminals 614 and 616 and two output terminals 615 and 617 and connected to ground electrodes 533 and 541 formed in the varistor sheet layer 630. 612 and 621 are formed to provide a bead-varistor composite device that generally reduces six components to one component by simultaneously mounting a single element to simultaneously act as a noise filter and a varistor for two adjacent signal lines.

Example 3

9 is an assembled perspective view showing an example sheet lamination structure of a quadruple bead-varistor composite device using a dissimilar material according to the present invention.

As shown, the bead electrodes 721 to 724 and 761 to 764 serving as signal lines of the inductor beads formed on the ferrite sheets 720 and 760 are printed using a conductive paste such as silver, respectively, and the varistor sheet ( Capacitor electrodes 731 to 735 and 741 to 745 were printed on the 730 and 740.

The printed sheets were heat-treated between 600 ° C. and 850 ° C., and the sheets 710, 720, 730, 740, 750, and 760 were joined using an adhesive such as epoxy in the order as shown.

After completion of the adhesion sheet is cut to a predetermined size to complete the body of the composite device, and after polishing, using the same method as in the above embodiment, the external electrode and the plating was performed.

The external shape of the composite device made of the sheet as shown in FIG. 9 is shown in FIG. 10.

The product manufactured as shown has four input terminals 812, 814, 816, 818 and four output terminals 813, 815, 817, 819, and two common ground terminals 821, 822. A quadruple bead-varistor can be spherical, in which case a total of 12 parts can be completed in one product.

The multiple bead-varistor composite device functions as four high frequency noise filters in parallel in general, and serves as a varistor that removes high voltage noise generated in four signal lines during electrostatic discharge and surge.

Example 4

FIG. 11 is a further embodiment according to the present invention, the manufacturing process is the same as the manufacturing process of Figure 9, but the bead electrode 721 serving as a signal line of the inductor beads formed on the ferrite sheet 720 ' ', 722', 761 ', and 762' are formed in two layers in one layer, unlike the electrodes shown in FIG. 9, and these electrodes 721 ', 722', 761 ', and 762' increase inductance values. It has a meandering meander structure.

Example 5

12 is an assembled perspective view showing another example of the sheet stack structure of the quadruple bead-varistor composite device using a dissimilar material according to the present invention.

In the quadruple bead-varistor composite device of the present embodiment, bead electrodes 911, 912, 961, and 962 are formed on ferrite sheets 910 and 960 manufactured through the same process as the above embodiments.

In addition, the capacitor electrodes 931 to 935 and 941 to 945 were printed on the varistor sheets 930 and 940 in the same manner as in the above embodiment.

In the present embodiment, when the ferrite sheet 910 and the varistor sheet 930 are bonded, the thickness of the ferrite sheet 910 and the varistor sheet 930 may be reduced by using a thin polymer sheet or an adhesive sheet 920.

In addition, by performing adhesion between the ferrite sheet 910 and the polymer sheet or the adhesive sheet 920 by using an epoxy containing ferrite particles, it is possible to take a form that can interrupt the magnetic flux formed around the bead electrode.

In this manner, the sheets 910, 920, 930, 940, 950, and 960 were bonded to each other, cut, and formed electrodes to fabricate quadruple bead-varistor composite devices of the type shown in FIG.

Therefore, by firing the ferrite ceramic sheet and the varistor ceramic sheet, respectively, and forming an electrode, they are bonded to produce a three-terminal bead-varistor and multiple bead-varistor composite elements. Bead varistors of various characteristics could be produced.

The bead-varistor composite device using a heterogeneous material configured as described above independently sinters two materials such as zinc oxide-based ceramics having varistor properties and ferrite ceramics with high permeability to form electrodes, and then performs adhesion at low temperatures. It is possible to prevent the interdiffusion phenomenon between two materials inevitably generated by simultaneous firing of dissimilar materials, thereby providing a high performance composite device by fundamentally blocking the deterioration of characteristics of the two materials due to the interdiffusion. .

In addition, by bonding the sintered ceramic sheet using a low temperature process, it provides a reliable product by fundamentally blocking the cracks and layer separation of the interface due to the shrinkage difference that occurs during the simultaneous firing of foreign matter, Since it is not affected by the plastic shrinkage rate, ferrite and varistor materials having various characteristics can be used, thereby providing a bead-varistor composite device having various characteristics.

Since beads and varistors have the form of noise filters, they usually act as noise filters, and provide a composite device that performs two roles to protect the surrounding circuits in the event of electrostatic discharge and surge. It offers ease of installation and space savings.

Since internal electrodes can be formed regardless of the sintering temperature, expensive electrode materials such as palladium (Pd) and platinum (Pt) are excluded, and low-cost electrode materials such as silver (Ag) and excellent electrical conductivity can be used. It is possible to provide a plurality of bead-varistor composite devices which are inexpensive and have low insertion loss, and the thin-walled bead-varistor composite devices can be used because the intermediate insulating layer can be used using a very thin polymer or adhesive sheet. There is an effect that can be implemented.

Claims (8)

In the composite device to block the electrostatic discharge or surge, Constructed by stacking one or more varistor sheets and one or more bead sheets, The varistor sheet is constructed by forming a capacitor electrode having varistor characteristics on a sheet surface made of a material having varistor characteristics, The bead sheet is formed by forming a bead electrode having inductor bead characteristics on the surface of the sheet made of a ferrite-based material having a high permeability, Each sheet is a bead-varistor composite device using a heterogeneous material, characterized in that the adhesive is configured by bonding. The capacitor electrode and the bead electrode formed on the varistor sheet and the bead sheet are formed by thickening any one of electrode materials such as Cu, Ni, Pd, Pt, Ag, Au, etc. at a temperature lower than the firing temperature of each sheet. Bead-varistor composite device using a heterogeneous material, characterized in that formed by printing by printing. The bead-varistor composite device according to claim 1, wherein the adhesive for adhering each varistor sheet and the bead sheet is any one of an epoxy or a polymer. The bead-varistor composite device according to claim 1, wherein an insulating sheet is further provided between the bead sheet and the varistor sheets. The bead-varistor composite device of claim 1, wherein the bead electrode implementing the inductor has a linear or meander structure. The bead-varistor composite device according to claim 1, wherein the varistor sheet is made of zinc oxide-based oxide. The bead-varistor composite device according to any one of claims 1 to 5, wherein the inductor bead electrode and the capacitor electrode are formed of a metal paste including a glass frit. The bead-varistor composite device according to any one of claims 1 to 5, wherein the electrode for forming the inductor bead and the capacitor is formed of a conductive epoxy paste containing a polymer component.

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