KR102105401B1 - ESD Paste and Method of the Same - Google Patents

Abstract

The present invention can provide an electrostatic protection device with improved durability by providing a paste for an electrostatic protection device comprising nano-ceramic powder in the form of conductive particles, hydroxide, hydrate, carbonate or borate, and an organic binder.

Description

Paste for electrostatic protection device and its manufacturing method {ESD Paste and Method of the Same}

The present invention relates to a paste for an electrostatic protection device and a method for manufacturing the same.

As the size of electronic products decreases, mounting density of mounting components increases, and mounting of integrated circuits such as ICs increases for high performance and volume, and the need for electro-static discharge (ESD) protection measures for electronic products is increasing. Is increasing. In addition, recently, the types and dissemination of portable products such as smartphones and tablet PCs have increased, and as a function of connecting data for communication between products such as USB and Direct cables between each portable product or between portable products and PCs is included, In addition, the probability of occurrence of surge in the signal connection part increases.

As a countermeasure against this, an electrostatic protection device such as a varistor was previously used, but in the case of a varistor, a capacitance value is large. Due to the recent increase in the amount of data communication, the data transmission speed and the amount of transmission have also increased significantly, but if the capacitance value of the ESD component is large, normal data transmission is interrupted due to signal distortion and noise. Therefore, there is a need for a product having excellent ESD protection characteristics while having a low capacitance value for high-speed data transmission.

Electro-static discharge (ESD) is one of the inevitable phenomena when integrated circuits such as electronic systems and ICs are used. When ESD occurs, a peak current of several amperes (A, Ampere) occurs within hundreds of nanoseconds, and it is not delivered to a protection circuit such as GND or ground within tens of nanoseconds. Otherwise, the generated high current moves to an integrated circuit such as an IC, resulting in deterioration or destruction of product functions. In addition, since an integrated circuit such as an IC has a very fine line width of several tens to hundreds of nanometers, serious damage and irreversible function deterioration occur when surge occurs, so application of an electrostatic protection element is essential. Is required.

Four methods are applied as a static electricity protection element for protecting mounted components in a circuit. The first is a device composed of a metal oxide having semiconductor characteristics such as ZnO and a sintered body of an electrode, and there is a stacked chip varistor. Varistors have a characteristic in which the current is generated and flows when the applied voltage exceeds a certain value, but the manufacturing process is complicated and the capacitance is large because it undergoes processes such as sheet forming, electrode printing, lamination and sintering. There is an unsuitable problem in high-speed data transmission.

The second is a discharge type device, and the discharge characteristics can be controlled by the distance of the discharge gap, the type and pressure of the gas (Gas) sealed together. Although this device has excellent electrostatic discharge characteristics, its shape is complicated and it is difficult to reduce its size as a surface-mounting device, so there is a limit to its application, and its operation principle is simple, but there is a problem in durability. Thirdly, there is a method of forming a discharge gap and adjusting the discharge voltage by the gap gap. However, in this case, there is a possibility that the conductor is contaminated by external humidity and gas, and there is a possibility that the discharge voltage may change, and the electrode may short-circuit due to carbonization of the substrate during discharge.

Therefore, there is also a method of applying a discharge gap with a metal or metal oxide-resin mixture paste in order to solve this problem and improve insulation properties at a low voltage. The metal oxide used for the preparation of such paste must have semiconductor properties such as ZnO, and in the case of metal, it is necessary to form an oxide film on the metal surface to maintain the insulation properties until a constant voltage is reached.

In order to lower the operating voltage of the ESD paste composition, it is necessary to reduce the distance between conductive particles in the ESD composition. To do this, it is necessary to increase the proportion of the conductive particles by increasing the size of the conductive particles, reducing the amount of polymer added in the composition, or increasing the amount of the conductive particles added. However, in this case, as the distance between the conductive particles decreases, the surface insulating film of the conductive particles is damaged by the heat generated when the ESD paste is turned on, or the conductive particles are melted and the current as shown in FIGS. 2A and 2B. The probability that a problem in which a current path is formed also increases.

In order to prevent this, conventionally, by adding nano-sized insulating particles to the ESD paste composition, the distance between conductive particles was maintained to prevent short, but the range of the discharge heat generated when high voltage such as static electricity occurs Because it is larger, it is not effectively preventing defects.

Republic of Korea Patent Publication No. 2012-0092137

The present invention has been devised to solve the above-mentioned shortcomings raised in the conventional electrostatic protection device, the conductive ceramic particles, hydroxide, hydrate, carbonate or borate form of nano ceramic powder and organic binder to manufacture an improved electrostatic protection device It is an object to provide a paste for an electrostatic protection device comprising a.

The object of the present invention is achieved by providing a paste for an electrostatic protection device comprising conductive particles, hydroxide, hydrate, nano ceramic powder in the form of carbonate or borate, and an organic binder.

At this time, the conductive particles may be one or more metal powders of manganese, zirconium, tantalum, molybdenum, nickel, cobalt, aluminum, and chromium, and the nano ceramic powder in the form of hydroxide is Al (OH) ₃ or Mg (OH) ₂ May be, the hydrate form of the nano-ceramic powder may be Al ₂ O ₃ · (H ₂ O) ₃ .

In addition, the carbonate-type nano ceramic powder may be Na ₂ CO ₃ , the borate-type nano ceramic powder may be B (OH 4) ⁻ , and the organic binder may be any one of an epoxy resin, a urethane resin, and a silicone resin. Can be

Another object of the present invention is a step of preparing a nano-ceramic powder in the form of conductive particles, hydroxide, hydrate, carbonate or borate, mixing the conductive particles and the nano-ceramic powder with an organic binder to prepare a conductive particle-nano ceramic powder mixture. It is achieved by providing a method for preparing a paste for an electrostatic protection device comprising the step of adding a solvent to the conductive particle-nano ceramic mixture and co-rotating the mixture.

In this case, the conductive particles may be one or more metal powders of manganese, zirconium, tantalum, molybdenum, nickel, cobalt, aluminum, and chromium, and the nano ceramic powder is Al (OH) ₃ , Mg (OH) ₂ , Al ₂ O ₃ · (H ₂ O) ₃ , Na ₂ CO ₃ And B (OH4) ^- , or a mixed powder of two or more, and the organic binder may be any one of an epoxy resin, a urethane resin, and a silicone resin.

As described above, the paste for an electrostatic protection device according to the present invention is a nano-ceramic in the form of hydroxide, hydrate, carbonate or borate instead of or in combination with the nano-sized ceramic powder contained in the conventional electrostatic protection device paste. When the nano ceramic powder in the form of hydroxide, hydrate, carbonate, or borate is heated, the functional group such as H ₂ O, OH or CO ₃ bound to the ceramic element is separated as shown in the following Chemical Formula 1 It absorbs the heat of the particles and released H ₂ O, CO _2, etc. play a role in preventing deterioration.

Accordingly, when the electrostatic protection device is manufactured using the paste for the electrostatic protection device according to the present invention, an electrostatic protection device with improved durability can be manufactured.

1 is a cross-sectional view of an electrostatic paper protection device including a paste for an electrostatic protection device according to an embodiment of the present invention.
2A is a scanning micrograph of a current-path generated after electrostatic discharge.
2B is an enlarged view of a scanning micrograph of a current-path generated after electrostatic discharge.
3 is a flow chart of a method for manufacturing a paste for an electrostatic protection device according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. This embodiment can be provided to make the disclosure of the present invention complete, and to fully disclose the scope of the invention to those skilled in the art. The same reference numerals throughout the specification refer to the same components.

The terms used in this specification are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless otherwise specified in the phrase. As used herein, 'comprise' and / or 'comprising' refers to the components, steps, operations and / or elements mentioned above, the presence of one or more other components, steps, operations and / or elements. Or do not exclude additions.

In addition, embodiments described herein will be described with reference to cross-sectional views and / or plan views, which are ideal exemplary views of the present invention. In the drawings, the thicknesses of the films and regions are exaggerated for effective description of technical content. Accordingly, and / or the shape of the exemplary drawings may be changed due to tolerances. Accordingly, the embodiments of the present invention are not limited to the specific shapes shown, but also include changes in shapes generated according to the manufacturing process. For example, the etched area illustrated at a right angle may be rounded or have a predetermined curvature.

The paste for an electrostatic protection device according to an embodiment of the present invention may include nano ceramic powder and organic binder in the form of conductive particles, hydroxide, hydrate, carbonate or borate.

In the case of the paste for an electrostatic protection device according to the present embodiment, instead of the nano-sized ceramic powder contained in the conventional electrostatic protection device paste, a nano ceramic powder in the form of hydroxide, hydrate, carbonate or borate, or a nano-sized ceramic powder and Together, it may include a nano ceramic powder in the form of hydroxide, hydrate, carbonate or borate. When the nano ceramic powder in the form of hydroxide, hydrate, carbonate or borate is heated, H bound to a ceramic element as shown in Chemical Formulas 1 and 2 below. _As functional groups such as ₂ O, OH, or CO ₃ are separated, the surrounding heat absorbs and the released particles of H ₂ O, CO ₂ act to prevent deterioration.

Therefore, the paste for the electrostatic protection device including the nano ceramic powder in the form of hydroxide, hydrate, carbonate or borate is damaged in the polymer resin in the paste due to discharge when external static electricity is generated, insulation resistance decreases due to generation of conductive carbon and leakage current ( It is possible to prevent defects such as an increase in leakage current).

The conductive particles may be any one or more metal powders of manganese, zirconium, tantalum, molybdenum, nickel, cobalt, aluminum, and chromium, but are not limited thereto.

The size of the conductive particles is preferably 8 μm or less, and when the size of the conductive particles exceeds 8 μm, a defect in which a current path occurs due to ESD discharge of two or more times may occur.

The hydroxide-type nano ceramic powder may be Al (OH) ₃ or Mg (OH) ₂ , and the hydrate-type nano ceramic powder may be Al ₂ O ₃ · (H ₂ O) ₃ , and the carbonate form The nano ceramic powder may be Na ₂ CO ₃ , and the borate form nano ceramic powder may be B (OH 4) ⁻ .

The organic binder may be any one of epoxy resin, urethane resin, and silicone resin, but is not limited thereto.

The paste for an electrostatic protection device according to this embodiment may be used for an electrostatic protection device such as a chip varistor.

1 is a cross-sectional view of an electrostatic protection device including a paste for an electrostatic protection device according to an embodiment of the present invention.

Referring to FIG. 1, in the case of a general static electricity protection device 100, the device body 200 having an internal electrode 300 and an external electrode 400 formed by being electrically connected to the internal electrode 300 have a configuration. In the process of forming the device body 200, a paste for an electrostatic protection device of this embodiment may be used between the internal electrodes 300.

In addition, when the electrostatic protection circuit is embedded in the printed circuit board, the paste for the electrostatic protection element of the present embodiment may be used in the space between the internal electrodes. Damage, a decrease in insulation resistance due to the generation of conductive carbon, and an increase in leakage current can be prevented.

3 is a flowchart of a method for manufacturing a paste for an electrostatic protection device according to an embodiment of the present invention.

Referring to FIG. 3, a method of manufacturing a paste for an electrostatic protection device according to the present embodiment includes preparing a conductive particle and a nano ceramic powder in the form of hydroxide, hydrate, carbonate or borate, and the conductive particle and the nano ceramic powder as an organic binder Mixing with and preparing a conductive particle-nano-ceramic powder mixture and a step of adding a solvent to the conductive particle-nano-ceramic mixture and co-rotating.

In the step of preparing the conductive particles and the nano ceramic powder in the form of hydroxide, hydrate, carbonate, or borate, the conductive particles, metal powder, nano ceramic powder, and inorganic Hydrate, are each weighed according to a constant addition ratio, and then ball-mill, Mix with a binder using Apex-mill or 3-roll-mill.

The metal powder may be any one or more of manganese, zirconium, tantalum, molybdenum, nickel, cobalt, aluminum, and chromium, and in the case of a high-viscosity paste, a 3-roll-mill component particle and a binder Mixing can be more effective.

The hydroxide-type nano ceramic powder may be Al (OH) ₃ or Mg (OH) ₂ , and the hydrate-type nano ceramic powder may be Al ₂ O ₃ · (H ₂ O) ₃ , carbonate-type nano The ceramic powder may be Na ₂ CO ₃ , and the borate-type nano ceramic powder may be B (OH 4) ⁻ .

 In the step of preparing a conductive particle-nano ceramic powder mixture by mixing the conductive particles and the nano ceramic powder with an organic binder, an organic binder is mixed with the metal powder as the conductive particles and the nano ceramic powder in the form of hydroxide, hydrate, carbonate or borate. By doing so, a conductive particle-nano ceramic mixture can be prepared.

The organic binder may be any one of epoxy resin, urethane resin, and silicone resin, but is not limited thereto.

In the step of adding a solvent to the conductive particle-nano-ceramic mixture and co-rotating, the solvent is added to the conductive particle-nano-ceramic mixture to adjust the viscosity, and air bubbles are removed while dispersing the injected solvent through co-rotation mixing. By doing so, a paste for an electrostatic protection device can be completed.

After applying the finished electrostatic protection device paste on the ESD-function electrode by screen printing or dispensing, after curing for a certain period of time at a temperature of 150 to 200 ° C, the electrostatic protection device Can be completed.

In this embodiment, the static electricity protection element is not limited to independent electronic components, for example, a chip varistor, and may be implemented by a method of coating between ESD electrodes in a printed circuit board.

Comparative example

Conductive powder mixed with aluminum (Al) and nickel (Ni) having a size of 8 μm or less and Al ₂ O ₃ nanoceramic powder are weighed and prepared at a constant ratio, and then mixed with a silicone resin and a solvent. For the dispersion of the Al ₂ O ₃ nanoceramic powder and silicone resin, methods such as ball-mill, apex-mill, or 3-roll-mill are possible. In this comparative example, a 3-roll mill, which is advantageous for high-viscosity dispersion, was used.

After the mixing of the Al ₂ O ₃ nanoceramic powder and the silicone resin is completed, an additional solvent is added and adjusted to a viscosity suitable for printing or application.

Thereafter, the additionally added solvent is dispersed through co-rotating mixing, and air bubbles in the paste are removed to complete the paste for the electrostatic protection device.

The electrostatic protection device paste is coated on a substrate fabricated for ESD characteristics evaluation by a method such as screen printing or dispersing on electrodes disposed symmetrically to the left and right at a temperature of 200 ° C. It undergoes curing for a certain period of time.

Thereafter, an ESD Gun Test was performed at 8 kV according to the IEC61000-4-2 standard. An ESD shock of 8 kV was applied in units of 10 times, and a leakage current defect at 5 V was observed.

Example

Conductive powder mixed with aluminum (Al) and nickel (Ni) having a size of 8 μm or less and Al ₂ O ₃ · (H ₂ O) ₃ nanoceramic powder are weighed and prepared at a constant ratio, and then mixed with a silicone resin and a solvent. do. In the dispersion of the Al ₂ O ₃ · (H ₂ O) ₃ nanoceramic powder and silicone resin, a ball-mill, apex-mill, or 3-roll-mill The same method is possible, but in this comparative example, a 3-roll mill, which is advantageous for high viscosity dispersion, was used.

After mixing of the Al ₂ O ₃ · (H ₂ O) ₃ nanoceramic powder and the silicone resin is completed, an additional solvent is added and adjusted to a viscosity suitable for printing or application.

Thereafter, the additionally added solvent is dispersed through co-rotating mixing, and air bubbles in the paste are removed to complete the paste for the electrostatic protection device.

Al ₂ O ₃ · (H ₂ O) ₃ Nano ceramic powders and conductive metal particles and a silicone resin paste were applied between the internal electrodes to prepare 20 electrostatic protection elements.

Thereafter, an ESD Gun Test was performed at 8 kV according to the IEC61000-4-2 standard. An ESD shock of 8 kV was applied in units of 10 times, and a leakage current defect at 5 V was observed.

Table 1 is the durability evaluation result data of the electrostatic protection device according to the application of the nano-ceramic hydrate.

Referring to Table 1, in the case of an electrostatic protection device made of a paste containing Al ₂ O ₃ · (H ₂ O) ₃ nano ceramic powder, the leakage current defect does not occur even in the ESD Gun Test of 500 times or more. On the contrary, Al ₂ O _{3 as a} comparative example In the case of an electrostatic protection device made of a paste containing nano ceramic powder, defects begin to occur in the ESD Gun Test more than 10 times, and leakage current defects occur in more than 75% of the devices when more than 100 tests are conducted. can see.

Therefore, in the case of the electrostatic protection device according to the embodiment of the present invention, even if the ESD discharge is repeated several times, the electrostatic protection function can be maintained without a leakage current defect.

The above detailed description is to illustrate the present invention. In addition, the foregoing is merely a description and description of a preferred embodiment of the present invention, and the present invention can be used in various other combinations, modifications and environments. That is, it is possible to change or modify the scope of the concept of the invention disclosed herein, the scope equivalent to the disclosed contents, and / or within the scope of the skill or knowledge in the art. The above-described embodiments are for explaining the best condition for carrying out the present invention, and the use of other inventions such as the present invention is performed in other states known in the art, and is required in specific application fields and uses of the invention. Various changes are possible. Accordingly, the detailed description of the invention is not intended to limit the invention to the disclosed embodiments. In addition, the appended claims should be construed to include other embodiments.

100: static electricity protection element
200: element body
300: internal electrode
400: external electrode

Claims (12)

Conductive particles;
Nano ceramic powder in the form of hydroxide, hydrate, carbonate or borate; And
Contains an organic binder,
The nano ceramic _{powder, Al (OH) 3, Mg} (OH) 2, Al 2 O 3 · (H 2 O) 3, Na 2 CO 3 , and B (OH4) ^- any one or the two or more powder mixture of,
Paste for electrostatic protection elements.
According to claim 1,
The conductive particles are manganese, zirconium, tantalum, molybdenum, nickel, cobalt, aluminum, chrome, any one or two or more metal powder is a paste for an electrostatic protection device.
delete delete delete delete According to claim 1,
The organic binder is any one of an epoxy resin, urethane resin, and silicone resin.
According to claim 1,
The size of the conductive particles is 8㎛ or less paste for an electrostatic protection device.
Preparing nano ceramic powders in the form of conductive particles, hydroxide, hydrate, carbonate or borate;
Preparing a conductive particle-nano ceramic powder mixture by mixing the conductive particle and the nano ceramic powder with an organic binder; And
The step of adding a solvent to the conductive particle-nano ceramic mixture and co-rotating,
The nano ceramic _{powder, Al (OH) 3, Mg} (OH) 2, Al 2 O 3 · (H 2 O) 3, Na 2 CO 3 , and B (OH4) ^- any one or the two or more powder mixture of,
Method for manufacturing a paste for an electrostatic protection device.
The method of claim 9,
The conductive particles are manganese, zirconium, tantalum, molybdenum, nickel, cobalt, aluminum, any one or more metal powder of chromium powder electrostatic protection device paste manufacturing method.
delete The method of claim 9,
The organic binder is a method of manufacturing a paste for an electrostatic protection device, which is any one of epoxy resin, urethane resin, and silicone resin.

Images