JPH0737720A - Chip component and its usage - Google Patents

Abstract

PURPOSE:To eliminate concern for static electricity for surface-mounting and allow high-density mounting by permitting the whole surface of an element to be conductive and eliminating the generation and accumulation of static electricity. CONSTITUTION:A chip component is an inductor or resistor or capacitor, and at least one part on the outer circumference excluding the external electrodes 4 is provided with a charge preventing layer temporarily or permanently. Conducting material 7, which is the charge preventing layer, is provided on the surface layer of the chip component until soldering process so as to prevent electrostatic attraction between the chip components or between the chip component and other materials, and the conducting material 7 which is the charge preventing layer is removed in the soldering process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip component such as a laminated inductor, and more particularly to countermeasures against static electricity during surface mounting.

[0002]

2. Description of the Related Art Personalization of electronic equipment has been expanded to be smaller and more multifunctional, and together with the occurrence of noise and the digitalization of contradictory information, the demand for miniaturization of chip components such as laminated inductors has been increasing at an accelerating rate. The shape of the multilayer inductor as a surface mount component has been reduced in size in recent years, and the length x width x height is
2.0 mm x 1.25 mm x 0.85 mm (2012 type) or 1.6 mm x 0.8 mm x 0.8 mm (16
08 type) is becoming mainstream. These surface-mounted components are packed in a tape shape and mounted on a board by an automatic mounting device. As miniaturization (weight reduction) progresses, the static electricity generated in the element may cause the element itself to interact with a part of the automatic mounting device, causing repulsion or suction. It is designed with consideration.

[0003]

However, in high-density mounting, repulsion or attraction may occur due to electrostatic interaction between adjacent elements, resulting in reduction in production yield and efficiency. Furthermore, the influence of static electricity not only makes handling difficult and hinders the smooth progress of automatic mounting, but also reduces the positioning accuracy of chip components on the printed circuit board, which is increasing in mounting density year by year, and increases the mounting density. However, there is a problem that obstructs the demand for high efficiency (fine pitch surface mounting). In addition, regarding the packaging technology of chip components, the static electricity of the resin tape accommodating the chip components imparts static electricity to the chip components, causing the above-mentioned problems. As described above, the problem that chip components are adversely affected by static electricity not only by themselves but also by their packaging has become apparent because of their light weight and small size. The present invention solves the above problems and provides a chip component such as a laminated inductor in which static electricity is less likely to occur and a method of using the same.

[0004]

As a method for solving the above problems, in the present invention, a magnetic printed layer or a magnetic green sheet and a printed conductor pattern are laminated and integrally fired so that both ends of the conductor pattern are electrically connected. A chip component such as a laminated inductor having a pair of external electrode terminals formed therein and a method of using the same, wherein at least a magnetic material exposed portion of the chip component such as the laminated inductor and the surface thereof. It has a conductive substance. That is, the present invention is a chip component of any one of an inductor, a resistor, and a capacitor, characterized in that an antistatic layer is temporarily or permanently provided on at least a part of the outer peripheral portion of the component other than the electrode. Is. As a typical example of the present invention,
The chip inductor will be described below. That is, the present invention is, as an example, a magnetic printed layer or a magnetic green sheet and a printed conductor pattern are laminated and integrally fired, and a pair of external electrode terminals are provided so that both ends of the conductor pattern are electrically connected. A multilayer inductor formed, of the surface of the multilayer inductor and the method of using the same,
A laminated inductor having a conductive material layer on at least a magnetic material exposed portion. Here, the magnetic material is generally Ni-Zn ferrite or Ni-Cu-Zn ferrite. Further, the present invention is a magnetic printed layer or a magnetic green sheet and a printed conductor pattern are laminated,
A method of using a laminated inductor in which a pair of external electrode terminals are formed so as to be integrally fired so that both ends of the conductor pattern are electrically connected, wherein the laminated inductor and the surface thereof are used in a step before soldering. A method of using a laminated inductor is characterized in that at least a magnetic material exposed portion is provided with a conductive material layer, and the conductive material layer is removed in steps after the soldering step.

[0005]

In the present invention, by providing the chip parts with the antistatic layer, it is possible to prevent the chip parts from being attracted to each other or between the chip parts and other articles, the manufacturing apparatus, etc. due to electrification. This is to prevent the automation from being hindered due to electrification. In the present invention, the antistatic layer is roughly classified into a temporary layer and a permanent or semi-permanent layer. The distinction between the two is made by the presence of the antistatic layer before and after the soldering process. That is, the former is removed by heat during soldering, or even if it remains temporarily, it is removed by subsequent cleaning with a solvent, brushing, or the like. On the other hand, the latter remains on the surface of the chip component even after soldering, and the insulating surface of the chip component is not provided with an antistatic layer between both external electrodes to prevent short circuit between both external electrodes. Is used, a groove is provided, or an insulating paint is applied. In this case, it not only prevents the electrostatic charge of the chip components during surface mounting (surface mounting) but also functions as an electromagnetic shield. As the antistatic layer according to the present invention, first, a one-pack type thermoplastic acrylic resin, an emulsion type synthetic resin, a one-pack type low temperature dry type polyurethane resin, a two-pack type low temperature dry type polyurethane resin, a one-pack medium temperature curing There are various types of antistatic paints in which a conductive filler is mixed with a binder such as a type epoxy resin and a two-component low temperature curing type epoxy resin. That is, carbon-based paint (using carbon powder, graphite, etc. as the conductive filler), metallic paint (using aluminum flakes, nickel flakes, etc. as the conductive filler), metal oxide-based paint (tin oxide powder, oxidation). Zinc powder, titanium oxide powder, indium oxide powder, etc.), surfactant-added paint (using surfactant), and quaternary ammonia compound, amine and its derivatives, phosphoric acid ester, fatty acid polyglycol A material to which an antistatic agent such as ester, glycerin, sorbitol, or polysiloxane is applied can be appropriately selected according to the application. The antistatic layer is not limited to a paint prepared by kneading conductive particles such as carbon black, but may be a chip component which is cooled immediately before soldering to have a water layer adhered to the surface thereof. In the latter case, there is an advantage that the adverse effect of static electricity is prevented during surface mounting and the heat evaporates during soldering. In this case, if the surface roughness of the chip component is increased, not only the triboelectric charge amount decreases but also the water adhesion amount increases, so that the charging can be further prevented. The antistatic layer of the type that kneads the conductive fine particles is preferably one that disappears due to heat during soldering, but even if it remains after soldering, there is usually a resist layer on the corresponding surface of the printed circuit board and there is a leak. There is nothing to do. When it is desired to completely prevent the leak, it is possible to prevent the coating material from adhering by providing a predetermined distance from both ends of both electrodes of the chip component, a region where the antistatic layer is not applied, or providing a groove. According to the present invention, since the element surface is electrically conductive over the entire area, static electricity is not generated or accumulated.

[0006]

The present invention will be described in detail below with reference to examples. _{Fe 2 O 3, NiO, CuO} , the Ni-Cu-Zn ferrite powder based on ZnO, PVB (polyvinyl butyral) as an organic binder, B as a plasticizer
PBG (butylphthalyl butyl glycolate), ethanol and butanol as organic solvents were added and mixed to prepare a slurry. This slurry was formed into a sheet having a thickness of 100 μm on a carrier film made of polyester which had been treated with silicon by a doctor blade method. This was peeled from the film, cut into a sheet of about 50 mm square, and the green sheet 1 was attached to a stainless frame 5 having alignment guide holes 6 as shown in FIG. The frame 5 to which the green sheet 1 is attached is set in a punching die provided with guide pins for alignment so that the guide holes 6 of the frame 5 are aligned, and the through hole 3 is set at a predetermined position. Were formed in large numbers.
Next, the green sheet 1 in which the through holes 3 are formed
As described above, by the alignment method using the guide pin and the guide hole as described above, the predetermined conductive pattern 2 is aligned with the position of the through hole 3 as shown in FIG.
The conductive pattern 2 was printed with silver paste. 5 (A), (B), (C), (D), and (E) of FIG. 5 show the positions of the conductive pattern 2 and the through hole 3 formed on the green sheet 1 used for the production. Next, the printed green sheet 1 is cut into a predetermined size by a positioning method using guide pins and guide holes in the same manner as described above, and one coil has a pattern (A ), (B),
Those formed in the order of (C), (D), and (E) were stacked. At this time, three green sheets 1 each having no conductive pattern and through holes formed above and below were simultaneously laminated. Next, the stacked green sheets were thermocompression bonded under the conditions of a temperature of 120 ° C. and a pressure of 200 kg / cm ² to produce a laminate. Next, the laminate was cut into a chip shape with a cutting machine. FIG. 2 shows the internal structure of the chip-shaped laminated body. This was debindered in the air at 500 ° C., and subsequently baked at 900 ° C. for 1 hour.
Furthermore, an external electrode containing silver as a main component is applied, and the temperature is 600 ° C.
Burned in. Finally, Ni plating and solder plating were applied on the external electrodes by electrolytic barrel plating.
After evaluating the characteristics of the obtained device, a solder thin film having a thickness of 2 μm was formed on the acceptable product by barrel sputtering to form a conductive substance layer on the device surface. The element was set in an automatic mounting device and mounted on a substrate. No static electricity was found on the device. In the step of soldering the element to the substrate, the conductive substance was absorbed by the solder bath in the flow, became a ball shape in the reflow, and could be removed by compressed air.

[0007]

As described above, according to the present invention, the surface of the element becomes conductive over the entire area, so that static electricity is not generated or accumulated. Therefore, it is not necessary to consider static electricity at the time of surface mounting, and higher density mounting becomes possible.

[Brief description of drawings]

FIG. 1 is a perspective view of a manufactured laminated inductor and a method of using the same according to the present invention.

FIG. 2 is a view showing an internal structure of a chip-cut laminate according to the present invention.

FIG. 3 is an explanatory diagram after forming a through hole in the present invention.

FIG. 4 is an explanatory diagram after printing a conductive pattern according to the present invention.

FIG. 5 is a diagram showing a conductive pattern of a laminated inductor and a method of using the same according to the present invention.

[Explanation of symbols]

1 Green Sheet 2 Conductive Pattern 3 Through Hole 4 External Electrode 5 Stainless Steel Frame 6 Positioning Guide Hole 7
Conductive substance

Claims (4)

[Claims] 1. A chip component, which is any one of an inductor, a resistor, and a capacitor, wherein an antistatic layer is temporarily or permanently provided on at least a part of a peripheral portion of the component other than the electrode. . 2. A magnetic printed layer or magnetic green sheet and a printed conductor pattern are laminated and integrally fired, and a pair of external electrode terminals are formed so that both ends of the conductor pattern are electrically connected. Is a laminated inductor,
A laminated inductor having a conductive material layer on at least a magnetic material exposed portion of the surface of the laminated inductor and the method of using the same. 3. The laminated inductor according to claim 2, wherein the magnetic material is Ni—Zn ferrite or Ni—Cu—.
A laminated inductor comprising Zn ferrite. 4. Up to the step of soldering the chip parts, an antistatic layer is provided on the surface layer of the chip parts to prevent electrostatic attraction between the chip parts or between the chip parts and other articles. A method of using a chip part, which comprises removing an antistatic layer.