KR102107027B1 - Capacitor and board having the same mounted thereon - Google Patents

Abstract

One aspect of the present invention, a body including a dielectric layer and an internal electrode; And an external electrode disposed on the body, including Sn, wherein Sn provides a capacitor satisfying an alpha particle emission amount of 0.02 cph / cm ² or less.

Description

Capacitor and its mounting board {CAPACITOR AND BOARD HAVING THE SAME MOUNTED THEREON}

The present invention relates to a capacitor and its mounting substrate.

As the size of electronic products becomes smaller and the battery size increases to increase the sustained use time of portable electronic products, the restrictions on the number and size of printed circuit boards (PCBs) as well as the number of passive elements increase. have.

Accordingly, the demand for miniaturization and high capacity of the capacitor (Capacitr) is increasing, and the demand for high density and high capacity of the semiconductor device using Sn as a raw material is also increasing.

However, as miniaturization and densification increase, a lot of alpha radiation is emitted from Sn disposed in the vicinity of the semiconductor chip, resulting in a problem of soft error that causes information loss of memory cells.

In order to reduce soft errors, there is a movement to use Sn included in semiconductors and solders as Sn having a low emission amount of alpha radiation, but in the case of capacitors, which are components adjacent to semiconductors, such soft errors are not considered.

Korean Patent Publication No. 10-2013-0115357

One of the objectives of the present invention is to prevent soft errors by controlling the amount of Sn alpha particles emitted in the capacitor.

One aspect of the present invention, a body including a dielectric layer and an internal electrode; And an external electrode disposed on the body, including Sn, wherein Sn provides a capacitor satisfying an alpha particle emission amount of 0.02 cph / cm ² or less.

Another aspect of the present invention, a printed circuit board having an electrode pad disposed on one surface; And the capacitor mounted on the printed circuit board.

The capacitor according to an aspect of the present invention can prevent soft error by including Sn having an alpha particle emission amount of 0.02 cph / cm ² or less.

1 schematically illustrates a perspective view of a capacitor according to an embodiment of the present invention.
FIG. 2 schematically shows a cross-sectional view of II ′ in FIG. 1.
3 is a perspective view illustrating a state in which the capacitor of FIG. 1 is mounted on a printed circuit board.
4 schematically shows a cross-sectional view of II-II` of FIG. 3.

Hereinafter, embodiments of the present invention will be described with reference to specific embodiments and the accompanying drawings. However, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Moreover, the embodiment of this invention is provided in order to fully describe this invention to those skilled in the art. Therefore, the shape and size of elements in the drawings may be exaggerated for a more clear description. In addition, components having the same function within the scope of the same idea shown in the drawings of each embodiment are described using the same reference numerals.

In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and thicknesses are enlarged to clearly express various layers and regions, and components having the same function within the scope of the same idea have the same reference. It is explained using a sign. Furthermore, in the specification, when a part “includes” a certain component, this means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

In the drawing, the X direction may be understood as a first direction or a length direction, a Y direction as a second direction or a width direction, and a Z direction as a third direction, a thickness direction, or a stacking direction, but is not limited thereto.

Capacitor

1 schematically illustrates a perspective view of a capacitor according to an embodiment of the present invention. FIG. 2 schematically shows a cross-sectional view of I-I` in FIG. 1.

Hereinafter, a capacitor 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

Referring to FIG. 1, a capacitor 100 according to an embodiment of the present invention includes a body 110 including a dielectric layer 111 and internal electrodes 121 and 122, and an external electrode 131 disposed on the body 110. , 132), and includes Sn, wherein the Sn satisfies an alpha particle emission amount of 0.02 cph (counts per hour) / cm ² or less.

In general, tin (Sn) is the main raw material of a soldering material (Solder), the manufacture of semiconductor devices, the bonding of semiconductor chips and substrates, integrated circuits (Integrated Circuit (IC)) or large scale integrated circuits (Large Scale Integrated circuit, LSI), etc. Silicon chip is widely used in bonding to lead frames or ceramic packages, tape automated bonding (TAB) or flip chip, solder formation in the manufacture of capacitors, and wiring materials for semiconductors.

Sn can be classified into high alpha solder (HAS), low alpha solder (LAS), and ultra low alpha solder (ULAS) according to the amount of alpha particle emission. HAS means Sn with an alpha particle emission amount of greater than 0.02 cph / cm ² , LAS means Sn of 0.02 cph / cm ² or less, and ULAS means Sn of 0.002 cph / cm ² or less.

Alpha particles or alpha rays are one of the radiation particles with high ionization properties. The permeability is low and consists of two protons and two neutrons. That is, it has the same configuration as the helium atomic nucleus, and for this reason, it is also expressed as He 2+, which represents a helium ion having a positive charge of +2.

When HAS having a high alpha particle emission amount as a main raw material of a semiconductor element and a soldering material is used, high-energy alpha radiation irradiation that causes electric charge disturbance to the extent that data of a memory element or a recording device is turned over may occur in the semiconductor element. When a charge disturbance of a certain level or more occurs, a soft error occurs in which the digital signal in the storage element or the recording device changes from 0 to 1 or 1 to 0. Alpha radiation enters the silicon crystals to create a number of electron hole pairs, because these carriers are incorporated into the charge of a dynamic memory or logic circuit to reverse its state.

In general, in the case of not performing a separate purification process, most of Sn corresponds to a high alpha solder (HAS) having a high alpha particle emission amount, and thus, if not controlled separately, a soft error may occur. Therefore, in order to reduce the soft error, there is a movement in the semiconductor to use Sn having a low alpha particle emission amount, but in the case of a capacitor that is a component adjacent to the semiconductor, this soft error is not considered.

However, even when Sn having a low alpha particle emission amount is used in semiconductors and solders, if the capacitor includes Sn having a high alpha particle emission amount, the capacitor is disposed adjacent to the semiconductor, and thus there is a fear of generating a soft error.

The capacitor according to an aspect of the present invention includes Sn, and the Sn can prevent a soft error by controlling an alpha particle emission amount to satisfy 0.02 cph / cm ² or less.

In addition, in order to more reliably prevent soft errors, the Sn may be controlled to satisfy an alpha particle emission amount of 0.002 cph / cm ² or less.

The bodies 110 are connected to the first and second surfaces 1 and 2, which are opposite to each other in the thickness direction (Z direction), and are connected to each other in the width direction (Y direction). Opposing third and fourth faces (3, 4), first and second faces (1, 2), connected to third and fourth faces (3, 4), and in the longitudinal direction (X direction) to each other It has opposing fifth and sixth faces 5,6. At this time, the first surface may be a mounting surface.

The body 110 is formed by stacking a plurality of dielectric layers 111 in the thickness Z direction and then firing them, and the shape, dimensions, and number of layers of the dielectric layers 111 are shown in this embodiment. It is not limited.

The plurality of dielectric layers 111 forming the body 110 is in a fired state, and the boundary between the adjacent dielectric layers 111 can be integrated to a degree that it is difficult to check without using a scanning electron microscope (SEM). have.

The raw material for forming the dielectric layer 111 is not particularly limited as long as sufficient electrostatic capacity can be obtained, and may be, for example, barium titanate (BaTiO ₃ ) powder. As a material for forming the dielectric layer 111, various ceramic additives, organic solvents, plasticizers, binders, dispersants, etc. may be added to powders such as barium titanate (BaTiO ₃ ) according to the purpose of the present invention.

The upper and lower portions of the body 110 may include cover layers 112 and 113 formed by stacking dielectric layers on which internal electrodes are not formed, respectively. The cover layers 112 and 113 may serve to maintain the reliability of the capacitor against external impact.

In addition, Sn included in the capacitor 100 may be included in the dielectric layer 111 and may also be included in the cover layers 112 and 113.

Referring to FIG. 2, the body 110 is provided with internal electrodes 121 and 122 alternately exposed through the third and fourth surfaces 3 and 4 with the dielectric layer 111 and the dielectric layer 111 interposed therebetween. It may include.

The first and second internal electrodes 121 and 122 are a pair of electrodes having different polarities, and are electrically insulated from each other by a dielectric layer 111 disposed in the middle.

The first and second internal electrodes 121 and 122 are alternately exposed to the third and fourth surfaces 3 and 4 in the longitudinal direction (X direction) of the body 110, thereby being disposed outside the body 110. And the first and second external electrodes 131 and 132, respectively.

The thickness of the first and second internal electrodes 121 and 122 may be determined according to the application.

For example, the thicknesses of the first and second internal electrodes 121 and 122 may be formed to satisfy a range of 0.2 to 1.0 μm in consideration of the size of the body 110, but are not limited thereto.

The first and second internal electrodes 121 and 122 may be formed of a single or alloy of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), lead (Pb), or platinum (Pt). It may include a conductive metal.

In addition, Sn included in the capacitor 100 may be included in the internal electrodes 121 and 122. By including Sn in the internal electrode, it is possible to improve the moisture resistance reliability. In addition, it is possible to suppress a trap of co-existence of the internal electrode and to improve electrode connectivity.

In this case, Sn included in the internal electrode may be included in an amount of 0.1 to 10% by weight based on the entire internal electrode. When the Sn content is less than 0.1% by weight, the effect of improving the moisture resistance reliability may be insufficient, and when the Sn content is more than 10% by weight, there is a fear that reliability and characteristics may be deteriorated.

In addition, Sn may exist alone inside the internal electrode, and may exist in the form of an alloy with the material constituting the internal electrode.

The external electrodes 131 and 132 are disposed on one surface of the body 110 and contact the internal electrodes 121 and 122. The external electrodes 131 and 132 may include first and second external electrodes 131 and 132 connected to the first and second internal electrodes 121 and 122, respectively.

The external electrodes 131 and 132 are formed on the electrode layers 131a and 132a disposed on the body 110, the first plating layers 131b and 132b formed on the electrode layers 131a and 132a, and the first plating layers 131b and 132b. The formed second plating layers 131c and 132c may be included.

The electrode layers 131a and 132a may be fired electrodes including a conductive metal and glass, and the conductive metal may be Cu. Further, the electrode layers 131a and 132a may be resin-based electrodes including a plurality of metal particles and a conductive resin.

The first plating layers 131b and 132b may be, for example, Ni plating layers, but are not limited thereto.

In this case, Sn included in the capacitor 100 may be included in the second plating layers 131c and 132c. That is, the second plating layer (131c, 132c) may be a plating layer containing Sn, serves to improve the adhesion with the solder 230, it is possible to prevent soft errors by satisfying 0.02 cph / cm ² or less.

As described above, the capacitor according to the present invention can prevent soft errors by including Sn having an alpha particle emission amount of 0.02 cph / cm ² or less.

However, it is necessary to note that the position in which the Sn is included in the capacitor 100 is not particularly limited and is not excluded from the scope of the present invention when included in a configuration excluding the above-described position.

Capacitor mounting board

3 is a perspective view illustrating a state in which the capacitor of FIG. 1 is mounted on a printed circuit board. 4 schematically shows a cross-sectional view of II-II` of FIG. 3.

3 and 4, another aspect of the present invention, the mounting board 1000 of the capacitor is a printed circuit board 210, the capacitor 100 is mounted to be horizontal, and the upper surface of the printed circuit board 210 It includes electrode pads (221, 222) formed on.

At this time, the electrode pads 221 and 222 may be formed to be spaced apart from each other to contact the first and second external electrodes 131 and 132 of the capacitor 100, respectively.

In addition, the external electrodes 131 and 132 of the capacitor are positioned to contact on the electrode pads 221 and 222, and the external particles 131 and 132 and the electrode pads 221 and 222 have an alpha particle emission amount of 0.02 cph / cm. ^It may be connected by a solder 230 containing Sn satisfying ² or less.

This is because soft error may occur when the alpha particle emission amount of Sn included in the solder 230 exceeds 0.02 cph / cm ² .

At this time, in order to more reliably prevent soft errors, the Sn included in the solder 230 may satisfy an alpha particle emission amount of 0.002 cph / cm ² or less.

Except for the above description, a description overlapping with the characteristics of the capacitor in one aspect of the present invention described above will be omitted herein.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited by the above-described embodiments and the accompanying drawings, and is intended to be limited by the appended claims.

Accordingly, various forms of substitution, modification, and modification will be possible by those skilled in the art without departing from the technical spirit of the present invention as set forth in the claims, and this also belongs to the scope of the present invention. something to do.

100: capacitor
110: body
111: dielectric layer
112, 113: cover layer
121, 122: internal electrode
131, 132: external electrode
131a, 132a: electrode layer
131b, 132b: first plating layer
131c, 132c: second plating layer
210: substrate
221, 222: electrode pad
230: solder

Claims (10)

A body including a dielectric layer and an internal electrode; And
Includes; an external electrode disposed on the body,
Any one or more of the dielectric layer, the inner electrode, and the outer electrode includes Sn, and the Sn is a capacitor that satisfies an alpha particle emission amount of 0.02 cph / cm ² or less.
According to claim 1,
The Sn is a capacitor that satisfies the alpha particle emission amount of 0.002 cph / cm ² or less.
According to claim 1,
The Sn is a capacitor included in the internal electrode.
According to claim 3,
The Sn included in the inner electrode is a capacitor that is included in an amount of 0.1 to 10% by weight based on the entire inner electrode.
According to claim 1,
The external electrode is a capacitor that is connected to the internal electrode and includes an electrode layer disposed on the body, a first plating layer formed on the electrode layer, and a second plating layer formed on the first plating layer.
The method of claim 5,
The Sn is a capacitor included in the second plating layer.
According to claim 1,
The Sn is a capacitor included in the dielectric layer.
A printed circuit board having electrode pads disposed on one surface; And
Capacitors of any one of claims 1 to 7 mounted on the printed circuit board; A mounting board of a capacitor comprising a.
The method of claim 8,
The external electrode of the capacitor is positioned to contact the electrode pad,
The external electrode and the electrode pad are mounted substrates of capacitors connected by solder containing Sn satisfying an alpha particle emission amount of 0.02 cph / cm ² or less.
The method of claim 9,
The Sn included in the solder is a mounting board of a capacitor that satisfies an alpha particle emission amount of 0.002 cph / cm ² or less.

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