KR100495132B1 - Surface mountable electrical device for printed circuit board and method of manufacturing the same - Google Patents

Abstract

Surface-mounted positive temperature coefficient (PTC) devices mounted on a printed circuit board to protect a circuit include first and second surfaces and first and second surfaces connected to the first and second surfaces. A sheet resistance component having two sides; A first electrode disposed on the first surface of the sheet resistance component and extending from the first side toward the second side such that a portion of the first surface is exposed; A second electrode disposed on the second surface of the sheet resistance component to extend from the first side to the second side; An insulating layer disposed on the first side of the sheet resistance component and the exposed portion of the first surface, the first and second electrodes, and exposing a portion of the first electrode; A first conductive layer formed on the insulating layer and in electrical contact with an exposed portion of the first electrode; And a second conductive layer formed on a second side of the insulating layer and the sheet resistance element, and in electrical contact with the second electrode at the second side, and electrically separated from the first conductive layer. .

Description

SURFACE MOUNTABLE ELECTRICAL DEVICE FOR PRINTED CIRCUIT BOARD AND METHOD OF MANUFACTURING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-mounted electrical device of a printed circuit board and a method for manufacturing the same, and more particularly, to a surface-mounted positive temperature coefficient mounted on a printed circuit board to perform a function of protecting a circuit; PTC) device.

In general, a so-called positive temperature coefficient (PTC) material composed of a mixture of a crystalline polymer resin and a conductive material has a wide range of application. At low temperatures, such as room temperature, PTC materials have a low resistance to pass current, but when the ambient temperature rises or the material temperature rises due to overcurrent, the resistance increases by 10 ³ to 10 ⁴ times or more, which blocks the current. Have

The PTC material is connected to a metal electrode and can be applied to various types of electric devices, and is mainly used for overcurrent blocking and circuit protection in an electric circuit. Such a PTC device is mainly mounted on a printed circuit board (PCB), which is subject to a lot of shape constraints by the components of the PCB board. In recent years, as the circuit design has been highly integrated, the demand for light and thin reduction of board mounted components has increased. To this end, many techniques for PTC devices have been proposed.

As a manufacturing technique related to a PTC device, for example, U.S. Pat. Nos. 6,124,781, 6,157,289, 6,172,591, 6,188,308, 6,211,771, 6,223,423, 6,242,997, 6,292,088, 6,297,722, 6,348,851, 6,377,6,3,6,3,6,3,8,380,393 have.

Most of these manufacturing process technologies are based on a printed circuit board processing technology, and are distinguished from each other according to a method of connecting upper and lower electrodes of a basic device having PTC characteristics. Some of the representative patents listed above are described below.

First, U.S. Patent Nos. 5,831,510 and 5,852,397 connect a top and bottom electrode by drilling a hole in a plate-shaped PTC device in which metal foil is bonded to both sides of a PTC material, and copper plating the entire surface of the PTC device including the inside of the hole. And then etch the electrode near the aperture to separate it into an anode. This process is borrowed from the general board manufacturing process in the printed circuit board field.

U.S. Patent No. 5,884,391 is configured to form long slits instead of holes in the PTC element sheet, and to connect the upper and lower electrodes by copper plating the entire surface of the sheet including the cross section of the slits. In addition, after the copper plated upper and lower electrodes are separated from each other by etching, and a solder resist is applied, both ends of the copper plated upper and lower electrodes are surrounded by solder plating.

U.S. Pat.Nos. 5,699,607 and 5,900,800 show a long slit on a PTC sheet, apply solder plating to the front surface of the sheet including this slit cross section, and then give a gap to the upper and lower portions to expose the electrode surface. Copper plating surrounds both ends. This method removes a portion of the first solder plating applied without etching the electrode so that copper plated on it can contact the electrode, so that the upper and lower electrodes are not connected through the inner or slit surface of the hole so that each electrode is effective. It is characterized by an increased area.

However, U. S. Patent Nos. 5,831, 510 and 5,852, 397 have a problem that they can be easily affected by the surrounding environment such as the width, thickness and position of the wire on the PCB because of the high heat transfer rate. In addition, there is a disadvantage that the effective area is reduced because each electrode formed on the upper and lower surfaces of the PTC material must be separated by etching. In addition, in the process of separating the electrode by etching, there is a concern that the PTC material made of a polymer may be chemically deteriorated or a part of the electrode may be damaged to prevent electrical connection. This problem is the same in the case of US Pat. No. 5,884,391.

In addition, U. S. Patent Nos. 5,831, 510 and 5,852, 397 both have side surfaces of the PTC material surrounded by an insulator, so that the effective area is relatively small. The effective area, which means the contact area between the PTC material and the electrode, is an important factor in exhibiting PTC properties. However, the above-mentioned patents all have contact with the electrodes only on the upper and lower surfaces of the PTC material, so that the PTC characteristic is relatively low.

The present invention has been made to solve the above problems, and provides a surface-mounted constant temperature coefficient electric device of a printed circuit board which can reduce the etching process of the electrode as much as possible while securing the effective area between the sheet resistance component and the electrode. Its purpose is to.

Another object of the present invention is to provide a method for manufacturing the above-described electrical device.

In order to achieve the above object, the surface-mounted electrical apparatus of a printed circuit board according to the present invention has a sheet resistance having a first and a second surface and first and second side surfaces connected to the first and second surfaces. ingredient; A first electrode disposed on the first surface of the sheet resistance component and extending from the first side toward the second side such that a portion of the first surface is exposed; A second electrode disposed on the second surface of the sheet resistance component to extend from the first side to the second side; An insulating layer disposed on the first side of the sheet resistance component and the exposed portion of the first surface, the first and second electrodes, and exposing a portion of the first electrode; A first conductive layer formed on the insulating layer and in electrical contact with an exposed portion of the first electrode; And a second conductive layer formed on a second side of the insulating layer and the sheet resistance element, and in electrical contact with the second electrode at the second side, and electrically separated from the first conductive layer. .

Preferably, the sheet resistance component is a conductive polymer having a constant temperature coefficient characteristic.

As an example, the electrical device may be configured such that the first and second side surfaces of the sheet resistance element are flat and the second conductive layer surrounds the entirety of the second side surface.

As another example, the electrical device may be configured such that a groove is formed in the second side, and the second conductive layer is stacked in the groove and electrically connected to the second electrode.

As another example, the electrical device may be configured such that a groove is formed in the first side surface of the sheet resistance element, and the insulating layer and the first conductive layer are formed in the groove.

Alternatively, the electrical device has grooves formed in both the first side and the second side of the sheet resistance element, and the insulating layer and the first conductive layer are formed in the groove of the first side. The second conductive layer may be stacked in the groove to be electrically connected to the second electrode.

In addition, the exposed portion of the first electrode is preferably located adjacent to the first side.

Preferably, the first electrode is disposed on the first surface of the sheet resistance component to extend from the first side to the second side, and then the end portion adjacent to the second side is etched by a predetermined length. 1 Expose a portion of the surface.

In addition, the first and second conductive layers are preferably formed together to surround all of the sheet resistance component, the first and second electrodes, and the insulating layer, and are then electrically separated from each other by removing a part by etching. .

Such an electric device includes a first solder layer surrounding a side surface of the first conductive layer; And a second solder layer surrounding a side surface of the second conductive layer.

Preferably, an additional insulator is disposed between the first conductive layer and the second conductive layer and between the first solder layer and the second solder layer.

According to another aspect of the invention, (a) providing a sheet resistance sheet having a first and a second surface, the first electrode is formed on the first surface and the second electrode is formed on the second surface ; (b) forming a plurality of elongated strips having a predetermined shape by forming a plurality of first slits in the sheet resistance sheet; (c) removing the first electrode by a predetermined distance from the center of each strip to form a non-conductive gap; (d) coating each strip of the sheet resistance sheet with an insulating layer; (e) removing a portion of the insulating layer such that the first electrode is exposed at two symmetric positions; (f) forming a second slit at the location of the non-conductive gap, exposing the second electrode towards the second slit; (g) forming a conductive layer in electrical contact with the exposed portions of the first and second electrodes on the surface of the sheet resistance element and the inner surfaces of the first and second slits; (h) separating the conductive layers into first and second conductive layers electrically separated from each other; And (i) dividing each of the divided strips into a plurality of electrical devices.

According to another aspect of the invention, (a) providing a sheet resistance sheet having a first and a second surface, the first electrode is formed on the first surface and the second electrode is formed on the second surface ; (b) drilling a plurality of holes in the sheet resistance sheet at regular intervals; (c) removing the first electrode at a central position of the hole by a predetermined distance to form a nonconductive gap; (d) coating the sheet resistance sheet with an insulating layer together with the inner surface of the hole; (e) removing a portion of the insulating layer such that the first electrode is exposed at two symmetric positions; (f) forming a slit at the location of the non-conductive gap, exposing the second electrode towards the slit; (g) forming a conductive layer on the surface of the sheet resistance sheet and the inner surface of the hole and the slit in electrical contact with the exposed portions of the first and second electrodes; (h) forming an additional nonconductive gap to separate the conductive layer into first and second conductive layers; And (i) dividing the sheet resistance element into a plurality of electrical devices.

According to another aspect of the invention, (a) providing a sheet resistance sheet having a first and a second surface, the first electrode is formed on the first surface and the second electrode is formed on the second surface ; (b) forming a plurality of slits in the thin sheet resistance sheet to form a plurality of long strips having a predetermined shape; (c) removing the first electrode by a predetermined distance from the center of each strip to form a non-conductive gap; (d) coating each strip of the sheet resistance sheet with an insulating layer; (e) removing a portion of the insulating layer such that the first electrode is exposed at two symmetric positions; (f) drilling a hole having a diameter smaller than the width of the non-conductive gap at the position of the non-conductive gap to penetrate the strip in the vertical direction, exposing an end of the second electrode into the hole; (g) forming a conductive layer on the surface of each strip and the inner surface of the hole in electrical contact with the exposed portions of the first and second electrodes; (h) separating the conductive layer into electrically separated first and second conductive layers; (i) dividing each of the strips so that the holes are cut; And (j) dividing each of the divided strips into a plurality of electrical devices.

According to another aspect of the invention, (a) providing a sheet resistance sheet having a first and a second surface, the first electrode is formed on the first surface and the second electrode is formed on the second surface ; (b) drilling a plurality of first holes in the sheet resistance sheet at regular intervals; (c) removing the first electrode at a central position of the hole by a predetermined distance to form a nonconductive gap; (d) coating the sheet resistance sheet with an insulating layer together with the inner surface of the hole; (e) removing a portion of the insulating layer such that the first electrode is exposed at two symmetric positions; (f) drilling a second hole having a diameter smaller than the width of the non-conductive gap at the position of the non-conductive gap to penetrate the strip in the vertical direction, thereby exposing the end of the second electrode into the second hole. step; (g) forming a conductive layer in electrical contact with the exposed portions of the first and second electrodes on the surface of the sheet resistance element and the inner surfaces of the first and second holes; (h) separating the conductive layers into first and second conductive layers electrically separated from each other; (i) dividing each strip so that the first and second holes are cut; And (j) dividing the divided resistive element into a plurality of electrical devices.

In the above four methods, the non-conductive gap formed in step (c) preferably has a width approximately twice that of one part of the insulating layer removed in step (e).

Further, the step (h) may include forming a conductive layer on the entire outer surface of each of the divided strips so as to be in electrical contact with the exposed portions of the first and second electrodes; And etching a portion of the conductive layer to electrically separate the first conductive layer in electrical contact with the exposed portion of the first electrode and the second conductive layer in electrical contact with the exposed portion of the second electrode. It is preferred to include the step.

In this case, after step (h), the method may further include forming first and second solder layers surrounding the side surfaces of the first and second conductive layers, respectively, between the first and second conductive layers. It is also desirable to apply an additional insulator between the first and second solder layers.

Alternatively, after step (h), an additional insulating layer is formed on the upper and lower surfaces except for a part of both sides of each of the divided strips, and the first and the second sides of each of the divided strips on which the insulating layer is not formed. It is also possible to form two solder layers.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

First embodiment

1 is a view showing the structure of a surface mount electric device of a printed circuit board according to a first embodiment of the present invention. Referring to FIG. 1, the electrical apparatus of the present embodiment includes a sheet resistance component 10 in the form of a sheet having a predetermined width, and the sheet resistance component 10 faces the first and second surfaces 12 and 14 facing each other. And first and second side surfaces 16, 18 connected to the first and second surfaces 12, 14. In the figure, the first surface 12 of the sheet resistance component 10 is shown as an upper surface, the second surface 14 as a lower surface, the first side 16 is the left side, and the second side 18 is the same. Is shown to represent the right side.

The sheet resistance component 10 preferably has a positive temperature coefficient (PTC) characteristic. Also preferably, this sheet resistance component 10 is made of a conductive polymer composed of a mixture of a crystalline polymer resin and a conductive material. As the conductive material, carbon black, metal particles or metal powder may be used.

The first electrode 20 is disposed on the first surface 12 of the sheet resistance component 10. The first electrode 20 extends from the first side 16 toward the second side 18, over the first surface 12 of the sheet resistance component 10. At this time, the first electrode 20 extends only to a position spaced apart from the second side surface 18 by a predetermined distance to expose a portion 24 of the first surface 12. The exposed portion 24 is interposed with an insulating layer 26 to prevent the second conductive layer 32 described later from being in electrical contact with the first electrode 20, which will be described in detail later.

The second electrode 22 is disposed on the second surface 14 of the thin sheet resistance component 10. The second electrode 22 extends from the first side 16 to the second side 18 over the first surface 12 of the sheet resistance component 10. At this time, the second electrode 22 completely covers the second surface 14 of the sheet resistance component 10.

An insulating layer 26 is formed on the first electrode 20 and the second electrode 22. The insulating layer 26 also completely surrounds the first surface 12 of the sheet resistance component 10. However, no insulating layer is formed on the second surface 14 of the sheet resistance component 10, leaving the end of the second electrode 22 exposed to the second surface 14. In addition, as described above, an insulating layer is also formed on the exposed portion 24 of the first surface 12.

A portion of the insulating layer 26 is removed by a process such as etching to expose a portion 28 of the first electrode 20. The exposed portion 28 of the first electrode 20 is preferably in a position adjacent to the first side 16. The exposed portion 28 is in electrical contact with the first conductive layer 30 described later. The exposed portion 28 of the first electrode 20 preferably has approximately the same width as the exposed portion 24 of the first surface 12.

First and second conductive layers 30 and 32 are formed on the insulating layer 26. The first conductive layer 30 surrounds the first surface 12 of the sheet resistance component 10 and is in electrical contact with the first electrode 20 through the exposed portion 28. The first conductive layer 30 also extends by a predetermined length to cover a portion of the first surface 12 and the second surface 14.

The second conductive layer 32 surrounds the second surface 14 of the sheet resistive component 10 and is in electrical contact with the end of the second electrode 22 exposed to the second side 18. However, the end portions of the first electrodes 12 are covered by the insulating layer 26, so that they do not come into contact with the second conductive layers 32. The second conductive layer 32 also extends by a predetermined length to cover a portion of the first surface 12 and the second surface 14.

The first conductive layer 30 and the second conductive layer 32 may be formed independently of each other. Preferably, the first conductive layer 30 and the second conductive layer 32 are formed of one conductive layer, and then a portion of the first conductive layer 30 and the second conductive layer 32 are removed by etching or the like. By forming the conductive gap 34, the first conductive layer 30 and the second conductive layer 32 may be formed to be electrically separated from each other.

In the electric device according to the present embodiment configured as described above, the first and second conductive layers 30 and 32 connected to the electrodes 20 and 22 serve as terminals and are mounted on the surface of the PCB. In this case, the first and second conductive layers 30 and 32 are on the same surface, and do not require a separate wiring to be electrically connected to the PCB. In addition, since the first and second conductive layers 30 and 32 are symmetrical in the vertical direction, the first and second conductive layers 30 and 32 may be mounted on the surface of the PCB on both the upper and lower surfaces thereof.

Such an electrical device is such that etching of the electrode is performed only for the exposed portion 24 of the sheet resistance component 10 to reduce the defects caused by the etching of the electrode. In addition, in the electrical apparatus of this embodiment, both the first surface 12 and the second surface 14 are formed to be flat, and the electrodes 20 and 22 have a majority of the first surface 12 of the sheet resistance component 10. And the entire second surface 14, with the conductive layers 30, 32 covering the entire second side 18 to provide a relatively large effective area.

2 is a modified example in which the above-described electrical apparatus is reinforced. Referring to FIG. 2, the electrical apparatus of the present modification includes all the configurations shown in FIG. 1, in which first and second solder layers 36 and 28 and an insulator 40 are added.

The first solder layer 36 is formed over the first conductive layer 30 while surrounding the first side surface 16. The first solder layer 36 is in electrical contact with the first conductive layer 30 and extends a predetermined distance to the first and second surfaces 12, 14. At this time, the extension distance of the first solder layer 36 on the first and second surfaces 12 and 14 is determined to a level capable of ensuring electrical connection with the PCB substrate, preferably the first conductive layer 30. It is formed shorter than).

The second solder layer 38 is also formed over the second conductive layer while surrounding the second side 18. The second solder layer 38 is in electrical contact with the second conductive layer and extends to the first and second surfaces 12 and 14 by a predetermined distance, with the extension distance preferably equal to the first solder layer 36. Do.

In this modification, unlike the example of FIG. 1, each of the solder layers 36 and 38 serves as a terminal and is electrically connected to the PCB substrate.

The insulator 40 is disposed between the first conductive layer 30 and the second conductive layer 32 and between the first solder layer 36 and the second solder layer 38. The insulator 40 helps the first conductive layer 30 and the second conductive layer 32 and the first solder layer 36 and the second solder layer 38 to be electrically separated from each other completely.

The electric device according to the present modification is more structurally stable by using more suitable solder layers 36 and 38 as terminals, and the first conductive layer 30 and the second conductive layer 32 using the insulator 40. And the first solder layer 36 and the second solder layer 38 are electrically separated more reliably.

Next, a method of manufacturing a surface mounted electric device of a PCB according to the present embodiment as described above with reference to FIGS. 3A to 3I will be described.

In order to manufacture the electrical apparatus of this embodiment, first, a wide resistive element as shown in FIG. 3A is prepared. The resistive element is composed of a sheet resistance sheet 110 and first and second electrodes 120 and 122. The first electrode 120 is formed on the first surface 112 of the sheet resistance sheet 110, and the second electrode is formed on the second surface 114 of the sheet resistance sheet 110.

The thin sheet resistance sheet 110 preferably has a positive temperature coefficient (PTC) characteristic and is made of a conductive polymer composed of a mixture of a crystalline polymer resin and a conductive material. As the conductive material, carbon black, metal particles or metal powder may be used.

Next, as shown in FIG. 3B, a plurality of slits are formed in the sheet resistance sheet 110 to form a plurality of long strips having a predetermined shape. A state in which a plurality of strips 111 are formed in the sheet resistance sheet 110 by forming a plurality of slits 200 is illustrated in FIG. 4. The strip 111 has a substantially rectangular cross section and is approximately twice as wide as the width of the electrical device to be finally produced. This strip, which consists of a thin sheet resistance sheet 110 and electrodes 120 and 122, functions as a resistive element.

Although the present embodiment has been described as forming a plurality of strips in one thin sheet resistance sheet 110, as another variation, it is also possible to prepare a single resistive element having the same width as the strip and proceed to the subsequent steps. Do. This variant differs only in the process of preparing the strip or the resistive element, and the other processes are the same. Therefore, it is to be understood that the term 'strip' used in the following description is similar in concept to a 'resistive element' in a modification.

After making a plurality of strips through the slit as shown in FIG. 3b, some of the first electrodes 120 are removed at the center of each strip as shown in FIG. 3c. Removing part of the first electrode 120 is performed by etching or the like. When a portion of the first electrode 120 is removed, a non-conductive gap 150 is formed between the divided electrodes, and the first surface 112 exposes the corresponding region 124 to the outside.

Next, as shown in FIG. 3D, each strip of the sheet resistance sheet 110 is coated with an insulating layer 126. An insulating layer 126 completely covers both sides 116 and 118 of each strip and each electrode 120 and 122, and also exposes the exposed area 124 of the first surface 112 through the non-conductive gap 150. Will be covered.

Since the insulating layer 126 completely covers all the electrodes 120 and 122, it is necessary to expose each electrode 120 and 122 to the outside for electrical connection with an external device. A process for exposing the electrodes 120 and 122 to the outside is shown in FIG. 3E.

Referring to FIG. 3E, a portion of the insulating layer 126 is removed by a process such as etching to expose the first electrode 120 to the outside. The exposed portion by removing the insulating layer 126 is referred to as an exposed surface 128 of the first electrode 120. In this process, the exposed surface 128 of the first electrode 120 is formed at two positions symmetrical with each other, and the position of each exposed surface 128 is preferably adjacent to both sides 116 and 118 of the strip. In this case, the exposed surface 128 of the first electrode 120 preferably has a width that is approximately half that of the non-conductive gap 150 shown in FIG. 3C.

Next, as shown in FIG. 3F, in order to expose the second electrode 120 to the outside, slits 160 are formed in each strip such that the non-conductive gap 150 is divided. The state in which the slit 160 is formed in each strip 111 is well illustrated in FIG. 5. The slit 160 divides one strip completely into two, so that the end of the second electrode 122 is exposed toward the slit 160.

With each electrode 120, 122 exposed, a conductive layer 130 is formed on each divided strip as shown in FIG. 3G. This conductive layer 130 is partially removed by etching or the like as shown in FIG. 3H to form the non-conductive gap 134. Non-conductive gaps 134 are formed one on the top and bottom of each divided strip. Preferably, the location of the non-conductive gap 134 is centered on the top and bottom of each divided strip. The conductive layer 130 is separated into the first conductive layer 131 and the second conductive layer 132 by the non-conductive gap 134.

The strip produced by the process up to FIG. 3H has the same cross section as the electrical device shown in FIG. 1. Accordingly, each of the divided strips having completed the process shown in FIG. 3H may be divided in the cross-sectional direction to make the surface mounted electric device according to the present embodiment. At this time, the dividing direction of the strip 111 is indicated by the reference numeral 202 in FIG.

On the other hand, an additional process is required to make the reinforced electrical device as shown in FIG. In order to make the electrical device shown in FIG. 2, before dividing each strip in the cross-sectional direction, an insulator 140 is first applied to the upper and lower surfaces of each divided strip, as shown in FIG. 3I. The insulator 140 contacts the insulating layer 126 through the non-conductive gap 134 to electrically and securely separate the first conductive layer 131 and the second conductive layer 132. This insulator 140 is not applied to both sides 116, 116a, 118, 118a and adjacent areas of each divided strip.

First and second solder layers 136 and 138 are formed in regions where the insulator 140 is not applied, as shown in FIG. 3J. The first solder layer 136 is electrically connected to the first conductive layer 130 while surrounding the first side surfaces 116 and 116a of each divided strip, and the second solder layer 138 is connected to each of the divided strips. It is electrically connected to the second conductive layer 132 while surrounding the second side surfaces 118 and 118a.

By dividing the divided strips having such a process into the cross-sectional direction indicated by reference numeral 202 in FIG. 5, a reinforced electric device as shown in FIG. 2 can be obtained.

In the processes of FIGS. 3I and 3J, an insulator 140 is first formed on each of the divided strips, and then solder layers 136 and 138 are formed. However, this order is not essential and can optionally be changed. That is, after forming the solder layers 136 and 138 on each of the strips, it is also possible to apply the insulator 140 between the conductive layers 130 and 132 and the solder layers 136 and 138.

The present embodiment as described above has been described as forming a plurality of strips in one thin sheet resistance sheet (110). However, as another variation, it is also possible to prepare one resistive element having the same width as the strip shown in FIG. 3B and proceed with the subsequent steps. This variant differs only in the process of preparing the strip or the resistive element, and the other processes are the same. Therefore, it is to be understood that the term 'strip' used in the above description is similar in concept to the 'resistive element' of the modified example from a structural point of view.

Second embodiment

The following describes a surface mount electric device of a PCB according to a second embodiment of the present invention. This embodiment is similar in many respects to the first embodiment, but differs in that a hole is formed in the process of FIG. 3B instead of forming a plurality of slits 200 in the sheet resistance sheet 110.

In the present embodiment, in the process of FIG. 3B, as shown in FIG. 6, a plurality of holes 210 are drilled in the sheet resistance sheet 110 with a width approximately twice as wide as the width of the desired electrical device. The hole 210 performs the same function as the slit 200 of the previous embodiment, and the insulating layer 126, the first conductive layer 131, and the first conductive layer are formed on the surface of the hole 210 as in the case of the slit 200. 1 plating layer 136 is formed sequentially. All other procedures are the same as in the previous embodiment. As such, the electric device manufactured by using the hole 210 instead of the slit 200 has a shape as shown in FIG. 7. Referring to FIG. 7, in the electrical apparatus of the present embodiment, grooves formed by the holes 210 are formed in the first lateral direction of the sheet resistance element 110. In addition, in the electric device according to the present embodiment, it can be seen that the insulating layer 126, the first conductive layer 131, and the first plating layer 136 are all formed through the hole 210.

Third embodiment

The following describes a surface mount electric device of a PCB according to another embodiment of the present invention.

In this embodiment, the electrodes 120 and 122 are stacked on the sheet resistance sheet 110 (FIG. 3A), and a plurality of slits are formed on the sheet resistance sheet 110 to form a plurality of strips (FIG. 3B). Removing the central portion of the first electrode 120 to form a non-conductive gap 150 (FIG. 3C) and forming an insulating layer 126 on each strip (FIG. 3D), each insulating layer 126 The process of removing a part of (Fig. 3e) is the same as in the previous embodiment.

However, in the process of FIG. 3F, in this variant, a plurality of holes 170 are drilled in the region of the non-conductive gap 150 instead of the slit 160. A state in which a plurality of holes 170 are drilled in the sheet resistance sheet 110 is illustrated in FIG. 8. The hole 170 does not divide each strip 111 completely, but is formed so as to completely penetrate each strip 111. The holes 170 are formed at regular intervals, and are preferably formed at intervals equal to the longitudinal length of the finally produced electrical device. The second electrode 122 is exposed toward the hole 170 by the process of FIG. 3F.

With each electrode 120, 122 exposed in this manner, a conductive layer 130 is formed on each perforated strip as shown in FIG. 3G. The conductive layer 130 covers both the upper and lower surfaces and the left and right sides 116 and 118 of each perforated strip as well as the inner surface 172 of the hole 170. Thus, the conductive layers 130 on the top and bottom surfaces are electrically connected to each other through the inner surfaces 172 of the holes 170 as well as the respective side surfaces 116 and 118.

This conductive layer 130 is partially removed by etching or the like as shown in FIG. 3H to form the non-conductive gap 134. The location and number of non-conductive gaps 134 are the same as in the previous embodiment. In addition, the conductive layer 130 is separated into the first conductive layer 131 and the second conductive layer 132 by the non-conductive gap 134.

In the figure, the first conductive layer 131 is shown to surround the side surfaces 116 and 118 of each strip, and the second conductive layer 132 is shown to be connected through the hole 170.

The strip produced by the process up to FIG. 3H can function as one surface mount electrical device as in the case of FIG. Accordingly, if each of the perforated strips having completed the process of FIG. 3H is divided in the direction in which the hole 170 is cut and then divided in the cross-sectional direction, the surface-mounted electric device as shown in FIG. 9 may be manufactured. Referring to the ninth embodiment, it can be seen that in the electrical apparatus according to the present embodiment, the first side surface of the sheet resistance element forms a flat surface, but the groove formed by the hole 170 is formed in the second side surface.

The electrical device according to the present embodiment may also have a more reinforced structure as in the previous embodiment, which requires an additional process similar to the previous embodiment. To this end, before dividing each strip, an insulator 140 is first applied to the top and bottom surfaces of each perforated strip, as shown in FIG. 3I. The insulator 140 contacts the insulating layer 126 through the non-conductive gap 134 to electrically and securely separate the first conductive layer 131 and the second conductive layer 132. This insulator 140 is not applied to both sides 116, 118 and adjacent areas of each of the divided strips, and also to the inner surface 172 of the holes 170 and areas adjacent to the holes 170.

First and second solder layers 136 and 138 are formed in regions where the insulator 140 is not applied, as shown in FIG. 3J. The first solder layer 136 is electrically connected to the first conductive layer 130 while surrounding the side surfaces 116 and 118 of each strip, and the second solder layer 138 is second conductive through the hole 170. Is electrically connected to layer 132.

By dividing each of the perforated strips through this process in the direction in which the holes are cut and then in the cross-sectional direction, a reinforced electric apparatus according to the present modification can be made. This electrical device is shown well in FIG.

Fourth embodiment

The following describes a surface mount type electrical apparatus of a PCB according to a fourth embodiment of the present invention.

This embodiment is mostly similar to the third embodiment, but instead of making a plurality of strips through the slit 200 in the process of FIG. 3B, the slit 200 is applied to the sheet resistance sheet 110 as in the case of FIG. 6. The hole 210 is carried out in a perforated state. In this case, holes 170 and 210 are formed in the sheet resistance sheet 110 as shown in FIG. 11, and the respective insulating layers 126, the conductive layers 131 and 132, and the solder layers 136 and 138 are each holes. It is formed via the inner wall of 170,210. The electrical device manufactured by this variant is shown in FIG. Referring to FIG. 12, it can be seen that the electric device completed according to the present embodiment has semicircular grooves formed by holes 170 and 210 on both sides thereof, respectively.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

The surface mounted electric device of the printed circuit board according to the present invention configured as described above may minimize the problem caused by etching the electrode since the process of etching the electrode is performed only once in the two electric devices.

In addition, the electrical apparatus of the present invention has the advantage that the electrode covers the entire surface and most of the lower surface of one side and the lower surface of the sheet resistance element, despite the small etching process of the electrode as described above, to prevent the effective area is reduced as much as possible have.

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to

1 is a cross-sectional view showing a surface mount electric device of a printed circuit board according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a modification in which the electric device of FIG. 1 is reinforced. FIG.

3A to 3J are views sequentially showing a method of manufacturing a surface mounted electric device of a printed circuit board according to the present invention.

4 illustrates a sheet resistance sheet in which a plurality of strips are formed using slots in the process of FIG. 3B.

5 is a view showing a state in which slits are formed in the strip of FIG. 4 in the process of FIG. 3F;

FIG. 6 illustrates a sheet resistance sheet with holes formed instead of slots in the process of FIG. 3B in accordance with a second embodiment of the present invention. FIG.

Fig. 7 is a perspective view showing the surface mount electric apparatus of the printed circuit board manufactured according to the second embodiment of the present invention.

FIG. 8 is a view showing a state in which holes are formed in the strip of sheet resistance sheet formed by the slots in the process of FIG. 3F according to the third embodiment of the present invention.

9 is a perspective view showing the appearance of a surface mount electric apparatus of a printed circuit board manufactured by a third embodiment of the present invention;

FIG. 10 is a perspective view showing a modification in which the electric device shown in FIG. 9 is reinforced. FIG.

FIG. 11 is a view showing a state in which a hole is formed in the sheet resistance sheet instead of a slot in the process of FIG. 3B and a hole is formed again in the process of FIG. 3F according to the fourth embodiment of the present invention.

12 is a perspective view showing a surface mount electric apparatus of a printed circuit board manufactured according to the fourth embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10. Thin sheet resistance component 12,112. First surface 14, 114. Second surface

16,116. First side 18,118. Second side 20,120. First electrode

22,122..2nd electrode 24,28,124,128 .. Exposure surface

26,126 Insulation layer 30,131 First conductive layer 32,132 Second conductive layer

34,134. Non-conductive gap 36,126. First solder layer 38,138 Second solder layer

40,140..Insulator 110..Lamination sheet

Claims (43)

A sheet resistance component having first and second surfaces and first and second side surfaces connected with the first and second surfaces; A first electrode disposed on the first surface of the sheet resistance component and extending from the first side toward the second side such that a portion of the first surface is exposed; A second electrode disposed on the second surface of the sheet resistance component to extend from the first side to the second side; An insulating layer disposed on the first side of the sheet resistance component and the exposed portion of the first surface, the first and second electrodes, and exposing a portion of the first electrode; A first conductive layer formed on the insulating layer and in electrical contact with an exposed portion of the first electrode; And And a second conductive layer formed on the insulating layer and the second side surface of the thin sheet resistance element, and electrically contacting the second electrode at the second side surface, and electrically separated from the first conductive layer. A surface mount type electrical device of a printed circuit board. The method of claim 1, The sheet resistance component is a surface-mounted electrical device of a printed circuit board, characterized in that the conductive polymer having a constant temperature coefficient characteristics. The method of claim 1, The first and second side surfaces of the sheet resistance element are flat, And the second conductive layer is formed to surround the entirety of the second side surface. The method of claim 1, Grooves are formed in the second side surface, And the second conductive layer is stacked in the groove and electrically connected to the second electrode. The method of claim 1, Grooves are formed in the first side surface of the sheet resistance element, And the insulating layer and the first conductive layer are formed in the groove. The method of claim 1, Grooves are formed in the first side and the second side of the sheet resistance element, respectively. The insulating layer and the first conductive layer are formed in the groove of the first side surface, And the second conductive layer is stacked in the groove and electrically connected to the second electrode. The method of claim 1, And the exposed portion of the first electrode is located adjacent to the first side surface. The method of claim 1, The first electrode is disposed on the first surface of the sheet resistance component to extend from the first side to the second side, and then an end adjacent to the second side is etched by a predetermined length of the first surface. Surface-mounted electrical device of a printed circuit board, characterized in that for exposing a part. The method of claim 1, The first and second conductive layers are formed together to surround all of the sheet resistance component, the first and second electrodes, and the insulating layer, and are then electrically separated from each other by removing a part by etching. Surface-mount electrical devices for circuit boards. The method according to any one of claims 1 to 9, A first solder layer surrounding a side surface of the first conductive layer; And And a second solder layer surrounding the side surface of the second conductive layer. The method of claim 10, And an additional insulator between the first conductive layer and the second conductive layer and between the first solder layer and the second solder layer. (a) providing a sheet resistance sheet having first and second surfaces, wherein a first electrode is formed on the first surface and a second electrode is formed on the second surface; (b) forming a plurality of elongated strips having a predetermined shape by forming a plurality of first slits in the sheet resistance sheet; (c) removing the first electrode by a predetermined distance from the center of each strip to form a non-conductive gap; (d) coating each strip of the sheet resistance sheet with an insulating layer; (e) removing a portion of the insulating layer such that the first electrode is exposed at two symmetric positions; (f) forming a second slit at the location of the non-conductive gap, exposing the second electrode towards the second slit; (g) forming a conductive layer in electrical contact with the exposed portions of the first and second electrodes on the surface of the sheet resistance element and the inner surfaces of the first and second slits; (h) separating the conductive layers into first and second conductive layers electrically separated from each other; And (i) dividing each of the divided strips into a plurality of electrical devices. The method of claim 12, The sheet resistance sheet is a method of manufacturing a surface mounted electrical device of a printed circuit board, characterized in that the conductive polymer having a constant temperature coefficient characteristics. The method of claim 12, And wherein the exposed portion of the first electrode is positioned adjacent to both sides of each strip. The method of claim 12, And wherein the nonconductive gap formed in step (c) has approximately twice the width of one portion of the insulating layer removed in step (e). The method according to any one of claims 12 to 15, In the step (h), the first conductive layer in contact with the exposed portion of the first electrode by etching a portion of the conductive layer and the second conductive layer in electrical contact with the exposed portion of the second electrode. Method for manufacturing a surface-mounted electrical device of a printed circuit board, characterized in that the electrical separation from each other. The method of claim 16, wherein after step (h), And forming first and second solder layers surrounding side surfaces of the first and second conductive layers, respectively. The method of claim 17, And applying additional insulators between the first and second conductive layers and between the first and second solder layers. The method of claim 16, wherein after step (h), Forming an additional insulating layer on upper and lower surfaces except for a part of both sides of each of the divided strips; And And forming first and second solder layers on both sides of each of the divided strips on which the insulating layer is not formed. (a) providing a sheet resistance sheet having first and second surfaces, wherein a first electrode is formed on the first surface and a second electrode is formed on the second surface; (b) drilling a plurality of holes in the sheet resistance sheet at regular intervals; (c) removing the first electrode at a central position of the hole by a predetermined distance to form a nonconductive gap; (d) coating the sheet resistance sheet with an insulating layer together with the inner surface of the hole; (e) removing a portion of the insulating layer such that the first electrode is exposed at two symmetric positions; (f) forming a slit at the location of the non-conductive gap, exposing the second electrode towards the slit; (g) forming a conductive layer on the surface of the sheet resistance sheet and the inner surface of the hole and the slit in electrical contact with the exposed portions of the first and second electrodes; (h) forming an additional nonconductive gap to separate the conductive layer into first and second conductive layers; And (i) dividing the thin plate resistor into a plurality of electrical devices. The method of claim 20, The resistive element is a method of manufacturing a surface-mounted electrical device of a printed circuit board, characterized in that the conductive polymer having a constant temperature coefficient characteristics. The method of claim 20, And wherein the exposed portion of the first electrode is positioned adjacent to both sides of each strip. The method of claim 20, And wherein the nonconductive gap formed in step (c) has approximately twice the width of one portion of the insulating layer removed in step (e). The method according to any one of claims 20 to 23, In the step (h), the first conductive layer in contact with the exposed portion of the first electrode by etching a portion of the conductive layer and the second conductive layer in electrical contact with the exposed portion of the second electrode. Method for manufacturing a surface-mounted electrical device of a printed circuit board, characterized in that the electrical separation from each other. The method of claim 24, wherein after step (h), And forming first and second solder layers surrounding side surfaces of the first and second conductive layers, respectively. The method of claim 25, And applying additional insulators between the first and second conductive layers and between the first and second solder layers. The method of claim 24, wherein after step (h), Forming an additional insulating layer on upper and lower surfaces except for a part of both sides of each of the divided strips; And And forming first and second solder layers on both sides of each of the divided strips on which the insulating layer is not formed. (a) providing a sheet resistance sheet having first and second surfaces, wherein a first electrode is formed on the first surface and a second electrode is formed on the second surface; (b) forming a plurality of slits in the thin sheet resistance sheet to form a plurality of long strips having a predetermined shape; (c) removing the first electrode by a predetermined distance from the center of each strip to form a non-conductive gap; (d) coating each strip of the sheet resistance sheet with an insulating layer; (e) removing a portion of the insulating layer such that the first electrode is exposed at two symmetric positions; (f) drilling a hole having a diameter smaller than the width of the non-conductive gap at the position of the non-conductive gap to penetrate the strip in the vertical direction, exposing an end of the second electrode into the hole; (g) forming a conductive layer on the surface of each strip and the inner surface of the hole in electrical contact with the exposed portions of the first and second electrodes; (h) separating the conductive layer into electrically separated first and second conductive layers; (i) dividing each of the strips so that the holes are cut; And (j) dividing each of the divided strips into a plurality of electrical devices. The method of claim 28, The resistive element is a method of manufacturing a surface-mounted electrical device of a printed circuit board, characterized in that the conductive polymer having a constant temperature coefficient characteristics. The method of claim 28, And wherein the exposed portion of the first electrode is positioned adjacent to both sides of each strip. The method of claim 28, And wherein the nonconductive gap formed in step (c) has approximately twice the width of one portion of the insulating layer removed in step (e). The method according to any one of claims 28 to 31, In the step (h), the first conductive layer in contact with the exposed portion of the first electrode by etching a portion of the conductive layer and the second conductive layer in electrical contact with the exposed portion of the second electrode. Method for manufacturing a surface-mounted electrical device of a printed circuit board, characterized in that the electrical separation from each other. The method of claim 32, wherein after step (h), Manufacturing a surface mount type electrical device of a printed circuit board, further comprising forming a first solder layer covering each side of the perforated strip and a second solder layer covering an inner wall of the hole and a periphery thereof. How to. The method of claim 33, And applying additional insulators between the first and second conductive layers and between the first and second solder layers. The method of claim 32, wherein after step (h), Forming an additional insulating layer on upper and lower surfaces of the perforated strip except for a portion of both sides and a peripheral area of the hole; And And forming first and second solder layers in the region where the insulating layer is not formed. (a) providing a sheet resistance sheet having first and second surfaces, wherein a first electrode is formed on the first surface and a second electrode is formed on the second surface; (b) drilling a plurality of first holes in the sheet resistance sheet at regular intervals; (c) removing the first electrode at a central position of the hole by a predetermined distance to form a nonconductive gap; (d) coating the sheet resistance sheet with an insulating layer together with the inner surface of the hole; (e) removing a portion of the insulating layer such that the first electrode is exposed at two symmetric positions; (f) drilling a second hole having a diameter smaller than the width of the non-conductive gap at the position of the non-conductive gap to penetrate the strip in the vertical direction, thereby exposing the end of the second electrode into the second hole. step; (g) forming a conductive layer in electrical contact with the exposed portions of the first and second electrodes on the surface of the sheet resistance element and the inner surfaces of the first and second holes; (h) separating the conductive layers into first and second conductive layers electrically separated from each other; (i) dividing each strip so that the first and second holes are cut; And (j) dividing the divided resistive element into a plurality of electrical devices. The method of claim 36, The resistive element is a method of manufacturing a surface-mounted electrical device of a printed circuit board, characterized in that the conductive polymer having a constant temperature coefficient characteristics. The method of claim 36, And wherein the exposed portion of the first electrode is positioned adjacent to both sides of each strip. The method of claim 36, And wherein the nonconductive gap formed in step (c) has approximately twice the width of one portion of the insulating layer removed in step (e). The method according to any one of claims 36 to 39, wherein In the step (h), the first conductive layer in contact with the exposed portion of the first electrode by etching a portion of the conductive layer and the second conductive layer in electrical contact with the exposed portion of the second electrode. Method for manufacturing a surface-mounted electrical device of a printed circuit board, characterized in that the electrical separation from each other. The method of claim 40, wherein after step (h), And manufacturing a first solder layer covering each side of the perforated strip and a second solder layer surrounding the inner wall and the periphery of the hole. How to. 42. The method of claim 41 wherein And applying additional insulators between the first and second conductive layers and between the first and second solder layers. The method of claim 40, wherein after step (h), Forming an additional insulating layer on upper and lower surfaces of the perforated strip except for a portion of both sides and a peripheral area of the hole; And And forming first and second solder layers in the region where the insulating layer is not formed.