JP2001167929A - Laminated chip parts and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide laminated chip parts with high dimensional accuracy that are suitable for high productivity and can cope with bulk chip mounting, and the manufacturing method of the same. SOLUTION: In laminated chip parts equipped with a chip-shaped laminate 12 having a coil-like internal conductor 10 formed by multilayered conductive patterns and a laminated chip part having an external electrode connected electrically to the end of the coil-like internal conductor 10, external electrodes 14 are so formed as to cover the circumferences of small-sized layers 12a provided in both ends of the chip-shaped laminate 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer chip component such as a multilayer high-frequency inductor and a multilayer ferrite bead and a method of manufacturing the same, and more particularly to a multilayer chip that can be surface-mounted using a square bulk-compatible chip mounter. The present invention relates to a component and a method for manufacturing the same.

[0002]

2. Description of the Related Art A so-called bulk-compatible chip mounter in which a large number of chip parts are housed in a cartridge and these chip parts are surface-mounted one by one on a printed circuit board or the like is becoming widespread. Suitable for such a chip mounting, for example, as a laminated chip component functioning as an inductance element,
A conductor pattern is formed inside a green sheet made of magnetic ceramics or the like, and one end of this conductor pattern is connected to the end of the conductor pattern of the green sheet positioned above, and the other end of the conductor pattern of the green sheet positioned below. It is generally known that a coil-shaped internal conductor is formed by a conductor pattern by laminating a plurality of layers while electrically conducting each end, and an external electrode is electrically connected to an end of the coiled internal conductor. Have been.

As shown in FIG. 6 (a), this type of laminated chip component has a green laminated body 1 in which green sheets are laminated in multiple stages and a large number of coiled internal conductors 10 are provided inside.
6, the green laminate 11 is divided along cutting lines 30 and 31 for each chip-like laminate 12 having one coil-shaped internal conductor 10 as shown in FIG. (Barrel cut), and thereafter, binder removal (binder burnout), firing, and barrel polishing are performed. Then, as shown in FIG. 6C, the chip-shaped laminate 12 is aligned at a predetermined position of a dedicated external electrode coating machine 13, and in this state, the five surfaces (end surfaces) of the end of the chip-shaped laminate 12 are arranged. And the step of applying and drying the conductor layer on each of the four side surfaces is repeated twice for each end surface, and further baked to obtain FIG.
As shown in (d), the external electrodes 1 electrically connected to the coiled internal conductors 10 at both ends of the chip-shaped laminate 12.
4 was generally produced.

[0004]

However, in the above-described laminated chip component, the dimensional accuracy of the external electrode 14 is apt to vary, and in particular, due to the recent demand for miniaturization and high frequency, the dimensional size of the laminated chip has become mainstream. But 100
5 (1.0 × 0.5 mm) and 0603 (0.6
In the course of commercialization of (.times.0.3 mm) size, it is quite difficult to form external electrodes with high dimensional accuracy, and this has become a major bottleneck in the production of chip components.

In addition, since the electrodes are attached after the barrel cut, this electrode attaching step is a step that involves time-consuming operations such as alignment using a dedicated electrode coating machine.
There was a problem that productivity was poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a multilayer chip component having good productivity, suitable for chip mounting in bulk, and having high dimensional accuracy, and a method of manufacturing the same. I do.

[0007]

According to a first aspect of the present invention, there is provided a chip-shaped laminated body having a coil-shaped internal conductor formed of a multi-layered conductor pattern, and an electric terminal provided at an end of the coil-shaped internal conductor. Wherein the external electrodes are formed so as to cover small parts provided at both ends of the chip-shaped laminated body. It is.

According to the present invention having such a configuration, the external electrodes are prevented from protruding outward from the end side surfaces of the laminated chip component by the thickness thereof, and the dimensional accuracy is improved accordingly. be able to.

According to a second aspect of the present invention, there is provided the multilayer chip component according to the first aspect, wherein a hollow portion is provided in the external electrode located at an end face of the chip-shaped multilayer body. As a result, the loss (eddy current and stray capacitance) caused by the external electrode can be further reduced, and the influence on the product characteristics such as the stray capacitance due to the miniaturization of the chip component can be reduced. When a hollow portion is provided in the external electrode, the binder can come out of the hollow portion, so that the external electrode can be formed on the laminated sheet (green laminate) before the binder is removed. .

According to a third aspect of the present invention, there is provided a green laminate having a large number of coil-shaped internal conductors formed by a multi-layered conductor pattern therein, and the coil-form on both upper and lower surfaces of the green laminate. A grid-shaped groove is formed at a position along a cutting line that separates the internal conductors to remove the binder, and the conductor layers constituting the external electrodes are formed on both upper and lower surfaces of the unfired laminate after the removal of the binder. After the provision, the cutting and baking along the groove are performed, and the method for manufacturing a laminated chip component is provided.

Thus, by forming a conductor layer constituting an external electrode on one surface of the unfired laminated body, variation in the external electrode is suppressed, the dimensional accuracy is improved, and cutting (chipping) is performed after the conductor layer is formed. By doing, eliminate the troublesome work such as alignment using a dedicated electrode coating machine,
In addition, the conductor layer can be formed at once on the five surfaces of the chip end.

According to a fourth aspect of the present invention, there is provided a green laminate having a large number of coil-shaped internal conductors formed therein with a multi-layered conductor pattern, and a grid-like structure is formed on both upper and lower surfaces of the green laminate. The cut sheet is laminated so as to be sandwiched from above and below, and the groove is formed by the cut at a position along a cutting line that separates the coil-shaped internal conductors individually, and the binder is removed. A method for manufacturing a laminated chip component, comprising: providing a conductor layer constituting an external electrode on one surface of upper and lower surfaces of a fired laminated body; and cutting and firing along the groove.

By forming a groove at a position along a cutting line with a sheet having a notch by using a laser or the like having a high processing accuracy, the processing accuracy of the groove is increased and the chip itself can be reduced in size. I can deal with it.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a laminated chip component applied to a laminated high-frequency inductor according to an embodiment of the present invention. The laminated chip component is a square prism-shaped chip-shaped laminate having a coiled internal conductor 10 formed therein. 12 and external electrodes 14 formed at both ends of the chip-shaped laminated body 12, and the coil-shaped internal conductor 10 and the external electrodes 14 are electrically connected.

At the end of the chip-shaped laminate 12, there is provided a small-diameter portion 12a which is drawn inward by a thickness corresponding to the thickness of the external electrode 14, and the external electrode 14 covers the entire area of the small-diameter portion 12a. That is, the four side surfaces and the five end surfaces are integrally covered. As a result, the side surfaces of the chip component are flush with each other, and no protrusion by the external electrode 14 is generated here.

In this way, by preventing the external electrodes 14 from protruding outward from the end side surfaces of the laminated chip component by the thickness thereof, the dimensional accuracy of the laminated chip component can be improved.

Here, as shown in FIG. 2, the coil-shaped inner conductor 10 is formed with a conductor pattern 21 extending from the corner to the center in, for example, a U-shaped 3/4 circumference or diagonally. A plurality of green sheets 20 made of magnetic ceramics or the like are prepared, and the ends of the conductor patterns 21 of the green sheets 20 positioned above and below are wound so as to be wound in one direction (in the drawing, the right direction when viewed from above). Are alternately electrically conducted through the through holes 22 while the green sheets 20 are sequentially laminated. The coiled inner conductor 10 and the outer electrode 1
4 is electrically connected to the green sheets 20a located on both upper and lower surfaces through through holes 22a provided in the green sheets 20a.

FIG. 3 shows a laminated chip component according to another embodiment of the present invention, and FIG.
A circular hollow portion 14a is provided in the external electrode 14 located at the end face of the chip-shaped laminated body 12, and in FIG. 3B, a square hollow portion 14b is provided, and the chip-shaped laminated portion is provided through the hollow portions 14a and 14b. The end face of the body 12 is exposed to the outside. The hollow portions 14a and 14b are formed by pattern printing of a conductive paste when forming a conductive film by, for example, drilling a hole with a laser or applying a conductive paste as described below.

As described above, by preventing the end surface of the chip-shaped laminated body 12 from being covered with the external electrode 14 over the entire surface through the hollow portions 14a and 14b, the external electrode 14
(Eddy currents and stray capacitances) due to the above. Therefore, with the miniaturization of chip components, external electrodes 1
4 and the coil-shaped internal conductor 10 are prevented from affecting the characteristics of the chip component as much as possible, and the high-frequency characteristics are improved. When the hollow portions 14a and 14b are provided in the external electrode 14, the hollow portions 14a and 14b
As a result, the external electrode can be formed on the laminated sheet (green laminate) before the binder is removed.

Next, a method of manufacturing the laminated chip component shown in FIG. 1 according to the embodiment of the present invention will be described with reference to FIG. First, as shown in FIG. 4A, a green laminate 11 having a large number of coil-shaped internal conductors 10 whose external electrode formation surfaces are upper and lower surfaces is formed. The green laminated body 11 is an aggregate of the chip laminated bodies 12 that are cut into a chip laminated body 12 before firing when cut in a lattice shape along the cutting lines 30 and 31, and has a predetermined shape of a conductor pattern. And / or by laminating and crimping green sheets having formed through holes.

The upper and lower surfaces of the green laminate 11 are polished so that the end face of the coil-shaped internal conductor 10 is exposed to the surface of the green laminate 11 to ensure adhesion and conduction with the external electrodes 14. In addition, the following conductor layer 40 can be printed with a more uniform film thickness.

Next, as shown in FIG. 4B, along the cutting lines 30 and 31, the lattice-shaped grooves 32 and 33 of a predetermined depth are formed on the upper and lower surfaces of the green laminate 11 by dicing, for example. To form Then, if necessary, the square corners of the entrances of the grooves 32 and 33 are chamfered by a polishing jig or sand blast. By performing the chamfering in this way, it is possible to improve the sticking of the paste and improve the reliability at the time of applying the paste described below.

Then, the binder contained in the green laminate 11 is blown off (removal of the binder). At this time, the upper and lower surfaces of the green laminate 11 are provided with lattice-shaped grooves 32, 33, respectively.
Are formed over the entire surface thereof, so that the grooves 32,
The binder can be easily removed from the inside of the green laminated body 11 via 33.

In this state, as shown in FIG. 4C, a step of solid-coating a conductor paste such as an Ag paste or an Ag-Pd paste by metal screen printing, metal mask printing, or the like, and drying is performed on both the upper and lower surfaces. Then, the conductor layers 40 constituting the external electrodes 14 are formed on the upper and lower surfaces of the unfired laminated body 11a after the binder removal. As described above, by forming the conductor layer 40 constituting the external electrode 14 on one surface of the unfired laminated body 11a, it is possible to suppress the variation of the external electrode 14 and increase the dimensional accuracy. Here, since the unfired laminate 11a after the binder removal is very brittle in strength, it is fired at a temperature that does not completely sinter,
You may make it apply | coat the conductor paste.

Next, after drying and baking of the electrodes at a predetermined temperature, the grooves 32, 3 are formed as shown in FIG.
Along 3, the unfired laminated body 11 a is cut and divided (barrel cut) into each chip-shaped laminated body 12 before firing, and thereafter, the unfired laminated body 11 a is fired at, for example, 800 to 950 ° C. This barrel cutting may be performed after drying and before baking the electrodes, or may be performed after the electrodes and the unfired laminate 11a are integrally fired.

By performing barrel cutting after drying and before firing, abrasion of the blade can be reduced. However, if only drying is performed, the adhesive force between the chip-shaped laminate 12 and the external electrode 14 is weak, and the chip is peeled off by the impact of dicing. Might be. Further, if the electrodes are baked after the barrel cut, the number of steps is increased.
In this regard, when barrel cutting is performed after the electrode is baked, the wear of the blade is accelerated, but the reliability and productivity are high.

As described above, after the conductor layer 40 forming the external electrode 14 is formed, cutting (chipping) along the grooves 32 and 33 takes time and effort such as alignment using a dedicated electrode coating machine. The operation can be eliminated, and the conductor layer 40 can be formed at once on the five surfaces (end surface and four side surfaces) of the chip end.

FIG. 5 shows a method for manufacturing a laminated chip component according to another embodiment of the present invention. First, as shown in FIG. 5 (a), a light-transmitting smooth material such as glass is used. For example, a through hole 22 shown in FIG.
a, a sheet 51 is formed by laminating a green sheet 20a filled with a conductive paste by a printing method or the like, and this sheet 51 is subjected to, for example, laser processing to correspond to the cutting lines 30 and 31 of the green laminate 11. Cuts 52 and 53 reaching the plate body 50 are made at the positions where they will be.

Next, as shown in FIG. 5B, a sheet 51 is placed above and below the green laminate 11 with a plate 50 therebetween.
Is placed in a sandwich shape with the outside facing, and thermocompression-bonded. Thereafter, the plate body 50 is removed. Thereby, as shown in FIG. 5C, grooves 32 and 33 are formed in the upper and lower surfaces of the green laminate 11 by the cuts 52 and 53, respectively.

In this state, the binder removal,
The laminated chip component is completed by performing electrode attachment and drying, cutting (chipping) along the grooves 32 and 33, and further firing. According to this embodiment, for example, cuts 52 and 53 are made in the sheet using a laser or the like having high processing accuracy, and grooves 32 and 33 are formed at positions along cut lines 30 and 31 by these cuts 52 and 53. This makes it possible to increase the processing accuracy of the grooves 32 and 33 and to cope with downsizing of the chip itself.

In the above-described embodiment, an example in which the laminated chip component is manufactured by the green sheet method has been described. However, it is needless to say that the printing method can be similarly applied without departing from the gist of the present invention. is there.

[0032]

As described above, according to the present invention, the external electrodes are formed so as to cover the small portions provided at both ends of the chip-shaped laminated body, so that the external electrodes have a small thickness. It prevents dimensional protrusion from protruding outward from the end side surface of the laminated chip component, improves dimensional accuracy, and furthermore,
By providing a hollow portion in the external electrode located at the end face of the chip-shaped laminate, the loss (eddy current and stray capacitance) caused by the external electrode is further reduced, and product characteristics such as stray capacitance accompanying miniaturization of chip components To meet the demand for miniaturization and higher frequency. Further, according to the manufacturing method of the present invention, it is possible to manufacture a multilayer chip component which is suitable for so-called bulk-compatible chip mounting, has good frequency characteristics, and has improved dimensional accuracy of external electrodes, with increased productivity. In addition, the manufacturing cost can be reduced, and the lead time can be shortened.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a laminated chip component according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the laminated chip component shown in FIG. 1 before firing.

FIG. 3 is a perspective view showing different laminated chip components according to another embodiment of the present invention.

FIG. 4 is a diagram illustrating a method of manufacturing a laminated chip component according to an embodiment of the present invention in the order of steps.

FIG. 5 is a diagram illustrating a method of manufacturing a laminated chip component according to another embodiment of the present invention in the order of steps.

FIG. 6 is a diagram showing an example of manufacturing a conventional laminated chip component in the order of steps.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Coil-shaped inner conductor 11 Green laminated body 11a Unfired laminated body 12 Chip-shaped laminated body 12a Small diameter part 14 External electrode 14a, 14b Hollow part 20, 20a Green sheet 21 Conductor pattern 22, 22a Through hole 30, 31, Cutting line 32, 33 groove 40 conductor layer 50 plate 51 sheet 52, 53 cut

Claims (4)

[Claims] 1. A laminated chip component comprising: a chip-shaped laminated body having a coil-shaped internal conductor formed by a multi-layered conductor pattern; and an external electrode electrically connected to an end of the coil-shaped internal conductor. The multilayer chip component, wherein the external electrodes are formed so as to cover small parts provided at both ends of the chip-shaped laminate. 2. The multilayer chip component according to claim 1, wherein a hollow portion is provided in an external electrode located at an end face of the chip-shaped multilayer body. 3. A green laminate having a large number of coiled internal conductors formed by a conductor pattern laminated in multiple stages inside is formed, and the coiled internal conductors on the upper and lower surfaces of the green laminate are individually separated. After forming a lattice-like groove at a position along the cutting line and performing binder removal, a conductor layer constituting an external electrode is provided on one surface on both upper and lower surfaces of the unfired laminate after the binder removal, and then the groove is formed. A method for manufacturing a laminated chip component, comprising cutting and firing along. 4. A green laminate having a large number of coil-shaped internal conductors formed by a multi-layered conductor pattern formed inside, and a sheet having a grid-shaped cut on both upper and lower surfaces of the green laminate is moved up and down. A groove is formed by cutting at a position along a cutting line that separates the coil-shaped internal conductors by sandwiching them from each other to perform binder removal, and on the upper and lower surfaces of the unfired laminated body after the binder removal. A method for manufacturing a laminated chip component, comprising: providing a conductor layer constituting an external electrode on one surface; and performing cutting and firing along the groove.