JPH11260653A - Laminated electronic component and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated electronic component with a terminal electrode capable of increasing the mounting density on a printed board. SOLUTION: A rectangular parallelepiped laminated electronic part includes one or more inner elements in a laminated body 5. A terminal electrode 4 formed by the use of a component member in a conductive layer is provided at each edge of the laminated body 5 in the laminating direction. The edge face of the terminal electrode 4 in the laminating direction is covered with a coating layer 1B made up of an insulating body or resistance body. In this case the terminal electrode 4 and the coating layer 1B are formed by laminating the green sheets to manufacture a laminated electronic component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of laminating a conductor and an insulator (including a dielectric) or a resistor to form at least one element such as an inductor, a capacitor, a thermistor, a filter, a resonator, and a varistor. And a method of manufacturing the same.

[0002]

2. Description of the Related Art A conventional laminated electronic component has a green sheet made of a magnetic material or a non-magnetic material as shown in a laminated structure diagram of FIG. 8A and a perspective view of FIG. After forming a coil conductor 2 on 1 and providing a through-hole 3 on top of each other, cutting into individual chips and firing, the both ends of the element body 10 are dipped in silver paste or the like, and baked. Further, the terminal electrode 11 is formed by electroplating nickel, tin, or the like.

FIG. 9 shows a conventional multilayer electronic component.
As shown in the mounting diagrams (A) and (B), the printed circuit board 1
2 constitutes a circuit which is soldered to the pads 13 arranged on the surface. This positional relationship makes the area of the pad 13 larger than the terminal electrode 11 of the multilayer electronic component. As a result, when the solder 14 is melted and soldered, a solder fillet is formed up to the middle of the terminal electrode 11. ing.

[0004]

However, in order to increase the mounting density on the printed circuit board 12, it is only necessary to reduce the size of the pads 13 and the spacing between the pads 13 to reduce the spacing between components. However, if the pad 13 is simply made smaller, there is a high risk that the solder 14 melted in the reflow step will flow around the entire surface of the terminal electrode 11 and short-circuit with the terminal electrode 11 of an adjacent component.

In the structure of the conventional multilayer electronic component, when the mounting density is increased by reducing the size of the pad 13 and the interval between the pads 13 to thereby increase the mounting density, a reflow process is required. In this case, when the solder 14 is melted, a solder shift occurs, and there is a high risk that the terminal electrodes 11 of adjacent components are short-circuited.

The present invention has been made in view of the above-mentioned problems, and in order to increase the mounting density on a printed circuit board, even when the dimensions of the pads are reduced and the interval between the pads is reduced, the solder melting in the reflow process is not required. To provide a multilayer electronic component having a terminal electrode for making it difficult to short-circuit even if a terminal electrode between adjacent electronic components is short-circuited or a solder shift that causes a short-circuit, and a method of manufacturing the same. Aim.

[0007]

According to a first aspect of the present invention, there is provided a multilayer electronic component having a substantially rectangular parallelepiped shape in which at least one element is formed inside a multilayer body. Terminal electrodes are formed at both ends of the laminate in the laminating direction by the conductor layer constituting member of the laminate, and the end faces of the terminal electrodes at both ends in the laminating direction are covered with a coating layer made of an insulator or a resistor. And

According to the first aspect, since the end surface of the terminal electrode in the stacking direction is covered with the coating layer, when soldered in the reflow step, no solder fillet is formed on the end surface side of the terminal electrode, and the mounting density is reduced. Therefore, it is possible to reduce the size of the pads on the printed circuit board and to reduce the pad spacing.

[0009] The multilayer electronic component according to a second aspect is characterized in that, in the first aspect, the multilayer electronic component is formed by laminating a coil conductor and an insulator to form a coil inside.

According to a third aspect of the present invention, there is provided the multilayer electronic component according to the first aspect, wherein the multilayer electronic component includes a coil portion formed by laminating a coil conductor and an insulator, a capacitor electrode and a dielectric. A plurality of capacitor parts are stacked in cascade.

According to a fourth aspect of the present invention, there is provided the multilayer electronic component according to any one of the first to third aspects, wherein the covering layer covering the terminal electrodes at both ends of the multilayer body is formed except for substantially the center of the end face in the laminating direction. It is characterized by having.

In the fourth aspect, since the central portion of the end face of the terminal electrode is not covered with the coating layer, the probability of the terminal electrode contacting the medium when plating by barrel plating is increased, and the plating time can be shortened.

According to a fifth aspect of the present invention, there is provided the multilayer electronic component according to any one of the first to fourth aspects, wherein the covering layer covering the terminal electrode is formed to have a size smaller than that of the terminal electrode. The present invention is characterized in that a portion near the periphery is exposed.

According to the fifth aspect, since the portion covered by the coating layer is not the entire end face but the area excluding the vicinity of the peripheral portion of the terminal electrode, the soldering strength is increased while suppressing the formation of the solder fillet as compared with the conventional structure. be able to.

According to a sixth aspect of the present invention, there is provided the multilayer electronic component according to any one of the first to fourth aspects, wherein a periphery of the terminal electrodes at both ends of the multilayer body is removed from at least one of four surfaces of the multilayer body except for a corner portion. The exposed portion is exposed.

According to the sixth aspect, the formation of the solder fillet on the side surface is eliminated, and the space between the side surfaces of the electronic component can be reduced.

According to a seventh aspect of the present invention, there is provided the multilayer electronic component according to any one of the first to sixth aspects, wherein the terminal electrode is plated.

According to the seventh aspect, plating can improve solder wettability, corrosion resistance, and the like.

[0019] The method for manufacturing a multilayer electronic component according to claim 8 is as follows.
At the same time, a plurality of green sheets in which a plurality of element-constituting conductors are arranged vertically and horizontally are overlapped so that vertically adjacent conductors are connected through through-holes filled with conductors formed in each green sheet. On the upper and lower sides of the green sheet, through a green sheet having through-holes filled with conductors of individual conductor lead-out portions, a conductor green sheet serving as a terminal electrode is laminated, and then a green sheet of an insulator or a resistor is further formed. Then, these green sheets are entirely press-bonded, and then the press-bonded green sheets are cut into chips for each element and fired, so that terminal electrodes made of a conductor layer constituent member of a laminate at both ends are provided. A laminated type in which a surface excluding at least a part of a peripheral portion of the terminal electrode is covered with a coating layer made of the insulator or the resistor Wherein the obtaining a child component.

According to the eighth aspect, the terminal electrodes and the covering layers are formed efficiently by the sheet laminating method simultaneously with the laminating step.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a perspective view showing a laminated structure for one chip of an embodiment of a laminated electronic component according to the present invention, and FIG. 1B is a completed product of the electronic component. 2A is a perspective view showing a multi-cavity laminated structure according to the present embodiment, and FIG. 2B is a perspective view showing a state in which sheets are laminated.

As shown in FIG. 1A, the electronic component of this embodiment is a green sheet 1 made of a non-magnetic material having a low dielectric constant.
In addition, a plurality of coil conductors 2 made of a metal such as silver or an alloy thereof having a U-shape (3/4 turn) or an L-shape (1/2 turn) as shown are formed by printing, and these greens are formed. As shown in FIG. 1 (A), the end of the coil conductor 2 is adjacent to the green sheet 1 adjacent to the sheet 1.
Hole 3 for connection to the end of the coil conductor 2
Is provided, and the conductive paste is filled therein.

As the green sheet 1, for high frequency use, alumina, cordierite, umlite, low dielectric glass or the like having a relative dielectric constant of 30 or less is preferably used in order to reduce the distributed capacitance. In the above, a ceramic sheet made of a ceramic composition having a composition of 70% of glass made of strontium, calcium, alumina and silicon oxide and 30% of alumina (all by weight) was used. The coil conductor 2 was printed with a pattern width of 60 μm and a thickness of 10 μm.

As shown in FIGS. 1A and 1B,
The terminal electrode 4 uses a conductor green sheet 4 so as to be integrally formed as a part of the laminated sintered body. As the conductive green sheet 4, silver powder as conductive material powder was used.
6.7% by volume, 18.8% by volume of glass powder as an insulator powder (sintering aid), and the remaining 64.5% by volume as a vehicle. These powders were mixed with a synthetic resin binder,
The film was designed and designed such that the thickness after firing was 110 μm.

Preferably, 7.10% to 13.47% by volume of silver powder as the conductive material powder, 0.49% to 43.97% by volume of glass powder as the insulating powder, and 48% of the remaining vehicle. 0.83% by volume to 75.
94 vol%.

More preferably, the silver powder as the conductive material powder is 10.61% by volume to 10.10% by volume, and the glass powder as the insulator powder is 11.12% by volume to 35.10% by volume.
37% by volume, and the remainder as a vehicle from 54.02% to 68.58% by volume.

The composition of the conductive green sheet after sintering is 47.0% by volume of silver and 53.0% by volume of glass as an insulating material. Between the conductor green sheet 4 and the green sheet 1 having the coil conductor 2, at least one green sheet 1A having only the through hole 3 filled with the lead conductor of the coil is laminated.

The conductive material powder for producing the conductive green sheet 4 includes silver, a silver alloy, nickel, copper, and the like.
Gold, platinum, vanadium and the like can be used alone or in combination of two or more. In addition, as the insulating powder mixed in the conductor green sheet, in addition to the above examples, zinc, lead,
Oxides of silicon, boron, bismuth, manganese, yttrium and the like can be used alone or in combination of two or more.

Further, an insulator 1B is provided outside the terminal electrode 4.
Are laminated, the same insulator green sheet 1B as the green sheet 1 is laminated.

The green sheets 1, 1A, 1B, and 4 produced in this manner are separated in the order shown in FIG.
As shown in FIG. 2B, after the layers are pressed together, they are cut along a dotted line 15 shown in FIG.

Here, the coil conductors 2 of each layer are connected by conductors in the through holes 3, and both ends of the coil and the terminal electrodes 4 are connected by filling the through holes 3.

Thus, after cutting into individual chips,
The terminal electrode 4 is electroplated. As the electroplating, for example, copper and nickel, nickel and tin, nickel and tin-lead, nickel and gold, nickel and palladium and gold, nickel and palladium and silver, nickel and silver, or other electroplating Can be used.

In FIG. 1B, reference numeral 5 denotes a laminate obtained as described above. The laminate 5 has terminal electrodes 4, 4 formed on both ends thereof, and further has a terminal The coating layer 1B made of an insulator is formed so as to cover the terminal electrodes 4 except for the peripheral portions of the electrodes 4, 4.

FIGS. 3A and 3B are mounting diagrams of an electronic component according to the present embodiment. In FIGS.
2 is a printed circuit board, 13 is a pad, and 14 is solder. When this electronic component is soldered in a reflow process, no solder fillet is formed on the end face side of the terminal electrode 4, and the pad 13 of the printed circuit board 12 is made small to increase the mounting density. , And the interval G2 in the direction perpendicular to the laminating direction can be narrowed, and high-density mounting of the laminated electronic component including the laminated body 5 becomes possible.

According to this structure, the terminal electrodes 4, 4 are formed at both ends of the laminate 5, and the distance between the terminal electrodes 4, 4 is determined with high precision by the width between the opposing terminal electrodes 4, 4. Therefore, as in the case of the conventional dip, there is no variation in the formation range of the terminal electrode due to the draw of the conductive paste or the like, so that the variation in characteristics is reduced and the yield is improved.

Further, the plating layer on the terminal electrode 4 is as thin as about 5 μm, there is no projection as in the case of the conventional dip method, the accuracy of the outer dimensions is improved, and the automatic mounting on a printed circuit board or the like is performed. In the mounting machine, the mounting can be performed in an orderly arrangement, the mounting in an inclined posture can be prevented, and the displacement can be prevented.

In the present embodiment, FIG.
As shown in (B), the cross section perpendicular to the direction of the magnetic flux generated by the coil 2 of the laminate 5 is square, so that any one of the side surfaces of the laminate is mounted toward the printed circuit board 12. Even so, the distance between the center of the magnetic flux and the printed circuit board becomes substantially constant, and the variation in characteristics due to the difference in the mounting surface is reduced.

Further, in the present embodiment, FIG.
(A), as shown in FIG. 3 (B), a green sheet 1A which is a winding start portion and a winding end portion of the coil in the laminate.
At the center of the rectangular cross section,
Even if the mounting surface of the laminate is changed, the reactance does not fluctuate much and the characteristics do not fluctuate much. Therefore, it is not necessary to worry about the mounting surface, and mounting becomes easy.

FIG. 4A is a laminated structure diagram showing another embodiment of the present invention, and FIG. 4B is a perspective view showing the appearance thereof. By removing the portion a, the periphery of the terminal electrode 4 is
It is exposed on the surface of the laminate 5 excluding the corners. FIG. 4C is a perspective view of a conductor green sheet for explaining a method for removing such a terminal electrode 4 at a corner a of the laminated body 5. A hole 7 is punched in a location corresponding to the above, and this is laminated with another green sheet as described above,
By cutting along the line 5, it is possible to realize a structure in which the terminal electrode 4 is missing at the corner portion a.

With such a structure, as shown in FIG. 3C, the formation of the solder fillet on the side surface of the electronic component is eliminated, and the gap G2 between the pads 13, 13 is further reduced.
Can be reduced, and further high-density mounting of electronic components becomes possible.

In the structure in which the terminal electrode 4 is exposed on the surface excluding the corners of the electronic component as described above, the terminal electrode 4 is not exposed on the entire four surfaces, but as shown in FIG. It may be realized as a structure in which the terminal electrode 4 is exposed on one to three surfaces of the electronic component.

FIG. 5A is a laminated structure diagram showing another embodiment of the present invention, and FIG. 5B is a perspective view showing the appearance thereof. Is formed except for a substantially central portion of the end face in the laminating direction (6 indicates a cutout portion of the insulator).

According to this structure, since the center of the end surface of the terminal electrode 4 is exposed, barrel plating (this barrel plating is a method in which a chip is put in a rotary cylinder together with sand-like metal particles called media). Immerse it in the plating solution,
This is a method in which plating is performed using the rotating cylinder as a minor electrode while rotating the rotating cylinder.) When plating is performed, the probability that the terminal electrode contacts the medium increases, and the plating time can be reduced.

FIG. 6A is a laminated structure diagram showing another embodiment of the present invention, and FIG. 6B is a perspective view showing its appearance. In this embodiment, the terminal electrode is covered. The coating layer 1C made of an insulator is formed to be smaller in size than the terminal electrode 4, thereby exposing the vicinity of the outer peripheral portion of the end face of the terminal electrode 4.

In the embodiment shown in FIG. 6, the terminal electrode 4
In addition to exposing not only the peripheral part but also the peripheral part on the end face, the soldering strength can be increased as compared with the embodiment of FIGS.

The formation of the coating layer 1C narrower than the terminal electrode 4 is performed by applying an insulating green sheet to a film before the green sheet laminating step and scanning the film vertically and horizontally. This can be done by skipping the green sheet to leave insulating portions such as a plurality of square floating islands, and peeling the film after the laminating step.

As another method, the chip is cut after the laminating step, and before firing, a green barrel (a step in which a small ball called a chip and a medium before firing and water are placed in a container and turned) is used to turn the corner of the chip. By removing the edge of the coating layer 1C when the corner of the chip is removed, the time of the green barrel process is adjusted.
It is also possible to make the shape almost the same as when the small coating layer 1C is laminated from the beginning.

FIGS. 7A to 7C show the terminal electrode 4 and its covering layer 1 at both ends of a laminated electronic component having inductors L or L1 and L2 and capacitors C1 to C3 formed therein.
This adopts a coating structure of B (or 1C).

FIG. 7A shows an example in which one electrode of C1 is connected to the terminal electrode 4 by the conductor in the through hole 3. In the example of FIG. 7B, the capacitor C2 is formed by interposing a dielectric 8 between the intermediate terminal electrode 4A whose periphery is exposed to the outer surface and the terminal electrode 4 at the end. FIG.
In the example of (C), a capacitor C3 is formed between the internal electrode 9 and the intermediate terminal electrode 4B whose periphery is exposed on the outer surface, and one of the electrodes and one inductor L1 and the other inductor L2 are connected. These are connected by conductors in the through holes 3. These are used as filters and resonators. As the combination structure of the inductor L and the capacitors C1 to C3, a configuration in which a plurality of capacitors are used can be adopted.

In addition to the above example, the present invention can be applied to a case where electronic components such as a capacitor, a thermistor, and a varistor are formed. In these cases, a dielectric (in the case of a capacitor), a resistor having a negative or positive resistance-temperature characteristic (in the case of a thermistor), and a non-linear resistance-voltage characteristic are provided between the pair of terminal electrodes 4 and 4. A resistor (in the case of a varistor) is provided in a laminated structure, and the terminal electrodes 4 at both ends thereof are covered with an insulator (including a dielectric) or a resistor in the structure shown in each of the above embodiments. In this case, as a material for covering the terminal electrode 4, as in the case of the inductor or the like,
The same insulator (magnetic material,
The use of a non-magnetic or dielectric material) or a resistor is advantageous in terms of material management and simplification of the manufacturing process.

According to the present invention, a plurality of coils may be juxtaposed in the laminated body, and both ends of each coil may be connected to terminal electrodes formed on both end surfaces of the laminated body. In this case as well, the effect of reducing the dimensional accuracy and the variation in characteristics can be obtained, and the mounting space can be reduced as compared with a case where the individual inductors are mounted separately. Furthermore, it can also be realized with a structure in which a plurality of inductors and capacitors are built.

[0052]

According to the first to third aspects, since the end faces in the stacking direction of the terminal electrodes at both ends in the stacking direction of the stacked body are covered with the insulator or the resistor, the terminals are not soldered in the reflow process. No solder fillet is formed on the end face side of the electrode, the pad of the printed circuit board can be made small, and the pad interval can be narrowed, so that high-density mounting of electronic components becomes possible. According to the first to seventh aspects, the following effects can be further obtained.

According to the fourth aspect, since the coating layer covering the terminal electrodes at both ends of the laminate is formed except for the substantially central portion of the end face in the laminating direction, the terminal electrode is formed when plating by barrel plating. Increases the probability of contact with the media and shortens the plating time.

According to the fifth aspect, the coating layer covering the terminal electrode is formed to be smaller in size than the terminal electrode and the peripheral portion of the end face in the stacking direction of the terminal electrode is exposed. Further, the soldering strength can be increased.

According to the sixth aspect, the periphery of the terminal electrodes at both ends of the laminate is exposed to a portion excluding a corner portion on at least one of the four surfaces of the laminate. Eliminates the formation of solder fillets,
The distance between the side surfaces of the electronic component can be reduced.

According to the seventh aspect, since the terminal electrode is plated, it is possible to improve solder wettability, corrosion resistance and the like.

According to the eighth aspect, in order to obtain the laminated electronic component by laminating the green sheets, the terminal electrode and the coating layer outside the terminal electrode are simultaneously and efficiently formed.

[Brief description of the drawings]

FIG. 1A is a perspective view showing a laminated structure for one chip according to an embodiment of the present invention, and FIG. 1B is a perspective view of a completed product of the electronic component.

FIGS. 2A and 2B are perspective views each showing a multi-cavity laminated structure in a manufacturing process of the present embodiment.

3A and 3B are a side view and a front view, respectively, showing a mounting structure according to the present embodiment, and FIG. 3C is a front view showing a mounting structure according to another embodiment of the present invention.

FIG. 4A is a perspective view showing a laminated structure for one chip according to another embodiment of the present invention, FIG. 4B is a perspective view of a completed electronic component, and FIG. FIG. 9D is a perspective view of a conductor green sheet for explaining a method for causing a chip to be cut off at a corner portion of a laminate as described above, and FIG. 10D is a perspective view showing a modification of FIG.

FIG. 5A is a perspective view showing a stacked structure of one chip according to still another embodiment of the present invention, and FIG. 5B is a perspective view of a completed electronic component.

FIG. 6A is a perspective view showing a laminated structure for one chip according to still another embodiment of the present invention, and FIG. 6B is a perspective view of a completed electronic component.

7 (A) to 7 (C) are cross-sectional views showing other embodiments of the present invention.

FIG. 8A is a perspective view showing a laminated structure for one chip of a conventional laminated electronic component, and FIG. 8B is a perspective view of a completed product of the electronic component.

FIGS. 9A and 9B are a side view and a front view, respectively, showing a mounting structure of a conventional electronic component.

[Explanation of symbols]

1, 1A: insulator green sheet, 1B, 1C: insulator green sheet (coating layer), 2: coil conductor, 3: through hole, 4: conductor green sheet (terminal electrode), 4
A, 4B: intermediate terminal electrode, 5: laminated body, 6: lacking part of insulator, 7: hole, 8: dielectric, 9: internal electrode, 12: printed circuit board, 13: pad, 14: solder, L , L1, L
2: inductor, C1 to C3: capacitor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // H01C 7/02 H01G 4/40 321A (72) Inventor Takeo Ogimoto 1-13-1 Nihombashi, Chuo-ku, Tokyo T Inside DK Corporation (72) Inventor Makoto Kobayashi 1-13-1 Nihonbashi, Chuo-ku, Tokyo T-DK Corporation (72) Noriyuki Saito 1-13-1 Nihonbashi, Chuo-ku, Tokyo No. Inside TDK Corporation

Claims (8)

[Claims] 1. A laminated electronic component having a substantially rectangular parallelepiped shape in which one or more elements are formed inside a laminated body, wherein terminal electrodes are formed on both ends of the laminated body in the laminating direction by a conductor layer constituting member of the laminated body. A laminated electronic component, comprising: forming an end face of the terminal electrode at both ends in a laminating direction with a covering layer made of an insulator or a resistor. 2. The multilayer electronic component according to claim 1, wherein the multilayer electronic component is formed by laminating a coil conductor and an insulator to form a coil inside. 3. The laminated electronic component according to claim 1, wherein the laminated electronic component comprises: a coil portion formed by laminating a coil conductor and an insulator;
A multilayer electronic component, comprising: a capacitor electrode and one or a plurality of capacitor portions made of a dielectric material, which are cascaded. 4. The laminate according to claim 1, wherein the covering layers covering the terminal electrodes at both ends of the laminate are formed except for a substantially central portion of the end face in the lamination direction. Electronic components. 5. The terminal device according to claim 1, wherein the coating layer covering the terminal electrode is formed to have a size smaller than that of the terminal electrode, thereby exposing a portion in the vicinity of an end surface of the terminal electrode in the stacking direction. A multilayer electronic component characterized by the following. 6. The laminate according to claim 1, wherein the periphery of the terminal electrodes at both ends of the laminate is exposed to at least one of the four surfaces of the laminate except for the corners. Characterized multilayer electronic components. 7. The multilayer electronic component according to claim 1, wherein the terminal electrode is plated. 8. A plurality of green sheets in which a plurality of element-constituting conductors are arranged vertically and horizontally so that conductors vertically adjacent to each other are connected via conductor filled through holes formed in each green sheet. At the same time, a conductor green sheet serving as a terminal electrode is stacked on the upper and lower sides of the plurality of green sheets via green sheets each having a through hole filled with a conductor of a lead portion of each conductor, and then an insulator or The green sheets of the resistor are stacked, and the whole of the green sheets is pressed, and then the pressed green sheet is cut into chips for each element and fired, so that the conductor layer constituting members of the laminate are provided at both ends. Having a terminal electrode made of, and a surface excluding at least a part of the peripheral portion of the terminal electrode is covered by a coating layer made of the insulator or the resistor. Method of manufacturing a multilayer electronic component, characterized in that to obtain the multilayer electronic component having a crack was terminal electrodes.