JP2976088B2 - Surface mounting component having side electrode and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount component having side electrodes and a method of manufacturing the same. More specifically, the present invention relates to a surface mounting component formed by dividing a ceramic substrate and a method of manufacturing the same, and more particularly, to a surface mounting component having a multi-terminal side electrode formed on a side surface of the component and a method of manufacturing the same.

[0002]

2. Description of the Related Art Surface mount devices (SMDs) typified by chip resistors and chip capacitors are:
It is indispensable for miniaturization and high performance of electronic devices, and higher densification and higher functions are further required. In response to such demands, recently, components with side electrodes having electrodes on the component side surface have been manufactured.

At present, as shown in FIG. 5, a side electrode is usually formed by vertically dividing a through hole 20 provided in a substrate 1 together with the substrate, exposing an inner surface 22 of the through hole, and using this as an electrode. That is, as shown in the cross-sectional view of FIG. 6, in the ceramic substrate, in order to electrically connect both surfaces of the substrate or to electrically connect a component mounted on the substrate to the substrate, the inner surface of the through hole is formed. The conductive layer 24 is formed mainly by printing a conductive paste. In the conventional method, the conductive layer 24 on the inner surface is exposed by dividing the through hole by using this, and this is converted to an electrode. Separately from this method, the substrate side surface is immersed in a liquid containing a conductive material (FIGS. 7A to 7F), or a paste-like conductive material is applied to the substrate side surface using a brush or a roller. Alternatively, a method of forming an electrode by transfer (see FIG.
(a) to (c) and (g) to (h)) are also known.

[0004] Among them, the through-hole division method is relatively simple in process, but has a problem in securing electrode pitch and reliability. In other words, printing on the inside of the through hole
It is performed by sucking the conductor paste from one end of the hole to the other end. At this time, if the suction is increased, the problem that the conductor layer becomes discontinuous is likely to occur, and if the suction is weakened, the hole is easily clogged. . In the drilling technique, a small diameter through hole can be formed. However, as the hole diameter is smaller, the above-mentioned hole clogging is more likely to occur, the conductor paste is less likely to be printed on the inner surface of the through hole, and product reliability is reduced. For this reason, at present, the diameter is usually about 0.4 mmφ at the minimum, and the width from the hole edge of the land 28 (FIG.
T. Usually, about 0.2 mm) and land spacing (s in FIG. 6).
Considering the minimum of about 0.2 mm, the electrode pitch (p in FIG. 6) is at least about 0.8 mm.
In the immersion method, the conductor is coated on the entire side surface of the component, so that only one electrode can be formed per side surface. The conductive paste printing method theoretically has no restrictions such as the through-hole division method and the immersion method, and it is possible to make the electrode pitch extremely small. It is necessary to perform high-accuracy alignment between the printing original plate and the printing surface in a narrow range, which complicates the manufacturing process and the device configuration. In addition, unevenness is unavoidable on the divided surface of the ceramic substrate, and there is a possibility that insulation failure between electrodes due to printing unevenness or the like may occur.

[0005]

An object of the present invention is to solve the above-mentioned conventional problems in a surface mounting component, and to provide a surface mounting component having a highly reliable and multi-terminal side electrode formed at high precision and at a fine pitch. And a method for manufacturing the same.

[0006]

According to the present invention, a via formed by filling a conductive paste into a via hole is exposed and used as an electrode, instead of the conventional method using a conductive layer on the inner surface of a through hole. In other words, the present inventors have found that a via, which was not conventionally considered to be used as a side electrode, can be used very effectively as a side electrode if divided along its axis. Since the plurality of side electrodes thus formed can be formed at a fine pitch, it has been found that all conventional problems can be solved.

According to the present invention, there is provided a surface mounting component having the following configuration and a method of manufacturing the same. (1) The conductive paste is filled in the recess provided on the side of the component.
A component for surface mounting, characterized by having an electrode which is baked. (2) The surface mounting component according to the above item 1, wherein the electrode is formed by vertically dividing a via hole filled with a conductive paste to expose a conductor. (3) The component for surface mounting according to 1 or 2, which has a multi-terminal electrode in which two or more electrodes are formed on one side surface. (4) Any one of the above items 1 to 3 having a multilayer substrate structure
Surface mount parts. (5) A via is formed by filling a via hole provided in a ceramic substrate with a conductive paste, and the substrate is divided along the axis of the via after firing, or the substrate is divided along the axis of the via and then fired. A method of manufacturing a surface mounting component having a side electrode, wherein the fired conductor is exposed on the side surface of the component to form an electrode. (6) The method for manufacturing a surface mounting component according to the above ( 5) , wherein the conductive paste and the substrate are simultaneously fired after the via is formed by filling the via holes of the unfired ceramic substrate with the conductive paste. (7) Before or after forming vias, laminate substrates
After that, the conductor paste and the substrate are baked simultaneously.
Of surface mount components having a multilayer board structure as described in
Law.

[0008]

FIG. 1 is a schematic perspective view of a component for surface mounting according to the present invention. Illustrated surface mounting component 1 of the present invention
0 is a part obtained by dividing the multilayer ceramic substrate,
A plurality of side electrodes 12 are formed on both sides by firing the conductive paste. As shown schematically in FIG. 2, the surface mounting component is provided with a via hole 8 in a base plate 1 for manufacturing a ceramic substrate made of a green sheet or the like, and filled with a conductive paste 9 (step (a) in the figure). After the via is formed, the original plate is cut in the form of vertically dividing the via along the axial direction (stages (c) to (e) in the drawing), and firing is performed to obtain the side surface of the individual side 6. The electrode 12 is formed on the substrate.

An original plate for manufacturing a ceramic substrate is typically a so-called green sheet. A known green sheet can be used as long as it is a ceramic material. As the material, for example, oxide or crystallized glass such as alumina or dolomite, borosilicate glass, glass such as lead borosilicate glass or magnesium aluminosilicate glass or alumina or quartz to these glasses, cristobalite, beryllia, zirconia, Based on fillers such as zircon, forsterite, magnesia and steatite. In addition to the low-temperature sintered substrate materials described above, high-temperature sintered substrate materials such as alumina and mullite may be used. In the following description, a single-layer substrate composed mainly of one green sheet will be mainly described, but the same applies to a multi-layer substrate except that a green sheet laminating step is added.

[0010] The green sheet usually has a plurality of regions (regions divided by dotted dividing lines in FIG. 2) corresponding to the finally obtained parts. The size of the area depends on the size of the target part, but usually the length of one side is 0.5 to
It is about 10 mm. Via holes for forming electrodes are formed in the green sheet. Here, the via hole means a hole which is not plated on the inner wall formed in the thickness direction of the substrate, and includes a through hole and a non-through hole.

The via hole diameter is preferably 0.05 to 1.0 mm. If the hole diameter is less than 0.05 mm, the width of the longitudinal section is too small, so that it is inconvenient to use as a connection terminal. Also
If it exceeds 1.0 mm, it becomes too large as a via hole, which is an obstacle to miniaturization of components. Generally 0.1 ~
0.4 mm is more preferred. The cross-sectional shape of the via hole is not limited. A conventional method can be used for forming the via hole. Other via holes and through holes are formed in the green sheet as needed.
In the case of a multilayer substrate, the substrates are stacked before and after this.

In the present invention, a via hole for an electrode is provided on the dividing line. As shown in FIGS.
Is desirably provided so that the center thereof rests on the dividing line 11. The number of electrode via holes is determined by the required number of component side electrodes formed thereby. In the illustrated example, two via holes are formed on each side surface of the component on both sides. Via holes may be provided on four sides so as to surround each region as shown in FIG. 3, or the number of electrodes on each side may be asymmetric as shown in FIG.

After the via holes are provided on the green sheet, the electrode via holes are filled with a conventional conductive paste. The conductor paste that can be used here may be any paste that has a shrinkage ratio at the time of firing close to that of the green sheet and has good solderability, and a Cu-based or Ag-based paste can be used. That is, a paste obtained by adding oxide particles such as glass particles as necessary to a conductive powder having an average particle diameter of 2 to 10 μm containing the above-described metal as a main component and using a binder can be used. Preferably, a paste whose shrinkage during firing is close to the shrinkage of the substrate and less than 10 to 20% is used. Note that a low-shrinkage conductor paste to which ruthenium oxide or rhodium powder is added may be used. Examples of such a low-shrinkage conductor paste include conductor pastes described in Japanese Patent Application Nos. 5-167439 and 6-51306.

Known binders can be used for the conductor paste. Examples of the binder include ethyl cellulose, acrylic resin and the like. The amount of the binder used may be an amount capable of uniformly dispersing and holding the powder and maintaining a paste state.
It is used in a ratio of about 2 to 10 parts by weight with respect to 00 parts by weight. The binder is used together with a solvent such as acetate or terpineol. 10 to 3 with respect to 100 parts by weight of the solvent
About 0 parts by weight of binder is preferred. If the ratio is outside the above range, the fluidity becomes too low or too high, so that it is difficult to fill the via holes. In addition, for the purpose of imparting appropriate fluidity to the conductor paste, other additives such as fatty acid esters can be used in the same manner as in known conductor pastes. The method of filling the via is not particularly limited, but, for example, a method of covering one end of the via hole with an air-permeable sheet, suctioning and injecting the conductive paste from the other end to fill, or press-fitting the conductive paste into the hole. Any of the above methods can be used.

After filling the via hole with the conductive paste,
The circuit is printed according to a known method (FIG. 2 (b)). In one embodiment of the present invention, after forming the circuit and before firing,
Is divided into a plurality of small pieces corresponding to the finally obtained parts. In the division, first, a division groove 3 is formed by punching a die or the like (FIG. 2C). The depth of the groove is about 10 to 60% of the thickness of the original sheet (about 0.5 to 1.0 mm thick), and the width is about 0.1 to 0.3 mm. Next, the small pieces are divided along the dividing grooves and fired (FIG. 2 (e)).
The division may be performed after the firing, but the firing after the division is appropriate for the purpose of avoiding disturbance of the side surface of the individual side due to the division.

The firing may be performed in the same manner as in the prior art. That is, when using the low-temperature sintered substrate material as described above,
After drying, heating is performed at 800 to 1050 ° C. for about 30 minutes to 3 hours in an inert atmosphere when the conductive paste is Cu-based, or in the air for Ag or another material that is not easily oxidized.

[0017]

EXAMPLES Examples 1 to 4 Using green sheets (thickness 0.14 mm, length 129 mm, width 129 mm) made of 50% alumina-50% glass, a via hole was provided at a predetermined position on each sheet.
Each via hole was filled with a conductive paste composed of Ag 90% and Pd 10% by weight. After printing the circuit on the green sheet to be the inner layer, 10 sheets of the above sheets are laminated so that the via positions coincide, and the laminated sheet is cut in the axial direction of the vias along the dividing lines as shown in FIG. And divided into individual pieces. The length of each piece after firing is 3.2 mm. After the division, baking was performed at 880 ° C. for 60 minutes in the atmosphere to produce a surface mounting component. Production was attempted with via diameters of 0.1 mm (Example 1), 0.2 mm (Example 2), 0.3 mm (Example 3) and 0.8 mm (Example 4), and after dividing and firing according to the above procedure. Microscopic observation of the shape of the conductor for the side electrode revealed no cracks or voids in the conductor in the via. The electrode via pitch is minimum
0.3 mm was realized.

Comparative Example 1 A through hole having a diameter of 0.2 mm was used in place of the via hole, and the inner surface of each through hole had a weight ratio of 90% Ag and Pd.
A conductive paste composed of 10% was suction-printed, baked and divided in the same manner as in Example 1, and an attempt was made to manufacture a surface mounting component having side electrodes. When the conductor for the side electrode was observed in the same manner as in Example 1, clogging of the conductor was found in about 60% of the through-holes, and the conduction due to the through-holes was incomplete, so that the individual sides after division were substantially separated. 10 that can withstand use
It was only%.

[0019]

Since the surface mounting component of the present invention has a plurality of side electrodes, high-density mounting using these as a multi-terminal electrode is possible. Further, since the side electrodes are formed at the positions of the via holes, a plurality of side electrodes can be easily formed at accurate positions without using a special device for forming the electrodes. In addition, since the side surface of the component is substantially flat, the contact with the terminal receiving portion is stabilized. Accordingly, a highly reliable component having stable electric characteristics can be manufactured. Further, since the amount of conductor of the electrode is large, the resistance of the electrode portion does not become excessive, and the diameter of the via hole can be reduced to achieve fine electrode patterning. From the viewpoint of manufacturing, the method of the present invention can divide or cut out the substrate and form the electrodes at the same time, which is particularly useful in a method of manufacturing a component by dividing the ceramic base plate. Further, in the multi-layer substrate, since the via hole penetrates the circuit in the inner layer, the connection between the inner layer circuit and the electrode is reliably realized. Further, the filling of the via hole can be easily performed without special control at the time of injecting the conductive paste, unlike the conventional inner surface printing of the through hole, so that the manufacturing is simple and advantageous.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a surface mounting component according to the present invention.

FIG. 2 is a process chart showing one embodiment of the production method of the present invention.

FIG. 3 is a partial plan view showing a relationship between a via hole forming position and a dividing line of a component forming region according to the present invention.

FIG. 4 is a partial plan view showing a relationship between a via hole forming position different from that of FIG. 3 according to the present invention and a dividing line of a component forming region.

FIG. 5 is a process chart showing a conventional method for manufacturing a surface mounting component.

FIG. 6 is a cross-sectional view of a conventional through hole in which an inner surface is plated.

FIG. 7 is a process chart showing a conventional method for manufacturing a surface mounting component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Original plate for ceramic substrate production (green sheet) 2 ... Circuit 3 ... Division groove 4 ... Primarily divided substrate 5 ... Conductive substance 6 ... Subdivided substrate 7 ... Side electrode (conventional method) 8 ... Electrode formation Via hole 9 ... Conductive paste 10 ... Parts for surface mounting (the present invention) 11 ... Parting line 12 ... Side electrode (the present invention) 20 ... Through hole 22 ... Through hole inner surface 24 ... Through hole inner surface conductor coating layer 26 ... Corner of through hole 28 ... Land

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01G 4/252 H05K 1/11 H05K 3/40

Claims (7)

(57) [Claims] 1. A conductive paste is applied to a concave portion provided on a side surface of a component.
A component for surface mounting, comprising an electrode filled and baked. 2. The surface mounting component according to claim 1, wherein the electrode is formed by vertically dividing a via hole filled with a conductive paste to expose a conductor. 3. The surface mounting component according to claim 1, further comprising a multi-terminal electrode having two or more electrodes formed on one side surface. 4. The method according to claim 1, which has a multilayer substrate structure.
Any surface mount components. 5. A via is formed by filling a via hole provided in a ceramic substrate with a conductive paste, and after firing, the substrate is divided along the axis of the via, or the substrate is divided along the axis of the via. A method of manufacturing a surface mounting component having a side electrode, wherein the fired conductor is exposed later to expose the fired conductor on the side surface of the component to form an electrode. 6. The method according to claim 5 , wherein the conductive paste and the substrate are simultaneously fired after filling the via holes of the unfired ceramic substrate with the conductive paste to form vias. 7. Laminating a substrate before or after forming a via
Then, the conductor paste and the substrate are fired simultaneously.
A surface mounting part having a multilayer substrate structure according to claim 6.
Product manufacturing method.