JPH07297080A - Surface mount parts with side surface electrode and its manufacturing method - Google Patents

Abstract

PURPOSE:To obtain a reliable side surface electrode of a plurality of terminals which are formed accurately and with a fine pitch by providing an electrode where a conductor paste is baked to a recessed part provided on the side surface of parts. CONSTITUTION:In a surface mount parts 10, a lamination ceramic substrate is divided and a plurality of side surface electrodes 12 where a conductor paste is formed are formed on both sides. To manufacture the surface mount parts 10, a via hole 8 is provided at a negative for manufacturing ceramic substrate consisting of a green sheet, a conductor paste 9 is filled into the via hole for forming a via, and then the negative is split and baked so that the via is split vertically along the axial direction, thus forming the electrodes 12 on the side surface of an individual side 6, thus easily forming a plurality of side surface electrodes at an accurate position and stabilizing the contact with a terminal acceptance part since the side surface of parts is nearly flat and further manufacturing reliable parts with stable electrical characteristics.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Surface mount devices (SMD: Surface Mount Device) represented by chip resistors and chip capacitors are
It is indispensable for downsizing and high functionality of electronic equipment, and higher density and higher functionality are required more. In response to such a demand, recently, a component with a side electrode having an electrode on the side face of the component has been manufactured.

At present, as shown in FIG. 5, the side surface electrode is normally used by dividing the through hole 20 provided in the substrate 1 along with the substrate vertically to expose the inner surface 22 of the through hole and using it 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 and to electrically connect the components mounted on the substrate to the substrate, the inner surface of the through hole is The conductive layer 24 is formed mainly by printing a conductive paste. In the conventional method, by utilizing this, the through hole is divided to expose the conductive layer 24 on the inner surface, and this is used as an electrode. In addition to this method, the side surface of the substrate may be dipped in a liquid containing a conductive material (Figs. 7 (a) to (f)), or the conductive material in paste form may be applied to the side surface of the substrate using a brush or a roller. Alternatively, a method of transferring to form electrodes (see the same figure)
(a) to (c) and (g) to (h)) are also known.

Of these methods, the through-hole division method is relatively simple in terms of process, but there is a problem in securing the electrode pitch and reliability. That is, printing on the inner surface of the through hole is
It is performed by sucking the conductor paste from one end to the other end of the hole. At this time, if suction is increased, problems such as discontinuity of the conductor layer are likely to occur, and if suction is weakened, hole clogging is likely to occur. . Although a small-diameter through hole can be formed by the drilling technique, the smaller the hole diameter, the more easily the above-mentioned hole clogging occurs, and the conductor paste is less likely to be printed on the inner surface of the through hole, which lowers the reliability of the product. For this reason, at present, the minimum diameter is usually 0.4 mmφ, and the width of the land 28 from the hole edge (see FIG.
T. Normally, about 0.2 mm) and land spacing (s in Fig. 6).
Usually, if the minimum is about 0.2 mm, the electrode pitch (p in FIG. 6) will be about 0.8 mm at the minimum.
Further, in the dipping method, the entire side surface of the component is covered with the conductor, so that only one electrode can be formed per side surface. The conductive paste printing method is theoretically not limited by the through-hole division method and the dipping method and can also make the electrode pitch extremely small. It is necessary to align the printing original plate and the surface to be printed with high accuracy within a narrow range, which complicates the manufacturing process and the apparatus configuration. In addition, unevenness is unavoidable on the divided surface of the ceramic substrate, which may cause insulation failure between electrodes due to uneven printing.

[0005]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems in the conventional surface mounting component, and has a surface mounting component having highly accurate and highly reliable side electrodes of a plurality of terminals formed at a fine pitch. And a method of manufacturing the same.

[0006]

According to the present invention, instead of the conventional method of using a conductor layer on the inner surface of a through hole, a via formed by filling a via paste with a conductor paste is exposed and used as an electrode. That is, the inventors of the present invention can extremely usefully use as a side surface electrode by dividing a via, which has not been conventionally considered to be used as a side surface electrode, along the axis thereof, and in particular, accurately positions the substrate simultaneously with the division. It was found that the conventional problems can be solved because the plurality of side surface electrodes thus formed can be formed with a fine pitch.

According to the present invention, there are provided a surface mounting component having the following structure and a method for manufacturing the same. (1) A surface mounting component having an electrode formed by baking a conductor paste in a recess provided on a side surface of the component. (2) The electrode is formed by vertically dividing a via hole filled with a conductor paste to expose the conductor.
Surface mount component in (1). (3) The surface mounting component as described in (1) or (2) above, which has a multi-terminal electrode having two or more electrodes formed on one side surface. (4) Filling a via paste formed in a ceramic substrate with a conductive paste to form a via, and dividing the substrate along the axis of the via after firing, or dividing the substrate along the axis of the via and firing. By doing so, the baked conductor is exposed on the side surface of the component to be used as an electrode, and a method for manufacturing a surface mounting component having a side electrode. (5) The method for manufacturing a surface mounting component according to the above (4), wherein after filling the via holes of the unfired ceramic substrate with the conductor paste to form the vias, the conductor paste and the substrate are fired at the same time.

[0008]

DETAILED DESCRIPTION FIG. 1 shows a schematic perspective view of a surface mounting component according to the present invention. Illustrated surface mounting component 1 of the present invention
0 is a component formed by dividing the laminated ceramic substrate,
A plurality of side surface electrodes 12 formed by firing the conductor paste are formed on both sides thereof. As shown in FIG. 2, the surface mounting component is provided with a via hole 8 in an original plate 1 for manufacturing a ceramic substrate made of a green sheet or the like and filled with a conductor paste 9 (at a step (a) in the figure). After forming the via, the original plate is cut by vertically splitting the via along the axial direction (steps (c) to (e) in the figure), and the side surface of the individual side 6 is baked. It is manufactured by forming the electrode 12 on.

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

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 normally the length of one side is 0.5 ~.
It is about 10 mm. Via holes for forming electrodes are formed in the green sheet. The via hole mentioned here is a hole in which the inner wall formed in the thickness direction of the substrate is not plated, 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 vertical cross section is too small, which 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 the miniaturization of parts. Generally 0.1 ~
0.4 mm is more preferable. The cross-sectional shape of the via hole is not limited. A conventional method can be used to form the via hole. Note that other via holes and through holes are formed in the green sheet as needed.
In the case of a multilayer substrate, the substrates are laminated before and after this.

In the present invention, a via hole for an electrode is provided on the above-mentioned segment line. As shown in FIGS. 2 to 4, the via hole 8
Is preferably provided so that the center thereof is placed on the demarcation line 11. The number of electrode via holes is determined by the required number of component side surface electrodes formed thereby. In the illustrated example, two via holes are formed on each side surface at both ends of the component. The via hole 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 providing a via hole on the green sheet, a conventional conductive paste is filled in the via hole for an electrode. The conductor paste that can be used here may be one that has a shrinkage factor at firing close to that of a green sheet and has good solderability, and a Cu-based or Ag-based paste can be used. That is, it is possible to use a conductive powder containing the above metal as a main component and having an average particle diameter of 2 to 10 μm, if necessary, by adding oxide particles such as glass particles and forming a paste with a binder. It is preferable to use a paste having a shrinkage factor during firing which is close to that of the substrate and less than 10 to 20%. 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 No. 5-167439 and Japanese Patent Application No. 6-51306.

Known binders can be used for the conductor paste. Examples of the binder include ethyl cellulose, acrylic resin and the like. The binder may be used in such an amount that the powder can be uniformly dispersed and held and the paste state can be maintained. Specifically, the mixed powder 1
It is used in a proportion 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. 10-3 for 100 parts by weight of solvent
About 0 parts by weight of binder is preferred. If it is out of the above range, the fluidity becomes too small or too large, so that it becomes difficult to fill the via hole. Other additives such as fatty acid esters can be used in the same manner as in known conductor pastes for the purpose of imparting appropriate fluidity to the conductor paste. The method of filling the via is not particularly limited.For example, one end of the via hole may be covered with an air permeable sheet and then sucked, and the conductor paste may be injected from the other end to fill the via hole or the conductor paste may be pressed into the hole. Any of the filling methods can be used.

After filling the via holes with the conductive paste,
The circuit is printed according to a known method (FIG. 2 (b)). According to one embodiment of the present invention, the above-mentioned fraction line 11 is formed after the circuit is formed and before firing.
The green sheet is divided along with to make a plurality of small pieces corresponding to the finally obtained parts. For the division, first, the division groove 3 is formed by die punching or the like (FIG. 2 (c)). The depth of the groove is about 10 to 60% of the original plate thickness (about 0.5 to 1.0 mm thickness) and the width is about 0.1 to 0.3 mm. Then, the small pieces are divided along the dividing grooves and fired (FIG. 2 (e)).
Although division may be performed after firing, firing after division is suitable for reasons such as avoiding disorder of individual side faces due to division.

The firing may be performed in the same manner as the conventional one. That is, when the low temperature sintered substrate material as described above is used,
After drying, it is heated at 800 to 1050 ° C. for about 30 minutes to 3 hours in an inert atmosphere when the conductor paste is Cu-based, and in the atmosphere when it is a material such as Ag which is not easily oxidized.

[0017]

【Example】

Examples 1 to 4 Using a green sheet (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 of 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 that is the inner layer, 10 layers of the above sheets are laminated so that the via positions match, and the laminated sheet is cut along the dividing line in the axial direction of the via as shown in FIG. It was divided into pieces. The length of the side 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 manufacture a surface mounting component. After manufacturing 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 splitting and firing according to the above procedure Microscopic observation of the shape of the conductor portion for the side surface electrode revealed no cracks or voids in the via conductor. Also, the electrode via pitch is the minimum
We were able to achieve 0.3 mm.

Comparative Example 1 Instead of via holes, through holes having a diameter of 0.2 mm were used, and the inner surface of each through hole had a weight ratio of Ag 90% and Pd.
A conductive paste consisting of 10% was suction-printed, and fired and divided in the same manner as in Example 1 to try to manufacture a surface mounting component having a side electrode. When the conductor portion for the side surface electrode was observed in the same manner as in Example 1, about 60% of the through holes were clogged with the conductors, and since the conduction due to the through holes was incomplete, the individual side after the division was substantially formed. Can withstand 10
It was only%.

[0019]

Since the surface mounting component of the present invention has a plurality of side surface electrodes, it can be mounted at a high density by using the side surface electrodes as multi-terminal electrodes. Further, since the side surface electrode is formed at the via hole position, it is possible to easily form a plurality of side surface electrodes at accurate positions without using a special device for electrode formation. Moreover, since the side surface of the component is substantially flat, the contact with the terminal receiving portion is stable. Therefore, it is possible to manufacture a component having stable electrical characteristics and high reliability. Further, since the amount of conductor of the electrode is large, the resistance of the electrode portion does not become excessive, and the via hole diameter can be reduced to achieve fine electrode patterning. From the viewpoint of manufacturing, since the method of the present invention can simultaneously divide or cut out the substrate and form the electrodes, it is particularly useful in a method of manufacturing a component by dividing a ceramic original plate. Further, in the multilayer substrate, the via hole penetrates the circuit in the inner layer, so that the connection between the inner layer circuit and the electrode is surely realized. Further, unlike the conventional through-hole inner surface printing, the filling of the via holes can be easily performed without special control at the time of injecting the conductor paste, which is simple and advantageous in manufacturing.

[Brief description of drawings]

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

FIG. 2 is a process drawing showing one embodiment of the manufacturing method of the present invention.

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

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

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

FIG. 6 is a sectional view of a conventional through hole having an inner surface plated.

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

[Explanation of symbols]

 1 ... Original plate (green sheet) for manufacturing ceramic substrate 2 ... Circuit 3 ... Dividing groove 4 ... Primary divided substrate 5 ... Conductive material 6 ... Secondary divided substrate 7 ... Side electrode (conventional method) 8 ... Electrode formation Via hole 9 ... Conductive paste 10 ... Surface mounting component (present invention) 11 ... Dividing line 12 ... Side electrode (present invention) 20 ... Through hole 22 ... Through hole inner surface 24 ... Through hole inner surface conductor adhered layer 26 ... Through-hole corner 28 ... Land

Claims (5)

[Claims] 1. A surface mounting component comprising an electrode formed by baking a conductive paste in a recess provided on the side surface of the component. 2. The surface mounting component according to claim 1, wherein the electrode is formed by vertically dividing a via hole filled with a conductor paste to expose the 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. A via hole formed in a ceramic substrate is filled with a conductive paste to form a via, and the substrate is divided along the axis of the via after firing, or the substrate is divided along the axis of the via. A method for manufacturing a surface mounting component having a side surface electrode, characterized by exposing the fired conductor to a side surface of the component to form an electrode by firing later. 5. The method for manufacturing a surface mounting component according to claim 4, wherein after the conductor paste is filled in the via holes of the unfired ceramic substrate to form the vias, the conductor paste and the substrate are fired at the same time.