JPH07249540A - Capacitor array - Google Patents

Abstract

PURPOSE:To provide a capacitor array which is made of printed ceramic capacitors and which has a small size, uniform thin thickness, and good solderability, does not require any lead frame, and can be manufactured at high productivity and easily mounted on a printed board, etc. CONSTITUTION:A capacitor array is provided with printed ceramic capacitors formed on a substrate l and terminal electrodes 7 and 7' having solderable bumps 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor array for which electronic components are required to be compact and have high performance.

[0002]

2. Description of the Related Art Conventionally, a chip-shaped element network device in which individual chip capacitors are aligned on a substrate (Japanese Utility Model Publication No. 4-15825) or individual chip capacitors are directly mounted on a printed wiring board or the like for use. Has been done.

[0003]

The capacitor array as described above has many complicated and complicated arrangements such that individual chip capacitors are aligned and mounted on a substrate on which circuit wiring is formed, soldered, and lead frames are attached. There are processes, the cost is high, and the miniaturization and thinning are hindered. Even when the chip capacitors are directly mounted on the printed wiring board or the like, it is necessary to arrange and arrange the individual chip capacitors on the printed wiring board or the like, and to perform many soldering steps.

Therefore, an object of the present invention is to provide a capacitor array which is compact and thin, does not require a lead frame, and is inexpensive.

[0005]

The present invention provides a lower electrode 2,
A plurality of printed ceramic capacitors 10 each having a dielectric layer 3, an upper electrode 4, a protective coat 5 and the like formed on an alumina ceramic substrate 1 by screen printing or the like, and terminal electrodes 7, 7'of the printed ceramic capacitors. Is an electrode that can be soldered, and provides a low-priced capacitor array that is compact and thin, does not require a lead frame.

The capacitor array according to the present invention will be described in detail below. FIG. 1 (A) is a top view showing an embodiment of the capacitor array according to the present invention, and FIG.
Is a cross-sectional view taken along the line JJ ′ of FIG.
In addition, FIG. 1C is a cross-sectional view taken along the line II ′ of FIG.

The capacitor array according to the present invention is generally as shown in FIG. 1, and includes a lower electrode 2, a dielectric layer 3, an upper electrode 4 and a protective coat 5 on an alumina ceramic substrate 1 or the like.
Etc. are printed, dried and fired by a method known per se such as a thick film printing technique to form the printed ceramic capacitor 10. The protective coat 5 is formed and printed so that a part of the upper electrode of the printed ceramic capacitor and a part of the lower electrode which is a common electrode are exposed. Such terminal electrodes are preferably solderable. The printed ceramic capacitor of the present invention is not particularly limited in its printing method, material and shape. Preferably, the dielectric layer is Pb (Mg
_1/3 Nb _2/3 ) O ₃ , Pb (Zn _1/3 Nb _2/3 ) O ₃ , PbT
A composition containing at least one of iO ₃ and Bi ₂ O ₃ is preferable, and when a high capacitance is required, it is preferable to use a multilayer printed ceramic capacitor having a multilayer printing structure, and especially the number of layers is limited. is not. Further, the dielectric layers may be common, but it is preferable that each of the printed ceramic capacitors is independent.

The printed ceramic capacitor thus manufactured can be used as it is as a capacitor array, but further, the terminal electrode 7 of the upper electrode 4 corresponding to each of the printed ceramic capacitors and the printed ceramic capacitor are commonly used. It is preferable to use a capacitor array in which bumps 6 made of solder or the like are formed on the terminal electrodes 7'of the lower electrode 2.

Further, in the capacitor array, it is preferable to cover the printed ceramic capacitor portion and the alumina ceramic substrate, which omit the exposed terminal electrode portions and bump portions, with a resin or the like in order to further improve reliability.

Further, in the capacitor array of the present invention, the shape and the capacitance of the printed ceramic capacitor
The number of elements and the combination of the upper electrode and the lower electrode are not particularly limited.

The capacitor array thus manufactured can be widely applied as an electronic component, and the number of steps of mounting on a printed circuit board or the like can be greatly reduced and the reliability can be improved.
For example, the capacitor array can be used for applications such as filtering, coupling, and tuning.

[0012]

EXAMPLES Examples of the capacitor array according to the present invention will be described below. The capacitor array according to the present invention is
It is not limited to the following examples.

(Embodiment 1) First, an Ag-Pd-based conductive paste was screen-printed on the upper surface of an alumina ceramic substrate 1 having cuts 8 for determining the orientation by a multi-cavity formation in which break lines were formed, and then dried. The lower electrode 2 serving as a common electrode was formed by firing at 850 ° C. for 10 minutes.

Next, [Pb (Mg _1/3 Nb _2/3 ) O ₃ : P
bTiO ₃ : Bi ₂ O ₃ = 97: 2.7: 0.3 mol%]
A dielectric paste made of the dielectric powder of 1 was screen-printed on the lower electrode 2 and dried. Screen printing of the dielectric paste may be performed once or plural times, but in the present embodiment, screen printing and drying are performed three times to obtain a peak temperature of 900 ° C. 10
The dielectric layers 3 were formed by maintaining the temperature for a minute.

Next, an Ag-Pd type conductive paste is screen-printed on the dielectric layer 3 and dried to 900 ° C. 10
After baking for a minute, the upper electrode 4 that does not contact the lower electrode 2 was formed. However, only in the common electrode terminal 15 part, the pattern of the upper electrode was formed so as to contact the lower electrode, and the lower electrode and the upper electrode were electrically connected. The height of the terminal electrode 7 of the printed ceramic capacitor 10 and the terminal electrode 7 ′ of the common electrode terminal 15 thus formed is almost the same.

Next, an overcoat glass paste is screen-printed with a pattern for forming the terminal electrodes 7, 7'so that a part of the upper electrode 4 is not covered, dried, baked at 530 ° C. for 10 minutes, and then dried. A protective coat 5 that sufficiently covers the electrodes, the dielectric layer, and the upper electrode was formed to form a printed ceramic capacitor 10 and a common electrode terminal 15. The heights of the terminal electrode 7 of the printed ceramic capacitor 10 and the terminal electrode 7 ′ of the common electrode terminal 15 formed in this manner were almost the same.

Further, the printed ceramic capacitor 10
-Passing the alumina ceramic substrate 1 on which the common electrode terminal 15 is formed through a wave solder bath, the terminal electrode 7 of the upper electrode,
Bumps 6 made of Ag-containing solder were formed on 7'to prepare a capacitor array.

The capacitor array thus manufactured is small, thin, and has a substantially uniform thickness. No lead frame is required. A large number of capacitors can be manufactured at the same time.
It is very useful as an electronic component because it is easy to mount on a printed circuit board and has good solderability. In this example, the thickness of the alumina ceramic substrate 1 was 0.5 mm, the thickness of the printed ceramic capacitor was 0.10 mm, and the thickness of the entire capacitor array was 1.2 mm.

Further, in the common electrode terminal 15 part, the same effect was obtained even in the capacitor array in which the dielectric layer 3 and the upper electrode 4 were not formed and the bump was directly formed on the lower electrode.

(Embodiment 2) Multilayer printing is performed on the upper surface of the alumina ceramic substrate 1 in substantially the same manner as in Embodiment 1, and a lower electrode, a dielectric layer, an upper electrode, a dielectric layer, a lower electrode, a dielectric layer, An upper electrode / protective coat was formed to produce a multilayer printed ceramic capacitor having three dielectric layers.

Further, in the same manner as in Example 1, bumps 6 made of Ag-containing solder were formed on the terminal electrodes to produce a capacitor array.

The capacitor array manufactured in this manner is small, thin, and has a substantially uniform thickness. No lead frame is required .. With high capacitance. A large number of capacitors can be manufactured at the same time. It is very useful as an electronic component because it is easy to mount on a printed circuit board and has good solderability. The total thickness of the capacitor array of this example was 1.4 mm.

(Embodiment 3) Printing is performed on the upper surface of the alumina ceramic substrate 1 in substantially the same manner as in Embodiment 1 to form the lower electrode 2, the dielectric layer 3, the upper electrode 4 and the protective coat 5, and a printed ceramic capacitor is formed. To form a capacitor array having no bumps on the terminal electrodes 7 and 7 '.

The bump-free capacitor array thus manufactured is small, thin, and has a substantially uniform thickness. No lead frame is required. A large number of capacitors can be manufactured at the same time. It is very useful because it is easy to mount on a printed circuit board and has good solderability.

[0025]

The capacitor array according to the present invention is extremely thin, has a substantially uniform thickness, is small, does not require a lead frame, has high productivity, is inexpensive, and can be mounted on a printed circuit board or the like. We can provide useful electronic parts that are easy and have good solderability.

[0026]

[Brief description of drawings]

1 (A), (B) and (C) are a top view and a cross-sectional view showing an embodiment of a capacitor array with solder bumps of a printed ceramic capacitor according to the present invention. (A) is a view seen from the top,
(B) is a sectional view taken along the line JJ 'of (A), and (C) is a sectional view taken along the line II' of (A).

[0027]

[Explanation of symbols]

 1 Alumina Ceramic Substrate 2 Lower Electrode 3 Dielectric Layer 4 Upper Electrode 5 Protective Coating 6 Bumps 7 · 7 'Terminal Electrode 8 Notch 10 Printed Ceramic Capacitor 15 Common Electrode Terminal

Claims (3)

[Claims] 1. A lower electrode is formed on the upper surface of a substrate by a printing method, a dielectric layer is formed on the lower electrode, and an upper electrode is formed on the dielectric layer. A capacitor array comprising a plurality of printed ceramic capacitors manufactured by protecting and coating a part of the upper electrode and a part of the upper electrode. 2. The capacitor array according to claim 1, comprising a multilayer printed ceramic capacitor formed by multilayer printing. 3. The capacitor array according to claim 1, wherein bumps are formed on the terminal electrodes of the printed ceramic capacitor without the protective coat.