JPH0722070B2 - Ceramic capacitor and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to have very small capacity error
It relates Se la ceramic capacitor and a manufacturing method thereof.

[0002]

2. Description of the Related Art Ceramic capacitors use a porcelain dielectric, and in recent years, a laminated type has been widely used due to a demand for miniaturization of electronic parts. In this multilayer ceramic capacitor, a conductive film to be an internal electrode is formed by printing on a dielectric ceramic green sheet, the sheets are stacked and pressure-bonded, die-cutting is performed to obtain a predetermined capacitance, and then firing and firing are performed. An external extraction electrode for connecting an internal electrode film is provided on the side surface of the bonded laminated body to form a capacitor chip, which is then made into an electronic component suitable for mounting on a circuit.
It The electronic component forming means adheres the chip to a pair of electrode films formed on the base plate , connects external lead wires to the electrode films, and molds other parts with resin in a state where only the external lead wires are projected. It will be.

[0003]

By the way, the above-mentioned conde
In multilayer capacitor chips and non-multilayer capacitor chips used for sensor parts, the cause may be the thickness of the ceramic, which is the dielectric material, and the subtle differences in area during die cutting.
In general, a capacitor having a capacity of about 200 PF causes a manufacturing capacity error of about ± 8%. In addition,
Capacitor chips, because it uses a single thing, co-down de
The capacitance error of the sensor chip itself is
There will be a capacity error. Therefore with the manufacturing <br/> Shinafu reservoir as an electronic component worse, as the electronic component, the tolerance of the capacitor capacitance becomes necessarily large, not be said necessarily the quality is good electronic components. Therefore, the present invention proposes a means for efficiently producing a capacitor with a small capacitance error.

[0004]

A ceramic capacitor according to the present invention has a built-in ceramic capacitor chip.
For electronic parts, make the capacity a fraction of the design value capacity
In addition, the capacity is accurately measured in advance, and the capacity
Small-capacity capacitors appropriately classified according to manufacturing error
Capacitance error when manufacturing each small capacitance capacitor
A predetermined number of combinations that complement each other and match the design value capacity.
It is characterized in that it has built in as Align. Also
The above-mentioned capacitor is characterized in that an electrode film for fine adjustment of the capacitor capacity is formed on the back surface of the base plate.

Further, in the method for manufacturing a ceramic capacitor according to the present invention, the built-in capacitor chip is particularly designed.
A small capacity ceramic capacitor chip that is a fraction of the amount
It is a combination of small capacity capacitor chips.
After firing, measure a small-capacity capacitor chip in advance and
This is classified according to the manufacturing error of plus or minus of the capacity.
Small capacitor chips complement each other's manufacturing errors
Match the design value as a predetermined number of combinations
A predetermined number of ceramic capacitor chips are electronically
And it is characterized in that formed by part of. In the method of manufacturing a ceramic capacitor described above, a fine adjustment electrode film is formed on the back surface of the base plate, and a plurality of base plates having different areas of the fine adjustment electrode film are formed to reduce the capacity of the capacitor.
Minute capacitance that cannot be complemented by a combination of capacitor chips
The feature is that a base plate that compensates for an error is selected and used.

[0006]

Even if the capacitance of the small-capacity capacitor chip has an error of several%, the total capacitance can be made the design value capacitance by combining those having the plus and minus errors. Further, the adjustment electrode film on the back surface of the base plate constitutes a capacitance between the internal electrode film of the capacitor chip and the electrode film connecting the capacitor chip,
The capacitance of the entire capacitor can be finely adjusted depending on the area of the electrode film.

[0007]

Next, an embodiment of the present invention will be described in the case of a laminated type ceramic capacitor along with its manufacturing procedure. First, a laminated ceramic capacitor chip 1 is formed. This is the same as the conventional method, in which an internal electrode film 12 is printed and formed on a dielectric ceramic green sheet 11, and this sheet is laminated and pressure-bonded to a predetermined size. Further, it is formed by punching, firing, and sintering, and then providing external lead-out electrodes 13 connected to the alternately laminated electrode films 12 on the side surface of the laminated body. For example, when the capacitor chip 1 is formed, the capacity of the capacitor to be produced is 30
If 0PF is set, the capacitor chip 1 is formed with 100PF, which is one third of the capacitance, as a reference. 100P
If the capacitance error of the F ceramic capacitor chip 1 is ± 10% at the maximum, a ceramic capacitor chip 1 of 110 to 90 PF will be produced. So, the chip 1 of 110-90PF
Are individually measured and appropriately sorted, for example, 110 to 108PF chips 1a and 108 to 106PF chips 1b and 106.
.About.104 PF chip 1c ... Separated like 92 to 90 PF chip 1j.

A base plate 2 incorporating the chip 1
Is provided with a pair of electrode films 21 for adhering the chip 1 (using solder or a conductive adhesive) on the surface and an external lead wire 22 connected to the electrode film 21, and an adjustment electrode film 23 on the back surface. In particular, base plates 2a, 2b ... Having different areas of the adjustment electrode film 23 are formed.
When a capacitor having a capacity of 300 PF is not produced, for example, 1 b is selected from among the sorted chips 1a to 1j.
(108 to 106PF), 1f (100 to 98PF) 1
When three of j (94 to 92 PF) are selected and they are installed in parallel in the base plate 2, the capacity becomes 302 to 296 PF. Then, the actual capacitance is measured, and if the value is close to 302 PF, a base plate with a small area of the adjusting electrode film 23 is used. Conversely, if the value is close to 296 PF, the area of the adjusting electrode film 23 is large. If the base plate is used, the capacitor produced will be 300 PF. After the capacitor chips 1b, 1f, 1j are assembled in the base plate 2 in this manner, they are molded with the resin 3 to serve as electronic parts.

Therefore, the capacitor chip 1 is particularly strict.
Do not charge the quantity and form within normal manufacturing error
You just need to sort this according to the size of the error plus or minus
And combine them appropriately to complement each other.
It is possible to obtain a more accurate capacitor electronic component by using the same . Thus even capacitor chip 1 is used without waste by appropriate combination, further base plate 2
1P by adjusting the area of the electrode film 23 formed on the back surface of the
It is also possible to make adjustments in F units. Further, since the capacitor chips are connected in parallel, the resonance sharpness Q is increased and the sensitivity of the circuit using the product of the present invention is improved. The present invention is not limited to the above embodiment, the capacitor chip may be a non-stacked type, and the number of chips to be incorporated in one capacitor and the range of chip separation can be arbitrarily determined. is there.

[0010]

As described above, the present invention provides a capacitor chip having a capacitance which is a fraction of that of the capacitor to be produced.
The out Ltd., it was fractionated in accordance with this manufacturing error of its capacity
Later , the combination of manufacturing errors will complement each other.
Capacitance error that naturally occurs in the production of capacitor can be absorbed
, High quality capacitor electronics with less error than design capacity
Products can be provided, and there is no waste of capacitor chips.
It also increases the product yield. Furthermore the kick set the electrode film on the base plate back surface incorporating chip, the surface of the electrode film
Higher accuracy because it is possible to adjust a small capacity with the product size
Can provide high quality products.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a capacitor chip.

FIG. 2 is an explanatory view of manufacturing a capacitor component.

FIG. 3 is a side view of the capacitor component before the resin molding.

FIG. 4 is an external view of a capacitor component.

[Explanation of symbols]

 1, 1a, 1b ... 1j Capacitor chip 2 Base plate 21 Electrode film 22 External lead wire 23 Adjustment electrode film 3 Resin

Claims (4)

[Claims] 1. A pair of electrode films are formed on the surface of a base plate.
The ceramic capacitor chip fired between the electrode films
Conductively adhere the cable to the electrode film and connect the external lead wire to the electrode film.
At the same time, in a ceramic capacitor made by projecting only the external lead wire to the outside and molding the other part with resin, set the capacitance to a fraction of the design value capacitance and set the capacitance in advance.
Accurately measure and to the manufacturing error of plus or minus of the capacity
The small-capacity capacitor chips appropriately classified according to
Compensating for the capacitance error during manufacturing of each small-capacity capacitor
And a predetermined number of combinations that match the design value capacity,
A ceramic capacitor characterized in that it is electrically conductively bonded between electrode films . 2. The ceramic capacitor according to claim 1, wherein an electrode film for fine adjustment of the capacitor capacity is formed on the back surface of the base plate. 3. A small capacity ceramic which is a fraction of the design capacity.
The capacitor chip is fired to
Plus minus of a manufacturing error of its capacity measured in advance-flops
According to the above, a pair of electrode films are separately set on the surface of the base plate.
Forming the small capacitance capacitor chip between the electrode films
And a predetermined number of combinations that complement the manufacturing error
To match the design value and set the specified number of ceramic capacitors.
Sensor chip by conductive adhesion between the electrode films
Connect the external lead wires and disconnect only the external lead wires.
A method of manufacturing a ceramic capacitor, which is characterized in that it is made to project to a portion and resin-molded . 4. A ceramic capacitor according to claim 3 .
In the manufacturing method, a fine adjustment electrode film is formed on the back surface of the base plate, and a plurality of base plates having different areas of the fine adjustment electrode film are formed to combine a small capacity capacitor chip.
A method of manufacturing a ceramic capacitor, which comprises selecting and using a base plate that compensates for a minute capacitance error that cannot be compensated for .