JPH0543281B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is intended to reduce noise generated from various industrial and household electronic, electrical and communication equipment, and noise that enters into these equipment from the outside. The present invention relates to a method for manufacturing a composite multilayer feedthrough capacitor suitable for use as a noise filter.

[Background Art] Communication devices and other electronic devices are becoming smaller and more multifunctional, and as a result, semiconductor devices such as ICs and LSIs are increasingly being used. However, these devices have weaknesses such as malfunctions or destruction of internal circuit elements due to noise that enters from outside the device through power lines, signal lines, or propagates through the air.

In addition, as the processing speed of personal computers and control equipment using microprocessors increases, the operating frequency of semiconductor devices is moving to higher frequency bands, and the operating frequency of semiconductor devices is moving to a higher frequency band, which has not been a problem in the past. high-frequency noise is becoming more and more influential.

Conventionally, in order to remove the above-mentioned high-frequency noise, a filter such as a three-terminal capacitor or a ferrite core or a combination thereof has been mounted for each signal path.

[Problems to be Solved by the Invention] In the conventional system as described above, a filter must be mounted on each of the plurality of signal paths, and the ground terminal of each filter must be connected to the ground pattern of the circuit board. In addition to complicating the wiring design of the circuit board, it also became difficult to make the entire device smaller and thinner, leading to higher costs.

In addition, for noise removal filters with lead terminals such as 3-terminal capacitors, in high frequency bands of several hundred MHz, no matter how short the ground lead wire is mounted, the residual inductance due to the structure will affect the high frequency noise, preventing the bypass effect. Therefore, there were cases where a sufficient noise removal effect could not be obtained.

Furthermore, when using feed-through capacitors with extremely low residual inductance, which are extremely effective in removing high-frequency noise, it has traditionally been difficult to mount them directly on a circuit board and make effective use of their performance due to shape constraints. , a method such as attaching it to a sub-board or metal case in advance, mounting it on the circuit board, and then soldering the wiring using a soldering iron is adopted, which makes the installation complicated and increases the size of the entire device. This led to higher costs.

[Means for Solving the Problems] The method for manufacturing a composite multilayer feedthrough capacitor of the present invention is carried out as follows.

An internal electrode layer is printed on the green dielectric layer,
Furthermore, a dielectric layer is laminated on this internal electrode layer, the internal electrode layer is printed, and this process is repeated to produce a laminate in which dielectric layers and internal electrode layers are alternately laminated.

After forming a plurality of through holes in the laminate in a staggered arrangement in the thickness direction, the laminate is divided into desired sizes by cutting the required portions between the through holes. Then, the cut laminate is dried and fired, and a center conductor is inserted into the fired laminate.

Note that, after any one of the above-mentioned cutting step, firing step, and center conductor insertion step, an external electrode layer is formed on at least the side end surface of the laminate. Further, the internal electrode layers are printed in the laminate manufacturing process so that each layer is alternately electrically connected to the center conductor and the external electrode.

[Function] According to the method for manufacturing a multilayer feedthrough capacitor of the present invention, the dielectric of a plurality of capacitors can be made common and integrated, so that the multilayer feedthrough capacitor can be miniaturized as a whole. Therefore, according to the method for manufacturing a composite multilayer feedthrough capacitor of the present invention, a plurality of noise filters using feedthrough capacitors can be simultaneously mounted at high density on a circuit board.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of a composite multilayer feedthrough capacitor manufactured by the method of the present invention, FIG. 2 is a sectional view taken along the line of FIG. 1, and FIGS.
The figures are sectional views taken along lines - and - in FIG. 2, respectively.

Reference numeral 1 denotes a laminate in which dielectric layers and internal electrode layers are alternately laminated, and the laminate 1 has a plurality of (six in this example) center conductors 2 extending through the laminate 1 in the thickness direction. It is installed through. External electrodes 3 are formed on the side end faces of the laminate 1 and on both board faces.

As shown in FIGS. 2 to 4, the laminate 1 has dielectric layers 4 and internal electrode layers 5 alternately laminated, and each internal electrode layer 5 has a center conductor 2 and an external electrode 3. They are alternately conductive. Below, center conductor 2
The internal electrode layer electrically connected to the external electrode 3 may be indicated by the symbol 5a, and the internal electrode layer electrically conductive to the external electrode 3 may be indicated by the symbol 5b.

In this embodiment, the internal electrode layer 5a has a square shape as shown in FIG. 3, and the center conductor 2 passes through the center of the inner electrode layer 5a and is electrically connected to the center conductor 2. Therefore, the same number of internal electrode layers 5a as the center conductor 2 are provided.

As shown in FIG. 4, the internal electrode layer 5b is provided to cover the entire surface of the dielectric layer 4 except for the area near the center conductor 2. Therefore, this internal electrode layer 5b is not electrically connected to the center conductor 2, but its edge reaches to the edge of the dielectric layer 4, where it is joined to the external electrode 3 and electrically connected.

The composite multilayer feedthrough capacitor constructed in this manner has a structure in which a plurality of capacitors have a common dielectric material and are integrated, so the capacitor is compact as a whole. Therefore, according to this composite multilayer feedthrough capacitor, a plurality of noise filters using feedthrough capacitors can be simultaneously mounted at high density on a circuit board.

FIG. 5 is a perspective view showing another embodiment of a composite multilayer feedthrough capacitor manufactured by the method of the present invention. In this embodiment, the center conductors 2 are arranged in a staggered arrangement. By arranging the center conductors 2 in a staggered manner in this way, the arrangement pitch p of the center conductors 2 can be reduced to 1/1 of the composite multilayer feedthrough capacitor shown in FIG.
2, and feedthrough capacitors can be mounted with higher density.

Such a composite feedthrough capacitor can be manufactured according to the present invention by the method shown in FIGS. 6-8.

That is, first, an internal electrode layer 5a or 5b (5b in this embodiment) is placed on the dielectric layer 4 in a green state.
print. Then, a dielectric layer 4 in a green state is further laminated on this internal electrode layer 5b,
As shown in FIG. 7, an internal electrode layer 5a is printed on this newly laminated dielectric layer 4. By repeating this process, a laminate in which dielectric layers 4 and internal electrode layers 5 are alternately stacked is manufactured.

As shown in FIG. 6, when printing the internal electrode layer 5b, a non-printed part 8, which is slightly larger than the cross section of the center conductor, is formed in the area where the center conductor 2 is planned to be drilled. 4 will be exposed. Further, as shown in FIG. 7, the internal electrode layer 5a
The center thereof is made to coincide with the center of the non-printed portion 8, and a distance 9 is formed between each internal electrode layer 5a for a required period.

After manufacturing the laminate 1 in this manner, a plurality of through holes 6 are bored in the laminate 1 in the thickness direction, as shown in FIG. The through holes 6 are formed so as to pass through the center of the non-printing portion 8, and therefore, the through holes 6 are provided in a staggered arrangement as shown in FIG.

Thereafter, the laminate 1 is cut along the required portions between the through holes 6 to divide the laminate 1 into desired sizes. For example, when cutting along cutting line A, a multilayer feedthrough capacitor is formed in which the center conductors shown in FIGS. 1 to 4 are arranged in a row. Further, when cutting is performed every two rows of through holes 6 as indicated by cutting line B, a composite multilayer feedthrough capacitor in which the center conductors are arranged in a staggered manner as shown in FIG. 5 is manufactured.

After the cut laminate is dried and fired, a conductive layer is formed on the inner peripheral surface of the through hole 6 by coating, printing, plating, etc., and the internal electrodes 5a are connected to each other. Then, the center conductor 2 is introduced into the through hole 6. Thereafter, external electrodes are formed on at least the side end surfaces of the laminate 1 by printing, coating, plating, etc., thereby completing the multilayer feedthrough capacitor of the present invention. When forming the external electrodes, the composite multilayer feedthrough capacitors shown in FIGS. 1 to 5 are manufactured by configuring the external electrodes on both surfaces of the laminate.

In the above embodiment, the external electrode layer is formed after inserting the center conductor 2, but the external electrode layer may be formed after cutting the laminate, or after a cutting process or a firing process.

When external electrodes are also formed on the board surface of the laminate as shown in FIGS. 1 and 5, it is preferable to form the external electrodes before inserting the center conductor.

In the present invention, when external electrodes are formed on both surfaces of the laminate as in the above embodiment, it is possible to make the external electrodes function as a conductive plate that becomes the ground type common electrode of the composite noise filter. be.

[Effects] As described above, according to the method for manufacturing a composite multilayer feedthrough capacitor of the present invention, a composite multilayer feedthrough capacitor that is extremely small and can be mounted simultaneously on a circuit board with high density can be easily and efficiently produced. Manufactured in

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a composite multilayer feedthrough capacitor manufactured by the method of the present invention, FIG. 2 is a sectional view taken along the line of FIG. 1, and FIGS.
The figures are sectional views taken along lines - and - in FIG. 2, respectively. FIG. 5 is a perspective view showing another embodiment of a composite multilayer feedthrough capacitor manufactured by the method of the present invention. 6 and 7 are perspective views showing the manufacturing process of the composite multilayer feedthrough capacitor of the present invention, and FIG. 8 is a plan view thereof. DESCRIPTION OF SYMBOLS 1... Laminate, 2... Center conductor, 3... External electrode, 4... Dielectric layer, 5 (5a, 5b)... Internal electrode layer, 6... Through hole, 8... Non-printed part, 9...
Between.

Claims (1)

[Claims] 1. By printing an internal electrode layer on a green dielectric layer, further laminating a dielectric layer on this internal electrode layer, printing an internal electrode layer on top of this, and repeating this process. A step of manufacturing a laminate in which dielectric layers and internal electrode layers are alternately laminated, a step of drilling a plurality of through holes in the laminate in a staggered arrangement in the thickness direction, a through hole in the laminate. A cutting process in which the laminate is divided into required sizes by cutting the required portion between the laminates, a firing process in which the cut laminate is dried and fired, and a center conductor insertion process in which the center conductor is inserted into the fired laminate. , after any one of the cutting step, firing step, and center conductor insertion step, forming an external electrode layer on at least the side end surface of the laminate; A method for manufacturing a composite multilayer feedthrough capacitor, characterized in that the multilayer capacitor is printed in the step of manufacturing the multilayer body so that the conductor and the external electrode are alternately electrically connected.