JPH0677073A - Manufacture of monolithic electronic part - Google Patents

Abstract

PURPOSE:To obtain a method of manufacturing a monolithic electronic part where a pattern is protected against disconnection in a through-hole. CONSTITUTION:A through-hole 4 used for connecting coil conductor patterns is provided to a magnetic ferrite green sheet 3 at a prescribed place. On the other hand, a coil conductor pattern corresponding to the pattern of the through- hole 4 and a transfer pad 2 and printed on a transfer release film with conductive paste. Then, a first process where a coil conductor pattern is transferred onto the surface of a sheet, a second process where the magnetic ferrite green sheets 3 each provided with the through-hole 4 are superposed on one another and bonded by pressure, and a third process where a transfer pad 2 is transferred on a lower coil conductor pattern inside the through-hole 4 are provided. These processes are repeatedly carried out for the formation of a monolithic body. Then, the obtained monolithic body is fully bonded together by pressure and burned, and an outer electrode is provided to the end faces of the monolithic body where coil ends and led out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated electronic component such as a laminated chip inductor.

[0002]

2. Description of the Related Art Conventionally, as one of methods for manufacturing a laminated electronic component, a step of transferring an internal conductor pattern printed on a transfer release film to a green sheet and a step of laminating a green sheet having through holes formed therein. A method is known in which the above is alternately repeated to obtain a laminated body, and the obtained laminated body is pressure-bonded and then external electrodes are formed. In particular, this method is applied to a laminated electronic component made of a thin green sheet. It has been widely used in manufacturing.

The steps of producing a laminated body in the above-mentioned method for producing a laminated electronic component will be specifically described below by taking the case of producing a laminated chip inductor as an example. First, a transfer made of a transparent plastic film on which an internal conductor pattern (coil conductor pattern) is formed by stacking and connecting through holes to form a spiral coil on a dummy part composed of a plurality of dummy sheets. Release film is laminated with the pattern facing downward. Then, press the film from above with a flat plate,
After the coil conductor pattern is transferred onto the sheet, the transfer release film is peeled off from the sheet.

Next, a green sheet having through holes formed at predetermined positions is laminated on the sheet to which the conductor pattern has been transferred, and the coil conductor pattern is transferred to the surface of this sheet in the same manner as described above. This step is repeated until a predetermined number of coil turns is obtained, and then a plurality of dummy sheets are laminated to form a dummy part, and a laminated body is obtained.

[0005]

According to the conventional method for producing a laminated electronic component using the transfer release film, the internal conductor pattern printed on the transfer release film is overlaid on the green sheet, and the film is placed upward. The internal conductor pattern is transferred by pressing with a flat plate from the above. For the conductive connection between the internal conductor pattern and the internal conductor pattern of the lower layer, the release film for transfer is overlaid on a sheet having a through hole. At this time, the portion located on the through hole in the internal conductor pattern printed on the transfer release film is transferred to the internal conductor pattern of the lower layer through the through hole.

However, when the transfer release film having the internal conductor pattern formed thereon is stacked on the green sheet and pressed by a flat plate from above, a sufficient pressure for transfer is uniformly applied to the portions other than the through holes. However, since the pressure applied to the hollow through-hole portion is weak, it was not possible to obtain sufficient adhesion strength with the internal conductor pattern of the lower layer.

Therefore, when the transfer peeling film is peeled off, the internal conductor pattern located on the through hole may be peeled off while being attached to the transfer peeling film, and the pattern may be broken.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the above-mentioned problems of the prior art and to provide a method of manufacturing a laminated electronic component in which disconnection of a pattern in a through hole portion is prevented.

[0009]

As a result of earnest research for achieving the above-mentioned object, the present inventor has found that before transferring the internal conductor pattern, conductive transfer is performed on the lower internal conductor pattern in the through hole. It has been found that the above-mentioned problems can be solved by transferring the pad for a computer, and has reached the present invention.

That is, according to the present invention, a laminated body is obtained by alternately repeating a step of transferring an internal conductor pattern printed on a transfer peeling film to a green sheet and a step of laminating green sheets having through holes. A method for manufacturing a laminated electronic component in which an external electrode is formed after the obtained laminated body is pressure-bonded, which is printed on a transfer release film before the internal conductor pattern is transferred to a green sheet in which a through hole is formed. Provided is a method for manufacturing a laminated electronic component, characterized in that a conductive transfer pad having a diameter equal to or smaller than the diameter of the through hole is transferred onto an internal conductor pattern of a lower layer in the through hole.

[0011]

According to the method of the present invention, before transferring the internal conductor pattern to the green sheet having the through hole, the conductive transfer pad printed on the transfer release film is provided as the lower internal conductor pattern in the through hole. The transfer of the pattern prevents the disconnection of the pattern.
Incidentally, the conductive transfer pad in the present invention, after filling the recess of the through hole with a conductive paste, to prevent disconnection of the through hole by printing an internal conductor pattern, the diameter of the through hole It is preferable that the diameter is the same as or smaller than that of the sheet, and preferably has the same thickness as that of the sheet.

Thus, before transferring the internal conductor pattern, a conductive transfer pad having a thickness preferably equal to the thickness of the sheet is transferred onto the lower internal conductor pattern in the through hole. By placing the transfer release film having the internal conductor pattern printed on the sheet, the internal conductor pattern located on the through hole does not have to be directly transferred onto the lower layer internal conductor pattern in the through hole. , Is electrically connected by printing on the transfer pad which is printed in the through hole in advance. Preferably, when the transfer is performed on the surface of the transfer pad located on the same surface as the sheet surface, it is electrically connected to the internal conductor pattern of the lower layer.

That is, the transfer pad transferred onto the internal conductor pattern of the lower layer in the through hole has no step (step between the through hole portion and the other portion) in the transferred object, and the transfer release film is formed by the flat plate. When the pressure is applied, a sufficient pressure to transfer to all parts is uniformly applied, and the adhesive force of the internal conductor pattern located on the through hole is increased. Therefore, when the transfer peeling film is peeled off, the internal conductor pattern positioned on the through hole is not peeled off while being attached to the film, and the disconnection of the pattern is prevented.

Further, according to the present invention, since the transfer pad is transferred by using the transfer release film which is separate from the internal conductor pattern, the transfer can be performed very easily and reliably.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by the following examples.

[0016]

EXAMPLE As one example of the present invention, a method of manufacturing a laminated chip inductor will be described.

First, a magnetic material powder containing ferrite as a main component was mixed with a binder containing polyvinyl butyral as a main component to prepare a slurry, which was formed into a sheet by the doctor blade method. Next, through holes 4 for connecting the coil conductor patterns, which form a spiral coil, are formed at predetermined positions on the obtained magnetic ferrite green sheet 3 by laminating and connecting through holes.

On the other hand, the coil conductors A pattern 6 to F pattern 11 corresponding to the pattern of the through holes 4 formed in the sheet 3 and the transfer pad are formed on the transparent transfer release film 1 having a release coating. 2 were each printed with a conductive paste and dried.

Next, the magnetic ferrite green sheet 3 having the through holes 4 formed therein, the transfer peeling film 1 having the coil conductors A pattern 6 to F pattern 11 printed thereon, and the transfer pad 2 having the transfer pad 2 printed thereon are transferred. A release film 1 was used to produce a laminate as follows. First, a green sheet 3 (dummy sheet) having no through holes 4 formed therein was laminated and pressure-bonded to a predetermined thickness to obtain a dummy portion 5 (FIG. 3). Then, on the surface of the dummy portion 5, the coil conductor A pattern 6 having an external lead-out port is formed.
The transfer peeling film 1 on which the pattern is printed is laid down, and the coil conductor A pattern 6 is transferred onto the sheet by pressing the film from above with a flat plate. It was peeled off (FIG. 4).

Next, the magnetic ferrite green sheet 3 having the through holes 4 formed thereon is laminated and pressure-bonded on the dummy portion 5 having the coil conductor A pattern 6 transferred to the surface (FIGS. 5 and 22), As shown in FIG. 1A, the transfer pad 2 is provided on the surface at a position corresponding to the through hole 4.
After aligning the transfer release film 1 on which is printed as shown in FIG. 1 (b) with the printing surface of the transfer pad 2 facing downward, stacking and pressure bonding as shown in FIG. 1 (c). The transfer pad 2 was transferred onto the coil conductor A pattern 6 in the lower layer in the through hole 4 and the transfer release film 1 was peeled from the sheet 3 as shown in FIG. 1D (FIGS. 6 and 23). .

Then, the coil conductor B pattern 7 is transferred onto the surface of this sheet in the same manner as described above (FIGS. 7 and 24), and the green sheet 3 having the through holes 4 formed therein.
After stacking and pressure bonding (FIG. 8), the transfer pad 2 was transferred onto the lower layer coil conductor B pattern 7 in the through hole 4 (FIG. 9). In this way, the coil conductor C pattern 8 shown in FIG. 10 is transferred, the green sheet 3 having the through holes 4 shown in FIG.
Transfer of the transfer pad 2 shown in FIG. 13, transfer of the coil conductor D pattern 9 shown in FIG. 13, stacking and pressure bonding of the green sheet 3 having the through holes 4 shown in FIG. 14, transfer of the transfer pad 2 shown in FIG. The transfer of the coil conductor E pattern 10 shown in FIG. 16, the lamination and pressure bonding of the green sheet 3 having the through holes 4 shown in FIG. 17, and the transfer pad 2 shown in FIG. 18 were performed.

After the coil having a desired number of turns is constructed by repeating the above-mentioned operation, the coil conductor F pattern 11 having the other external outlet is transferred (see FIG. 1).
9) Then, the green sheet 3 (dummy sheet) having no through holes formed thereon was laminated and pressure-bonded to a predetermined thickness to form a dummy portion 5, thereby obtaining a laminated body (FIG. 20). After that, the obtained laminated body is heated at a temperature of 120 ° C. and a pressure of 500 kg / cm ²
Then, main bonding was performed to obtain a chip element body. In the actual mass production process, a plurality of laminated bodies are manufactured at once as shown in FIG. 2, and therefore, a step of cutting into individual chips is inserted after the main pressure bonding.

After the main press bonding, the chip element body is fired at 900 ° C. in the atmosphere, and a conductive paste for external electrodes is applied to a pair of opposing end faces of the chip element body where the external extraction ports are exposed. Was baked at 600 ° C. in the atmosphere to form the external electrode 12 (FIG. 21).

The multilayer chip inductor manufactured as described above was extremely reliable because there was no disconnection of the coil provided therein.

[0025]

As a result of the development of the present invention, the disconnection of the internal conductor pattern in the through hole portion can be prevented. Therefore, the reliability and the yield of the product are remarkably improved. Further, the method of the present invention, without significantly changing the manufacturing process of a laminated electronic component using a conventional release film for transfer,
It is extremely commercial value because it can be implemented easily and cheaply.

[Brief description of drawings]

FIG. 1 is a diagram showing stepwise a mode of transferring a transfer pad in the method of the present invention, in which (a) is a perspective view showing a transfer release film having a transfer pad printed thereon, and (b).
Is a perspective view showing a mode when the transfer release film of (a) is aligned, (c) is a perspective view showing a mode when the transfer release film is superposed on the sheet and pressure-bonded, (d)
[Fig. 3] is a perspective view showing an aspect in which the transfer release film is being peeled from the sheet.

FIG. 2 is a diagram showing stepwise a mode in which a transfer pad is transferred in the case where the method of the present invention is applied to a mass production process. FIG. 2 (a) is a view when a transfer release film is aligned. A perspective view showing a mode, (b) is a perspective view showing a mode when a release film for transfer is superposed on the sheet and pressure-bonded,
(C) is a perspective view showing a mode in which the transfer release film is peeled from the sheet.

FIG. 3 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention,
It is a perspective view which shows the dummy part comprised by laminating | stacking and pressure bonding of a dummy sheet.

FIG. 4 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention,
It is a perspective view which shows the aspect at the time of transferring the coil conductor A pattern which has an external drawing port on the surface of the sheet body of FIG.

FIG. 5 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention,
It is a perspective view which shows the aspect at the time of laminating | stacking and pressure-bonding the sheet in which the through hole was formed on the sheet body of FIG.

FIG. 6 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention,
It is a perspective view which shows the aspect at the time of transferring the transfer pad to the sheet body of FIG.

FIG. 7 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention,
It is a perspective view which shows the aspect at the time of transferring the coil conductor B pattern on the surface of the sheet body of FIG.

FIG. 8 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention,
FIG. 8 is a perspective view showing an aspect in which sheets having through holes are formed on the sheet body of FIG. 7 by stacking and pressure bonding.

FIG. 9 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention,
It is a perspective view which shows the aspect at the time of transferring the transfer pad to the sheet body of FIG.

FIG. 10 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing the laminated chip inductor according to the method of the present invention, showing a mode in which the coil conductor C pattern is transferred to the surface of the sheet body of FIG. 9; It is a perspective view.

FIG. 11 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention, in which a sheet having through holes is laminated and pressure-bonded on the sheet body of FIG. It is a perspective view which shows the aspect at the time.

12 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention, and is a perspective view showing an aspect when a transfer pad is transferred to the sheet body of FIG. is there.

FIG. 13 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing the laminated chip inductor according to the method of the present invention, showing a mode in which the coil conductor D pattern is transferred to the surface of the sheet body of FIG. 12; It is a perspective view.

FIG. 14 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention, in which a sheet having through holes is laminated and pressure-bonded on the sheet body of FIG. 13; It is a perspective view which shows the aspect at the time.

15 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention, which is a perspective view showing an aspect when a transfer pad is transferred to the sheet body of FIG. 14; is there.

16 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing the laminated chip inductor according to the method of the present invention, showing a mode in which the coil conductor E pattern is transferred to the surface of the sheet body of FIG. It is a perspective view.

FIG. 17 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention, in which a sheet having through holes is laminated and pressure-bonded on the sheet body of FIG. 16; It is a perspective view which shows the aspect at the time.

18 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing the laminated chip inductor according to the method of the present invention, which is a perspective view showing an aspect when the transfer pad is transferred to the sheet body of FIG. is there.

FIG. 19 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention, in which transfer of a coil conductor B pattern or D pattern, transfer of a transfer pad and formation of a through hole. It is a perspective view showing a mode when a coil conductor F pattern having an external lead-out port is transferred onto the surface of a sheet body obtained by repeatedly stacking the formed green sheets a predetermined number of times.

FIG. 20 is a diagram showing stepwise a manufacturing process of a laminated body at the time of manufacturing a laminated chip inductor according to the method of the present invention, wherein the laminated body obtained by laminating / press-bonding a dummy sheet on the sheet body of FIG. 19; FIG.

FIG. 21 is a perspective view showing a multilayer chip inductor manufactured by the method of the present invention.

22 is an enlarged side sectional view in the vicinity of a through hole in the sheet body of FIG.

FIG. 23 is an enlarged side sectional view of the sheet body of FIG. 6 near the through hole.

FIG. 24 is an enlarged side sectional view of the sheet body of FIG. 7 near the through hole.

[Explanation of symbols]

 1 ... Release film for transfer 2 ... Transfer pad 3 ... Magnetic green sheet 4 ... Through hole 5 ... Dummy part 6 ... Coil conductor A pattern 7 ... Coil conductor B Pattern 8 ... Coil conductor C pattern 9 ... Coil conductor D pattern 10 ... Coil conductor E pattern 11 ... Coil conductor F pattern 12 ... External electrode

Claims (1)

[Claims] 1. A laminate is obtained by alternately repeating a step of transferring an internal conductor pattern printed on a transfer release film to a green sheet and a step of laminating green sheets having through holes formed therein. A method of manufacturing a laminated electronic component, comprising forming external electrodes after pressure-bonding a laminated body, wherein a through-hole printed on a transfer release film before transferring an internal conductor pattern to a green sheet on which a through-hole is formed. A method of manufacturing a laminated electronic component, comprising: transferring a conductive transfer pad having a diameter equal to or smaller than a diameter onto an internal conductor pattern of a lower layer in a through hole.