JPH04206910A - Manufacture of laminated coil - Google Patents

Abstract

PURPOSE:To prevent a conductive paste from coming off, sagging, etc., by printing a coil pattern on an insulating material sheet with a conducting hole formed therein and simultaneously by filling the through hole with the conductive paste. CONSTITUTION:A through hole 3a for connecting coil patterns 2 and 3 is filled with a conductive paste in a state where a second insulating sheet 1b is temporarily contact-bonded to a first insulating sheet 1a with the coil pattern 2 formed therein. Consequently, it is possible to fill the hole simply and surely by the use of a thick film printing method known heretofore irrespective of the diameter of the through hole 3a relative to the thickness of the second insulating sheet 1b. In the title manufacture, therefore, the connection of the coil patterns 2 and 3 becomes more certain than that of a lamination contact bonding method known heretofore and there occurs neither defective conduction in the through hole part nor separation between the insulating sheets. That is, the through hole is completely conducted by a thin insulating sheet irrespective of the diameter of the through hole.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for manufacturing a laminated coil having a coil pattern between laminated insulating sheets. BACKGROUND ART Conventionally, there are the following two methods for manufacturing chip-shaped laminated coils. "Insulating magnetic layer" A half-turn L-shaped coil pattern is thickly printed and dried, and a magnetic 14Pt paste is printed and dried to expose a part of the coil pattern to form the magnetic layer. There was a method of manufacturing a coil component by forming a printed laminate, repeating this process alternately, and firing this printed laminate (coil forming method using printed laminate). In addition, a method of manufacturing coil parts by laminating and firing a plurality of magnetic green sheets each having a coil pattern and through-holes filled with conductive material (USP 37)
65082) (coil formation method using through holes).

[Invention or problem to be solved]

However, in the above-described coil forming method using printed lamination, a drying process is required after printing the coil pattern and magnetic layer, and it takes 2 to 4 drying processes to form a coil pattern for one coil. If it becomes necessary, its workability and mass productivity will be greatly reduced. In addition, since the connection is made by coil pattern connection or by pattern printing on a printing screen, it is necessary to take into account misalignment of the screen and perform the connection in a fairly large area, making it possible to form a smaller inductor. It was quite difficult. In addition, the above-mentioned method of forming a coil using through holes,
There are various drawbacks to joining the green sheets at the through-hole portions. In recent years, inductor parts have become smaller. Assuming that the thickness of the chip component after lamination is 1 mm and the component has a 20-turn coil pattern inside, the thickness of one insulating green sheet is 50 μm or less. Considering the processing technology of the through hole, the reliability of conduction, and the conduction resistance, the diameter of the through hole is approximately 100 to 200 μm. For example, if the thickness of the insulating green sea 1 is 50 μm, if you fill a through hole with a diameter of 100 to 200 μm with conductive paste, the diameter will be excessively large compared to the thickness, so when filling the through hole with conductive paste, , as shown in FIG. 4(a), the paste 42 may come off from the through poles 43 of the insulating green sheet 41, or
Moreover, as shown in FIG. 4(1)), the paste 42 ends up dripping onto the back side of the insulating clean sheet 41. If this kind of paste failure occurs, poor conductivity will occur after the insulating sheets are laminated, and if any paste occurs, there will be problems such as a dense laminate cannot be obtained. Is it possible to reduce the diameter of the through-hole in order to prevent this paste from falling out or dripping? If the diameter is made smaller, the electrical resistance of the conductive part will increase, causing deterioration of the characteristics. . The present invention has been devised in view of the above-mentioned problems.
The purpose is to provide a method for manufacturing a laminated inductor with continuity reliability in a portion of the through-hole, taking workability into consideration.

[Means to solve the problem]

The method for manufacturing a laminated inductor of the present invention includes the following steps. Step 1: Printing the first coil pattern on the first insulating magnetic sheet or insulating material sheet and drying. A second insulating magnetic sheet or insulating material sheet having a first through hole formed at a position connected to the first coil pattern is laminated on the first insulating magnetic sheet or insulating material sheet. The process of doing. A second coil pattern is printed on the second insulating magnetic sheet or the insulating material sheet 1i2, including the first through holes, with conductive paste 1, and at the same time, conductive paste is printed on the first through holes. The process of filling and drying. A step of laminating a third insulating magnetic sheet or insulating material sheet on the second insulating magnetic sheet or insulating material sheet 1i on which the second coil pattern is printed. A step of firing the laminate made of the first to third insulating magnetic sheets or insulating material sheets.

[Effect]

According to the manufacturing method of the present invention described above, when a coil pattern is printed on an insulating magnetic sheet or an insulating material sheet in which conductive holes are formed, and at the same time the through holes are filled with conductive paste, the insulating magnetic Since a coil pattern or a printed insulating magnetic material or an insulating material layer is already present at the bottom of the body sheet or insulating material sheet, the conductive paste 1 is used as in the coil forming method using through holes.
No leakage or dripping of conductive paste occurs. Furthermore, since the insulating magnetic sheet or the insulating material sheet layer is formed of a green sheet, the drying step during the lamination step is carried out after printing the coil pattern, resulting in a manufacturing method that does not significantly reduce workability. In addition, 1 on an insulating magnetic sheet or an insulating material sheet layer
A coil pattern for one tan can be formed in one printing process, and punching can be performed with the minimum diameter considering the through-hole diameter or conduction resistance.

【Example】

Hereinafter, the present invention will be explained based on the drawings. For the sake of explanation, a chip inductor component having a 2.5-turn coil pattern inside will be used. FIG. 1(a) is an external view of a chip inductor component according to the present invention, and FIG. 1(b) is a sectional view of the chip inductor component according to the present invention. The chip inductor component is composed of a laminated body l on which coil patterns 2 to 4 are formed, and terminal electrodes 5.6 connected to the coil patterns 2.4. The laminated body 1 is an insulating material sheet made of an insulating magnetic material sheet such as ferrite or alumina, and is formed by laminating and firing insulating sheets 1a to 1d. A coil pattern 2.3 for approximately one turn or a coil pattern 4 for approximately half a turn is formed between the layers of each insulating sheet 1a-1d. These coil patterns 2 to 4 are A
The conductive paste is formed by a thick film printing method using a conductive paste consisting of a conductive material mainly composed of G, Ag alloy, etc., a glass component, and an organic vehicle. In addition, each coil pattern 2 to 4 is an insulating sheet lb,
Through hole 3 that penetrates lc and is filled with conductive material
a and 4a are electrically connected to each other. Further, the coil pattern 2.4 has terminal connecting portions 2b, /Ib which are widened in the width direction at the ends of the laminated body 1, and terminal electrodes 5.6 formed at both longitudinal ends of the laminated body 1. is connected to. The terminal electrodes 5.6 are formed by applying paint or using a dip mainly made of Ag or Ag alloy. A chip inductor component with such a structure has a terminal electrode 5
This means that coil patterns 2 to 4 are formed between the terminal electrodes 6, and a coil of 2.5 turns is achieved. Next, the manufacturing method of the present invention is illustrated in the process diagram of FIG. First, a predetermined magnetic material, such as Ferrai 1 powder, an organic binder, etc., is kneaded, an insulating magnetic green tape is created using a pulling method or a doctor blade method, and then it is cut into an appropriate size and made into multiple sheets. Create a green sheet. In step 21, as shown in FIG. 3(a), the first insulating sheet 1-1a serving as the bottom layer is coated with a base substrate (not shown).
Fixed to. This base substrate serves as a reference in the subsequent lamination process using temporary pressure bonding and the coil pattern formation process, and is made of, for example, a flat metal plate. The fixing method is the first
The insulating sheet 1-1a is adhered to the base surface using a binder or the like. The next step 22 is a step of forming approximately one turn of the first coil pattern 2 on the first insulating sheet 1a, as shown in FIG. 3(b). Specifically, a conductive paste made mainly of Ag or Ag-Pd conductive material, mixed with a glass component, an organic binder, etc. is printed and formed using a screen printing method, and then dried for a predetermined period of time. . An insulating sheet 1 is provided at one end of this first coil pattern 2.
□] A terminal connecting portion 2b extending to one end side of a and connecting to the terminal electrode 5 is formed. The terminal connection portion 2b is provided with an insulating sheet 1- to improve the reliability of conduction with the terminal electrode 5.
, is formed wide in the width direction of a. Further, at the other end of the first coil pattern 2, a second
A through-hole runt 2c is formed to ensure conduction with the coil pattern 3. The line width of this coil pattern 2 is, for example, 80 to 200 μm.
The through hole land 2c is the through hole land 2b.
Taking into account misalignment, etc., it has a rectangular shape with at least 100 to 300 squares, or a circle with a diameter of 100 to 300 μm or more. In the next step 23, as shown in FIG. 3(c), the second insulating sheet IaJ:
This is a process of laminating layers by temporary pressure bonding. This second insulating sheet 11] has the through-I
O= A through hole 3a is formed in advance by punching at a position corresponding to the hole land 2c. The diameter of this through hole 3a is small (also), 00μ
m, reducing the conduction resistance at the through hole 3a portion. Regarding the specific temporary crimping conditions, do the appropriate pressures differ depending on the thickness of the insulating magnetic sheet or the size of the coil pattern?
It is about 5 to 501<g/cm2 at room temperature. 5 kg
/ cm 2, there is a high possibility that peeling will occur at the temporary pressure bonding part in the subsequent lamination process, and if it is less than 50 kg/cm
If it exceeds 2, the through hole 3a may be deformed or the laminated sheet may become uneven, and the next through hole 3a may be
It is difficult to fill and print with conductive paste accurately. The next step 24 is a step of forming approximately one turn of the second coil pattern 3 on the second insulating sheet 1-1b-J2, as shown in FIG. 3(d). Specifically, the above-described conductive paste is printed and formed using a screen printing method, and then dried for a predetermined period of time. One end of this second coil pattern 3 is shaped to cover a through hole 3a of the second insulating sheet 1-1b. This ensures that the conductive paste is filled in the through hole 3a and connected to the other end of the first coil pattern 2. Further, the other end of the second coil pattern 3 is similar to the other end of the first coil pattern 2.
A through-hole land 3c is formed to ensure conduction with the coil pattern 4. The next step 25 is a step of laminating the third insulating sheet IC on the second insulating notebook lb by temporary pressure bonding, as shown in FIG. 3(e). In this third insulating sheet 1□lc, a through hole 4a is formed in advance by punching at a position corresponding to the through pole land 3c. The diameter of this through hole 4a is "double through hole 3"
It has a diameter similar to that of a. The specific pre-compression bonding conditions are similar to the second insulating sheet 1)], and the pre-compression bonding is carried out by applying pressure of about 5 to 50 kg/cm2 at room temperature. The next step 26, as shown in FIG. 3(f), is a step of forming approximately half a turn of the third coil pattern 4 on the third insulating sheet t-1cl-. Specifically, the above-described conductive paste is printed and formed using a screen printing method, and then dried for a predetermined period of time. One end of this third coil pattern 4 is shaped to cover the through hole 4a of the third insulating sheet 1b. This ensures that the conductive bases 1 to 1 are filled in the through holes 4a and connected to the other end of the second coil pattern 3. Further, the other end of the third coil pattern 4 extends to the other end side of the insulating sheet 1-1c, and a terminal connection portion 4b is formed to connect to the terminal electrode 6. Similarly to the terminal connection part 2b, the terminal connection part /Ib is formed wide in the width direction of the insulating sheet 1c in order to improve the reliability of conduction between the terminal electrodes 6 and the like. The next step 27 is a step of laminating the fourth insulating sheet 1-1d on the third insulating sheet 1c by temporary pressure bonding, as shown in FIG. 3(g). The temporary crimping conditions for this fourth insulating sheet 1-1d are as follows:
, third insulating sheet 11], the temperature was 5 to 50 at room temperature.
Temporary pressure bonding is performed with a pressure of about T<g/cm2. As a result, the first to fourth insulating sheets 1-1d are temporarily pressed onto the base substrate, and a laminate in which the coil patterns 2 to 4 are formed is achieved. The next step 28 is to remove the base substrate from the laminate achieved in the two steps. Specifically, it can be removed mechanically, or the first
If you use a binder whose adhesive strength decreases when heat is applied as the binder that fixed the insulating sheet 1□ 1 a,
The laminate can be easily removed from the base substrate by applying heat. As a result, the first to fourth insulating sheets 1□ l a to I
d is temporarily pressed and the laminated magnetic material is completed. The next step 29 is a step of completely crimping the temporarily crimped magnetic body 1. Specifically, at 50-130°C and 200-300K
Thermocompression bonding is performed by applying approximately g/cm2. As a result, the first to fourth insulating seals 1-1a to 1-1 and the completely crimped laminate are completed. The next step 30 is to prepare the first to fourth insulating sheets 1a to 1.
This is a step of cutting the crimped laminate of step d into predetermined external dimensions and sintering it. Although the two series of Figures 3(a) to (g) show the manufacture of a single inductor component, each insulating sheet) 1
Set a to 1d to a size that allows extraction of multiple inductor parts, coil patterns 2 to 4, and through hole 3a.
, 4a may be formed in advance and cut into individual inductor parts in this step. By cutting to this external size, the terminal connecting portions 2b, 4b are completely exposed from the ends of the crimp laminate. In addition, the sintering process includes a binder removal process in which the organic vehicle contained in the insulating sheets 11a-Id and the conductive paste is eliminated, and a sintering process in which the conductive materials of the insulating sheets 1a-1d and the conductive pastes 1 to 1 are sintered. This includes a main sintering step of causing a sintering reaction. The sintering temperature of main sintering is the peak temperature 850-11
It can be sintered at 00°C for 1 to several hours, or it can be sintered at a low temperature (850°C or less) by reducing the particle size of the magnetic material. At this time, it is possible to select a conductive material for the internal coil patterns 2 to 4, such as a predetermined material such as pure Ag or other metals, in accordance with the sintering temperature. Through this step, a completely sintered laminate body 1 is completed. The next step 31 is as shown in FIGS. 1(a) and (b).
This is a step of forming terminal electrodes 5 and 6 at the ends of the laminated body 1 in which the coil patterns 2 to 4 exist, respectively. The terminal electrode 5.6 is made of a conductive paste mainly made of Ag.
It is formed by dipping one end of the laminated body l, drying, dipping the opposite end, drying, and then firing. At this time, the conductive material is appropriately determined by law so that the sintering temperature is set lower than the sintering temperature of the magnetic body 1. Through this process, the terminal electrode 5 or the internal coil pattern 2
It is connected to the terminal connection part 2b of the terminal electrode 6 or to the terminal connection part 41) of the internal coil pattern 4. In the manufacturing method described below, a conductive paste is applied to the through pole 3a that connects the coil pattern 2 and the coil pattern 3, or a second insulating paste is applied to the first insulating sheet 1a on which the coil pattern 2 is formed. The adhesive sheet II) is temporarily pressed and then filled. Therefore, the second insulating sheet 1
-] Regardless of the size of the diameter of the through hole 3a cut into the thickness b, it can be easily and reliably filled using the conventional thick film printing method. Therefore, compared to the conventional lamination pressure bonding method, the connection between the coil pattern 2 and the coil pattern 3 is more reliable, and the manufacturing method does not cause conduction failure at the through-hole portion or peeling between the insulating sheets. That is, regardless of the diameter of the through-hole, the thin insulating sheet can provide complete conduction through the through-hole, making it possible to achieve a small chip inductor. Note that the above-mentioned points also apply to the second insulating sheet 1), the third insulating sheet 1c, and the through holes 4a. In addition, the coil pattern 2.3 for one tank can be formed in a single thick film printing process, and the laminated body 1 is manufactured from a green sheet, so the drying process can be omitted, making it easy to use with conventional printing lamination methods. Compare the workability and
Mass productivity will be dramatically improved. In the above manufacturing method, the base substrate can be replaced from metal by a thick or sufficiently insulating sheet 1-1a. In this case, the step of removing the base body in step 28 can be omitted. Alternatively, a thermocompression bonding step may be performed before the step 28 of removing the base substrate, and then a step of removing the base substrate may be performed. Further, the thermocompression bonding process may be performed as in step 29 immediately after simply placing the fourth insulating sheet without temporarily press-bonding the fourth insulating sheet. Although the manufacturing method described above has been explained using an inductor component having a coil pattern of 2.5 turns, the number of turns of 2.5 turns is not limited to the number of turns of 1. Alternatively, a composite inductor component may be used in which a single chip inductor is formed with coil patterns of the same phase or opposite phase. Furthermore, a dielectric sheet with through holes formed to allow conduction of the coil pattern is interposed between the insulating sheets.
It is also possible to use a C-reel composite component in which capacitor internal electrodes are formed using a thick film printing method so as to sandwich the dielectric sheet.

【effect】

As described above, according to the present invention, the conductive holes connecting the first coil pattern and the second coil pattern are formed in advance in the second insulating sheet crimped onto the first insulating sheet. The conductive paste is filled with the conductive paste at the same time as the formation of the second coil pattern on the second insulating sheet. Connection with the coil pattern can be made reliably and easily. In addition, since the magnetic material is formed using Green Sea, there is no need for a drying step when laminating the magnetic material, resulting in a manufacturing method that does not significantly reduce workability. In addition, the coil pattern of the second magnetic layer can be formed in one process per minute, and the diameter of the through hole can be processed to the minimum diameter without having to consider the thickness of the insulating sheet. Therefore, small, multilayer inductors can be easily manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1(a) is an external view of an inductor component according to the present invention, and FIG. 1(b) is a sectional view of the inductor component according to the present invention. FIG. 2 is a process diagram illustrating the manufacturing method of the present invention,
FIGS. 3(a) to 3(g) are plan views of main steps. FIGS. 4(a) and 4(1)) are cross-sectional views illustrating the filling state of the through-pole portion in the conventional pressure-bonded lamination manufacturing method. = 19-1...Laminated body 1a to 1d...Insulating sheet 2.3.4...Coil pattern 3a, 4a...Through hole

Claims (1)

[Claims] A step of printing a first coil pattern on a first insulating sheet, and a second insulating sheet in which a first conductive hole is formed at a position connected to the first coil pattern. a step of laminating a sheet on the first insulating sheet; a step of printing a second coil pattern with a conductive paste on the second insulating sheet, including the first conductive hole; Laminating a third insulating sheet on the second insulating sheet on which the second coil pattern is formed, and firing a laminate consisting of the first to third insulating sheets. Method for manufacturing laminated coils.