JPH10241908A - Composite device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the variation of the electric characteristic and dimensional accuracy of a composite element, by forming the blank body of the element by integrating a sintered thin plate-like thermistor ceramic body having electrode layers on both surfaces with a sintered thin plate-like dielectric ceramic body having electrode layers on both surfaces with an insulating adhesive. SOLUTION: The blank body of a composite element is formed by integrating a sintered thin plate-like thermistor ceramic body 1 having electrode layers 1A on both surfaces with a sintered thin plate-like dielectric ceramic body 2 having electrode layers 2A on both surfaces with an insulating adhesive 3, and coating layers 4 of a high polymer material are formed on the four side faces of the blank body. In addition, the external electrodes 5 formed on both end faces of the blank body are constituted of conductive resin layers 5a formed as terminal electrodes and plated Ni layers 5B and plates solder layers 5C formed on the surface of the resin layers 5a. Therefore, a highly accurate highly reliable composite element having a desired resistance value and capacity value can be obtained without any restriction from the component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite device and a method of manufacturing the same, and more particularly, to a temperature-compensating composite device surface-mounted on a circuit board or the like for a temperature compensation circuit such as a crystal oscillator, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, when a parallel circuit of a thermistor and a capacitor as shown in FIG. 3 is formed in a temperature compensation circuit or the like of a crystal oscillator, a plurality of electronic components such as a thermistor and a capacitor are individually mounted on the same substrate. Is mounted by flow or reflow soldering.

However, when a circuit is formed by using a plurality of individual electronic components such as a thermistor and a capacitor as described above, since a plurality of components are mounted on the same substrate, the mounting area inevitably increases. This has been a major constraint in downsizing circuits.

As one method of solving this problem, compounding of parts can be considered. That is, for example, the thermistor unit and the capacitor unit are combined and integrated to form one composite element. With such a composite device, the number of components mounted on the substrate can be significantly reduced, and the mounting area is small, so that the size of the circuit can be reduced.

Heretofore, in the production of such a composite element, a method of laminating different materials and simultaneously sintering and integrating them has been adopted. That is, for example, by laminating a green sheet of a thermistor ceramic and a green sheet of a dielectric ceramic and firing under pressure, sintering of the ceramic material and joining and integration of the thermistor material and the dielectric material are simultaneously performed. .

[0006]

In the above-mentioned conventional method, sintering and joining of each material can be achieved by one firing, thereby reducing the number of manufacturing steps. Since there is a difference in the contraction and shrinkage ratios, problems such as non-uniform dimensions of the obtained composite element occur, and it is difficult to obtain a product having desired electrical characteristics and dimensional accuracy. In addition, in order to simultaneously sinter the thermistor material and the dielectric material, it is necessary to match the sintering temperatures of the two materials. Therefore, in many cases, it has been difficult to design a composite device having desired characteristics.

[0007] The present invention solves the above-mentioned conventional problems, does not restrict the constituent materials, and has a small variation in electrical characteristics and dimensional accuracy, and has a high-precision, high-reliability high-characteristic composite element. It is an object of the present invention to provide a manufacturing method thereof.

[0008]

The composite element of the present invention has a structure in which a thermistor layer having an electrode layer formed on the surface and a dielectric layer having an electrode layer formed on the surface are laminated via an insulating layer. In a composite element having a rectangular parallelepiped element body and external electrodes provided on both end surfaces of the element body, the element body is a thin thermistor ceramic sintered body having an electrode layer formed on a surface thereof, It is characterized by being manufactured by laminating and integrating a thin plate-shaped dielectric ceramic sintered body having an electrode layer formed on its surface via an insulating adhesive.

In the composite element of the present invention, since the thin plate-shaped thermistor ceramic sintered body and the thin plate-shaped dielectric ceramic sintered body are bonded and integrated with an insulating adhesive, the dimensional accuracy and electric characteristics due to shrinkage during firing are reduced. Variation is avoided, and the resistance value and the capacitance can be adjusted with high accuracy. Also,
A desired composite element having excellent characteristics can be obtained without being restricted by the constituent materials due to the matching of the sintering temperatures.

The composite element of the present invention has an insulating bond between a thin plate-shaped thermistor ceramic sintered body having an electrode layer formed on the surface and a thin plate-shaped dielectric ceramic sintered body having an electrode layer formed on the surface. A step of obtaining a laminate by laminating via an agent, a step of cutting the laminate into strips to obtain a prismatic element, and cutting the prismatic element in a direction orthogonal to its longitudinal direction. It can be manufactured by the method for manufacturing a composite element of the present invention, which includes a step of obtaining a chip-shaped element and a step of forming external electrodes on both end surfaces of the chip-shaped element.

Further, the thin plate-shaped thermistor ceramic sintered body of the present invention is characterized in that a coating layer of a polymer material is formed on four side surfaces other than both end surfaces on which the external electrodes of the element body are formed, and that the substrate bending resistance is reduced. It is preferable because excellent performance such as reliability related to product strength such as heat resistance and temperature cycle and weather resistance related to heat resistance and moisture resistance can be obtained.

That is, since the coating layer of a polymer material as a protective layer of the element can be formed without exposing the element to a high temperature, the heat load on the element at the time of forming the coating layer is small.
The influence on characteristics (variation in characteristics, etc.) can be reduced.

Further, since the polymer material has a large coefficient of thermal expansion, the stress relationship between the element body and the coating layer after forming the coating layer at the curing temperature of the polymer material is as follows. Compressive stress is applied, and the mechanical strength of the product can be improved.

Further, since the polymer material itself is excellent in denseness and high in strength, when producing a composite element, it is necessary to cut the element body and the coating layer of the polymer material in a joined state. Problems (microcracks, etc.) can be avoided.

[0015] Therefore, there is provided a composite element excellent in reliability regarding product strength, weather resistance, and the like.

A composite device having a coating layer of a polymer material comprises:
In the manufacturing method of the present invention, after forming a coating layer of a polymer material on both main plate surfaces of the laminate, the laminate is cut into strips, and the resulting rectangular columnar body has four side surfaces extending in the longitudinal direction. Forming a coating layer of a polymer material on the two side surfaces where the element body is exposed and then cutting it into chips, or extending in the longitudinal direction of the prism-shaped element body obtained by cutting the laminate. It can be manufactured by forming a coating layer of a polymer material on the side surface and cutting it into chips.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 are sectional views showing an embodiment of the composite device of the present invention.

The element body of the composite element shown in FIG. 1 has a thin plate-like thermistor ceramic sintered body 1 having electrode layers 1A formed on both surfaces, and a thin plate-shaped dielectric body having electrode layers 2A formed on both surfaces. The ceramic sintered body 2 is bonded and integrated via an insulating adhesive 3, and a coating layer 4 of a polymer material is formed on four side surfaces of the element body. External electrodes 5 are formed on both end surfaces of the element body. The external electrode 5 includes a conductive resin layer 5A as a terminal electrode, a Ni plating layer 5B and a solder plating layer 5C formed on the surface thereof.
It consists of.

In the composite device shown in FIG. 2, the electrode layer 1A of the thin plate-shaped thermistor ceramic sintered body 1 and the electrode layer 2A of the thin plate-shaped dielectric ceramic sintered body 2 are formed in the same manner as in FIG.
Are different from the composite device shown in FIG. In the members shown in FIG. 2, members having the same functions as the members shown in FIG. 1 are denoted by the same reference numerals.

The circuit diagram of the composite device shown in FIGS. 1 and 2 is as shown in FIG.

Next, a method of manufacturing the composite device of the present invention for manufacturing such a composite device of the present invention will be described with reference to FIGS.

In the method of the present invention, first, a thin plate-shaped thermistor ceramic sintered body 11A and a thin plate-shaped dielectric ceramic sintered body 11B are prepared, and Ag is applied to the front and back main plate surfaces of each ceramic sintered body 11. , Ag / Pd or other conductive metal powder and a conductive paste containing glass frit are printed in a predetermined pattern to form an electrode layer 1 for resistance value adjustment.
2 (FIG. 4A).

Next, the thin plate-shaped thermistor ceramic sintered body 11A on which the electrode layer 12 is formed and the thin plate-shaped dielectric ceramic sintered body 11B on which the electrode layer 12 is formed are bonded using an insulating adhesive. To obtain a laminate 13 (FIG. 4).
(B)). A polymer material paste is printed and applied to the front and back main plate surfaces of the laminate 13 and then cured by heating to form a coating layer 14 of the polymer material (FIG. 4C).

Next, the laminate 13 on which the coating layer 14 of the polymer material is formed is cut into a strip shape to obtain a prismatic element body 15 (FIG. 4D). Then, of the four side surfaces extending in the longitudinal direction of the prismatic element body 15, the coating layer 14 of the polymer material is also formed on the two side surfaces 15a and 15b where the coating layer of the polymer material is not formed ( FIG. 4 (e).

The prism-shaped element body 16 having the polymer material coating layer 14 formed on the four side surfaces is cut in a direction perpendicular to the longitudinal direction to obtain a chip-shaped element body 17 (FIG. 4 (f)).

External electrodes 18 are formed on both end surfaces of the chip-shaped element body 17 where the coating layer of the polymer material is not formed (FIG. 4 (g)). That is, a conductive resin paste obtained by forming a conductive metal powder and a thermosetting resin into a paste with an organic solvent is applied, dried, and heat-cured to form the conductive resin layer 5.
A is formed, and further, a Ni plating layer 5B and a solder plating layer 5C are formed.

As described above, the coating layer 14 made of a polymer material is a laminate 1 of the thin plate-shaped thermistor ceramic sintered body 11A and the thin plate-shaped dielectric ceramic sintered body 11B.
After being formed on both main plate surfaces of No. 3, in addition to forming on the remaining two side surfaces of the prismatic element obtained by cutting this, the laminate is cut without forming a coating layer on the laminate 13, A coating layer of a polymer material may be formed on four side surfaces of the obtained prismatic element body.

That is, as shown in FIG.
-Shaped thermistor ceramic sintered body 11 formed with
A and a thin plate-shaped dielectric ceramic sintered body 11B on which an electrode layer is formed are laminated with an insulating adhesive, and the obtained laminate 13 is cut to obtain a prism element 19, and this prism element 19 is obtained. 1
As shown in FIG. 5 (b), a coating layer 14 of a polymer material is formed on four side surfaces extending in the longitudinal direction of No. 9 to form a prism element 16 having four side surfaces coated with a polymer material. The columnar element 16 is cut into chips in the same manner as in FIG.
The external electrode 18 is formed as in (g).

According to this method, the coating layer of the polymer material can be formed in one step.

In the present invention, the thickness of the thin plate-shaped thermistor ceramic sintered body and the thin plate-shaped dielectric ceramic sintered body differ depending on the target product shape. The thickness of the thermistor ceramic sintered body and the thin plate-shaped dielectric ceramic sintered body is about 0.20 to 0.40 mm.

The pattern of the electrode layer formed on the thin plate-shaped thermistor ceramic sintered body and the thin plate-shaped dielectric ceramic sintered body is not particularly limited, and is appropriately designed so as to obtain a desired composite element. Also, the number of laminated sheets of the thermistor ceramic sintered body and the laminated dielectric ceramic sintered sheet, thermistor material of the sintered thermistor ceramic sheet, the dielectric material of the sintered dielectric ceramic sheet, The electrode layer material and the like are also optional.

As the insulating adhesive used for bonding the thin plate-shaped thermistor ceramic sintered body and the thin plate-shaped dielectric ceramic sintered body, a thermosetting insulating adhesive such as a one-component epoxy resin is used. In this case, the bonding between the thin plate-shaped thermistor ceramic sintered body and the thin plate-shaped dielectric ceramic sintered body is performed by applying an insulating adhesive and then heating to the curing temperature. . In bonding, it is preferable to press the laminate of the thin plate-shaped thermistor ceramic sintered body and the thin plate-shaped dielectric ceramic sintered body.

Further, as the polymer material forming the coating layer of the polymer material, an insulating thermosetting polymer material such as a one-component epoxy compound resin can be used. After the molecular material is applied to the element body, it is heated and cured at the curing temperature to form a coating layer. As the coating layer, in terms of protection of the composite element, it is possible to use an inorganic material layer of a glass layer.
Highly dense, high-strength, and can be formed without exposing the element body to high temperatures.Because there is no problem of micro-cracking of the element body during cutting, forming a coating layer of a polymer material Is preferred.

The thickness of the coating layer of this polymer material is usually 1
It is about 0 to 30 μm.

In this embodiment, the conductive resin layer is formed as the terminal electrode of the external electrode. However, by forming the conductive resin layer instead of the conventional conductive metal layer as described above,
As in the case of the coating layer of the polymer material, the external electrodes can be formed without exposing the element body to a high temperature, which is preferable. Also, if it is a conductive resin layer, when mounted on a circuit board,
When mechanical stress caused by deflection when cutting the board, or thermal stress caused by the difference in the coefficient of thermal expansion of the element body, electrode, solder, board, etc. during temperature cycling is transmitted to the external electrode,
These stresses can be alleviated by the flexible conductive resin layer serving as the base layer of the external electrode, and the effect of preventing the element from cracking due to these stresses can also be obtained.

The ratio of the metal powder of the conductive resin paste used for forming such a conductive resin layer to the thermosetting resin is determined in order to secure the conductivity and flexibility of the electrode layer. Thermosetting resin 30 to 70-95% by weight
It is preferably about 5% by weight. Metal powder ratio is 7
If the content is less than 0% by weight, the electrical connection between the conductive resin layer and the electrode layer inside the element becomes insufficient, and the conductivity of the surface decreases when a plating film is formed by the electrolytic plating method. It becomes difficult to form a coating. If the proportion of the metal powder exceeds 95% by weight, the effect of relieving stress is reduced, which is not preferable.

As the metal powder, a noble metal powder such as Ag or Pd or Ni powder can be used. As the thermosetting resin, epoxy, phenol, xylene, urethane resin and the like can be mentioned.

The thickness of the conductive resin layer formed as described above is preferably 50 to 150 μm, for example, when the composite element of the final product has a length of about 1.6 mm. When the thickness of the conductive resin layer is less than 50 μm, the bonding strength and conduction with the chip-shaped thermistor element as the terminal electrode layer are insufficient, and the stress relaxation effect by forming the conductive resin layer is not sufficient. , 150 μm, there is a problem of variation in chip dimensions. Note that if the chip size increases, the upper limit may be increased accordingly.

The thickness of the Ni plating layer formed on the conductive resin layer is 1 to 5 μm, and the thickness of the solder plating layer is 3 to 7
It is preferably set to μm.

In the present embodiment, a Ni plating layer and a solder plating layer are provided as plating layers, and thus, the formation of the Ni plating layer and the solder plating layer is not required during mounting on a substrate. Although it is more preferable from the viewpoint of necessary solder wettability and heat resistance, as described above, since the conductive resin layer can sufficiently withstand solder erosion without the Ni plating layer, the manufacturing cost can be reduced by omitting the Ni plating layer. It can also be reduced. When the Ni plating layer is omitted, the thickness of the solder plating layer is preferably 5 to 10 μm.

[0042]

The present invention will be described more specifically below with reference to examples and comparative examples.

Example 1 The composite device shown in FIG. 1 was manufactured by the method shown in FIGS.

First, a thin plate-shaped thermistor ceramic sintered body (50 mm × 35 mm × 0.3 mm thick) and a thin plate-shaped dielectric ceramic sintered body (50 mm × 35 mm ×
Ag / Pd paste is printed in a belt-like pattern on both main plate surfaces (thickness: 0.3 mm), dried, and then dried.
Baking was performed at 820 ° C. for 10 minutes to form a multi-row electrode layer having a thickness of about 10 μm.

The thin plate-shaped thermistor ceramic sintered body and the thin plate-shaped dielectric ceramic sintered body on which the electrode layers are formed in this manner are accurately positioned, and an insulating adhesive (one-part epoxy-containing thermosetting (Resin) and heated at 150 ° C. for 30 minutes under pressure to adhere.

A polymer material paste (one-part epoxy-containing thermosetting resin) was applied to both main plate surfaces of the obtained laminate by screen printing, dried and then heated at 150 ° C. for 30 minutes to be cured. Then, it was cut into a strip having a width of 0.72 mm according to the pattern of the electrode by a dicing machine to obtain a prismatic element.

A coating layer of a polymer material was formed in the same manner as described above on the two sides of the prismatic element body which were not coated with the polymer material.

Each of the coating layers of the polymer material formed on the four side surfaces of the prismatic element body has a thickness of 20 μm.

Next, the prismatic element body whose four side surfaces were covered with the coating layer of the polymer material was cut out into a chip shape having a length of 1.52 mm by a dicing machine.

A conductive resin paste containing Ag powder (Ag powder: epoxy resin =
85:15 (% by weight) to which an organic solvent was added at 10% by weight) by a dipping method.
And then cured by heating at 230 ° C. for 2 hours to form a conductive resin layer having a thickness of 80 μm, and then forming a Ni plating layer having a thickness of 2 μm on the surface of the conductive resin layer. A solder plating layer having a thickness of about 5 μm was formed thereon.

With respect to the composite device thus manufactured,
An electrical property evaluation test was performed, and the results are shown in Table 1.

Comparative Example 2 In Example 1, the composite integration of the thermistor and the capacitor was simultaneously sintered and integrated, that is, a green sheet of thermistor ceramic with a conductive paste printed thereon and a dielectric ceramic And a printed sheet of conductive paste on a green sheet of
Except that it was baked at 00 ° C. for 5 hours to form a laminate, a composite element having the same material and dimensions and the same electrode pattern was manufactured,
An electrical property evaluation test was performed on the obtained composite device in the same manner as in Example 1, and the results are shown in Table 1.

In this comparative example, a glass layer having a thickness of 4 μm was formed instead of the coating layer of the polymer material, and instead of the conductive resin layer, an Ag paste containing glass frit was applied and baked to form a glass layer having a thickness of 80 μm. A conductive metal layer was formed.

[0054]

[Table 1]

From Table 1, it is apparent that the composite device of the present invention shows superior characteristics in terms of electrical characteristics and the like, as compared with a device obtained by simultaneously sintering and integrating a thermistor and a capacitor. .

[0056]

As described above in detail, according to the composite device of the present invention and the method of manufacturing the same, the composite device has dielectric characteristics and thermistor characteristics, and has a desired resistance value and capacitance value. It is possible to provide a high-accuracy, high-reliability, high-characteristic composite device that is not restricted by materials and has small variations in electrical characteristics and dimensional accuracy.

According to the present invention, a composite element having characteristics equivalent to a parallel circuit of a thermistor and a capacitor can be realized as a single element. Therefore, if the composite element of the present invention is used, for example, a parallel circuit of a thermistor and a capacitor It is possible to reduce the size of an electric circuit such as a temperature compensating circuit configured as above. INDUSTRIAL APPLICABILITY The present invention is extremely useful industrially as an element of a temperature compensation circuit such as a temperature-compensated crystal oscillator, which has a strong need for miniaturization.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a composite device of the present invention.

FIG. 2 is a sectional view showing another embodiment of the composite device of the present invention.

FIG. 3 is a parallel circuit diagram of a thermistor and a capacitor.

FIG. 4 is a perspective view showing one embodiment of a method for manufacturing a composite device according to the present invention.

FIG. 5 is a perspective view showing another embodiment of the method for manufacturing a composite device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11A Thin plate-shaped thermistor ceramic sintered body 2, 22B Thin plate-shaped dielectric ceramic sintered body 1A, 2A, 12 Electrode layer 3 Insulating adhesive 4, 14 Polymer coating layer 5A Conductive resin layer 5B Ni plating layer 5C Solder plating layer 11 Ceramic sintered body 13 Laminated body 15, 16, 19 Prismatic element 17 Chip element 18 External electrode

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Osamu Mori Inventor 2270 Yokoze, Yokoze-cho, Chichibu-gun, Saitama, Japan

Claims (5)

[Claims] 1. A rectangular parallelepiped element having a structure in which a thermistor layer having an electrode layer formed on its surface and a dielectric layer having an electrode layer formed on its surface are laminated via an insulating layer, A composite element having external electrodes provided on both end surfaces thereof, wherein the element body is a thin plate-shaped thermistor ceramic sintered body having an electrode layer formed on the surface, and a thin plate-shaped sintered body having an electrode layer formed on the surface. A composite element manufactured by laminating and integrating a dielectric ceramic sintered body via an insulating adhesive. 2. The composite element according to claim 1, wherein a coating layer of a polymer material is formed on four side surfaces other than the both end surfaces of the element body. 3. A laminated thermistor ceramic sintered body having an electrode layer formed on its surface and a laminated dielectric ceramic sintered body formed with an electrode layer formed on its surface via an insulating adhesive. A step of obtaining a body; a step of cutting the laminate into strips to obtain a prismatic body; and a step of cutting the prismatic body in a direction orthogonal to the longitudinal direction to obtain a chip-like body. Forming external electrodes on both end surfaces of the chip-shaped element body. 4. The method according to claim 3, wherein after forming a coating layer of a polymer material on both main plate surfaces of the laminate, the laminate is cut into strips and extends in the longitudinal direction of the obtained prismatic body. A method for manufacturing a composite element, comprising forming a coating layer of a polymer material on two of the side surfaces where the element body is exposed, and then cutting the chip into chips. 5. The method of manufacturing a composite element according to claim 3, wherein a coating layer of a polymer material is formed on four side surfaces extending in a longitudinal direction of the prism-shaped element body and then cut into chips. .