JPH0864488A - Method of forming external electrode for surface mount type electronic element - Google Patents

Abstract

PURPOSE: To form an external electrode at a low production cost and high accuracy by covering specified part of the surface of an electronic element with heat resistive films, then forming an electrode film, peeling these films from this surface and removing them, together with extra electrode film. CONSTITUTION: Tape-like heat resistive films 12-14 cover specified parts of the surface of a piezoelectric element 1. The vapor deposition or sputtering treatment, is applied in the arrow direction to form an electrode film 19, using Ag, Ag-Pd, Pd or the like. This film is formed also on the surfaces of the films 12-14. These films 12-14 are peeled off from the surface of the element 1 and removed, together with extra electrode film 19 formed on the surfaces of the films 12-14, to form an external electrode on the surface of the element 1. Thus an external electrode can be made at a high accuracy, without using a high-price stainless mask.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a surface mount type electronic component,
For example, the present invention relates to a method for forming external electrodes such as surface-mounted piezoelectric components.

[0002]

2. Description of the Related Art Conventionally, when an external electrode is formed on a surface mount type electronic component, it is formed by applying a plate-shaped stainless mask on the surface of the electronic component and then performing vapor deposition or sputtering treatment. Was there. However,
There is a problem that this mask is distorted by heat during vapor deposition or sputtering. Therefore, it is necessary to replace the expensive mask before the distortion due to heat is generated, which is one of the factors for increasing the manufacturing cost. Further, even if such strict mask management is performed, there are cases in which distortion due to heat is generated in the mask and the external electrodes cannot be accurately formed.

Therefore, an object of the present invention is to provide a method of forming an external electrode of a surface mount type electronic component which is inexpensive in manufacturing cost and has excellent accuracy of the external electrode.

[0004]

In order to solve the above problems, in the method of forming external electrodes of a surface mount type electronic component according to the present invention, (a) a predetermined portion of the surface of the electronic component is formed of a heat resistant film. And (b) a step of forming an electrode film on the surface of the electronic component, and (c) an extra electrode film formed on the surface of the heat resistant film by peeling the heat resistant film from the surface of the electronic component. And a step of forming a desired external electrode on the surface of the electronic component together with the step of removing the external electrode. Here, as the material of the heat resistant film, there is a physically peelable resin, for example, 3044 (trade name) manufactured by 3M Co. or aluminum foil with an adhesive. Alternatively, there are adhesive resins that are cured by UV irradiation to reduce the adhesive strength, and adhesive resins that are heated to expand and foam the gas in the adhesive to reduce the adhesive strength. A specific example of the latter is River Alpha (trade name) manufactured by Nitto Denko.

By the above method, the heat-resistant film is brought into close contact with the surface of the electronic component, the dimensional change hardly occurs due to heat during vapor deposition or sputtering, and an accurate external electrode is formed.
In addition, the external electrodes can be easily formed only by peeling the heat resistant film together with the extra electrode film formed on the surface thereof from the surface of the electronic component.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method of forming external electrodes of a surface mount type electronic component according to the present invention will be described below with reference to the accompanying drawings. In this embodiment, a piezoelectric component will be described as an electronic component, but a capacitor component, an inductor component, an I component
It goes without saying that it may be a C component or the like.

As shown in FIG. 1, a surface mount type piezoelectric component 1
Is composed of a piezoelectric substrate 2 and sealing substrates 7 and 8 that sandwich the piezoelectric substrate 2 to form a vibration space. The piezoelectric substrate 2 is made of a ceramic material such as PZT. The piezoelectric substrate 2 may be made of quartz, LiTaO ₃ or the like in addition to a ceramic material such as PZT. Vibration electrodes 3 and 4 are provided on the upper and lower surfaces of the piezoelectric substrate 2. Vibrating electrode 3
Is electrically connected to the extraction electrode 5 provided at the upper left corner of the piezoelectric substrate 2, and the vibrating electrode 4 is electrically connected to the extraction electrode 6 provided at the lower right corner of the piezoelectric substrate 2. . These electrodes 3 to 6 are formed by means such as sputtering, vapor deposition, or print drying.

The sealing substrates 7 and 8 are made of a ceramic material such as alumina and have vibration space forming recesses 7a and 8a formed on one surface thereof. The sealing substrates 7 and 8 are shown in FIG.
As shown in FIG. 3, the piezoelectric component 1 is fixed with the piezoelectric substrate 2 sandwiched therebetween via an epoxy adhesive or the like, and has a vibration space sealed inside.

As shown in FIG. 3, the piezoelectric components 1 are stacked and set so as to be manufactured by a method suitable for mass production. The piezoelectric components 1 are closely contacted with each other, and the vapor deposition metal and the sputtering metal described later are designed so as not to enter the gaps between the piezoelectric components 1. However, the plurality of piezoelectric components 1 may not be stacked as in the present embodiment, but may be set individually.

Next, a predetermined portion of the surface of the piezoelectric component 1 is covered with band-shaped heat resistant films 12, 13, 14. In the case of the present embodiment, a liquid heat-resistant material is applied to the upper surface and front and back side surfaces of the piezoelectric component 1 which are superposed by means such as screen printing, and then dried to form the heat-resistant films 12 to 14. To do. The screen mask used at this time is less expensive than the conventional stainless steel mask, and since it is not subjected to thermal stress, it is not likely to be distorted and has a very long life. Alternatively, heat-resistant films 12 to 14 are obtained by adhering sheet-shaped heat-resistant materials to the upper surface and the front and back side surfaces of the laminated piezoelectric component 1. In this case, the mask is unnecessary. As the heat-resistant material, a resin that can be physically peeled off in a subsequent step, for example, 3044 (trade name) manufactured by 3M, aluminum foil with an adhesive, or the like is used.

Next, as shown in FIG. 4, vapor deposition or sputtering of Ag, Ag-Pd, Pd, etc. is performed from the direction of the arrow in the figure. The vapor-deposited metal or the sputtered metal scattered from the vapor deposition source or the sputtering source reaches the upper surface and the side surfaces on the front side and the back side of the stacked piezoelectric component 1 and forms the electrode film 19. The electrode film 19 is also formed on the surfaces of the heat resistant films 12 to 14. Heat resistant film 12-14
Adheres to the surface of the piezoelectric component 1 and is unlikely to undergo dimensional change due to heat during vapor deposition or sputtering.

Next, as shown in FIG.
14 is peeled off from the surface of the piezoelectric component 1, and the heat resistant films 12 to 1
4 along with the extra electrode film 19 formed on the surface of 4,
External electrodes 20 and 21 are formed on the surface of the piezoelectric component 1. In the case of a physically peelable resin or an aluminum foil with an adhesive, the heat-resistant films 12 to 14 can be peeled off by peeling or a jig coated with an adhesive can be pressed against the heat-resistant films 12 to 14. The heat-resistant films 12 to 14 are attached to a jig and then peeled off, or the like by a mechanical or chemical means. When the heat resistant films 12 to 14 are made of a material whose adhesive strength is reduced by UV irradiation, UV irradiation is performed to weaken the adhesive strength of the heat resistant films 12 to 14 and then peeled off. Alternatively, when the heat resistant films 12 to 14 are made of a material whose adhesive force is reduced by heat,
After heating to weaken the adhesive strength of the heat resistant films 12 to 14, the heat resistant films 12 to 14 are turned over and peeled off.

Next, as shown in FIG. 6, the external electrodes 20,
The piezoelectric component 1 on which 21 is formed is separated for each product.
In the piezoelectric component 1 thus obtained, the external electrode 20 is electrically connected to the extraction electrode 5, and the external electrode 21 is the extraction electrode 6.
Electrically connected to. The method of forming the external electrodes of the surface-mounted electronic component according to the present invention is not limited to the above embodiment, and can be variously modified within the scope of the gist. In particular, various shapes and numbers of external electrodes are selected according to the specifications of electronic components. The shape and number of the external electrodes can be easily changed by arbitrarily changing the shape of the heat resistant film.

[0014]

As is apparent from the above description, according to the present invention, a peelable heat resistant film is formed so as to cover a predetermined portion of the surface of an electronic component, and then an electrode film is formed. Since this heat-resistant film was peeled off from the surface of the electronic component and removed together with the extra electrode film to form the desired external electrode on the surface of the electronic component, it is possible to manufacture the electronic component without using an expensive stainless steel mask. You can Further, the heat-resistant film is in close contact with the surface of the electronic component, and the dimensional change is less likely to occur due to heat during vapor deposition or sputtering, and an accurate external electrode can be formed.

Further, no special device is required for forming and peeling the heat resistant film, and batch processing is possible for forming the external electrodes, which facilitates mass production. Furthermore, the shape of the external electrode can be easily changed by arbitrarily changing the shape of the heat resistant film, and is suitable for high-mix low-volume production.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a method of manufacturing a surface mount electronic component according to the present invention.

FIG. 2 is a perspective view showing a manufacturing method following FIG.

FIG. 3 is a cutaway perspective view showing the manufacturing method following FIG. 2;

FIG. 4 is a cutaway perspective view showing the manufacturing method following FIG. 3;

5 is a cutaway perspective view showing the manufacturing method following FIG. 4. FIG.

FIG. 6 is a perspective view showing the manufacturing method following FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piezoelectric component 12, 13, 14 ... Heat resistant film 19 ... Electrode film 20, 21 ... External electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H03H 9/02 L 9/13

Claims (1)

[Claims] 1. A step of coating a predetermined portion of a surface of an electronic component with a heat resistant film, a step of forming an electrode film on the surface of the electronic component, and a step of peeling the heat resistant film from the surface of the electronic component to form the heat resistant film. Forming a desired external electrode on the surface of the electronic component by removing the excess electrode film formed on the surface of the conductive film, and forming the external electrode on the surface of the electronic component.