JP2002263563A - Manufacturing method of spindle motor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A base substrate on which a motor is to be mounted,
The present invention relates to a spindle motor in which a gap between a terminal member of a motor and a motor is sealed with an ultraviolet-curing adhesive. . An irradiance of about 100 to 150 (mW / c) is applied to a base substrate (1) on which an ultraviolet curing adhesive is applied between a terminal member of a motor and an ultraviolet irradiation device (5).
The adhesive is cured by irradiating with m ² ) ultraviolet light for 20 seconds or more. The irradiation time of 20 seconds or more is divided into 3 to 5 seconds,
It may be divided into a plurality of times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a spindle motor exclusively used for a magnetic disk drive or the like,
In particular, it is intended to improve the method of sealing the motor terminal.

[0002]

^2. Description of the Related Art Conventionally, a method of sealing a terminal portion of a spindle motor with an ultraviolet-curable adhesive is performed in a short time by irradiating ultraviolet rays of high illuminance (1000 mW / cm ² or more) at once. Was. For example, JP-A-6-22549
No. 5 describes a method of irradiating strong ultraviolet rays in a short time to quickly cure an adhesive.

[0003] A conventional spindle motor and its manufacturing method will be described below. In FIG. 3, 1 is a base substrate for mounting a motor, 2 is a stator member, and 3 is a terminal member. A stator member 2 is attached to the base substrate 1, and a terminal member 3 is implanted on a part of the stator member 2. Also, base substrate 1
Is provided with a through hole, through which the terminal member 3 communicates and is electrically connected to a drive circuit (not shown) outside the motor. Reference numeral 4 denotes a sealing adhesive portion, which seals a gap between the base substrate 1 and the terminal member 3 with an ultraviolet-curing adhesive to prevent foreign matter from entering the inside of the motor. Glued.

FIG. 4 is a configuration diagram of a conventional ultraviolet irradiation equipment. As shown in FIG. 4, reference numeral 1 denotes a base substrate, which is formed by forming the above-described stator member 2 and terminal member 3 and applying an ultraviolet-curable adhesive. 5 is a direct spot type ultraviolet irradiation device, 6 is a pallet for mounting the base substrate 1, 7 is a stopper for stopping the irradiation target for a certain irradiation time,
8 is a conveyor for conveyance.

When the pallet 6 on which the base substrates 1 are placed is conveyed by the conveyor 8 and reaches a predetermined position of the ultraviolet irradiation device 5, the pallet 6 is stopped by the stopper 7. Then, ultraviolet rays having a strong illuminance of, for example, 1700 (mW / cm ² ) are irradiated by the ultraviolet irradiation device 5 for 3.0 seconds. Curing the adhesive of the sealing bonding portion 4 of the base substrate 1;
After that, the stopper 7 is released, and the pallet 6 is conveyed by the conveyor 8 to perform the next assembling process.

[0006]

In the above-mentioned conventional bonding method, since strong illuminance and ultraviolet light are irradiated in a short time, before a sufficient adhesive force is obtained between the adhesive and the adherend, Since the curing shrinkage of the adhesive starts, a gap is generated at the boundary between the adhesive and the adherend, so that complete sealing cannot be obtained and airtightness cannot be reliably maintained. there were.

[0007]

Means for Solving the Problems To solve the above-mentioned problems, the sealing method of the present invention uses an illuminance of 100 to 150 (mW /
cm ² ) of ultraviolet rays. In particular, the irradiation time is at least 20 seconds.
It is characterized in that the adhesive is cured. Also, the same effect can be obtained by performing the ultraviolet irradiation for 3 to 5 seconds in a plurality of times and irradiating for a total irradiation time of 20 seconds or more.

According to the present invention, ultraviolet curing which suppresses shrinkage during curing of the adhesive, prevents the formation of a gap at the boundary between the adhesive and the object to be bonded, and can reliably maintain airtightness. A sealing method using a mold adhesive can be provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first aspect of the present invention, there is provided a method of manufacturing a spindle motor, comprising: inserting a terminal member of a motor into a through hole formed in a base substrate to which the motor is to be mounted; And the terminal circuit is electrically connected to the drive circuit, and the irradiation amount of ultraviolet light is 100 to 150 (mW) in a spindle motor in which the base member and the terminal member in the through hole are bonded with an ultraviolet curable adhesive.
/ Cm ² ) by irradiating ultraviolet rays, whereby the adhesive is cured.
It is possible to harden the adhesive and maintain airtightness.

Next, the invention according to a second aspect of the present invention is the method of manufacturing a spindle motor according to the first aspect, wherein the ultraviolet irradiation is performed in a plurality of times. The airtightness can be maintained more reliably.

Next, in the method of manufacturing a spindle motor according to a third aspect of the present invention, irradiation for 3 to 5 seconds is performed a plurality of times, and the total irradiation time is 20 seconds or more. A method for manufacturing a spindle motor according to Item 2, wherein the airtightness can be more reliably maintained.

(Embodiment 1) Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an ultraviolet irradiation equipment of a spindle motor according to an embodiment of the present invention. Illuminance is 105 (mW / cm ² )
Then, six UV irradiation devices with irradiation time of 4.2 seconds are arranged,
The total irradiation time is configured to be 25.2 seconds.

Reference numeral 1 denotes a base substrate, 5 denotes an ultraviolet irradiation device (conveyor-attached type), 6 denotes a pallet on which the base substrate 1 is mounted, and 7 denotes an object to be irradiated for a predetermined irradiation time (4.2 seconds). Is a stopper for stopping the transfer, and 8 is a conveyor for conveyance.

When the pallet 6 on which the base substrate 1 is placed is conveyed by the conveyor 8 and reaches the first predetermined position of the ultraviolet irradiation device 5, the pallet 6 is stopped by the stopper 7 and, for example, 105 (mW / cm ² ). UV light having an illuminance of 4.2 seconds is irradiated by the UV irradiation device 5 for 4.2 seconds. As a result, the adhesive in the sealing bonding portion 4 of the base substrate 1 is cured, and then the stopper 7 is released, and is conveyed by the conveyor 8 to a predetermined position of the next ultraviolet irradiation device. By repeating this series of steps, ultraviolet irradiation is performed six times.

Here, the reason why the illuminance is set to about 100 mW / cm ² is that when the illuminance is even weaker, 50 mW / cm ² , the illuminance is too weak and may not be sufficiently cured.
If not sufficiently cured, in the subsequent burn-in step, that is, in a step of applying heat by putting in a temperature bath to degas the adhesive, the adhesive contracts due to heat, and peeling occurs, so that a gap is formed. There is a problem. Also 200
If the irradiation is performed at a high illuminance of mW / cm ² or more, shrinkage starts before the adhesive is cured, so that a gap is formed.

The reason why the ultraviolet irradiation is divided into six times is that each process in assembling the spindle motor takes less than 5 seconds on average, so that if it takes more than 20 seconds at one place, the flow of the production line will be smooth. Because they cannot do it. In other words, this is to match the time required for each assembly process.

As described above, according to the present invention, when performing the sealing operation of the spindle motor, it is possible to harden the adhesive and to maintain the airtightness by eliminating a gap.

[0018]

Next, specific effects of the present invention will be described with reference to FIG. FIG. 2 is a graph showing the effect of the present invention based on actually measured values. It shows the irradiation time and the rate of generation of gaps (incomplete sealing) when the illuminance of ultraviolet light is changed. Illuminance is 100-150
When ultraviolet rays of mW / cm ² are divided into 5 to 6 times and continuously irradiated for 4 seconds each, the rate of occurrence of gaps is 100%, but after 20 seconds, it drops to 0%.

However, the strong illuminance (100
(0 mW / cm ² or more) at a time, and the sealing adhesion is performed in a short time (3 to 5 seconds). I couldn't do it at all.

[0020]

As described above, according to the present invention, the shrinkage of the adhesive during curing is suppressed, the occurrence of a gap at the boundary between the adhesive and the object to be bonded is prevented, and the airtightness is ensured. It becomes possible to keep.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ultraviolet irradiation equipment according to an embodiment of the present invention.

FIG. 2 is a graph showing a gap generation rate according to an ultraviolet irradiation time in one embodiment of the present invention.

FIG. 3 is a cross-sectional view of a main part of a portion for performing sealing and bonding of a spindle motor.

FIG. 4 is a configuration diagram of a conventional ultraviolet irradiation equipment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base board 2 Stator member 3 Connector terminal 4 Sealing adhesion part 5 Ultraviolet irradiation device 6 Pallet 7 Stopper 8 Conveyor

Claims (3)

[Claims] 1. A motor according to claim 1, wherein a terminal member of the motor is inserted into a through hole formed in a base substrate to which the motor is to be mounted, so that the motor is electrically connected to an external drive circuit. In a spindle motor in which the member and the member are bonded with an ultraviolet-curing adhesive, the irradiation amount of ultraviolet light is 100 to 150 (mW / cm ² ).
A method of manufacturing a spindle motor, wherein the adhesive is cured by performing the ultraviolet irradiation. 2. The method of manufacturing a spindle motor according to claim 1, wherein the ultraviolet irradiation is performed in a plurality of times. 3. The method for manufacturing a spindle motor according to claim 2, wherein irradiation for 3 to 5 seconds is performed a plurality of times, and the total irradiation time is 20 seconds or more.