JP4822386B2 - Part joining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for bonding with which an initial shift and an internal stress of a bonding material due to curing shrinkage are reduced and a change with time (a shift with time) of the bonding material is reduced when parts are joined with an energy ray-curable adhesive. <P>SOLUTION: An adhesive having energy ray-curing characteristics is partially irradiated with energy rays and the irradiated part is scanned to cure the whole adhesive layer. Curing is partially and successively carried out while maintaining a state in which an uncured part is present in the periphery of the irradiated part by curing the whole adhesive layer. The amount of curing and shrinking of the adhesive (a reduction in volume due to the curing shrinkage) is supplemented from the uncured adhesive having fluidity in the periphery of the irradiated part. Thereby, the production of stress (tensile stress) in the interior of the adhesive due to the curing shrinkage is suppressed. As a result, the initial shift of the bonding material due to the curing shrinkage of the adhesive is reduced and the positional shift (shift with time) of the bonding material caused by natural and gradual release of the residual stress in the adhesive layer is remarkably reduced. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding method and a bonding apparatus for parts using an adhesive, and reduces initial stress caused by shrinkage of an adhesive layer to reduce initial stress during bonding between parts to be bonded (bonded object and bonded object). (Initial position deviation) is prevented to improve the initial position accuracy, and over time, the position deviation between the above parts caused by changes in residual stress can be prevented, and this position deviation affects the performance. It is extremely effective for bonding precision components such as optical components of optical pickups of information recording apparatuses and liquid crystal panels of liquid crystal projectors.

In general, as an adhesive for adhering parts, a heat curing type, an anaerobic curing type, a light (ultraviolet ray, visible light, etc.) curing type, etc. are representative, and some have some properties. Among them, energy ray curable resins typified by ultraviolet curable resins are used in various fields because of their high reaction speed and greatly shortened curing time.
In the case of the thermosetting type, a process of applying heat in an oven or the like is required, which hinders the speeding up of the process, and some parts cannot tolerate heat. Is unusable, and the anaerobic curing type needs to have a limited adhesion structure due to the characteristics of the curing process, and therefore is unusable for bonding optical components.
In addition, in the case of an energy ray curable adhesive, a photo-curing type is used because there is almost no thermal influence and there are no special restrictions on the adhesive structure. In particular, ultraviolet (UV) curable molds are frequently used for joining necessary parts.

On the other hand, the heat curing type, the anaerobic curing type, and the photo-curing type have a problem that when the adhesive is cured, it is cured and contracted (volume contraction), and this contraction generates internal stress (curing contraction force). is there. This curing shrinkage is generally about 5 to 10% for an acrylic ultraviolet curable resin and about 2 to 5% for an epoxy ultraviolet curable resin, and the curing shrinkage force increases as the shrinkage amount increases. This curing shrinkage force does not significantly affect the adhesive strength, but in precision assembly, high positional accuracy between the parts to be bonded is required. It has a great influence on the performance and quality of the product. In other words, even when bonded in a state of being positioned with high accuracy, the adjusted inter-component position may be displaced due to the effect of curing shrinkage of the adhesive (initial deviation), or the internal stress of the adhesive accumulated by curing shrinkage may be reduced. There is a possibility that it will be released due to a temperature change after curing, etc., and the bonding position of the parts will change over time, impairing the function of the precision assembly.
In the prior art, the problems of the initial deviation and the change with time (time deviation) are roughly divided into the following four methods.

  The first method is described in Japanese Patent Application Laid-Open No. 2000-090481 and Japanese Patent Application Laid-Open No. 10-309801, which is a method for reducing the amount of curing shrinkage by reducing the amount of adhesive used in a thin amount. It is. However, the thing of the said Unexamined-Japanese-Patent No. 2000-090481 is basically surface adhesion, and it is necessary to use a special adhesive agent. Further, the one disclosed in Japanese Patent Laid-Open No. 10-309801 has a problem in that the bonding structure is limited and indirect bonding is required, so that another part is required and the number of bonding points increases.

  The second method is described in Japanese Patent Application Laid-Open No. 2001-350072, which is a method of controlling the UV light to be irradiated to eliminate variations and improve the uniformity of curing shrinkage. In this method, there is a problem that the bonding structure is basically limited to surface bonding, and there is a problem that misalignment due to curing shrinkage cannot be avoided when there is uneven application of adhesive. Further, since the entire adhesive layer is cured almost simultaneously, there is a problem that internal stress due to curing shrinkage is high, and a change with time (time shift) is likely to occur.

  The third method is described in JP-A-10-121013, JP-A-07-201028, and JP-A-05-041408, which is a method of modifying the adhesive itself. Thus, for example, the timing of occurrence of curing and shrinkage is separated by the technique of reducing the curing shrinkage of the adhesive by the addition of ceramic fine particles or the addition of a filler or the addition of a heat shrink resin. And development of these adhesives is actively performed for the solution of the said subject. However, in this case, it is necessary to use a special adhesive, and as the amount of the adhesive increases, there is a problem that the amount of cure shrinkage increases proportionally, the internal stress increases, and a change with time is likely to occur.

The fourth method is described in Japanese Patent Application Laid-Open No. 09-197105, which is performed by adjusting the thickness of the bonding layer following the shrinkage of the bonding layer accompanying the curing shrinkage of the adhesive. Thus, the stress due to shrinkage is reduced. However, this technology can reduce only the stress that occurs at the interface between the adhesive that cures and shrinks and the part that does not shrink, and it cannot sufficiently reduce the residual stress inside the adhesive after curing. High position accuracy cannot be maintained.
JP 2000-090481 A JP-A-10-309801 JP 2001-350072 A JP-A-10-121013 Japanese Patent Application Laid-Open No. 07-201028 Japanese Patent Laid-Open No. 05-041408 JP 09-197105 A

  Therefore, the present invention provides a bonding method and a bonding apparatus that can reduce initial stress due to curing shrinkage of an adhesive, reduce internal stress accumulated at the time of curing, and reduce change with time (time shift) of the adhesive. The challenge is to devise.

[Solution 1] (corresponding to claim 1)
Means 1 taken in order to solve the above problems is based on the premise of a component bonding method in which an adhesive is bonded to an adherend by an adhesive having energy ray curing characteristics.
A part joining method in which a part of an adhesive layer is irradiated with the energy beam and the irradiated part is scanned to sequentially cure the entire adhesive layer, wherein the adhesive part is a plurality of irradiated parts. It is to irradiate and scan a position that is symmetrical with respect to the center at the same time .
[Action]
By irradiating part of the adhesive layer with energy rays such as ultraviolet rays and scanning the irradiated part to cure the entire adhesive layer, it is partially sequentially while maintaining the state where the uncured part exists around the irradiated part Curing and curing shrinkage of the adhesive (volume decrease due to curing shrinkage) is replenished from fluid uncured adhesive around the irradiated area, so stress (tensile stress) is generated inside the adhesive by curing shrinkage. Occurrence is suppressed. Therefore, the initial deviation of the adhesive due to the curing shrinkage of the adhesive is reduced, and the positional deviation (time deviation) of the adhesive which occurs as the residual stress in the adhesive layer is gradually gradually released is remarkably reduced.
Furthermore, by setting the irradiation part to the adhesive layer as a plurality of irradiation parts and simultaneously irradiating and scanning a position symmetrical with respect to the center of the adhesive to cure the entire adhesive layer, the curing shrinkage force is brought to the adhesive center. Since they are offset and balanced as a whole, the deviation of the adhesive due to the curing shrinkage force is remarkably reduced .

[Embodiment 1] (corresponding to claim 2)
Embodiment 1 relates to the component joining method of Solution 1 above, first irradiating the central portion of the adhesive layer with energy rays, and scanning the irradiated portion in a plane so as to be sequentially cured from the vicinity of the outer periphery of the adhesive layer cured portion. Is to cure the entire adhesive layer.
[Action]
By first irradiating the center of the adhesive layer with energy rays and scanning the irradiated part in a plane so that the adhesive layer is continuously cured sequentially from the vicinity of the outer periphery of the adhesive layer, curing is sequentially performed from the center of the adhesive layer toward the outer periphery. As it proceeds, the cure shrinkage is replenished from the uncured adhesive around the cured portion.
Note that the uncured portions of the cured portion around by the plane scanning, because as long as enough to replenish by its fluidity of shrinkage of the hardening unit, which may be very small. Accordingly, the stress and residual stress associated with the subsequent curing of the uncured portion are extremely small, and the positional deviation (initial deviation and temporal deviation) due to this is extremely small.

[Embodiment 2] (corresponding to claim 3)
In the second embodiment, with respect to the component joining method of the solution 1, the energy rays are condensed and focused on the inside of the adhesive layer to be irradiated first, and then sequentially cured from the vicinity of the outer periphery of the adhesive layer curing portion. In other words, the entire adhesive layer is cured by three-dimensionally scanning the irradiated portion.
[Action]
Concentrate the energy rays, irradiate the focal point first inside the adhesive layer and irradiate the irradiated part three-dimensionally so that the adhesive part is continuously cured from the vicinity of the outer periphery of the adhesive layer, thereby thickening the adhesive layer. Even in this case, the curing shrinkage is replenished sequentially from the uncured adhesive around the cured part, and the curing proceeds sequentially from the inside of the adhesive layer toward the outer surface, so replenishment from the uncured adhesive around the cure shrinkage. The action is continued until irradiation of the entire adhesive is completed.

[Embodiment 3] (corresponding to claim 4)
Embodiment 3 relates to the component joining method of Solution 1 described above. Irradiation is performed by irradiating the energy beam from a plurality of directions, using an intersection of each energy beam as an irradiation unit, and scanning the irradiation unit in three dimensions. It is to cure the entire layer.
[Action]
By irradiating energy rays from a plurality of directions and using the intersection of each energy beam as an irradiator, and scanning the irradiator in three dimensions, a portion having a high energy density can be easily formed inside the adhesive layer. In addition, curing by irradiation with energy rays is promoted at a portion where the energy density is high. And since the cured part is controlled in three dimensions by scanning the intersection (irradiation part ) of the energy beam in three dimensions, the replenishment action from the uncured adhesive around the cure shrinkage is the adhesion This is continued until irradiation of the entire agent is completed.

[Embodiment 4] (corresponding to claim 5)
Embodiment 4 relates to the component joining method of Solution 1 , Embodiment 1 or Embodiment 2 described above, and when scanning the irradiated portion of the energy beam toward the outer periphery of the adhesive layer, intermittent irradiation is performed with a scanning interval. This is to leave the uncured part so as to be connected to the outer periphery of the adhesive layer, and then irradiate the uncured part with energy rays to cure the entire adhesive layer.
[Action]
When scanning the irradiated part toward the outer periphery of the adhesive layer, intermittent irradiation is performed with a scanning interval left so that the uncured part is connected to the outer periphery of the adhesive layer, and then the uncured part is irradiated with energy rays to irradiate the entire adhesive layer. By curing, even if there is a delay in the curing shrinkage of the adhesive, an uncured portion that can flow is left in the vicinity of the irradiated portion, so that the cured shrinkage is supplemented from the surrounding uncured adhesive.
Since the uncured portion is connected to the outer periphery of the adhesive layer, when the uncured portion is cured and contracted, the occurrence of stress in the inside is suppressed as much as possible.

[Embodiment 5] (corresponding to claim 6)
Embodiment 5, the component bonding method of the above solution 1, when scanning toward the irradiated portion in the adhesive layer outer periphery, by scanning radially open the scan spacing, the uncured portion is connected to the adhesive layer periphery And then irradiating the uncured part with energy rays to cure the entire adhesive layer.
[Action]
When scanning the irradiated part toward the outer periphery of the adhesive layer, leave the uncured part connected to the outer periphery of the adhesive layer by scanning radially with a scan interval, and then irradiate the uncured part with energy rays and bond By curing the entire layer, an uncured portion remains around the irradiated portion even when there is a reaction delay in the cure shrinkage of the adhesive, so that the cure shrinkage is supplemented from the surrounding uncured adhesive.

[Embodiment 6] (corresponding to claim 7)
Embodiment 6, the above solution 1, for component bonding method of embodiment 1, or embodiment 2, when you scan the irradiation portion of the light energy beam toward the outer periphery from the adhesive layer central portion, intermittently irradiated Not It is to disperse the cured portion and then irradiate the uncured portion with energy rays to cure the entire adhesive layer.
[Action]
Toward the outer periphery from the adhesive layer center part when you scan the irradiation unit, by dispersing an uncured portion intermittently irradiated, then, by curing the entire adhesive layer is irradiated with energy rays uncured portion, adhesive Even when there is a reaction delay in curing shrinkage, uncured portions are dispersed around the irradiated portion, so that the curing shrinkage is supplemented from the surrounding uncured adhesive.

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[ Embodiment 7 ] (corresponding to claim 8 )
In the seventh embodiment , the energy beam is first irradiated to the adhesive other than the portion where the adhesive and the adhesive and / or the adherend are in contact with each other in the solution 1 , the embodiment 2, or the third embodiment. Then, the adhesive at the portion where the adhesive and the adhesive and / or the adherend are in contact is finally cured.
[Action]
The energy rays are first irradiated to the adhesive other than the part where the adhesive and the adhesive and / or the adherend are in contact, and the adhesive at the part where the adhesive and the adhesive and / or the adherend is in contact is finally cured. In addition to suppressing internal stress due to curing shrinkage, the adhesive shrinkage is absorbed by the uncured layer, and most of the adhesive layer is cured without acting between the adhesive and the adherend. , The initial displacement of the adhesive is reduced.

[ Embodiment 8 ] (corresponding to claim 9 )
Embodiment 8, solutions 1, the component bonding method of the embodiment 2, or embodiment 3, the line of intersection if the adhesive material and the adherend is in direct contact, the contact kimono and adherends with the adhesive It is to first irradiate and cure the energy ray, and then scan the irradiated portion from the central portion of the adhesive layer toward the outer periphery.
[Action]
If the adhesive material and the adherend is in direct contact, previously cured by irradiating an energy beam from the intersection section of the contact kimono adherend and the adhesive, then irradiated toward the outer periphery from the adhesive layer central portion by scanning the part, adhesion thereof with intersection section of contact kimono adherends and adhesive is temporarily fixed, the curing of the other portions in a state in which the thus temporarily fixed proceeds. Further, the cured shrinkage is sequentially cured while being replenished from the surrounding uncured adhesive.
Therefore, the positional deviation of the parts at the initial stage of curing is avoided, and the temporal deviation of the adhesive after curing is reduced.

[ Embodiment 9 ] (corresponding to claim 10 )
Embodiment 9 is the component joining method according to Solution 1 to Embodiment 8 , in which after the irradiation portion is scanned, the entire adhesive layer is uniformly irradiated with energy rays to completely cure the adhesive.
[Action]
By uniformly irradiating the entire adhesive layer with energy rays after scanning the irradiated area and completely curing the adhesive, there will be no uncured part left due to the scanning leakage of the irradiated area. The time lag of the bonded product due to the curing reaction after bonding of the agent is remarkably suppressed.
The uniform irradiation of the energy beam to the entire adhesive layer is a secondary irradiation performed to cure the uncured portion remaining after the primary irradiation by scanning, and is cured by this secondary irradiation. Since the volume of the adhesive layer to be formed is smaller than the cured volume by primary irradiation, the accompanying internal stress and residual stress are small. Therefore, the initial deviation and the temporal deviation due to this are extremely small.

[Solution 2]
Means 2 taken to solve the above problems is based on the premise of a component joining apparatus that adheres an adhesive to an adherend with an adhesive having energy ray curing characteristics.
An irradiation means for irradiating a part of the adhesive layer with energy rays and a scanning means for scanning the irradiation portion are provided.
[Action]
An irradiation means for irradiating a part of the adhesive layer with energy rays and a scanning means for scanning the irradiating portion are provided. The energy rays from the irradiating means are locally irradiated on the adhesive layer to be adhesively cured, and this irradiation portion is scanned as described above. Scan by means. As a result, adhesion hardening is locally promoted, and this adhesion hardening range is sequentially expanded to reach the entire adhesive layer. In this way, the component joining method of the solving means 1 can be executed.

[Embodiment 1]
This embodiment 1 includes a condensing irradiating means for condensing and irradiating the energy rays inside the adhesive layer, and a three-dimensional scanning means for three-dimensionally scanning the irradiating portion of the component joining apparatus of the solving means 2. That is.
[Action]
Condensing irradiation means for condensing and irradiating energy rays inside the adhesive layer, and a three-dimensional scanning means for three-dimensional scanning of the irradiation part, so that adhesion is performed at a position where light is condensed and irradiated by the condensing irradiation means. The adhesive curing action of the layer is advanced, and the position to be condensed and irradiated is three-dimensionally scanned in the adhesive layer by the three-dimensional scanning means. As a result, the adhesive curing range is sequentially expanded in the three-dimensional direction inside the adhesive layer to reach the entire adhesive layer. In this way, the component joining method according to the second embodiment of the solving means 1 can be easily performed.

[Embodiment 2]
The second embodiment includes an irradiation unit that irradiates the energy beams so as to intersect from a plurality of directions, and a plurality of scanning units that scan the energy beams, and overlaps the irradiation. And an operating means for three-dimensionally scanning the part.
[Action]
An embodiment of solving means 1 comprising a plurality of irradiation means for irradiating energy rays from a plurality of directions and a plurality of scanning means for three-dimensionally scanning each irradiation means, and scanning the plurality of energy rays so as to overlap each other. The component joining method 3 can be easily executed.

[Embodiment 3]
Embodiment 3 is that the component joining apparatus according to Solution 2 to Embodiment 2 is provided with light shielding means for turning on and off the energy beam irradiation at high speed and its control means.
[Action]
Equipped with a light-blocking means that turns on and off the irradiation of energy rays, leaving an uncured part so that it can be connected to the outer periphery of the adhesive layer in the middle of scanning, even if there is a delay in the curing shrinkage of the adhesive, it flows near the irradiated part Possible uncured parts can be left. Thereby, the component joining method of Embodiment 4 of the solution means 1 can be performed.

[Embodiment 4]
This embodiment 4 includes a recognizing means for recognizing the position of the adhesive layer, the position of the adherend, and the position of the adherend of the component joining apparatus according to the solution 1 to the embodiment 3 above, It is provided with the selection means which selects the optimal scanning pattern according to the adhesive substance position.
[Action]
Recognizing means for recognizing the position of the adhesive layer, the position of the adherend, and the position of the adhesive is provided, and an optimum scanning pattern can be set regardless of variations in the adhesive application range and application shape.

[Embodiment 5]
Embodiment 5 is that the component joining apparatus according to Solution 5 to Embodiment 4 includes irradiation means for irradiating the entire adhesive layer with energy rays after scanning the energy ray irradiation portion.
[Action]
After irradiating the energy ray irradiation part to the adhesive layer, it is equipped with an irradiation means that irradiates the entire adhesive layer with energy rays, so there is no residue of uncured parts due to energy beam scanning leakage, and adhesion of uncured adhesive It is possible to further prevent the occurrence of time lag of the adhesive due to the subsequent reaction.

The effects of the present invention will be summarized for each claim as follows.
(1) The invention according to claim 1 By irradiating a part of the adhesive layer with energy rays and scanning the irradiated part to cure the entire adhesive layer, the volume shortage due to the curing shrinkage of the adhesive is around the irradiated part. Since the uncured adhesive is replenished, the stress in the adhesive layer at the time of curing can be relieved, and the initial misalignment of the adhesive due to curing shrinkage can be reduced. In addition, the residual stress in the adhesive layer is reduced by the relaxation of the stress in the adhesive layer at the time of curing, and it is possible to prevent the subsequent aging of the adhesive due to the change of the residual stress with time.
Furthermore, by setting the irradiation part to the adhesive layer as a plurality of irradiation parts and simultaneously irradiating and scanning a position that is symmetric with respect to the center of the adhesive, curing proceeds simultaneously at the symmetrical position of the center of the adhesive. The contraction force is symmetric with respect to the center point, and acts in opposite directions to be offset and balanced. As a result, it is possible to further significantly reduce the displacement of the adhesive due to curing shrinkage .

(2) The invention according to claim 2 The irradiation layer is scanned from the central portion of the adhesive layer by first irradiating the central portion of the adhesive layer with energy rays and scanning the irradiation portion so as to be sequentially cured from the vicinity of the outer periphery of the adhesive layer cured portion. Curing progresses sequentially, and the volume shortage due to curing shrinkage is replenished from the uncured adhesive around it (periphery in plan view). Since the scanning of the energy beam irradiation part is a planar scanning, the scanning control is very simple, and the adhesive layer is thin and particularly suitable for planar component joining.

(3) The invention according to claim 3 The irradiation part is three-dimensionally scanned so that the focal point on which the energy beam is condensed is first irradiated inside the adhesive layer and then cured sequentially from the vicinity of the outer periphery of the adhesive layer cured part. Then, the curing proceeds three-dimensionally from the inside of the adhesive layer, and the cure shrinkage is replenished from the uncured adhesive around the cured portion (spatial periphery), so that the adhesive layer is thickly filled (see FIG. 5). In the case of adhesive bonding) and build-up bonding (bonding form in FIG. 6), the stress generation in the adhesive in the depth direction is alleviated and the residual stress in the adhesive layer is reduced.

(4) The invention according to claim 4 The energy rays are irradiated from a plurality of directions, the crossing portion of each energy ray is set as the irradiation portion, and the irradiation portion is easily three-dimensionally bonded to a portion having a high energy density. Can be made inside the layer. Accordingly, the inside of the adhesive layer is partially and intensively cured, and this cured portion is controlled three-dimensionally, so that the effect of the invention according to claim 1 can be realized more remarkably.

(5) The invention according to claim 5 When scanning the irradiation part toward the outer periphery of the adhesive layer, intermittent irradiation is performed with a scanning interval left so that the uncured part is connected to the outer periphery of the adhesive layer, and then the uncured part is left. By irradiating the energy beam and curing the entire adhesive layer, even if there is a delay in the curing shrinkage of the adhesive, it can be cured sequentially while always leaving an uncured part that can flow near the irradiated part. The effects of the inventions according to claims 1 to 3 can be realized more remarkably.

(6) The invention according to claim 6 When scanning the irradiated portion toward the outer periphery of the adhesive layer, by scanning radially with a scanning interval, the uncured portion is left so as to be connected to the outer periphery of the adhesive layer, and then unexposed. By irradiating the cured part with energy rays and curing the entire adhesive layer, even if there is a reaction delay in the curing shrinkage of the adhesive, it can be sequentially cured while leaving an uncured part around the irradiated part, Thereby, the effect of the invention according to claim 1 can be realized more remarkably.

(7) wherein when you scan the irradiation portion toward the outer periphery from the invention the adhesive layer center part according to claim 7, dispersing the uncured portion by intermittently irradiating the adhesive layer and thereafter irradiated with an energy beam in the uncured portion By curing the whole, even when there is a reaction delay in the curing shrinkage of the adhesive, it is possible to sequentially cure while leaving an uncured portion around the intermittent irradiation portion. The effect of the invention according to Item 3 can be realized more remarkably.

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( 8) The invention according to claim 8 The portion where the adhesive and the adhesive and / or the adherend are in contact with each other by first irradiating the adhesive other than the portion where the adhesive and the adhesive and / or the adherend are in contact with each other. When the adhesive is finally cured, the portion where the adhesive and the adhesive and / or the adherend are in contact with each other remains as an uncured layer, so that the curing shrinkage of the adhesive is reduced in the uncured layer. / Also, most of the adhesive layer is cured without being blocked between the adherend and acting between the adherend and the adherend. Therefore, the effect of the invention according to claim 1 , claim 3, or claim 4 can be realized more remarkably, and the deviation of the adhesive due to curing shrinkage is further reduced remarkably.

(9) according If invention adhesive material and adherend according to claim 9 is in direct contact, previously cured by scanning the energy beam from the line of intersection between tangent kimono adherend adhesive, then the adhesive layer center by scanning the irradiated portion from the part toward the outer periphery, the adhesive material is temporarily fixed by the small amount of cure of intersection section of contact kimono and adherends with the adhesive in the initial irradiation step. Since the hardening of the entire adhesive layer sequentially proceeds in such a temporarily fixed state, the effect of the invention according to claim 1 , claim 3, or claim 4 can be realized more remarkably. The above-described misalignment is more reliably reduced.

( 10) Invention according to claim 10
By uniformly irradiating the entire adhesive layer with energy rays after scanning of the irradiated portion and completely curing the adhesive, there remains no uncured portion due to scanning leakage of the irradiated portion . Therefore, the effects of the inventions according to claims 1 to 9 can be realized more remarkably, and the occurrence of time lag of the bonded product accompanying the progress of the curing reaction after bonding of the uncured adhesive can be further significantly reduced. can do.

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For example, when a housing (material: aluminum) that is a component constituting an optical pickup of an information recording apparatus and an optical prism having a size of about 10 mm × 10 mm × 10 mm are overlapped and bonded with a UV curable adhesive, two adhesives are used. Even if the thickness of the adhesive is strictly uniform and the irradiation is strictly uniform on the entire surface, it is applied to the housing with a thickness of 20 to 30 μm. At the beginning of bonding, the optical prism and the optical prism have a worst-case misalignment (initial misalignment) of about 5 μm. Thereafter, the worst-case misalignment with time is about 2-3 μm.
An embodiment such as an example in which the present invention is applied when an optical pickup of the information recording apparatus is manufactured by bonding with a UV curable adhesive will be described.

A joining apparatus according to an embodiment of the present invention will be described with reference to FIG.
The bonding apparatus according to the embodiment includes an object to be bonded (the housing in the first embodiment) 1 held by the object holding means 12 and an adhesive (the optical prism in the first embodiment) held by the adhesive holding means 13. ) 2, an adhesive adjusting means 11 for optically recognizing the position of the object to be adhered by the adhesive position recognizing means 9 and adjusting the position to an adhesion target position on the adherend, and before or after the position adjustment Application means (not shown) for applying an energy ray curable adhesive to the bonding surface between the adherend and the adhesive is provided. In addition, FIG. 1 has shown the state which the position adjustment of the adhesives and to-be-adhered objects, and application | coating of the energy-beam curable adhesive (the thickness of the contact bonding layer 3 is 20-30 micrometers similar to the above) was finished.
In this state, the UV curable adhesive is irradiated with ultraviolet rays (UV) to cure the adhesive and bond the adherend 1 and the adhesive 2 together.

The ultraviolet irradiation device includes irradiation means 6 that irradiates the adhesive layer with ultraviolet rays (energy rays) and scanning means 7 that scans the irradiated ultraviolet rays in the XY directions (horizontal two-dimensional directions). Ultraviolet rays are applied to a part of the adhesive (optical prism) 2 through the light shielding means 10, and this is transmitted through the adhesive (optical prism) 2 and applied to the adhesive layer 3. Irradiation position location 5 of the ultraviolet to the adhesive layer 3 is scanned by the scanning unit 7 so as to spread outward from the center portion of the adhesive layer 3. Scanning route 4 in the first embodiment is as shown in FIG. 2 (a), the spiral path on the (1) to (8) of ultraviolet numerous parts as shown in (FIG. 2 (b)) irradiation (Each part of the above (1) to (8) is a schematic display. Actually, the irradiation range is a circle having a diameter of 0.2 to 0.3 mm. 2 to 0.3 mm and scan).
Irradiation during scanning is normal continuous irradiation, but scanning may be performed while leaving the uncured layer on the scanning line by controlling the light shielding means 10 on and off with a computer.
The light shielding means 10 is an electromagnetically driven shutter, but a light shielding means such as a rotary shutter or a liquid crystal shutter can be used. Since there are advantages such as easy control and easy change of the light shielding time, the first embodiment uses an electromagnetically driven shutter.

  At each irradiation position, the curing reaction occurs only in the portion irradiated with ultraviolet rays, and the surrounding adhesive is kept in a fluid state in an uncured state, so as schematically shown in FIG. Then, the uncured adhesive is drawn from the surrounding uncured portion toward the adhesive that is undergoing cure shrinkage, thereby replenishing the cure shrinkage. Such a replenishment effect is made in all each irradiation part, the irradiation part finally reaches the outer peripheral part of the adhesive layer, and in the curing in this outer peripheral part, the uncured part that supplements the shrinkage is not adjacent, There is no resistance to shrinkage, so no internal stress is generated. Therefore, no strong stress is generated along with the curing shrinkage in the entire adhesive layer, and no strong internal stress remains.

  The ultraviolet scanning means 7 for performing the above-described plane scanning is to scan the irradiation position 5 in the XY direction by moving the irradiation head 71 on which the light shielding means 10 is mounted in the XY direction by the XY stage 72 (FIG. 3). In addition, it is also possible to use a galvanometer mirror 7a, 7b driven by a motor m that scans with the optical axis deflected in the XY directions (FIG. 4).

Example 2 in the case where the adhesive layer is thick will be described (FIG. 5).
The irradiation head 71 a is provided with condensing means composed of a condensing lens, a condensing mirror, etc., and is supported by the XY stage 72. The irradiation head 71a moves in the Z-axis (vertical axis) direction, and can scan the focal position (irradiation position) 5 with respect to the adhesive layer in the vertical direction. Thereby, it is possible to scan in the XYZ directions.
First, the focal position 5 of the ultraviolet ray is aligned with the internal position of the adhesive layer to irradiate the internal position, and the irradiated portion is three-dimensionally scanned so as to be sequentially cured from the vicinity of the outer periphery of the adhesive layer cured portion. Thereby, it is made to harden | cure sequentially, maintaining the state in which an unhardened part always exists in the outer periphery vicinity of a hardening part.
As a three-dimensional scanning method, ultraviolet rays are irradiated onto the adhesive layer by an irradiation head 71a having a condensing means, and the focal point is scanned in the XYZαβ direction (4a is the main scanning direction, 4b is the sub-scanning direction) by the XYZαβ stage. (Fig. 5). According to this, in addition to scanning in the XYZ directions, scanning is also performed in the αβ direction (rotation of the optical axis in the αβ direction), so that even if there is a portion (for example, a corner) that cannot be applied in the scanning in the XYZ direction. The irradiated light can be reliably applied to this part.

Next, Example 3 in which overlay bonding is performed will be described (FIG. 6).
In the case of using a non-uniform adhesive layer such as overlay adhesion (adhesion with an adhesive deposited at the corner), for example, ultraviolet rays are emitted from a plurality of directions of X and Z directions by irradiation means 6-1 to 6-8. Are irradiated, the irradiated portions are overlapped, and the irradiated overlapping portion is scanned in three dimensions. That is, the longitudinal direction of the irradiation means 6-2,4,6,8 scanned in XY direction in the horizontal plane by locally irradiating while scanning means an adhesive 3a, lateral illumination means 6-1,3, By irradiating the entire width of the adhesive 3a with a very thin horizontal plane light 5 and 7 while scanning it in the Z direction (vertical direction) by the scanning means, the portion where the two irradiation lights intersect is inside the adhesive. It is designed to be scanned three-dimensionally.

Next, Example 4 will be described (FIG. 7).
By the way, in the case of an adhesive having a large delay until the curing shrinkage occurs with respect to the increase in viscosity after irradiation with ultraviolet rays, the curing shrinkage sufficiently occurs before the irradiation with the energy rays around the irradiated part. However, after the fluidity of the surrounding adhesive layer is lowered, there is a problem that curing shrinkage occurs and internal stress accumulates. In such a case, the light shielding means 10 for turning on / off the irradiation of ultraviolet rays is provided (see FIG. 1), and when the irradiation portion is scanned toward the outer periphery of the adhesive layer, the irradiation is not performed by intermittent irradiation with a scanning interval. By leaving the hardened part connected to the outer periphery of the adhesive layer (FIG. 7 (a)), even if there is a delay in the reaction of the adhesive and the occurrence of the hardening shrinkage is slow, the scanning speed is not slowed down. An uncured portion 4d can be interposed nearby. Then, the uncured portions are arranged to be connected to the adhesive layer periphery, without the uncured portions 4d are isolated, can be smoothly replenished from the uncured portions of the curable shrinkage. Open the scanning interval by scanning radially, the same effect by uncured portions min 4d leaves to be connected to the adhesive layer periphery is obtained (FIG. 7 (b)). Also, ON the light blocking means at high speed, thereby OFF dispersing the uncured part minute 4d intermittently irradiated by a (FIG. 7 (c)) as the same results are obtained.

Next, an embodiment that is particularly effective for preventing misalignment (initial misalignment) during bonding will be described (FIG. 8).
In the case where the adhesive layer is cured by scanning a plurality of irradiated portions, a position that is symmetrical with respect to the center of the adhesive is simultaneously irradiated and scanned. In this way, even if the curing shrinkage force in the direction of the arrow acts on the adhesive, the curing shrinkage force is counterbalanced and balanced against each other, so the initial deviation of the adhesive due to cure shrinkage is reduced. The
Note that there is no reason that the pair of irradiated portions that are symmetrical with respect to the center of the adhesive and are irradiated at the same time should be one, and two sets and three sets can be irradiated at the same time.

Furthermore, examples of the bonding method for preventing the initial displacement of the bonded material due to filling of the adhesive and building up are shown in FIGS. 9-1 and 9-2.
In the example of FIG. 9A, the adhesive 3a is filled with a thickness of 3 to 5 mm in a gap of 2 to 3 mm in width between the adherend 1 and a square adhesive 2 having a side of 20 mm and a thickness of about 5 mm. Adhesion. An energy beam is first scanned and irradiated to the adhesive 3a other than the part where the adhesive 3a and the adhesive 2 and / or the adherend 1 are in contact with each other, whereby the adhesive 3a and the adhesive 2 and / or the adherend 1 are irradiated. By finally curing the adhesive of the part in contact with the adhesive (see the cured part 4c), the shrinkage force due to the curing shrinkage of the adhesive is absorbed by the uncured part (fluidized layer) 4d until the final stage of the adhesive curing, Since it is avoided to act on the adhesive 2 or the adherend 1, the initial deviation is reduced.
Moreover, the example of FIGS. 9-2 is the meat | flesh by the adhesive agent 3a piled up in height 3-5 mm in the corner | angular part between the to-be-adhered object 1 and the square adhesive material 2 whose side is 20 mm x thickness 5 mm. It is prime bonding. Thus, in the bonding form in which the adhesive 2 and the adherend 1 are in direct contact, the ultraviolet ray is scanned first from the intersection line of the adhesive 2 and the adherend 1 and the adhesive 3a, and the portion is cured. (Refer to the hardened portion 4c) By this initial bonding at this intersection line, the bonded product is temporarily fixed to the bonded object, so that the initial displacement is further reduced by this temporary fixing fixing action.

Further, for example, the bonding apparatus is provided with recognition means (adhesive position, adhesive position recognition means 9 in FIG. 1) for recognizing the position of the adhesive layer, the position of the adherend, and the position of the adhesive from the image taken by the CCD camera. By detecting the edge of the adhesive along with the position of the adhesive and automatically recognizing the application shape, even if the application state (application position, application shape) of the adhesive varies, the scan start position, the scan range, and the scan It is possible to determine the optimum pattern and scan with the optimum scanning pattern.
For example, in the bonding form shown in FIG. 1, the edge of the adhesive is detected, the center of gravity of the surrounded area is obtained, the center of gravity is irradiated with ultraviolet rays, and scanning is sequentially performed based on a predetermined scanning pitch. Irradiation and scanning may be terminated when the region completely exceeds the region surrounded by the edge of the adhesive.

Further, after scanning the entire surface of the adhesive layer with the ultraviolet irradiation portion, the irradiation layer uniformly irradiates the entire adhesive layer with energy rays, for example, the irradiation light diffusing means, and uniformly irradiates the entire surface of the adhesive layer. Even if uncured parts remain due to leakage, all adhesives can be finally cured, so the occurrence of time lag due to the adhesive curing reaction after bonding due to the remaining uncured adhesives. Can be prevented.
This uniform irradiation is a secondary irradiation performed to cure the uncured portion left after the primary irradiation by scanning, and the volume of the adhesive layer cured by this secondary irradiation is the primary Therefore, the internal stress and residual stress are small, and the influence on the positional deviation and temporal deviation is very small.

These are the whole figures of an Example. (A) is a perspective view which shows typically an example of the scanning path | route of the irradiation part by Example 1, (b) is a top view which shows typically a motion of the adhesive agent in an adhesive layer. These are perspective views which show an example of the scanning means in Example 1. FIG. These are the perspective views which show another example of the scanning means in Example 1. FIG. (A) is a perspective view which shows the principal part of Example 2, (b) is a partial expanded sectional view which shows the subscanning direction in Example 2. FIG. (A) is a perspective view which shows the principal part of Example 3, (b) is a partial expanded sectional view which shows the irradiation position in Example 3. FIG. (A) is a top view which shows typically an example of the irradiation pattern which opens a scanning space | interval and intermittently irradiates, (b) is a schematic diagram which shows the example of another irradiation pattern, (c) is further It is a schematic diagram which shows the example of another irradiation pattern. (A) is a schematic diagram which shows an example of the irradiation pattern in plane adhesion | attachment of what offsets and shrinks hardening shrinkage force, (b) is a schematic diagram which shows an example of the irradiation pattern in build-up adhesion | attachment. These are sectional drawings showing typically Example 6 about filling adhesion. These are sectional drawings showing typically Example 6 about build-up adhesion.

1: Adhered object 2: Adhered object 3: Adhesive layer 3a: Adhesive 4: Scanning pattern 4a: Main scanning direction 4b: Sub-scanning direction 4c: Cured portion 4d: Uncured portion 5: UV (energy ray) irradiation position 6 : Ultraviolet irradiation means 7: Ultraviolet scanning means 9: Adhesive position, adhesive position recognition means 10: Ultraviolet light shielding means 11: Adhesive adjusting means 12: Adhered object holding means 13: Adhesive holding means 71, 71a: Irradiation head 72: XY stage

Claims (10)

A part joining method in which energy rays are irradiated onto a part of an adhesive layer, the irradiated portion is scanned, and the entire adhesive layer is sequentially cured,
A component joining method comprising: irradiating and scanning a position that is symmetrical with respect to the center of an adhesive, using a plurality of irradiated portions on the adhesive layer as a plurality of irradiated portions .   2. The component bonding method according to claim 1, wherein the central portion of the adhesive layer is first irradiated with energy rays, and the irradiated portion is planarly scanned so as to be sequentially cured from the vicinity of the outer periphery of the adhesive layer cured portion. .   3. The component joining method according to claim 1, wherein the energy ray is condensed and focused on the inside of the adhesive layer for irradiation first, and the irradiation part is three-dimensionally scanned so as to be sequentially cured from the vicinity of the outer periphery of the adhesive layer hardening part. A part joining method characterized by curing the entire adhesive layer. The component bonding method according to claim 1, wherein energy rays are irradiated from a plurality of directions, an intersection portion of each energy ray is set as an irradiation portion, and the entire adhesive layer is cured by scanning the irradiation portion in three dimensions. Part joining method characterized. 4. The component joining method according to claim 1 , wherein when the irradiated portion is scanned toward the outer periphery of the adhesive layer, the uncured portion is connected to the outer periphery of the adhesive layer by intermittently irradiating with a scanning interval. And then curing the entire adhesive layer by irradiating the uncured portion with energy rays. In the component bonding method according to claim 1, when the irradiated portion is scanned toward the outer periphery of the adhesive layer, the uncured portion is left so as to be connected to the outer periphery of the adhesive layer by scanning radially with a scanning interval. A method for joining parts, comprising irradiating the cured portion with energy rays to cure the entire adhesive layer. In component bonding method of any one of claims 1 to 3, toward the outer periphery from the adhesive layer center part when it scans the irradiation unit, by dispersing an uncured portion intermittently irradiated, then uncured portions A method for joining parts, wherein the entire adhesive layer is cured by irradiating with energy rays. 5. The component joining method according to claim 1 , claim 3, or claim 4 , wherein an energy ray is first irradiated to an adhesive other than a part where the adhesive and the adhesive and / or the adherend are in contact, and the adhesive and the adhesive are bonded. And / or a method of joining parts, wherein the adhesive at the portion where the adherend is in contact is finally cured. Claim 1, irradiation according to claim 3, or component bonding method according to claim 4, if the adhesive material and the adherend is in direct contact, the energy beam first from intersection line of contact kimono and adherends with the adhesive And then curing, and then scanning the irradiated portion from the central portion of the adhesive layer toward the outer periphery. The component bonding method according to any one of claims 1 to 9 , wherein the adhesive is completely cured by uniformly irradiating the entire adhesive layer with energy rays after scanning of the irradiation portion. .

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