JP2009244003A - Method for detecting degree of hardening of adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for detecting the degree of hardening of adhesives and capable of detecting the degree of all adhesives applied to a continuous sheet without contact when the adhesives are applied to a large number of locations at regular intervals onto the continuous sheet and sequentially hardened during its transfer. <P>SOLUTION: In the method for detecting the degree of hardening of adhesives, a method for detecting the degree of hardening of an adhesive 14 applied onto a transparent base material 11, the degree of hardening of the adhesive 14 is detected by making a laser beam incident onto the transparent base material 11 from the other surface 11b of the transparent base material 11 and measuring the angle β of reflection and the light intensity I' of first reflected light 31 of the laser beam 21 and measuring the angle β-δ of reflection and the light intensity I<SB>δ</SB>' of second reflected light 32 both reflected at the interface between the transparent base material 11 and the adhesive 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for detecting the degree of cure of an adhesive applied on a transparent substrate, and more specifically, an adhesive is applied to a continuous sheet (transparent substrate) being conveyed at regular intervals and at many locations. The present invention relates to a method for detecting the degree of cure of an adhesive that can detect the degree of cure of all adhesives applied on a continuous sheet in a non-contact manner when the adhesive is sequentially cured.

  As a method for measuring the degree of cure of a curable resin such as an adhesive applied to a substrate, etc., after pre-curing the applied resin and measuring the weight of the substrate in that state, the pre-cured resin is subjected to a predetermined condition. The method of calculating the weight difference of the substrate before and after wear by measuring the weight difference of the substrate after the wear is completed and determining the degree of cure of the resin based on the calculated weight difference is disclosed. (For example, refer to Patent Document 1).

In addition, as another method for measuring the degree of curing of the curable resin, (1) a reference sample corresponding to a curing progress state including a sample saturated with curing of the curable resin that is cured by satisfying the curing condition is prepared. And (2) a step of irradiating the reference sample with electromagnetic waves, electron beams, or ion particles containing any of microwaves, infrared rays, visible light, ultraviolet rays, or X-rays, and measuring the response from the reference sample (3) From the measurement result obtained in the response measurement, the reference curing signal having a strong correlation with the curing progress of the reference sample, and the curing progress of the reference sample compared to the reference curing signal (4) a step of extracting a reference curing signal having weak correlation; (4) a step of normalizing the reference curing signal with the reference curing signal and extracting a reference normalization signal; and (5) (2), (3 ), The measurement described in (4) is for reference A standardized curing signal for measurement corresponding to the progress of curing extracted in steps (6) and (4) by extracting the standardized curing signal for measurement by performing the measurement on the measurement sample instead of the sample And a method of extracting the curing state of the measurement sample by comparing the measurement standardized signals extracted in (5) (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 2003-130776 JP 2007-248431 A

However, in the above method, the degree of cure of the measurement sample can only be measured individually, and in the production process using the curable resin, the degree of cure must be measured separately from the production process. The degree of cure of all curable resins could not be measured during production.
Therefore, in the above-described method, when the adhesive is applied to the continuous sheet being conveyed at regular intervals and in many places, and this adhesive is sequentially cured, the curing degree of all the adhesives applied on the continuous sheet is set. It was not possible to detect without contact.

  The present invention has been made in view of the above circumstances, and is applied on a continuous sheet when the adhesive is applied on a continuous sheet being conveyed at equal intervals and in many places, and the adhesive is sequentially cured. It is an object of the present invention to provide a method for detecting the degree of cure of an adhesive that can detect the degree of cure of all the adhesives in a non-contact manner.

  The method for detecting the degree of cure of the adhesive of the present invention is a method for detecting the degree of cure of an adhesive applied on a transparent substrate, from the surface opposite to the surface of the transparent substrate to which the adhesive is applied. The adhesive is obtained by measuring the reflection angle and light intensity of the reflected light of the laser light that is incident on the transparent substrate and reflected at the interface between the transparent substrate and the adhesive. It is characterized by detecting the degree of curing.

  According to the method for detecting the degree of cure of an adhesive of the present invention, the method is for detecting the degree of cure of an adhesive applied on a transparent substrate, which is opposite to the surface of the transparent substrate on which the adhesive is applied. By measuring the reflection angle and the light intensity of the reflected light of the laser light, which is incident on the transparent base material from the surface and reflected at the interface between the transparent base material and the adhesive, Since the degree of cure of the adhesive is detected, the degree of cure of the adhesive can be detected in a non-contact manner without directly sampling the adhesive. In addition, when the transparent base material is composed of a long continuous sheet and a large number of IC chips are mounted on such a transparent base material at an equal interval via an adhesive, The degree of cure of the adhesive can be detected. Furthermore, the degree of cure of all adhesives is detected, and a mark is attached to the location of the adhesive that is not sufficiently cured. After the conveyance is finished, the transparent substrate is separated into individual pieces, and then the defective product is removed. You can also adopt this method.

The best mode of the method for detecting the degree of cure of the adhesive of the present invention will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

  According to the method for detecting the degree of cure of an adhesive of the present invention, the method is for detecting the degree of cure of an adhesive applied on a transparent substrate, which is opposite to the surface of the transparent substrate on which the adhesive is applied. By measuring the reflection angle and the light intensity of the reflected light of the laser light, which is incident on the transparent base material from the surface and reflected at the interface between the transparent base material and the adhesive, This is a method for detecting the degree of cure of the adhesive.

FIG. 1 is a schematic view showing an embodiment of a method for detecting the degree of cure of an adhesive according to the present invention.
In FIG. 1, 11 is a transparent substrate, 12 is an antenna, 13 is an IC chip, 14 is an adhesive, 20 is a laser beam oscillator, 21 is a laser beam, 30 is a light intensity measuring device, and 31 is a first reflection. Light 32 indicates second reflected light.
On one surface 11a of the transparent substrate 11, an antenna 12 for RFID (Radio Frequency IDentification) is provided.
The IC chip 13 is joined to the antenna 12 via a contact 13a.
Then, the IC chip 13 is fixed to the one surface 11 a of the transparent substrate 11 via an adhesive 14.

  In the adhesive curing degree detection method of this embodiment, first, the IC chip 13 is joined to the antenna 12 via the contact 13a on the one surface 11a of the transparent substrate 11, and the one surface 11a of the transparent substrate 11 is joined. A predetermined amount of adhesive 14 is applied between the IC chip 13 and the IC chip 13. At this time, the adhesive 14 is uncured.

  Immediately after applying the adhesive 14, the light intensity oscillated from the laser light oscillator 20 from the surface (the other surface 11b) opposite to the surface (the one surface 11a) to which the adhesive 14 is applied of the transparent substrate 11. The first reflected light 31 of the laser light 21 is incident on the transparent substrate 11 at a predetermined incident angle α and reflected at the interface between the transparent substrate 11 and the adhesive 14. The reflection angle β and the light intensity I ′ are measured.

Next, the adhesive 14 is cured by a predetermined method such as heating or irradiation with ultraviolet rays or electron beams.
Next, immediately after the adhesive 14 is cured, the laser beam 21 having the light intensity I oscillated from the laser beam oscillator 20 arranged at a predetermined distance from the other surface 11b of the transparent substrate 11 is transparent. Reflection angle β-δ and light intensity of the second reflected light 32 of the laser light 21 that is incident on the substrate 11 at a predetermined incident angle α and reflected at the interface between the transparent substrate 11 and the adhesive 14. I _δ ′ is measured.

The refractive index of the adhesive 14 changes before and after curing. As a result, as described above, the reflection angle β of the first reflected light 31 and the reflection angle β-δ of the second reflected light 32 change, and the light intensity I ′ of the first reflected light 31 The light intensity I _δ ′ of the second reflected light 32 changes.
At this time, the reflection angle β> the reflection angle β−δ and the light intensity I ′> the light intensity I _δ ′.

As described above, the amount of change in the reflection angle β-δ of the second reflected light 32 with respect to the reflection angle β of the first reflected light 31 and the second reflected light 32 with respect to the light intensity I ′ of the first reflected light 31. The degree of cure of the adhesive 14 can be detected by measuring the amount of change in the light intensity I _δ ′.

The distance between the oscillation part (laser light emission end) of the laser light oscillator 20 and the other surface 11b of the transparent substrate 11 is preferably 0.5 m or more and 2 m or less.
The incident angle α of the laser light 21 oscillated from the laser light oscillator 20 with respect to the other surface 11b of the transparent substrate 11 is preferably 40 ° or more and 85 ° or less.
The wavelength of the laser beam 21 oscillated from the laser beam oscillator 20 is preferably 700 nm or more and 1500 nm or less.
Light intensity of the laser light 21 oscillated from the laser beam oscillator 20, 1000 mW / cm ² or more, preferably 10000 mW / cm ² or less.

  As the transparent substrate 13, a light transmissive material is used. Examples of such a transparent substrate 13 include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene. -Film, sheet | seat, board, etc. which consist of acrylate copolymer and these metal bridge | crosslinking products etc. are mentioned.

The adhesive 14 is not particularly limited as long as its refractive index changes before and after curing, but a thermosetting adhesive, an ultraviolet curable adhesive, an electron beam curable adhesive, or the like is used. .
Examples of the thermosetting adhesive include phenol resin, epoxy resin, polyurethane curable resin, urea resin, melamine resin, and acrylic reaction resin. Specifically, bisphenol F-type epoxide is mentioned.
Examples of the UV curable adhesive include UV curable acrylic resin, UV curable urethane acrylate resin, UV curable polyester acrylate resin, UV curable polyurethane resin, UV curable epoxy acrylate resin, and UV curable imide acrylate resin. It is done.
Electron beam curable adhesives include electron beam curable acrylic resins, electron beam curable urethane acrylate resins, electron beam curable polyester acrylate resins, electron beam curable polyurethane resins, electron beam curable epoxy acrylate resins, and cationic curable resins. Resin etc. are mentioned.

  For example, as a thermosetting adhesive, a bisphenol F-type epoxide having a molecular structure before curing represented by the following chemical formula (1), when cured, has a molecular structure represented by the following chemical formula (2). Due to such a change in the molecular structure, the refractive index of the adhesive 14 changes.

According to the method for detecting the degree of cure of the adhesive of this embodiment, the laser beam having the light intensity I oscillated from the laser beam oscillator 20 arranged at a predetermined distance from the other surface 11b of the transparent substrate 11. 21 is incident on the transparent base material 11 at a predetermined incident angle α, and is reflected at the interface between the transparent base material 11 and the adhesive 14, and the second reflection with respect to the reflection angle β of the first reflected light 31. By measuring the change amount of the reflection angle β-δ of the light 32 and the change amount of the light intensity I _δ ′ of the second reflected light 32 with respect to the light intensity I ′ of the first reflected light 31, the adhesive 14. Therefore, the degree of cure of the adhesive 14 can be detected in a non-contact manner without directly sampling the adhesive 14.

  Further, when the transparent substrate 11 is formed of a long continuous sheet, and a large number of IC chips 13 are mounted on the transparent substrate 11 with the adhesive 14 as described above at equal intervals, the transparent substrate 11 The degree of cure of all the adhesives 14 can be detected while conveying the material 11. In this case, since the transparent base material 11 is intermittently conveyed, the detection of the degree of cure of the adhesive 14 (measurement of reflection angle and light intensity) is performed while conveyance is stopped (interrupted). Done in an instant. Further, the degree of cure of all the adhesives 14 is detected, and a mark is attached to the location of the defective adhesive 14 (insufficient curing), after completion of transportation (after completion of mounting of all the IC chips 13). ), And removing the defective product after separating the inlet made of the transparent substrate 11, the antenna 12, and the IC chip 13 into individual pieces.

  Hereinafter, the present invention will be described more specifically with experimental examples, but the present invention is not limited to the following experimental examples.

First, the adhesive 44 was applied to the one surface 41a of the polystyrene film 41 by spin coating so that the thickness became 20 μm.
As the adhesive 44, a bisphenol F-type epoxide containing 0.5% by mass of a biphenyl iodonium salt as a curing agent was used with respect to the monomer.
After the adhesive 44 is applied, from the other surface 41b of the polystyrene film 41 was oscillated from the laser beam oscillator 50, a laser beam 51 of the light intensity I, at a predetermined incidence angle alpha ₀ with respect to a polystyrene film 41 The reflection angle α ₁ and the light intensity I ′ of the first reflected light 61 of the laser light 51 incident and reflected at the interface between the polystyrene film 41 and the adhesive 44 were measured.
Here, the light intensity I was set to 1000 mW / cm ² .
The reflection angle α ₁ of the first reflected light 61 was 40.0 °, and the light intensity I ′ was 118 ± 10 mW / cm ² .

Next, the adhesive 14 was cured by heating at 100 ° C. for 1 hour.
From the other surface 41 b of the polystyrene film 41, a laser beam 51 having a light intensity I oscillated from the laser beam oscillator 50 is incident on the polystyrene film 41 at a predetermined incident angle α ₀ and adhered to the polystyrene film 41. The reflection angle α ₂ and the light intensity I _δ ′ of the second reflected light 62 of the laser beam 51 reflected at the interface of the agent 44 were measured.
The reflection angle α ₂ of the second reflected light 62 was 39.5 °, and the light intensity I _δ ′ was 40 ± 5 mW / cm ² .

Thus, before and after curing of the adhesive 44, the reflection angle of the laser beam 51 changes from 40.0 ° to 39.5 °, and the light intensity of the reflected beam of the laser beam 51 is from 118 ± 10 mW / cm ^2. It was confirmed to change to 40 ± 5 mW / cm ² . It was also confirmed that the position where the reflected light arrives changed by 1.9 cm.
From this result, from the other surface 41b of the polystyrene film 41 was oscillated from the laser beam oscillator 50, a laser beam 51 of the light intensity I, is incident at a predetermined incidence angle alpha ₀ with respect to a polystyrene film 41, polystyrene It was confirmed that the degree of cure of the laser beam 51 adhesive 44 can be detected by measuring the reflection angle and light intensity of the reflected light of the laser beam 51 reflected at the interface between the film 41 and the adhesive 44.

It is the schematic which shows one Embodiment of the hardening degree detection method of the adhesive agent of this invention. It is the schematic which shows the experimental example of the hardening degree detection method of the adhesive agent of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Transparent base material, 12 ... Antenna, 13 ... IC chip, 14 ... Adhesive, 20 ... Laser oscillator, 21 ... Laser beam, 30 ... Light intensity measurement Device, 31 ... first reflected light, 32 ... second reflected light.

Claims (1)

A method for detecting the degree of cure of an adhesive applied on a transparent substrate,
The laser beam that is incident on the transparent substrate from a surface opposite to the surface of the transparent substrate on which the adhesive is applied, and is reflected at the interface between the transparent substrate and the adhesive. A method for detecting the degree of cure of an adhesive, wherein the degree of cure of the adhesive is detected by measuring a reflection angle and light intensity of the reflected light.

Images