JPH0672743A - Adhesive composition and method for cutting multilayered substrate bonded with the same - Google Patents

Abstract

PURPOSE:To provide an adhesive compsn. and a cutting method by which multilayered substrate can precisely be cut by scribing and stress impression. CONSTITUTION:Plural substrates are bonded with an adhesive compsn. prepd. by blending a base with a hardening agent so that the relation of F1>F2 is satisfied between interfacial adhesive strength F1 and flocculation fracture strength F2, and the resulting multilayered substrate is cut. Exfoliation is not caused between the adhesive compsn. and the constituent substrates, and the multilayered substrate can accurately be cut in a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a bonding method that enables brittle plates such as glass or ceramic substrate plates to be bonded to each other to form a multilayer substrate, and the multilayer substrate can be accurately cut into a desired pattern. The present invention relates to an agent composition and a method for cleaving the multilayer substrate adhered with the adhesive composition.

[0002]

2. Description of the Related Art An image sensor in a contact-type copying machine or a facsimile machine protects a photoelectric conversion element formed on a glass substrate by adhering an extremely thin cover glass plate and cutting it into a predetermined pattern. Molded. FIG. 7 is an explanatory view of an example of a conventional technique for cutting two bonded glass substrates into a predetermined pattern. 1 is a glass substrate (for example, 1.1 mm), 2 is a cover glass plate (for example, 45 μm), 3 is an adhesive (for example, 6μ, maximum 12μm)
Is.

In the image sensor, a pattern of photoelectric conversion elements (not shown) for a plurality of image sensors is formed on the glass substrate 1, and the photoelectric conversion elements are covered with a transparent electrode such as ITO via an adhesive agent 3. The cover glass plate 2 on which is adhered is adhered to produce a multilayer substrate in which the photoelectric conversion element is protected. In order to separate the patterns for the plurality of image sensors into individual image sensors, it is necessary to cut the multi-layer substrate having a cover glass plate adhered thereto for each image sensor.

The conventional cleaving method is as follows:
The cutting process is performed while leaving the residual thickness d in three steps of step dicing, second step dicing, and third step dicing,
Finally, one image sensor is separated by a method of applying a bending moment to divide the residual thickness d. However, in this method, it is necessary to fix the multi-layer substrate to the processing table using wax in order to perform the dicing processing three times.
It takes several tens of minutes to separate one image sensor, and the number of blades is reduced because the blade tooth thickness of the dicing machine (dicer) is 300 μm or more. There are problems such as the need for replacement and the need for post-cleaning to remove the fixing wax and the glass powder generated by processing.

On the other hand, without using the above-mentioned dicer, in the same manner as the ordinary cutting method for one glass plate,
Using a scriber to crack glass substrate 1,
A method is also known in which a multilayer substrate is cleaved by applying a moment along the crack. However, when the multi-layer substrate having a three-layer structure bonded with an adhesive by this method is cut, the following problems occur.

That is, FIGS. 8 and 9 are explanatory views of another example of the prior art in which two bonded glass substrates are cut into a predetermined pattern, and the same reference numerals as those in FIG. 7 correspond to the same portions. 4 is a crack formed by scribing, 5 is a pressing force, 6 and 6'are moment forces, and 7 is an ITO transparent electrode film. Illustration of the photoelectric element pattern is omitted. Figure 8
As shown in FIG. 5, a crack 4 is formed on the side of the glass substrate 1 opposite to the cover glass plate, and a pressing force 5 is applied directly above the crack 4 from the cover glass plate 2 side, so that the cracks 4 are separated from each other. Moment force in opposite direction 6,
6'occurs. Due to the moment forces 6 and 6 ′ around the crack 4, the glass substrate 1 and the cover glass plate 2 are respectively 1-1, 1-2, 2-1 and 2-1, as shown in FIG.
Divided into 2-2. At this time, the adhesive 3-1 and 3-2
The adhesive force between the glass substrate 1-1 and the glass substrate 1-2 is the transparent electrode film 7.
-1,7-2 is larger than the adhesive force between the glass substrates 1-1 and 1-2 and the cover glass plates 2-1 and 2-2.
The adhesives 31 and 3-2 above are peeled off between the transparent electrode film 7 and the eaves-shaped burr 8 on one side 2-1 of the cover glass plate 2 and a chip 8 complementary to the burr 8 on the other side 2-2. ', And in the worst case, the cover glass plates 2-1 and 2-2 are the glass substrates 1.
It was peeled off from -1, 1-2, and safety and reliability were lowered.

As a disclosure of the prior art of this type of image sensor, there is JP-A-64-71173.

[0008]

In the above prior art, when burrs or chips are generated on the cover glass plate, it may be considered that the adhesive strength of the adhesive should be increased. When the value is increased, the interfacial adhesive strength and the cohesive failure strength are also increased. FIG. 10 is a schematic diagram for explaining the adhesive force of the adhesive. As shown in FIG. 10A, the plate A and the plate B are adhered via the adhesive C, and the arrow F in FIG.
A shearing force as indicated by t is applied to the layer of the adhesive C so that the plate A
It is assumed that a destructive test for separating the plate body B and the plate body B is performed.

At this time, as the strength of the adhesive C, there are interfacial adhesion and cohesive failure strength, and peeling occurs at the interface between the adhesive C and the plate A shown in FIG. As a result, burrs and chips of the cover glass plate as described in the above-mentioned prior art occur. In order to prevent the occurrence of such interfacial peeling, the layer of the adhesive C easily causes cohesive failure to maintain the interfacial adhesive force between the plate A and the plate B, as shown in FIG. Need to do so.

That is, as shown in FIG. 11, when the interfacial adhesive force of the adhesive 3 is large, peeling occurs between the adhesive 3 and the cover glass plate 2, and the cracks formed on the glass substrate 1 are directly above. A breakage portion 9 is generated in the cover glass 2 at a position other than the above, and burrs and chips as described in FIG. 9 are generated. However, generally, when the interfacial adhesive force of the adhesive is increased, the cohesive failure strength is also increased at the same time, and it is difficult to perform the cutting in the state shown in FIG.

Regarding the strength of the adhesive, Hiroshi Kakiuchi "New Basic Polymer Chemistry" (published by Shoseidou in 1979) P29
0-292. The first object of the present invention is to
It is an object of the present invention to provide an adhesive composition which solves the above-mentioned problems of the prior art and allows a multilayer substrate to be easily cleaved by a cleaving method by “scribe + predetermined stress application” with high productivity.

A second object of the present invention is to provide a method of cleaving a multi-layered substrate adhered using the above adhesive composition.

[0013]

Means for Solving the Problems The above-mentioned objects are to provide an adhesive composition in which cohesive fracture strength is relatively reduced with respect to interfacial adhesive strength, and a multi-layer substrate adhered using this adhesive composition. This is achieved by using a new cleaving method of cleaving. That is, in order to achieve the above-mentioned first object, the present invention is such that when the interfacial adhesive strength is F ₁ and the cohesive failure strength is F ₂ , F ₁ and F ₂ have a relationship of F ₁ > F _2. It is characterized in that the main agent and the curing agent are mixed.

In order to achieve the above first object,
The present invention is an adhesive composition for adhering a first substrate and a second substrate to form a multilayer substrate, which is composed by adding a modified aliphatic polyamine curing agent and a fluorine-containing surfactant as an epoxy resin as a main component. In the agent composition, the interfacial adhesive strength between the first substrate and the second substrate adhered with the adhesive composition is F _1, and the cohesive failure strength of the adhesive composition layer is F ₂ . At this time, the main component, the curing agent and the surfactant are blended so that F ₁ and F ₂ have a relation of F ₁ > F ₂ .

In order to achieve the above relationship of F ₁ > F ₂ , the amount of the main agent is less than the predetermined amount of the curing agent, and the amount of the main agent is less than the predetermined amount of the main agent. The cohesive failure strength is relatively appropriately reduced by making the atomic structure of a predetermined portion of the inside have a molecular structure in which the atomic force is weakened in a timely manner.
Further, a surfactant interfacial adhesion strength between the glass substrate was improved by adding a predetermined amount, a coupling agent was added a predetermined amount, to improve the interfacial adhesion strength between the glass substrate, the F ₁ > F ₂ relationship.

That is, the present invention describes the above-mentioned adhesive plastics as described in "New Basic Polymer Chemistry" by Hiroshi Kakiuchi (1).
1977, published by Shoseidou Co., Ltd.), which has a characteristic of small cutting strength (Su) is used (the segment having a small Su value is introduced into a part of the skeleton of the main agent). In order to achieve the second object, the present invention provides a scribing step of forming a crack of a predetermined depth on one of the first substrate and the second substrate that form the multilayer substrate, and the scribing process. Along the crack formed in the process,
At least one of tensile force, shear force or moment force
A stress applying step of applying the above stress, and the first substrate and the second substrate forming the multilayer substrate are collectively cut along the crack.

It is needless to say that the main agent, curing agent or surfactant constituting the adhesive composition according to the present invention is not limited to the above materials, and other substances having the same function can be used. Yes.

[0018]

[Operation] The first substrate and the first substrate, which are adhered with the adhesive composition,
The interfacial adhesion strength between the second substrate and F₁And the adhesive
The cohesive failure strength of the composition layer is F₂And then F₁And F₂But
F ₁> F₂The relationship between
By mixing the surface-active agent, the adhesive and the first substrate
And no peeling between the second substrate and
Burrs and chips like those in the conventional cutting method
Device consisting of multilayer substrate such as image sensor
Can be accurately cut and separated in a short time.

[0019]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an explanatory view of a molecular structural formula of a bisphenol A (BPA) type epoxy resin, which is an example of a main component of an adhesive composition according to the present invention, and its physical properties. This bisphenol A (BPA) type epoxy resin has a viscosity of 1
2000 cps, epoxy equivalent 190, n = 0 (86
%), N = 1 (14%), hydrolyzable Cl: 100 pp
m.

FIG. 2 is an explanatory view of the molecular structural formula of a fluorinated alkyl ester, which is an example of a fluorinated surfactant added to the adhesive composition according to the present invention, and its physical properties. This fluorinated alkyl ester has a viscosity of 15,000 cps.
_Max , active ingredient 100%, pale yellow, specific gravity 1.1 to 1.
2. The water surface tension is 31.5 dyne / cm, and the liquid epoxy resin is 20 dyne / cm.

FIG. 3 is an explanatory view of a molecular structural formula of a modified aliphatic polyamine which is an example of a curing agent added to the adhesive composition according to the present invention and its physical properties. This modified aliphatic polyamine has a viscosity of 50 to 100 cps and an active hydrogen equivalent of 8
0, H number is 3.2, amine-containing equivalent is 6.4, and water absorption is 1.
23 wt% (80 ° C x 85% RH x 13day), total amine 98%, residual alcohol 2% or less, water content 0.15%
Is.

In this embodiment, the viscosity 1200 shown in FIG.
To 100 parts by weight of 0 cps epoxy resin, 0.1 parts by weight of 15000 cps _Max fluorinated alkyl ester of FIG. 2 as a surfactant, and modified aliphatic polyamine of FIG. 3 as a curing agent are used to appropriately change the equivalence ratio. Was added.
FIG. 4 is an explanatory diagram of the results of testing the relationship between the equivalent ratio of the curing agent to the main component of the adhesive composition and the bending strength and the elongation of the plate bonded with the adhesive composition. The equivalent ratio (%) is shown by taking the bending strength (kgf / mm ² ) and the elongation (%) on the vertical axis.

The test is as follows. 1. Test method JISK7203 (bending test method for hard plastics) compliant 2. Measuring Machine Tensilon Orientec UCT-
30T type 3. Test piece 3 × 25 × 70 mm (about) 4. Distance between fulcrums 60 mm 5. Bending speed 2 mm / min As is clear from the test results of FIG. 4, the bending strength (≈ (apparent) cohesive failure strength) decreases as the equivalent ratio of the curing agent decreases from 100% to 50%. To go.

On the other hand, the elongation at break and at bending strength is
A minimum value is shown at a curing agent equivalent ratio of 70%. That is, when the curing agent equivalent ratio is 70%, it is possible to fracture with the minimum strain and stress (when it is less than 70%, necking stretching occurs, the fractured surface is disturbed and the dimensional accuracy deteriorates). As described in the above examples, a glass substrate bonded with an adhesive composition composed of an epoxy resin as a main component and a modified aliphatic polyamine curing agent and a fluorine-containing surfactant (first
The interfacial adhesion strength between the substrate) and the cover glass plate (second substrate) and F _1, when the cohesive failure strength of the adhesive composition layer was F _2, F ₁ and F ₂ are F ₁ By blending the main component, the curing agent, and the surfactant so as to satisfy the relation of> F ₂ , highly accurate cleaving can be performed.

In order to establish the relationship of F ₁ > F ₂ , the modified aliphatic polyamine as a curing agent is used in an amount less than a predetermined amount with respect to the equivalent amount of the bisphenol A (BPA) type epoxy resin as a main component. Compound. A bisphenol A (BPA) type epoxy resin base compound is blended in a predetermined amount less than the equivalent amount of the modified aliphatic polyamine which is a curing agent.

The cohesive failure strength is relatively reduced by forming a molecular structure in which the interatomic force at a predetermined portion in the adhesive molecule is weakened at appropriate times. Further, by adding a predetermined amount of the fluorinated alkyl ester shown in FIG. 2 as a surfactant, the interfacial adhesion strength with the glass substrate is improved. A coupling agent, for example, γ-2 aminoethylaminopropyl: NH ₂ CH ₂ CHCH ₂ —Si (OMe) ₃ CH ₂ CH ₂ NH ₂ is added in a predetermined amount to improve the interfacial adhesion strength with the glass substrate. .

An adhesive composition satisfying the above relationship of F ₁ > F ₂ is prepared by the above-mentioned method, and a multi-layer substrate is constructed by using this adhesive composition. It is possible to accurately cut and separate a device such as a multi-layer substrate in a short time. FIG. 5 is an explanatory view of the cut resistance of a straight portion after cleaving by the method for cleaving a multilayer substrate according to the present invention, in which the adhesive composition according to the present invention is applied to a glass substrate of an image sensor with a thickness of 13 ± 3 μm and ITO.
A multi-layer substrate having a conductive glass thin film and a cover glass plate having a thickness of 50 μm attached thereto is cracked using a scriber on the glass substrate described in the section of the prior art, and a moment is applied along the crack to form the multi-layer substrate. This is an evaluation of burr, chipping, and floating (peeling) of the cover glass plate when cleaving by the cleaving method.

This evaluation was carried out on an image sensor which was scribed under a cleaving condition using a scribe chip to form a crack, and was pressed and pressured at 1.4 kg / cm ² from directly above the crack to be cleaved and separated. . In the figure, the horizontal axis represents the curing agent equivalent ratio (%), and the vertical axis represents burrs, chips, and lifts (μm) of the cover glass plate.

FIG. 6 is an explanatory view of a main part of a multilayer board cut by using the method for cutting a multilayer board according to the present invention, and corresponds to FIG. In the figure, a glass substrate 1 which is a first substrate and a cover glass plate 2 which is a second substrate are adhered by the adhesive composition according to the present invention, and after cracking the glass substrate with a scriber, the crack Apply pressure from directly above to cut.

At this time, when the interfacial adhesive strength of the layer of the adhesive composition 3 is F ₁ and the cohesive failure strength is F ₂ , F
_{Since 1} and F ₂ have a relationship of F ₁ > F ₂ , peeling between the adhesive composition 3 and the glass substrate 1 and the cover glass 2 does not occur as shown in FIG. A crack 10 is formed along with the cleaving of the adhesive composition 3, and the adhesive composition 3 and the glass substrate 1 are cleaved integrally with the cleaving.

That is, as described above, "interfacial adhesion>
By using "cohesive fracture strength", it is possible to perform highly accurate cleaving even in a multi-layer substrate, and the above-mentioned cutting accuracy is 50 µm on average at a curing agent equivalent ratio of 70%, and ± 70 at worst.
It showed an excellent cutting accuracy of μm. In the above examples,
The cleaving of the perfect contact type image sensor has been described as an example, but in addition to this, precision cleaving of an LCD (liquid crystal display) panel or a plurality of glass substrates such as laminated glass for automobiles bonded with an adhesive Is something that can be done.

[0032]

As described above, according to the present invention,
When the interfacial adhesive strength of the adhesive composition layer is F ₁ and the cohesive failure strength is F ₂ , the main agent, the curing agent and the surfactant are combined so that F ₁ and F ₂ have a relationship of F ₁ > F _2. By blending, and more specifically, the interfacial adhesive strength between the first substrate and the second substrate adhered with the adhesive composition is defined as F _1, and the cohesive failure strength of the adhesive composition layer is the when the F _2, the main agent as F ₁ and F ₂ is the relation of F _1> F _2,
By incorporating the curing agent and the surfactant, peeling between the adhesive composition and the first substrate and the second substrate does not occur, and burrs and chips are generated on the substrate after cleaving due to the peeling. A brittle plate device composed of a multi-layer substrate such as an image sensor can be accurately cut and separated in a short time without causing any trouble.

[Brief description of drawings]

FIG. 1 is an explanatory view of a molecular structural formula of a bisphenol A (BPA) type epoxy resin which is an example of a main component of an adhesive composition according to the present invention and its physical properties.

FIG. 2 is an explanatory diagram of a molecular structural formula of a fluorinated alkyl ester, which is an example of a fluorinated surfactant added to the adhesive composition according to the present invention, and its physical properties.

FIG. 3 is an explanatory view of a molecular structural formula of a modified aliphatic polyamine, which is an example of a curing agent added to the adhesive composition according to the present invention, and its physical properties.

FIG. 4 is an explanatory diagram of the results of testing the relationship between the equivalent ratio of the curing agent to the main component of the adhesive composition and the flexural strength and elongation of the plate bonded with the adhesive composition.

FIG. 5 is an explanatory diagram of cut resistance of a straight portion after cleaving by the method for cleaving a multilayer substrate according to the present invention.

FIG. 6 is an explanatory view of a main part of a multilayer substrate cut by using the method for cutting a multilayer substrate according to the present invention.

FIG. 7 is an explanatory diagram of an example of a conventional technique for cutting two bonded glass substrates into a predetermined pattern.

FIG. 8 is an explanatory diagram of a pretreatment of another example of the prior art for cutting two bonded glass substrates into a predetermined pattern.

FIG. 9 is an explanatory view of a state after the cutting of another example of the prior art in which two bonded glass substrates are cut into a predetermined pattern.

FIG. 10 is a schematic diagram illustrating the adhesive force of an adhesive.

FIG. 11 is an explanatory diagram of a main part of a multilayer board which is cut by using a cutting method for a multilayer board according to a conventional technique.

[Explanation of symbols]

1 ... Glass substrate 2 ... Cover glass plate 3
··· Adhesive composition 4 ··· Cracks 5 ··· Pressurizing force 6, 6 ′ · ·
..Moment force 7 ... ITO transparent electrode film.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // C08G 59/50 NJA 8416-4J

Claims (8)

[Claims] 1. When the interfacial adhesive strength is F ₁ and the cohesive failure strength is F ₂ , the main agent and the curing agent are blended so that F ₁ and F ₂ have a relationship of F ₁ > F _2. Adhesive composition. 2. An adhesive composition for adhering a first substrate and a second substrate to form a multi-layer substrate, wherein the first substrate and the second substrate adhered with the adhesive composition. the interfacial adhesion strength between the as F _1, when the cohesive failure strength of the adhesive composition layer was F _2, F ₁ and F ₂ are F _1>
An adhesive composition comprising the above-mentioned main ingredient, a curing agent and a surfactant in the relationship of F ₂ . 3. An adhesive composition for adhering a first substrate and a second substrate to form a multi-layer substrate, wherein bisphenol A type epoxy resin is used as the base compound A small equivalent of modified aliphatic polyamine was blended as the curing agent, and the interfacial adhesion strength F ₁ between the first substrate and the second substrate and the cohesive failure strength F ₂ were set to F ₁ > F ₂ . An adhesive composition comprising: 4. An adhesive composition for adhering a first substrate and a second substrate to form a multi-layer substrate, wherein a modified aliphatic polyamine is used as the curing agent, and the amount is less than the equivalent amount by a predetermined amount. A bisphenol A (BPA) type epoxy resin was blended as the main component, and the interfacial adhesion strength F ₁ between the first substrate and the second substrate and the cohesive failure strength F ₂ were set to F ₁ > F ₂ . An adhesive composition comprising: 5. An adhesive composition for adhering a first substrate and a second substrate to form a multilayer substrate, comprising an atomic force of a predetermined portion in an adhesive molecule constituting the adhesive plastic material. Is made to have a weak molecular structure at appropriate times, and the first substrate and the second substrate
The interfacial adhesion strength F ₁ and the cohesive failure strength F ₂ between the
An adhesive composition having a relationship of ₁ > F ₂ . 6. An adhesive composition for adhering a first substrate and a second substrate to form a multilayer substrate, wherein a predetermined amount of a fluorinated alkyl ester is added as the surfactant, and the first composition is added. An adhesive plastic material, characterized in that the interfacial adhesion strength F ₁ between the substrate and the second substrate and the cohesive failure strength F ₂ have a relationship of F ₁ > F ₂ . 7. An adhesive composition for adhering a first substrate and a second substrate to form a multi-layer substrate, wherein γ-2 aminoethylaminopropyl is added as a coupling agent in a predetermined amount, and An adhesive plastic material, characterized in that the interfacial adhesion strength F ₁ between the first substrate and the second substrate and the cohesive failure strength F ₂ have a relationship of F ₁ > F ₂ . 8. A method for cleaving a multi-layered substrate adhered using the adhesive composition according to claim 1, wherein one of the first substrate and the second substrate constituting the multi-layered substrate has a predetermined depth. And a stress applying step of applying at least one stress of a tensile force, a shearing force, or a moment force along the crack formed in the scribing step to form the multilayer substrate. A method for cleaving a multi-layer substrate, characterized by collectively cleaving a first substrate and a second substrate along the crack.