Patent Application
20200064736
This application claims the priority benefit of Taiwan application serial no. 107129097, filed on Aug. 21, 2018. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification.
The disclosure relates to a photosensitive adhesive composition, and more particularly, to a photosensitive adhesive composition, a photosensitive conductive adhesive composition, and an electronic device including the photosensitive conductive adhesive composition.
In recent years, the photosensitive adhesive composition has been widely used in display assembly or OLED (organic light-emitting diode) lighting packaging materials. Instead of curing the composition via conventional heating, baking, and thermal curing, the photosensitive adhesive composition only needs to be cured via the irradiation of light rays such as external UV, electron beam, infrared, X-ray and the like, and is suitable for a heat-sensitive flexible polymer substrate. Therefore, the photosensitive adhesive composition is gradually replacing the thermosetting composition for applications on flexible printed electronics. At the same time, the photosensitive adhesive composition has the advantages of shorter process time, simplified equipment and so on.
However, in the currently-used photosensitive curing adhesive, external light irradiation causes the photoinitiator in the adhesive to rapidly pyrolyze, and a crosslinking reaction occurs between the resins such that the adhesive is rapidly cured. Moreover, with the requirements of multilayer stacking and repeated processing between devices on a package or in an OLED process, if the devices are directly adhered on the photosensitive adhesive and then irradiated by external light, the adhesive cannot be completely cured due to the devices shielding the light irradiating the photosensitive adhesive composition. As a result, reliability issues in the adhesion of a backend device or the packaging material occur.
Therefore, a photosensitive adhesive composition having photosensitive delayed curing characteristics is urgently needed, which may be first coated on a substrate, and then external energy is applied to the photosensitive adhesive composition and a backend device aligned and attached. Lastly, the photosensitive adhesive composition is gradually cured and has good adhesion.
An embodiment of the disclosure provides a photosensitive adhesive composition including 10 parts by weight to 90 parts by weight of a monomer having a vinyl ether functional group, 10 parts by weight to 90 parts by weight of a tertiary amine polymer, and 0.5 parts by weight to 10 parts by weight of a photoacid initiator. The weight-average molecular weight of the tertiary amine polymer is between 2000 and 20000.
Another embodiment of the disclosure provides a photosensitive conductive adhesive composition including a conductive powder and a photosensitive adhesive composition. The photosensitive adhesive composition includes 10 parts by weight to 90 parts by weight of a monomer having a vinyl ether functional group, 10 parts by weight to 90 parts by weight of a tertiary amine polymer, and 0.5 parts by weight to 10 parts by weight of a photoacid initiator. The weight-average molecular weight of the tertiary amine polymer is between 2000 and 20000.
Another embodiment of the disclosure provides an electronic device including a first substrate having a first electrode, a second substrate having a second electrode, and a photosensitive conductive adhesive composition disposed between the first substrate and the second substrate, and the first electrode and the second electrode are electrically connected via the photosensitive conductive adhesive composition, wherein the photosensitive conductive adhesive composition includes a conductive powder and a photosensitive adhesive composition. The photosensitive adhesive composition includes 10 parts by weight to 90 parts by weight of a monomer having a vinyl ether functional group, 10 parts by weight to 90 parts by weight of a tertiary amine polymer, and 0.5 parts by weight to 10 parts by weight of a photoacid initiator. The weight-average molecular weight of the tertiary amine polymer is between 2000 and 20000.
Several exemplary embodiments accompanied with FIGURES are described in detail below to further describe the disclosure in details.
The accompanying drawings are included to provide further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments and, together with the description, serve to explain the principles of the disclosure.
Hereinafter, embodiments of the disclosure are described in detail. The details provided in the embodiments are exemplary, and are not intended to limit the scope of the disclosure. Those having ordinary skill in the art may modify or change the details according to the requirements of actual implementation. “One” in the disclosure represents “at least one”.
An embodiment of the disclosure provides a photosensitive adhesive composition including a vinyl ether monomer, a tertiary amine structure polymer, and a photoacid initiator. Upon exposure to external energy, the photoacid initiator begins to pyrolyze and form an H+ cationic group and a negatively-charged photoacid salt. The H+ cation first generates a force similar to electric dipole with a lone pair of electrons on the nitrogen atom of a tertiary amine polymer structure. The magnitude of the electric dipole force is the key to influence the delayed curing of the photosensitive composition. When the composition is just irradiated with energy, the force reduces the double bond reaction of the H+ ion on the vinyl ether functional group; however, as the external environment interferes, the force is gradually weakened. At this time, the H+ ion begins an addition reaction to the double bond of the vinyl ether functional group and begins to cure the photosensitive composition.
According to several embodiments of the disclosure, a photosensitive adhesive composition of the disclosure includes 10 parts by weight to 90 parts by weight of a monomer having a vinyl ether functional group, 10 parts by weight to 90 parts by weight of a tertiary amine polymer, and 0.5 parts by weight to 10 parts by weight of a photoacid initiator. The weight-average molecular weight of the tertiary amine polymer is between 2000 and 20000.
According to several embodiments of the disclosure, the photosensitive adhesive composition of the disclosure has a monomer having a vinyl ether functional group of 30 parts by weight to 70 parts by weight, a tertiary amine polymer of 30 parts by weight to 70 parts by weight, and a photoacid initiator of 1 part by weight to 5 parts by weight.
According to several embodiments of the disclosure, the tertiary amine polymer has the structure represented by formula (1)
In formula (1), R1 and R2 may respectively be a methyl group, an ethyl group, a propyl group, or an isopropyl group, and R3 is a C1 to C5 alkylene group.
R4 is
The number n of the repeating unit is an integer between 8 and 132, and * is an end bonded to R3.
According to several embodiments of the disclosure, the monomer having a vinyl ether functional group of the photosensitive adhesive composition of the disclosure has
According to several embodiments of the disclosure, the photoacid initiator of the photosensitive adhesive composition of the disclosure is a diazonium salt, a phosphonium salt, a sulfonium salt, an iodonium salt, a sulfonate compound, or a combination of the above.
According to several embodiments of the disclosure, the photosensitive adhesive composition of the disclosure may further contain a thermally conductive powder or a conductive powder in an amount of 200 parts by weight to 1000 parts by weight. The thermally conductive powder may be a metal oxide, a ceramic, a diamond, a charcoal, boron nitride, aluminum oxide, aluminum nitride, magnesium nitride, zinc oxide, silicon carbide, beryllium oxide, tungsten carbide, or a combination of the above. The conductive powder may be a metal powder or a nano powder (such as silver, copper, gold, aluminum, platinum, nickel, palladium), graphite, graphene, carbon black, carbon nanotube, conductive polymer, metal oxide (such as tin dioxide, aluminum-doped zinc oxide, indium tin oxide), or a combination thereof.
According to several embodiments of the disclosure, a photosensitive adhesive composition of the disclosure includes a conductive powder and a photosensitive adhesive composition. The photosensitive adhesive composition includes 10 parts by weight to 90 parts by weight of a monomer having a vinyl ether functional group, 90 parts by weight to 10 parts by weight of a tertiary amine polymer, and 0.5 parts by weight to 10 parts by weight of a photoacid initiator. The weight-average molecular weight of the tertiary amine polymer is between 2000 and 20000.
According to several embodiments of the disclosure, the tertiary amine polymer has the structure represented by formula (2)
In formula (2), R1 and R2 may respectively be a methyl group, an ethyl group, a propyl group, or an isopropyl group, and R3 is a C1 to C5 alkylene group.
a number n of the repeating unit is an integer between 8 and 132, and * is an end bonded to R3.
According to several embodiments of the disclosure, the monomer having a vinyl ether functional group of the photosensitive conductive adhesive composition of the disclosure has
According to several embodiments of the disclosure, the photoacid initiator of the photosensitive conductive adhesive composition of the disclosure is a diazonium salt, a phosphonium salt, a sulfonium salt, an iodonium salt, a sulfonate compound, or a combination of the above.
According to several embodiments of the disclosure, the conductive powder may be a metal powder or a nano powder (such as silver, copper, gold, aluminum, platinum, nickel, palladium), graphite, graphene, carbon black, a carbon nanotube, a conductive polymer, a metal oxide (such as tin dioxide, aluminum-doped zinc oxide, indium tin oxide), or a combination thereof. According to an embodiment of the disclosure, the conductive powder is added in an amount of 200 parts by weight to 1000 parts by weight.
According to several embodiments of the disclosure, the tertiary amine polymer has the structure represented by formula (3)
In formula (3), R1 and R2 may respectively be a methyl group, an ethyl group, a propyl group, or an isopropyl group, and R3 is a C1 to C5 alkylene group.
In formula (3), R4 is
a number n of the repeating unit is an integer between 8 and 132, and * is an end bonded to R3.
According to several embodiments of the disclosure, the monomer having a vinyl ether functional group of the photosensitive conductive adhesive composition of the disclosure has
According to several embodiments of the disclosure, the photoacid initiator of the photosensitive conductive adhesive composition of the disclosure is a diazonium salt, a phosphonium salt, a sulfonium salt, an iodonium salt, a sulfonate compound, or a combination of the above.
According to several embodiments of the disclosure, the conductive particles are added in an amount of 200 parts by weight to 1000 parts by weight.
Measuring instruments and methods of product characteristics mentioned in the following examples of the disclosure:
The details of the chemicals used in the following examples and comparative examples of the disclosure are first described as follows:
The chemicals used in each example and comparative example of the disclosure are organized as shown in Table 1 below.
After 70 parts by weight of the DEGDE monomer was added in 30 parts by weight of the SMA1000I copolymer and mixed and dissolved via a planetary centrifugal mixer, 5 parts by weight of the photoacid initiator 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of SMA1000I copolymer and DEGDE monomer.
The same procedures as Example 1 were performed, except that the weights of the SMA1000I copolymer and the DEGDE monomer were both changed to 50 parts by weight.
The same procedures as Example 1 were performed, except that the weights of the SMA1000I copolymer and the DEGDE monomer were changed to 70 parts by weight and 30 parts by weight respectively.
After 70 parts by weight of the CHDE monomer was added in 30 parts by weight of the SMA1000I copolymer and mixed and dissolved via a planetary centrifugal mixer, 5 parts by weight of the photoacid initiator 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of SMA1000I copolymer and CHDE monomer.
The same procedures as Example 4 were performed, except that the weights of the SMA1000I copolymer and the CHDE monomer were both changed to 50 parts by weight.
The same procedures as Example 4 were performed, except that the weights of the SMA1000I copolymer and the CHDE monomer were changed to 70 parts by weight and 30 parts by weight respectively.
After 70 parts by weight of DVETEG monomer was added in 30 parts by weight of the SMA1000I copolymer and mixed and dissolved via a planetary centrifugal mixer, 5 parts by weight of the photoacid initiator 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of SMA1000I copolymer and DVETEG monomer.
The same procedures as Example 7 were performed, except that the weights of the SMA1000I copolymer and the DVETEG monomer were both changed to 50 parts by weight.
The same procedures as Example 7 were performed, except that the weights of the SMA1000I copolymer and the DVETEG monomer were changed to 70 parts by weight and 30 parts by weight respectively.
The SMA1000I copolymer and the DEGDE monomer were both kept at 50 parts by weight, and 3 parts by weight of the photoacid initiator 4-isopropyl-4′-methyl diphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of SMA1000I copolymer and DEGDE monomer.
The SMA1000I copolymer and the DEGDE monomer were both kept at 50 parts by weight, and 1 part by weight of the photoacid initiator 4-isopropyl-4′-methyl diphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of SMA1000I copolymer and DEGDE monomer.
The SMA1000I copolymer and the CHDE monomer were both kept at 50 parts by weight, and 3 parts by weight of the photoacid initiator 4-isopropyl-4′-methyl diphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of SMA1000I copolymer and CHDE monomer.
The SMA1000I copolymer and the CHDE monomer were both kept at 50 parts by weight, and 1 part by weight of the photoacid initiator 4-isopropyl-4′-methyl diphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of SMA1000I copolymer and CHDE monomer.
The SMA1000I copolymer and the DEVTEG monomer were both kept at 50 parts by weight, and 3 parts by weight of the photoacid initiator 4-isopropyl-4′-methyl diphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of SMA1000I copolymer and DEVTEG monomer.
The SMA1000I copolymer and the DEVTEG monomer were both kept at 50 parts by weight, and 1 part by weight of the photoacid initiator 4-isopropyl-4′-methyl diphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of SMA1000I copolymer and DEVTEG monomer.
15 g of a 2-(dimethylamino) ethyl methacrylate (DMA) monomer was mixed with 18 g of a solvent PMA, and AIBN was added in the reaction system at 1 wt % of the DMA. Synthesis was performed in a 90° C. environment for 4 hours, and the weight-average molecular weight of the synthesized polymer was about 20852.
After 50 parts by weight of the DEGDE monomer was added in 50 parts by weight of a self-synthesized poly(DMA) polymer and dissolved via a planetary centrifugal mixer, 5 parts by weight of the photoacid initiator 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of poly(DMA) and DEGDE monomer.
After 50 parts by weight of the CHDE monomer was added in 50 parts by weight of the poly(DMA) polymer and mixed and dissolved via a planetary centrifugal mixer, 5 parts by weight of the photoacid initiator 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of poly(DMA) polymer and CHDE monomer.
After 50 parts by weight of the DVETEG monomer was added in 50 parts by weight of the poly(DMA) polymer and mixed and dissolved via a planetary centrifugal mixer, 5 parts by weight of the photoacid initiator was added in the mixture of poly(DMA) polymer and DVETEG monomer.
The procedures and the weights of the vinyl ether monomer and the tertiary amine structure polymer were the same as Example 1, except that extra 400 parts by weight of silver flakes were added.
The procedures and the weights of the vinyl ether monomer and the tertiary amine structure polymer were the same as Example 2, except that extra 400 parts by weight of silver flakes were added.
The procedures and the weights of the vinyl ether monomer and the tertiary amine structure polymer were the same as Example 3, except that extra 400 parts by weight of silver flakes were added.
The procedures and the weights of the vinyl ether monomer and the tertiary amine structure polymer were the same as Example 4, except that extra 400 parts by weight of silver flakes were added.
The procedures and the weights of the vinyl ether monomer and the tertiary amine structure polymer were the same as Example 5, except that extra 400 parts by weight of silver flakes were added.
The procedures and the weights of the vinyl ether monomer and the tertiary amine structure polymer were the same as Example 6, except that extra 400 parts by weight of silver flakes were added.
The procedures and the weights of the vinyl ether monomer and the tertiary amine structure polymer were the same as Example 7, except that extra 400 parts by weight of silver flakes were added.
The procedures and the weights of the vinyl ether monomer and the tertiary amine structure polymer were the same as Example 8, except that extra 400 parts by weight of silver flakes were added.
The procedures and the weights of the vinyl ether monomer and the tertiary amine structure polymer were the same as Example 9, except that extra 400 parts by weight of silver flakes were added.
5 parts by weight of the photoacid initiator 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate was added in 100 parts by weight of the di(ethylene glycol) divinyl ether (DEGDE) monomer and mixed and dissolved via a planetary centrifugal mixer to complete the preparation of the photosensitive composition.
5 parts by weight of the photoacid initiator 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate was added in 100 parts by weight of the 1,4-cyclohexane dimethanol divinyl ether (CHDE) monomer and mixed and dissolved via a planetary centrifugal mixer to complete the preparation of the photosensitive composition.
5 parts by weight of the photoacid initiator 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate was added in 100 parts by weight of the tri(ethylene glycol) divinyl ether (DVETEG) monomer and mixed and dissolved via a planetary centrifugal mixer to complete the preparation of the photosensitive composition.
After 70 parts by weight of the DVETEG monomer was added in 30 parts by weight of the ethyl p-(dimethylamino) benzoate (EPD) tertiary amine structure molecule and mixed and dissolved via a planetary centrifugal mixer, 5 parts by weight of the photoacid initiator 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate was added in the mixture of EPD tertiary amine structure molecule and the DVETEG monomer.
The same procedures as Comparative example 4 were performed, except that the weights of the EPD molecule and the DVETEG monomer were both changed to 50 parts by weight.
The same procedures as Comparative example 4 were performed, except that the weights of the EPD molecule and the DVETEG monomer were changed to 70 parts by weight and 30 parts by weight respectively.
The composition and photosensitive composition characteristics of each example and comparative example are shown in Table 2.
Tables 1 and 2 contain the components of the photosensitive delayed curing compositions of Examples 1 to 18 and Table 4 shows the components of the photosensitive delayed curing compositions of Comparative Examples 1 to 6, and all the measurement units are parts by weight.
The examples and the comparative examples show that, in Examples 1 to 9, at the same 5% addition ratio of the photoacid initiator, the addition of monomers having a vinyl ether functional group with different parts by weight and different structures in the photosensitive adhesive composition, such as DEGDE, CHDE, DVETEG and the tertiary amine structure polymer SMA1000I, may all show the effect of delayed curing.
In Examples 10 to 15, different structures of monomers having a vinyl ether functional group and different structures of the tertiary amine structure polymer SMA1000I were both 50 parts by weight, 1 part by weight or 3 parts by weight of the photoacid initiator was added. The results show that the photosensitive adhesive compositions of Examples 10 to 15 also had a delayed curing effect.
In Examples 16 to 18, 50 parts by weight of a self-synthesized tertiary amine polymer structure poly(DMA) was respectively mixed with 50 parts by weight of three different monomers having a vinyl ether structure to form a photosensitive adhesive composition. The results also show the characteristic of delayed curing.
According to the results of Examples 1 to 18, when the composition had both a vinyl ether functional group structure and a tertiary amine structure polymer, the monomer having a vinyl ether functional group was 30 parts by weight to 70 parts by weight, the tertiary amine polymer was 30 parts by weight to 70 parts by weight, and the photoacid initiator was 1 part by weight to 5 parts by weight, such that the photosensitive composition had a delayed curing characteristic.
In Comparative examples 1 to 3, it is seen that without adding a tertiary amine polymer structure and at the same addition ratio of the photoacid initiator, the photosensitive adhesive composition formed by the monomer having a vinyl ether functional group and a photoacid initiator was cured rapidly, and some cases even showed intense reactions resulting in carbonized adhesive. Therefore, if only the monomer having a vinyl ether functional group and the photoacid initiator were used to form the photosensitive adhesive composition, then the delayed curing effect of the disclosure was not achieved.
The difference between the photosensitive adhesive compositions of Examples 7 to 9 and Comparative examples 4 to 6 is the use of a tertiary amine structure polymer or a tertiary amine structure molecule, and the results show that the delayed curing effect, adhesiveness, and adhesion are all better when a tertiary amine structure polymer was used than when a tertiary amine structure molecule was used. This is because the molecular weight and the volume effect per unit area of the tertiary amine structure polymer are both greater than those of the tertiary amine molecule used in the previous application, and therefore the delayed curing effect, adhesiveness, and adhesion are all better. In addition, under the UV energy exposure evaluation, when the photosensitive adhesive formed by the tertiary amine structure molecule was exposed to a higher UV energy of 4000 mJ/cm2 for one day or more, the adhesive surface still showed a sticky state, and the result of 0B was also measured in the adhesion evaluation. Compared to the photosensitive adhesive formed by the tertiary amine structure polymer of the disclosure, the exposure energy was significantly higher, and more energy and time were required.
In Examples 19 to 27, when the photoacid initiator was added in the same amount of 5 parts by weight, the monomer having a vinyl ether functional group was added in the photosensitive adhesive composition in different parts by weight and different structures, such as DEGDE, CHDE, DVETEG, and the tertiary amine structure polymer SMA1000I, and the surface resistivity thereof was measured, which was about 1.2×10−4 ohm·cm to 5.2×10−3 ohm·cm, which is comparable to the resistivity of 10−4 ohm·cm of the commercially available conductive adhesive from the Japanese TANAKA manufacturer.
In Comparative examples 4 to 6, when the original tertiary amine polymer structure was changed to a molecule having a tertiary amine structure, the photosensitive composition formed by the tertiary amine molecule was cured without delay at different addition ratios. After being left in a room temperature environment for one day or more, the adhesive surface still showed a sticky state, and the adhesion on the substrate was also deteriorated, and the test result was 0B via ASTM D 3359-97.
Therefore, the disclosure may successfully improve the adhesion of the small molecule tertiary amine structure via the tertiary amine structure polymer, and may delay the addition reaction of the double bond in vinyl ether by the photoacid initiator cation in a photoacid initiator environment to achieve the effect of delayed curing of the photosensitive composition.
It will be apparent to those skilled in the art that various modifications and variations may be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 107129097 | Aug 2018 | TW | national |
