Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M3/00—Printing processes to produce particular kinds of printed work, e.g. patterns
  • B41M3/006—Patterns of chemical products used for a specific purpose, e.g. pesticides, perfumes, adhesive patterns; use of microencapsulated material; Printing on smoking articles
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C69/00—Esters of carboxylic acids; Esters of carbonic or haloformic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
  • C08G63/06—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from hydroxycarboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D167/00—Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain; Coating compositions based on derivatives of such polymers
  • C09D167/06—Unsaturated polyesters having carbon-to-carbon unsaturation
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/09—Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers
  • G03F7/11—Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers having cover layers or intermediate layers, e.g. subbing layers
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/40—Treatment after imagewise removal, e.g. baking
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2603/00—Systems containing at least three condensed rings
  • C07C2603/02—Ortho- or ortho- and peri-condensed systems
  • C07C2603/04—Ortho- or ortho- and peri-condensed systems containing three rings
  • C07C2603/22—Ortho- or ortho- and peri-condensed systems containing three rings containing only six-membered rings
  • C07C2603/24—Anthracenes; Hydrogenated anthracenes

Definitions

• the present invention was made with the support of the Department of Defense's Defense Microelectronics Activity Grant No. DMEA90-02-C-0224. The Federal Government may have certain rights in this invention.
• the present invention relates, generally, to polymer films having improved laser ablation properties and, more particularly, to radiation curable polymer films having improved laser ablation properties and to radiation curable sensitizers that can be useful in making such polymer films.
• UV curable polymers have developed into an important coatings research area, in part, because of their environment-friendly chemistry. While coatings based on acrylate chemistry are the dominant technology, the development of non-acrylate UV curable coatings is a growing area of research interest especially in view of the health concerns associated with acrylate chemistry.
• the major categories in non-acrylate technology include cationic polymerization, thiol-ene systems, and free- radical induced alternating copolymerization. These chemistries exhibit properties that are similar to acrylates with respect to cure times. Low toxicity and, perhaps more importantly, design flexibility are other benefits.
• free-radical induced alternating copolymerization is one alternative to acrylate UV curable coating. Free-radical induced alternating copolymerization takes place when an electron-rich vinyl group is mixed with an electron deficient vinyl group. This chemistry is also referred to as donor-acceptor systems. The general features of this type of polymerization are stoichiometric dependence and formation of charge-transfer complexes. Ablative photodecomposition was discovered when high energy UV lasers were applied to polymers. One of the important applications envisaged for this process was its application as a dry-etching technique m photolithography. Higher resolution and a lower number of processing steps were the expected benefits. However, the use of standard polymers for laser ablation did not deliver the expected results.
• the present invention relates to a coating formulation.
• the coating formulation includes a copolyester and a vinyl ether.
• the copolyester is produced by copolymer!zing a monomer composition that includes a fused aromatic diacid monomer, an unsaturated diacid monomer, and a polyol .
• the present invention also relates to a method for producing a laser-ablatable film on a surface of a substrate.
• the method includes coating the substrate with a coating formulation that includes a copolyester and a vinyl ether and polymerizing the coating formulation.
• the copolyester includes a fused aromatic moiety covalently bonded therein.
• the present invention also relates to a compound having the formula:
• Q-L-Z where Q- represents a fused aromatic moiety; -L- represents a linking moiety; and -Z represents a moiety containing a oxetane or oxirane ring.
• the present invention also relates to a compound having the formula:
• A- represents a fused aromatic moiety, wherein R 7 represents a C2-C12 alkylene group, wherein R 8 represents an alkyl moiety, and wherein n is 0, 1, 2, 3, or 4.
• Figures IA- 1C are synthetic schemes that can be used to prepare various reactive sensitizers according to the present invention.
• Figure IA shows a synthesis of NDC-OX by transesterification between naphthalene dicarboxylate (“NDC”) and 3-ethyl-3 -hydroxymethyl oxetane (“EHMO”) .
• Figure IB shows a synthesis of ACA-OL by esterification of 9-anthracene carboxylic acid (“ACA”) and ⁇ -caprolactone polyol (“PCL”) .
• Figure 1C shows a synthesis of ACA-EP by ring-opening of 3 , 4-epoxycyclohex- ylmethyl-3 , 4-epoxycyclohexane carboxylate (“ECC”) by ACA.
• Figure 2 is a schematic representation of via arrays created by 355 nm YAG laser ablation of a coating produced with a coating formulation in accordance with the present invention.
• Figures 3A-3B are real-time infrared spectrometry ("RTIR") plots for oxetane conversion of coatings sensitized using various reactive sensitizers according to the present invention.
• RTIR real-time infrared spectrometry
• Figures 4A-4C are RTIR plots for oxetane conversion of coatings sensitized using various amounts of a reactive sensitizer according to the present invention.
• Figures 5A-5E are bar graphs showing the dimensions of the vias created by laser ablation of coatings produced with various coating formulations in accordance with the present invention.
• Figures 5A-5C show via depth data.
• Figures 5D-5F show via diameter data .
• Figure 6 is a graph showing the UV absorption spectra of coatings produced with various coating formulations in accordance with the present invention.
• Figure 7 is a bar graph showing the depth and diameter of vias created by laser ablation of coatings produced with various coating formulations in accordance with the present invention and of two reference coating materials, Kapton and PEN.
• Figures 8A-8B are composite bar/line graphs showing the effect of Tg on the dimensions of vias formed by laser ablation of coatings produced with various coating formulations in accordance with the present invention.
• Figures 9A-9B are bar graphs showing the depth (Figure 9A) and diameter ( Figure 9B) of vias created by laser ablation of coatings produced with various coating formulations in accordance with the present invention
• the coating formulation includes a vinyl ether and a copolyester, the latter having been produced by copolymer!zing a monomer composition that .includes a fused aromatic diacid monomer, an unsaturated diacid monomer, and a polyol .
• coating formulation is meant to refer (i) to a composition which can be used to produce a coating, typically on a substrate; (ii) to a composition which has been coated onto a substrate but not yet cured; and (iii) to a composition which has been coated onto a substrate and which has been partially cured.
• the coating formulation contains a copolyester.
• the copolyester is the polymerization product of a fused aromatic diacid monomer, an unsaturated diacid monomer, and a polyol .
• fused aromatic diacid monomer is meant to refer to a monomer containing two or more acid functional groups (or groups that can be readily converted into acid functional groups, such as salts, anhydrides, etc.) that are covalently attached to a fused aromatic moiety.
• fused aromatic moiety is meant to refer to a ring system containing at least two unsaturated homocyclic or heterocyclic rings 5 that are fused together so that the ring system, as a whole, is aromatic (i.e., electrons in the fused rings are delocalized) .
• fused aromatic moieties there can be mentioned ring systems such as naphthalene, anthracene, phenanthrene, azulene,
• fused aromatic diacid monomers include 2 , 6-naphthalene dicarboxylic acid, 2,7- naphthalene dicarboxylic acid, and other naphthalene dicarboxylic acids.
• unsaturated diacid monomer is meant to refer to a monomer containing at least two acid functional groups (or groups that can be readily converted into acid functional groups, such as salts, anhydrides, etc.) that are covalently attached to an
• unsaturated diacid monomers suitable for use in the practice of the present invention include maleic anhydride, maleic acid, fumaric acid, itaconic acid, aconitic acid, mesaconic acid, citraconic acid, dichloromaleic acid, and the like.
• Polyol as used herein, is meant to refer to any molecule bearing two or more hydroxyl groups (or groups that can be readily converted into hydroxyl groups) .
• examples of polyols suitable for use in the practice of the present invention include diethylene
• the aforementioned copolyester can be the polymerization product of a single fused aromatic diacid monomer, a single unsaturated diacid monomer, and a single polyol ; or the aforementioned copolyester can be the polymerization product of a single fused aromatic diacid monomer, a single unsaturated diacid monomer, and two or more different polyols; or the aforementioned copolyester can be the polymerization product of a single fused aromatic diacid monomer, two or more different unsaturated diacid monomers, and a single polyol; or the aforementioned copolyester can be the polymerization product of two or more different fused aromatic diacid monomers, a single unsaturated diacid monomer, and a single polyol; or the aforementioned copolyester can be the polymerization product of a single fused aromatic diacid monomer, two or more different unsaturated diacid monomers, and two or
• the aforementioned copolyester can be prepared by any suitable method.
• the copolyester can be readily prepared by heating the fused aromatic diacid monomer or monomers, the unsaturated diacid monomer or monomers, and the polyol or polyols at a suitable temperature (e.g., from about 120 0 C to about 300 0 C, such as from about 150 0 C to about 270 °C, from about 160 °C to about 250 °C, and/or from about 180 °C to about 230 0 C) for a suitable length of time (e.g., from about 1 hour to about several days, such as from about 5 hours to about 1 day and/or from about 10 hours to about 15 hours) .
• a suitable temperature e.g., from about 120 0 C to about 300 0 C, such as from about 150 0 C to about 270 °C, from about 160 °C to about 250 °C, and/or from about 180 °C to about 230 0 C
• Water produced during the OH/COOH esterification reaction can be removed using any suitable technique, such as sparging with an inert gas, like nitrogen or argon.
• the reaction can be carried out in the presence of a suitable catalyst, examples of which include paratoluenesulfonic acid, butylstannoic acid, dibutyl tin oxide, and stannous fluoride.
• the molecular weight of the polyester can range from about 100 g/mole to about 200,000 g/mole, such as from about 200 g/mole to about 100,000 g/mole, from about 500 g/mole to about 50,000 g/mole, from about 500 g/mole to about 20,000 g/mole, from about 500 g/mole to about 10,000 g/mole, from about 500 g/mole to about 5,000 g/mole, and/or from about 500 g/mole to about 2,000 g/mole.
• the number of moles of polyol can be selected such that it is from about 7 to about 0.2 times (such as from about 6 to about 0.3 times, from about 4 to about 0.4 times, from about 3 to about 0.5 times, from about 2.7 to about 0.6 times, from about 2 to about 0.8 times, from about 1.9 to about 0.9 times, from about 1.8 to about 1 times, and/or from about 1.6 to about 1.1 times) the sum of the number of moles of unsaturated diacid monomer (s) and the number of moles of aromatic diacid monomer(s).
• Molecular weight can be controlled by using a non-stoichiometric ratio of OH: COOH, for example, as in the case where OH: COOH is from about 1:1.1 to about 1:5 (such as from about 1:1.1 to about 1:4, from about 1:1.1 to about 1:3, from about 1:1.1 to about 1:2.25, from about 1:1.1 to about 1:2, from about 1:1.1 to about 1:1.5, from about 1:1.1 to about 1:1.4, from about 1:1.1 to about 1:1.3, from about 1:1.15 to about 1:1.25, and/or about 1:1.2) or as in the case where COOH: OH is from about 1:1.1 to about 1:5 (such as from about 1.: 1.1 to about 1:4, from about 1:1.1 to about 1:3, from about 1:1.1 to about 1:2.25, from about 1:1.1 to about 1:2, from about 1:1.1 to about 1:1.5, from about 1:1.1 to about 1:1.4, from about 1:1.1 to about 1:1.3, from about 1:1.15 to about 1:1. 1:1.2) or as in the case
• Suitable mole ratios of aromatic diacid monomer : unsaturated diacid monomer are from about 20:1 to about 1:20, such as from about 15:1 to about 1:15, from about 10:1 to about 1:10, from about 5:1 to about 1:5, from about 4:1 to about 1:4, from about 3:1 to about 1:3, and/or from about 2:1 to about 1:2.
• the coating formulation of the present invention in addition to containing a copolyester (as discussed above) , also contains a vinyl ether.
• Vinyl ether is meant to include monovinyl ethers, divinyl ethers, triviriyl ethers, tetravinyl ethers, and so forth.
• Illustrative monovinyl ethers that can be used in the practice of the present invention include ethyl vinyl ether, methyl vinyl ether, propyl vinyl ether, and the like.
• suitable divinyl ethers include divinyl ether, ethylene glycol divinyl ether, 1, 6-hexanediol divinyl ether, and the like.
• Suitable trivinyl ethers include glycerol trivinyl ether, trimethylolpropane trivinyl ether, and the like.
• a suitable tetravinyl ethers is pentaerythritol tetravinyl ether.
• Combination of these and other vinyl ethers can also be employed, and the phrase "a vinyl ether", as used herein, is meant to include such combinations.
• the aforementioned coating formulation can contain other materials in addition to the aforementioned copolyester (s) and vinyl ether (s) .
• the coating formulation can include a suitable photoinitiator, such as Darocur 1173 (2 -hydroxy-2 -methyl - 1-phenyl -propan-1-one) .
• the coating formulation can be cast into a film by a variety of techniques, including spraying, brushing, spin casting, or through the use of a Doctor blade or similar applicator.
• the thickness of the film can be from about 1 micron to about 250 microns, such as from about 1 micron to about 5 microns, from about 2 microns to about 4 microns, from about 1 micron to about 10 microns, from about 2 microns to about 10 microns, about 2 microns, from about 3 microns to about 4 microns, about 3.5 microns, from about 2 microns to about 200 microns, from about 10 microns to about 150 microns, from about 50 microns to about 125 microns, and/or about 100 microns.
• the aforementioned coating formulation for example, cast into a film form, can be cured or otherwise polymerized, for example, by exposure to UV radiation, and the present invention, in another aspect thereof, relates to polymers produced by such a curing or other polymerization process.
• the present invention relates to an electronic device.
• the electronic device includes an electronic chip that has at least one substantially planar surface.
• a polymeric coating is disposed on the electronic chip's substantially planar surface.
• the polymeric coating includes a polymer prepared by polymerizing a coating formulation according to the present invention.
• the electronic device may include other electronic components, such as resistors, capacitors, transistors, diodes, integrated circuits or other electronic chips, and power supplies. Where the electronic device includes other electronic components, these other electronic components can either be coated with a polymeric coating as described above or not .
• the electronic device can further include a hole disposed through the polymeric coating and a signal transmitting element (e.g., a wire, solder ball, or other electrically conductive element; an optical waveguide or other an optically conductive element; etc.) disposed through the hole and connected (e.g., by solder, by an suitable adhesive, such as a conducting epoxy adhesive, etc.) to the electronic chip.
• a hole is meant to refer to one or more holes
• a signal transmitting element as used herein, is meant to refer to one or more signal transmitting elements (which can be of the same type or different types) .
• the aforementioned hole (or holes) can be conveniently formed by laser ablation, for example by using a laser having a UV output, such as a UV output of from about 300 nm to about 400 nm, from about 310 nm to about 390 nm, from about 320 nm to about 380 nm, from about 330 nm to about 370 nm, and/or from about 340 nm to about 360 nm.
• a solid tripled pulsed YAG laser having an output of 355 nm can be employed. The number of pulses can be adjusted to ablate the polymeric coating to the desired depth. For example, where the polymeric coating is disposed on the surface of an electronic chip, the depth of ablation is usually equal to the thickness of the coating.
• the present invention relates to a method for producing a laser- ablatable film on a surface of a substrate.
• the method includes coating the substrate with a coating formulation of the present invention and curing or otherwise polymerizing the coating formulation.
• Suitable substrates include one or more surfaces of electronic chips; suitable methods for coating the substrate with the coating formulation include those described above in regard to coating electronic chips; and suitable methods for curing or otherwise polymerizing the coating formulation include those described above in regard to coating electronic chips.
• the present invention relates to a method for producing a preselected pattern on a surface of a substrate.
• the method includes producing a laser-ablatable film on a surface of a substrate in accordance with a method according to the present invention and exposing the film to ultraviolet electromagnetic radiation under conditions effective to ablate a portion of the film to produce the pre-selected pattern.
• the preselected pattern can be a hole or a plurality of holes arranged in a particular fashion, for example, so as to permit wires, solder balls, or other signal transmitting elements to be connected with the substrate at particular locations.
• the preselected pattern can be a pattern of ridges and valleys, where the valleys can (but need not) be of a depth which exposes the substrate.
• the preselected pattern can be a relief similar to relief wood carving but where the medium is not wood but, instead, the laser-ablatable film.
• the present invention relates to a method for producing a laser- ablatable film on a surface of a substrate.
• the method includes coating the substrate with a coating formulation comprising a copolyester and a vinyl ether and curing or otherwise polymerizing the coating formulation.
• the copolyester used in this method includes a fused aromatic moiety covalently bonded therein.
• suitable copolyesters and vinyl ethers that can be used in this aspect of the present invention include those discussed hereinabove.
• suitable methods for coating the substrate with a coating formulation include spraying, brushing, spin casting, as well as methods which employ a Doctor blade or similar applicator.
• the thickness of the film can be from about 1 micron to about 250 microns, such as from about 1 micron to about 5 microns, from about 2 microns to about 4 microns, from about 1 micron to about 10 microns, from about 2 microns to about 10 microns, about 2 microns, from about 3 microns to about 4 microns, about 3.5 microns, from about 2 microns to about 200 microns, from about 10 microns to about 150 microns, from about 50 microns to about 125 microns, and/or about 100 microns.
• suitable methods for curing or otherwise polymerizing the coating formulation include exposing the coating formulation to electromagnetic radiation, such as ultraviolet radiation.
• the coating formulation can contain other materials, such as photoinitiators .
• the laser-ablatable film thus produced on the surface of a substrate can be used in a method for producing a pre-selected pattern on a surface of a substrate, to which method the present invention also relates.
• the method involves producing a laser-ablatable film on a surface of a substrate (in accordance with a method of the present invention) and exposing the film to ultraviolet electromagnetic radiation under conditions effective to ablate a portion of the film to produce the pre-selected pattern.
• conditions effective to ablate a portion of the film to produce the pre-selected pattern are meant to refer to altering the intensity, duration, numbers of pulses, etc., of the ultraviolet electromagnetic radiation so as to ablate various portions of the laser-ablatable film to various depths.
• the aforementioned coating formulations, polymers, and methods of the present invention can be advantageously employed in the production of electronic chips by providing a method for readily forming holes, vias, or other openings in a photopolymerized packaging layer for receiving conductive elements, such as solder balls.
• Examples of methods for making electronic chips in which the aforementioned coating formulations, polymers, and methods of the present invention can be employed include those which involve fluidic self assembly (e.g., as described in U.S. Patent No. 6,417,025 to Gengel; U.S.
• Patent No. 6,417,025 to Gengel U.S. Patent No. 6,566,744 to Gengel, which are hereby incorporated by reference
• Still other examples of methods for making electronic chips in which the aforementioned coating formulations, polymers, and methods of the present invention can be employed include those which are described in U.S. Patent No. 6,816,380 to Credelle et al . , which is hereby incorporated by reference.
• the present invention in yet another aspect thereof, relates to a compound having the formula:
• fused aromatic moiety is meant to refer to a ring system containing at least two unsaturated homocyclic or heterocyclic rings that are fused together so that the ring system, as a whole, is aromatic (i.e., electrons in the fused rings are delocalized) .
• fused aromatic moieties there can be mentioned naphthalene moieties, anthracene moieties, and pyrene moieties.
• ring systems such as phenanthrene, azulene, quinoline, isoquinoline, acridine, and the like.
• -Z represents a moiety containing a oxetane or oxirane ring.
• Z can be a moiety having the formula:
• R 1 represents a hydrogen atom or a substituted or unsubstituted alkyl group, such as a substituted lower alkyl group, an unsubstituted lower alkyl group, a substituted C1-C6 alkyl group, an unsubstituted C1-C6 alkyl group, a substituted C1-C4 alkyl group, an unsubstituted C1-C4 alkyl group, a methyl group, an ethyl group, a propyl group, etc.
• -Z can be a moiety which contains an oxirane ring fused to a cycloalkyl ring, such as C5 or C6 cycloalkyl ring, for example, as in the case where -Z has the formula:
• -L- represents a linking moiety, such as an alkylene group, an arylene group, and linking groups based on one or more carboxylate ester moieties.
• linking groups based on one or more carboxylate ester moieties there can be mentioned groups having the formula:
• R 2 is an alkylene group.
• suitable R 2 alkylene groups include substituted lower alkylene groups, unsubstituted lower alkylene groups, substituted C1-C6 alkylene groups, unsubstituted C1-C6 alkylene groups, substituted C1-C4 alkylene groups, unsubstituted C1-C4 alkylene groups, methylene groups, ethylene group, propylene group, etc.
• linking groups based on one or more carboxylate ester moieties there can also be mentioned groups having the formula:
• R 3 and R 4 independently represent the same or different alkylene groups.
• suitable R 3 and R 4 alkylene groups include those which are linear as well as those which are cyclic.
• suitable R 3 and R 4 linear alkylene groups include substituted linear lower alkylene groups, unsubstituted linear lower alkylene groups, substituted linear C1-C6 alkylene groups, unsubstituted linear C1-C6 alkylene groups, substituted linear C1-C4 alkylene groups, unsubstituted linear C1-C4 alkylene groups, methylene groups, ethylene group, propylene group, etc.
• R 3 and R 4 cyclic alkylene groups include substituted cyclic lower alkylene groups, unsubstituted cyclic lower alkylene groups, substituted cyclic C4-C12 alkylene groups, unsubstituted cyclic C4-C12 alkylene groups, substituted cyclic C5-C8 alkylene groups, unsubstituted cyclic C5-C8 alkylene groups, substituted cyclic C5-C6 alkylene groups, unsubstituted cyclic C5-C6 alkylene groups, substituted cyclic C6 alkylene groups, unsubstituted cyclic C6 alkylene groups, substituted cyclohex-1, 4-diyl groups, and unsubstituted cyclohex-1, 4- diyl groups.
• the linking group, -L- can have the formula:
• Q- represents a substituted fused aromatic moiety having the formula:
• Z' -L' -Q' - wherein -Q'- represents a fused aromatic moiety,- -L'- represents a linking moiety; and Z 1 - represents a moiety containing a oxetane or oxirane ring.
• -L'- can be the same as -L-, or it can be different.
• Z 1 - can be the same as -Z (as in the case where Z'- and -Z represent the same oxetane or oxirane ring) , or it can be different (as in the case where Z 1 - represents an oxetane ring and where
• the compound of this aspect of the present invention can have the formula:
• Z'-L'-Q'-L-Z where -Q'- represents a fused aromatic moiety; -L'- represents a linking moiety; and Z 1 - represents a moiety containing a oxetane or oxirane ring, as discussed further hereinabove and hereinbelow.
• R 5 represents a substituted or unsubstituted alkyl group, such as a substituted lower alkyl group, an unsubstituted lower alkyl group, a substituted C1-C6 alkyl group, an unsubstituted C1-C6. alkyl group, a substituted C1-C4 alkyl group, an unsubstituted C1-C4 alkyl group, a methyl group, an ethyl group, a propyl group, etc.
• such compounds have ' the formula:
• -Q'- represents a fused aromatic moiety, such as a naphthalene moiety (e.g., a 2 , 6-naphthalene moiety, a 2 , 7-naphthalene moiety), an anthracene moiety, a pyrene moiety, etc.
• a naphthalene moiety e.g., a 2 , 6-naphthalene moiety, a 2 , 7-naphthalene moiety
• an anthracene moiety e.g., a pyrene moiety
• the aforementioned compounds of the present invention having the formula Q-L-Z can be prepared by any suitable method.
• R ⁇ can be a substituted or unsubstituted alkyl group, such as a substituted or unsubstituted linear or cyclic alkyl group, a substituted linear lower alkyl group, an unsubstituted linear lower alkyl group, a substituted linear C1-C6 alkyl group, an unsubstituted linear C1-C6 alkyl group, a substituted linear C1-C4 alkyl group, an unsubstituted linear C1-C4 alkyl group, a methyl group, an ethyl group, a propyl group, etc., a substituted cyclic lower alkyl group, an unsubstituted cyclic
• the transesterification reaction can be advantageously carried out by heating the mixture of ester having the formula Q-COOR 6 and alcohol having the formula HO-Z, illustratively at from about 50 °C to about 150 0 C, such as at about 100 0 C, for from about 2 hours to about 5 days, such as for from about 12 hours to about 2 days and/or for about 1 day.
• the transesterification reaction can be carried out in a suitable solvent, such as an aromatic solvent (e.g., benzene, toluene, and/or xylene) .
• the R S -OH transesterification byproduct can be removed, for example, to drive the transesterification reaction to completion.
• Removal of the R 6 -0H byproduct can be carried out, for example, by using a low molecular weight R 6 moiety, such that the R 5 - OH byproduct has a boiling point below the temperature at which the reaction is carried out.
• the transesterification reaction can also be advantageously carried out in the presence of a suitable transesterification catalyst, such as a tertiary amine.
• suitable tertiary amine transesterification catalysts include tertiary amine-containing ion exchange resins, such as an ion exchange resin having alkyl tertiary amine functionality, one example of which is AMBERLYSTTM A-21 ion exchange resin (available from Aldrich, Milwaukee, Wisconsin) .
• Suitable mole ratios of ester having the formula Q-COOR 6 to alcohol having the formula HO-Z include mole ratios ranging from about 1:5 to about 5:1, such as from about 4:1 to about 1:4, from about 3:1 to about 1:3, from about 2:1 to about 1:2, about 1:1.5, about 1:2, about 1:2.5, about 1:3, from about 1 : 1 to about 1:2, from about 1:1 to about 1:2.5, from about 1:1 to about 1:3, from about 1:1 to about 1:4, from about 1:1 to about 1:5 from about 1:1.5 to about 1:2, from about 1:1.5 to about 1:2.5, from about 1:1.5 to about 1:3, from about 1:1.5 to about 1:4, and/or from about 1:1.5 to about 1:5. Still alternatively, the aforementioned compounds of the present
• cycloaliphatic epoxide for example, a 3 , 4-epoxycyclohexylmethyl-3 , 4 -epoxycyclohexane carboxylate, such as a difunctional cycloaliphatic epoxide having the following formula
• the reaction can be advantageously carried out by heating the mixture of acid having the formula Q-COOH and difunctional cycloaliphatic epoxide (e.g., a 3,4- epoxycyclohexylraethyl-3 , 4-epoxycyclohexane carboxylate) , illustratively at from about 50 0 C to about 180 0 C, such as at from about 100 0 C to about 140 0 C and/or at about 120 0 C, for from about 1 hour to about 3 days, such as for from about 4 hours to about 2 days, for from about 12 hours to about 1 day, and/or for about 18 hours.
• difunctional cycloaliphatic epoxide e.g., a 3,4- epoxycyclohexylraethyl-3 , 4-epoxycyclohexane carboxylate
• the reaction can be carried out in a suitable solvent, such as an aromatic solvent (e.g., benzene, toluene, and/or xylene) .
• a suitable solvent such as an aromatic solvent (e.g., benzene, toluene, and/or xylene) .
• the reaction can be advantageously carried out with stirring or other forms of agitation.
• the ratio of starting materials is not particularly critical to the synthesis.
• Suitable mole ratios of acid having the formula Q-COOH to difunctional cycloaliphatic epoxide include mole ratios ranging from about 1:5 to about 5:1, such as from about 4:1 to about 1:4, from about 3 : 1 to about 1:3, from about 2:1 to about 1:2, from about 1.5:1 to about 1:1.5, from about 1.3:1 to about 1:1.3, from about 1.2:1 to about 1:1.2, from about 1.1:1 to about 1:1.1, and/or about 1:1.
• the present invention also relates to compositions which include the aforementioned compounds of the present invention having the formula Q-L-Z (as described above) and a polyol .
• polyol is meant to refer to any molecule bearing two or more hydroxyl groups (or groups that can be readily converted into hydroxyl groups) as well as to combinations of such molecules.
• polyols suitable for use in the compositions of the present invention include diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, glycerol, neopentyl glycol, trimethylol propane, pentaerythritol , sorbitol, 1, 6-hexanediol, 1,4- cyclohexanemethanol , 1, 2 -bis (hydroxyethyl) cyclohexane, and the like. Combinations of these and other polyols can also be used.
• these compositions of the present invention can further include other materials.
• these compositions can further include difunctional oxetane/oxirane resins, other monofunctional oxetane/oxirane resins, other compounds bearing a single hydroxy1 function, photoinitiators, and the like.
• a suitable difunctional oxetane/oxirane resin that can be used in such compositions of the present invention, there can be mentioned 3 , 4-epoxycyclohexylmethyl-3 , 4-epoxycyclohexane carboxylates, such as a difunctional cycloaliphatic epoxide having the following formula:
• difunctional oxetane/oxirane resin that can be used in such compositions include various commercially available difunctional oxetane reactive diluents, such as bis ([l-ethyl(3- oxetanyl) ] methyl) ether, which is available from Toagosei Co. Ltd. (Tokyo, Japan) as OXT-221.
• monofunctional oxetane/oxirane resins that can be used in such compositions of the present invention include various commercially available monofunctional oxetane reactive diluents (such as 3- ethyl-3-hydroxymethyl oxetane, which is available from Dow Chemical Company as CRYACURETM UVR 6000) and various commercially available monofunctional oxirane reactive diluents (such as a methyl or other ester of 3,4- epoxycyclohexane carboxylic acid, the methyl ester of which is available from Dow Chemical Company as ERL- 4140) .
• monofunctional oxetane reactive diluents such as 3- ethyl-3-hydroxymethyl oxetane, which is available from Dow Chemical Company as CRYACURETM UVR 6000
• monofunctional oxirane reactive diluents such as a methyl or other ester of 3,4- epoxycyclohexane carboxylic acid, the methyl este
• difunctional oxetane/oxirane resins other monofunctional oxetane/oxirane resins/ and/or compounds bearing a single hydroxyl function, relative to the amount of compound of the present invention having the formula Q-L-Z and relative to the amount of polyol can depend on the desired characteristics of the composition and the desired characteristics of the polymer to be produced by polymerization of the composition.
• the various components and their respective amounts can be chosen based on the desired characteristics of the coating formulation (e.g., rheology, stability, etc.) and the desired characteristics of the coating to be produced by polymerization of the coating formulation (e.g., hardness, stability, etc.) .
• the mole ratio of compound Q-L-Z :polyol : difunctional oxetane/oxirane resins: other monofunctional oxetane/oxirane resins : compounds bearing a single hydroxyl function is typically selected such that the total number of hydroxyl groups present in the system (e.g., from the polyol and from the compounds bearing a single hydroxyl function) and the total number of oxetane/oxirane groups present in the system (e.g., from the compound Q-L-Z, from other monofunctional oxetane/oxirane resins, and from difunctional oxetane/oxirane resins) are substantially the same (e.g., oxetane/oxirane : hydroxyl from about 1:1.2 to about 1.2:1, such as oxetane/oxirane : hydroxyl from about 1:1.1 to about 1.1:1, oxetane/oxirane :
• Suitable mole ratios of compound Q-L-Z :polyols are from about 10000:1 to about 1:10000, such as from about 5000:1 to about 1:5000, from about 2000:1 to about 1:2000, from about 1000:1 to about 1:1000, from about 500:1 to about 1:500, from about 200:1 to about 1:200, from about 100:1 to about 1:100, from about 50:1 to about 1:50, from about - z /
• compositions can further include a photoinitiator, such as a cationic photoinitiator.
• a photoinitiator such as a cationic photoinitiator.
• suitable photoinitiators include antimony-containing cationic photoinitiator, such as a triarylsulfonium hexafluoroantimonate salt (e.g., mixed triarylsulfonium hexafluoroantimonate salt in propylene carbonate, available from Dow Chemical Company) .
• the present invention in yet another aspect thereof, relates to a compound having the formula (“Formula I”) :
• n 0, 1, 2, 3, or 4
• A- represents a fused aromatic moiety.
• fused aromatic moiety is meant to refer to a ring system containing at least two unsaturated homocyclic or heterocyclic rings that are fused together so that the ring system, as a whole, is aromatic (i.e., electrons in the fused rings are delocalized) .
• fused aromatic moieties there can be mentioned naphthalene moieties, anthracene moieties, and pyrene moieties.
• fused aromatic moieties there can be mentioned ring systems such as phenanthrene , azulene, quinoline, isoquinoline, acridine, and the like.
• ring systems such as phenanthrene , azulene, quinoline, isoquinoline, acridine, and the like.
• the compound can have the formula : - 2 B -
• R 7 represents a C2-C12 alkylene group, which alkylene group can be substituted or unsubstituted.
• suitable substituents include alkyl groups, aryl groups, hydroxy groups, alkoxy groups, and/or halogen atoms.
• R 7 can be a substituted or unsubstituted C2-C8 alkylene group,- a substituted or unsubstituted C3-C6 alkylene group; a substituted or unsubstituted C2, C3 , CA 1 CS 1 C6 , Cl, C8 , CS, ClO 7 CIl, or C12 alkylene group,- an alkylene group having the formula - (CH 2 ) m - , where m is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or
• R 8 represents an alkyl moiety, such as an alkyl moiety having the formula R lo -C (-R 9 -) 3 , where R 10 represents a substituted or unsubstituted alkyl group and R 9 is a C1-C12 substituted or unsubstituted alkylene group.
• R 9 and/or R 10 are substituted, suitable substituents include alkyl groups, aryl groups, hydroxy groups, alkoxy groups, and/or halogen atoms.
• R 10 can be an alkyl group having the formula H 3 C-R 9 -, for example, as in the case where R 10 is an alkyl group having the formula H 3 C-R 9 - and R 9 is a substituted or unsubstituted C1-C6 alkylene group, a substituted or unsubstituted C1-C3 alkylene group.
• R 8 can be an alkyl moiety having the formula R 10 -C (-R 9 -) 3/ wherein R 10 - is a substituted or unsubstituted C1-C6 alkyl group (e.g., a substituted or unsubstituted Cl, C2, C3 , C4 , C5 , or C ⁇ alkyl group) and wherein -R 9 - is a substituted or unsubstituted C1-C3 alkylene group (e.g., a substituted or unsubstituted Cl, C2 , or C3) alkylene group, such as in the case where R 10 - is a substituted or unsubstituted C2 alkyl group and where R 9 is a substituted or unsubstituted Cl alkylene group or as in the case where R 10 - is a substituted or unsubstituted C1-C4 alkyl group and where R 9 is an alkylene group having the formula -
• the compounds of Formula I can have the following formula:
• A- represents a fused aromatic moiety and where n is 0, 1, 2, 3, or 4.
• the compounds of Formula I can have the following formula:
• n 0, 1, 2, 3, or 4.
• the aforementioned compounds of the present invention having Formula I can be prepared by any suitable method.
• the aforementioned compounds can be synthesized by contacting an acid having the formula A-COOH with a polyol , such as a polyol having the formula: - JU -
• the reaction can be advantageously carried out by heating the mixture of ester having the formula A-COOH and polyol , illustratively at from about 50 °C to about 180 0 C, such as at from about 100 0 C to about 140 0 C and/or at about 120 0 C, for from about 1 hour to about 4 days, such as for from about 4 hours to about 3 days, for from about 12 hours to about 36 hours, for from about 1 day to about 3 days, for from about 18 hours to about 36 hours, for from about 2 days to about 36 hours, and/or for about 29 hours.
• the reaction can be carried out in a suitable solvent, such as an aromatic solvent (e.g., benzene, toluene, and/or xylene) .
• a suitable solvent such as an aromatic solvent (e.g., benzene, toluene, and/or xylene)
• the water byproduct can be removed, for example, to drive the esterification reaction to completion.
• Removal of the water byproduct can be carried out, for example, by using a suitable drying agent or by purging with an inert gas (e.g., nitrogen, argon, etc.) .
• the esterification reaction can also be advantageously carried out in the presence of a suitable esterification catalyst, such as a compound having sulfonic acid functionality.
• Suitable sulfonic acid esterification catalysts include sulfonic acid-containing ion exchange resins, such as AMBERLYSTTM A-15 ion exchange resin (available from Aldrich, Milwaukee, Wisconsin) .
• the reaction mixture can be stirred or otherwise agitated.
• the ratio of starting materials is not particularly critical to the synthesis. - J l -
• Suitable mole ratios of acid having the formula A-COOH to polyol include mole ratios ranging from about 1:5 to about 5:1, such as from about 4:1 to about 1:4, from about 3 : 1 to about 1:3, from about 2:1 to about 1:2, from about 1.5:1 to about 1:1.5, from about 1.3:1 to about 1:1.3, from about 1.2:1 to about 1:1.2, from about 1.1:1 to about 1:1.1, and/or about 1:1.
• the present invention also relates to compositions which include the aforementioned compounds of the present invention (i.e., those of Formula I, as described above) and a difunctional oxetane/oxirane resin.
• Difunctional oxetane/oxirane resin is meant to refer to any molecule bearing two or more oxetane and/or oxirane groups, as well as to combinations of such molecules.
• difunctional oxetane/oxirane resin is meant to include molecules that bear at least two oxirane groups, molecules that bear at least two oxetane groups, as well as molecules that bear at least one oxetane group and at least one oxirane group.
• difunctional oxirane resins examples include 3,4- epoxycyclohexylmethyl-3 , 4-epoxycyclohexane carboxylates (such as a difunctional cycloaliphatic epoxide having the following formula:
• compositions of the present invention can further include other materials.
• these compositions can further include monofunctional oxetane/oxirane resins, other polyols, compounds bearing a single hydroxyl function, photoinitiators , and the like.
• polystyrene resin examples of other polyols that can be included in these compositions of the present invention, there can be mentioned diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, glycerol, neopentyl glycol, trimethylol propane, pentaerythritol , sorbitol, 1, 6-hexanediol, 1 , 4-cyclohexanemethanol , 1,2- bis (hydroxyethyl) cyclohexane, and the like. Combinations of these and other polyols can also be used.
• monofunctional oxetane/oxirane resins that can be used in such compositions include various commercially available monofunctional oxetane reactive diluents (such as 3-ethyl-3-hydroxymethyl oxetane, which is available from Dow Chemical Company as CRYACURETM UVR 6000) and various commercially available monofunctional oxirane reactive diluents (such as a methyl or other ester of 3 , 4-epoxycyclohexane carboxylic acid, the methyl ester of which is available from Dow Chemical Company as ERL-4140) .
• monofunctional oxetane reactive diluents such as 3-ethyl-3-hydroxymethyl oxetane, which is available from Dow Chemical Company as CRYACURETM UVR 6000
• monofunctional oxirane reactive diluents such as a methyl or other ester of 3 , 4-epoxycyclohexane carboxylic acid, the methyl ester
• difunctional oxetane/oxirane resin can depend on the desired characteristics of the composition and the desired characteristics of the polymer to be produced by polymerization of the composition.
• the various components and their respective amounts can be chosen based on the desired characteristics of the coating formulation (e.g., rheology, stability, etc.) and the desired characteristics of the coating to be produced by polymerization of the coating formulation (e.g., hardness, stability, etc.) .
• the mole ratio of compound of Formula I : difunctional oxetane/oxirane resin: other polyols :monofunctional oxetane/oxirane resins : compounds bearing a single hydroxyl function is typically selected such that the total number of hydroxyl groups present in the system (e.g., from the compound of Formula I, from the other polyols, and from the compounds bearing a single hydroxyl function) and the total number of oxetane/oxirane groups present in the system (e.g., from the difunctional oxetane/oxirane resins and from the monofunctional oxetane/oxirane resins) are substantially the same (e.g., oxetane/oxirane : hydroxyl from about 1:1.2 to about 1.2:1, such as oxetane/oxirane : hydroxyl from about 1:1.1 to about 1.1:1, oxetane/oxirane :
• Suitable mole ratios of compound Formula I : difunctional oxetane/oxirane resins are from about 10000:1 to about 1:10000, such as from about 5000:1 to about 1:5000, from about 2000:1 to about 1:2000, from about 1000:1 to about 1:1000, from about 500:1 to about
• compositions can further include a photoinitiator, such as a cationic photoinitiator.
• a photoinitiator such as a cationic photoinitiator.
• suitable photoinitiators include antimony-containing cationic photoinitiator, such as a triarylsulfonium hexafluoroantimonate salt (e.g., mixed triarylsulfonium hexafluoroantimonate salt in propylene carbonate, available from Dow Chemical Company) .
• the aforementioned compounds of the present invention can be used in a method for preparing polymers produced by photopolymerization, and the present invention, in another aspect thereof, relates to polymers produced by such a polymerization process.
• the compounds of the present invention having the formula Q-L-Z or the compounds of the present invention of Formula I can be formulated into a composition, as described above, and photopolymerized, as discussed in more detail below.
• the aforementioned coating compositions (e.g., containing a compound of the present invention having the formula Q-L-Z, a polyol, and optional photoinitiator and other optional components or containing a compound of the present invention of Formula I, a difunctional oxetane/oxirane resin, and optional photoinitiator and other optional components) can be used in a method for preparing polymers, and the present invention, in another aspect thereof, relates to polymers produced by such a polymerization process.
• the method includes providing such a composition and exposing the composition to electromagnetic radiation under conditions effective to polymerize the composition.
• the coating formulation Prior to polymerization, can be cast into a film by a variety of techniques, including spraying, brushing, spin casting, or through the use of a Doctor blade or similar applicator.
• the thickness of the film can be from about 1 micron to about 250 microns, such as from about 1 micron to about 5 microns, from about 2 microns to about 4 microns, from about 1 micron to about 10 microns, from about 2 microns to about 10 microns, about 2 microns, from about 3 microns to about 4 microns, about 3.5 microns, from about 2 microns to about 200 microns, from about 10 microns to about 190 microns, from about 50 microns to about 180 microns, about 90 microns, about 100 microns, about 110 microns, about 120 microns, and/or about 130 microns.
• Polymers produced in accordance with the above- described method e.g., photopolymerization of a composition containing a compound of the present invention having the formula Q-L-Z, a polyol, and optional photoinitiator and other optional components or photopolymerization of a composition containing a compound of the present invention of Formula I, a difunctional oxetane/oxirane resin, and optional photoinitiator and other optional components
• the present invention in yet another aspect thereof, relates to such electronic devices .
• such electronic devices of the present invention include an electronic chip that has at least one substantially planar surface and a polymeric coating disposed on the electronic chip's substantially planar surface, where the polymeric coating includes a polymer prepared by photopolymerization of a composition containing a compound of the present invention having the formula Q-L-Z, a polyol, and optional photoinitiator and other optional components or by photopolymerization of a composition containing a compound of the present - J b -
• the electronic device may include other electronic components, such as resistors, capacitors, transistors, diodes, integrated circuits or other electronic chips, and power supplies. Where the electronic device includes other electronic components, these other electronic components can either be coated with a polymeric coating as described above or not.
• the electronic device can further include a hole disposed through the polymeric coating and a signal transmitting element (e.g., a wire, solder ball, or other electrically conductive element; an optical waveguide or other an optically conductive element; etc.) disposed through the hole and connected (e.g., by solder, by an suitable adhesive, such as a conducting epoxy adhesive, etc.) to the electronic chip.
• a hole is meant to refer to one or more holes
• a signal transmitting element as used herein, is meant to refer to one or more signal transmitting elements (which can be of the same type or different types) .
• the aforementioned hole (or holes) can be conveniently formed by laser ablation, for example by using a laser having a UV output, such as a UV output of from about 300 nm to about 400 nm, from about 310 nm to about 390 nm, from about 320 nm to about 380 nm, from about 330 nm to about 370 nm, and/or from about 340 nm to about 360 nm.
• a solid tripled pulsed YAG laser having an output of 355 nm can be employed. The number of pulses can be adjusted to ablate the polymeric coating to the desired depth.
• the depth of ablation is usually equal to the thickness of the coating.
• the aforementioned compositions of the present invention containing a compound of the present invention having the formula Q-L-Z, a polyol , and optional photoinitiator and other optional components or the aforementioned compositions of the present invention containing a compound of the present invention of Formula I, a difunctional oxetane/oxirane resin, and optional photoinitiator and other optional components can also be used in a method for producing a laser-ablatable film on a surface of a substrate. The method includes coating the substrate with a coating formulation of the present invention and polymerizing the coating formulation.
• Suitable substrates include one or more surfaces of electronic chips; suitable methods for coating the substrate with the coating formulation include those described above in regard to coating electronic chips; and suitable methods for polymerizing the coating formulation include those described above in regard to coating electronic chips.
• the aforementioned compositions of the present invention containing a compound of the present invention having the formula Q-L-Z, a polyol, and optional photoinitiator and other optional components or the aforementioned compositions of the present invention containing a compound of the present invention of Formula I, a difunctional oxetane/oxirane resin, and optional photoinitiator and other optional components can also be used in a method for producing a pre-selected pattern on a surface of a substrate.
• the method includes producing a laser-ablatable film on a surface of a substrate in accordance with a method according to the present invention and exposing the film to ultraviolet electromagnetic radiation under conditions effective to ablate a portion of the film to produce the pre-selected pattern.
• the preselected pattern can be a hole or a plurality of holes arranged in a particular fashion, for example, so as to permit wires, solder balls, or other signal transmitting elements to be connected with the substrate at particular locations.
• the preselected pattern can be a pattern of ridges and valleys, where the valleys can (but need not) be of a depth which exposes the substrate.
• the preselected pattern can be a relief similar to relief wood carving but where the medium is not wood but, instead, the laser-ablatable film.
• the aforementioned compounds of the present invention having the formula Q-L-Z and the aforementioned compounds of the present invention of Formula I, as well as the compositions, polymers, and methods of the present invention containing such compounds can be advantageously employed in the production of electronic chips by providing a method for readily forming holes, vias, or other openings in a photopolymerized packaging layer for receiving conductive elements, such as solder balls.
• conductive elements such as solder balls.
• methods for making electronic chips in which these compounds, compositions, polymers, and methods of the present invention can be employed include those which involve fluidic self assembly (e.g., as described in U.S. Patent No. 6,417,025 to Gengel ; U.S. Patent No.
• EXAMPLE 1 Radiation Curable Polymer Films Having Improved Laser Ablation Properties
• a UV curable composition based on donor acceptor chemistry with enhanced laser ablation properties was obtained by the introduction of 2,6- naphthalene dicarboxylic acid in the backbone.
• the UV curable compositions involve unsaturated polyesters containing monomers that sensitize the resulting coating toward laser ablation.
• the unsaturated polyesters are synthesized by standard melt polyesterification techniques where diacids and diol monomers are esterified together to form the polyester . resin.
• Unsaturated polyester resins require the presence of an unsaturated monomer, usually maleic anhydride or maleic acid, fumaric acid, itaconic acid, aconitic acid, mesaconic acid, citraconic acid, or dicholorotnaleic acid.
• the polyols used can be one or more of the following: diethyleneglycol, ethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, glycerol, neopentyl glycol, trimethylol propane, pentaerythritol , sorbitol, 1, 6-hexanediol, 1,4-cyclo- hexanemethanol , and 1, 2-bis (hydroxyethyl) cyclohexane .
• a monomer yielding enhanced sensitivity to laser ablation is included. This monomer can be 2 , 6-naphthalene dicarboxylic acid ("2,S-NDA”) . Without intending to be bound by theory, it is believed that 2,6-NDA, being as its absorption is in the UV region, would be sensitive during UV irradiation. It is - I U -
• the coating would have maximum absorbance at the irradiation wavelength, thereby achieving an effective laser ablation.
• the unsaturated polyester resins may be prepared by heating the carboxylic component and an organic polyol for about 10 to 15 hours to temperatures from 180 0 C to 230 0 C.
• the water formed during esterification reaction is typically sparged off using an • inert gas, like nitrogen.
• catalysts that can be used in this reaction include paratoluenesulfonic acid, butylstannoic acid, dibutyl tin oxide, and stannous fluoride.
• the molecular weight of the polyester can range from 500 to 50,000. In a preferred embodiment, the polyester has a molecular weight in the range of from 500 to 2000.
• Radiation curable compositions can include a vinyl ether component as an electron donor component that provides at least two vinyl ether groups per molecule of the ether component. They are also known as reactive diluents. Such products are commercially available .
• the unsaturated polyester and the reactive diluent are mixed together.
• Photoinitiator is added to this composition, and the resulting composition is exposed to UV irradiation to form a film.
• a comparative example of a polyester without NDA was prepared by reacting 0.266 moles of triethylene glycol, 0.550 moles of 1, 6-hexanediol , 0.120 moles of isophthatic acid, and 0.551 moles of maleic anhydride. Triphenyl phosphite and butyl stannoic acid was 0.1 of the total weight of the monomers. The polyesterification reaction was conducted at 18O 0 C and stopped when an acid value of 6.4 mg of KOH per 100 g of the sample was reached.
• polyester with NDA was prepared by reacting 0.244 moles of triethylene glycol, 0.511 moles of 1, 6-hexanediol , 0.054 moles of isophthalic acid, 0.041 moles of 2,6-NDA, and 0.611 moles of maleic anhydride. Triphenyl phosphite and butyl stannoic acid was 0.1 of the total weight of the monomers.
• the polyesterification reaction was conducted at 18O 0 C and stopped when an acid value of 5.4 mg of KOH per 100 g of the sample was reached.
• a coating formulation and crosslinking is set forth below.
• the polyester was combined with triethylene glycol divinyl ether in a ratio of 1:1 of the reacting functional groups.
• Darocur 1173 which is a photoinitiator, was added to the composition, and the resulting mixture was homogenized.
• a coating was prepared from this homogenized mixture using an applicator with a clearance of 4 mil. The resultant film was tested for laser ablation properties, as follows.
• Table 1 contains the data for hole depths for different coatings.
• Kapton film polyimide
• optical microscope analysis also showed that cleaner ablation was obtained in case of the coating based on polyester with 2,6-NDA.
• copolyesters set forth in the ' following
• Table 2A were also prepared, and they were then crosslinked using the divinyl ether and photoinitiator described above in this Example 1. Note that, in Table
• DEG 1,6-hexanediol
• IPA isophthalic acid
• MA maleic anhydride
• MA maleic anhydride
• MA maleic anhydride
• MA maleic anhydride
• MA maleic anhydride
• MA maleic anhydride
• NPG neopentyl glycol
• PPG propylene glycol
• TOG triethylene glycol
• TMP trimethylolpropane
• Cycloaliphatic epoxide based cationic UV curable coatings offer the advantage of fast cure, low shrinkage rate, no oxygen inhibition (Sangermano et al . , J. Mater. Sci . , 37 (22) :4753-4757 (2002) (“Sangermano”), which is hereby incorporated by reference) , and good electrical properties (Koleske et al . , UV-Cured Cycloaliphatic Epoxide Coatings, National SAMPE Technical Conference .14: 249-256 (1982) ("Koleske I”); Koleske et al .
• dopant such as pyrene or naphthalene
• dopant is a common practice in aiding laser ablation (Wang et al . , Etching of Transparent Materials by Laser Ablation of an Organic Solution. RIKEN Review, 32: Focused on Laser Precision Microfabrication (LPM2000) (2001) , which is hereby incorporated by - 4 b -
• novel sensitizers were synthesized based on reaction between naphthalene or anthracene derivatives and -ingredients (cycloaliphatic epoxide, oxetane and polyol) in the coating.
• naphthalene or anthracene derivatives and -ingredients cycloaliphatic epoxide, oxetane and polyol.
• HPLC and GC-MS confirmed the formation of desired sensitizers.
• Three coating systems based on cycloaliphatic epoxide and oxetane or polyol were formulated with the reactive sensitizers.
• Sensitized coatings exhibited faster cationic UV curing and better UV laser ablation performance, coatings with anthracene based sensitizer even have better ablation performance than Kapton. Sensitized coatings have higher hardness, Tg and crosslink density than the original coatings. No adverse effect was observed on the coating's adhesion and solvent resistance after sensitizer addition. The relationship between coating's Tg and laser ablation behavior was investigated, -and this investigation revealed that the higher the Tg and crosslink density, the worse the ablation.
• Difunctional oxetane reactive diluent OXT-221 bis ( [1-ethyl (3 -oxetanyl) ] methyl) ether, "DOX” was provided by Toagosei Co., Ltd..
• AMBERLYST ® A-21 ion-exchange resin with alkyl tertiary amine functionality (“A21")
• NDC naphthalene dicarboxylate
• ACA 9-anthracene carboxylic acid
• the novel reactive sensitizers were synthesized using the synthetic routes described in Figure 1. Syntheses were carried out in a 100 ml three- neck flask equipped with nitrogen inlet, reflux condenser, and magnetic stirrer. The reaction temperature was maintained by a heating mantle and a thermocouple linked to a temperature controller. Reaction mixture was dried in vacuum oven (30 mm Hg, ⁇ 65°C) before characterization and use.
• the product is abbreviated as ACA-EP.
• the synthesized reactive sensitizers were characterized as follows. High performance liquid chromatography (“HPLC”) analysis was performed on an. Agilent 1100 series HPLC utilizing the diode array detector (“DAD”) for UV/Vis characterization. Chromatographic separation was achieved on a reversed-phase ZORBAX C8 column (from Agilent) with a C4 guard column (from Thermo Electron) . The mobile phase consisted of two solvents: Solvent A (0.05 M ammonium phosphate, pH unadjusted) and solvent B (methanol) . Column temperature was maintained at 40 0 C throughout the analysis. A 15 ⁇ l injection volume was used for all samples.
• HPLC High performance liquid chromatography
• DAD diode array detector
• the column was eluted with the following gradient: 0 min, 35% B; 18 min, 35% B; 18.1 min, 85% B; 28 min, 85% B; 28.1 min, 35% B.
• Flow rate was 0.7 ml/min with a 40 minute runtime per injection.
• GC-MS analysis was performed on HP 6890 gas chromatography and HP 5973 mass selective detector utilizing EI (electron ionization) with filament energy of 69.9 kev.
• Initial GC oven temperature was 70 0 C; then it was ramped up to 300 0 C at a rate of 20°C/min.
• the front inlet was in split mode with inlet temperature 250 0 C and pressure 8.24 psi .
• mass spectrometer was in scan mode with m/z ranges from 10 to 800, and the temperature for MS source and MS Quad were set at 230 0 C and 150 0 C respectively.
• Coating films were prepared by casting the liquid sample onto an aluminum panel or a polysulfone film (thickness -130 ⁇ m) with a Gardco 70# wire drawdown bar.
• the cured coating film generated has a thickness of 90-120 ⁇ m, which is much thicker than normal thickness of UV coatings (10-20 ⁇ m) .
• a problem that accompanies thicker coating film is the curling on the polysulfone substrate, especially for 3.8 and 3.9 systems due to internal stress generated during UV curing.
• the cured film thickness was reduced to around 20 ⁇ m, a flat film is achieved.
• UV curing of coating samples was performed using a Dymax light source with a 200 EC silver lamp (UV- A, 365 nm) .
• the intensity was 35 mW/cm 2 measured by NIST
• Photoinfrared experiments were performed using a Nicolet Magna-IR 850 spectrometer series II with detector type DTGS KBr, and a UV optic fiber mounted in a sample chamber which humidity is kept constant at around 20% by DRIERITE ® .
• the light source was a LESCO Super Spot MK II 10OW DC mercury vapor short-arc lamp.
• RTIR real-time infrared spectrometry
• the UV source was adjusted to about 3.6 mW/cm 2 , and the experiment was performed in air.
• the cycloaliphatic epoxide conversion of ECC was monitored at 789 cm "1
• the oxetane conversion of EHMO and DOX was monitored at 976 cm' 1 .
• DSC Differential scanning calorimetry
• TA Instruments QlOOO series calorimeter Samples were subjected to a heat-cool -heat cycle from - 50 0 C to 200°C at a ramp rate of 10°C/min. Tg values were determined as the midpoint of the inflection from the second heat cycle.
• Dynamic mechanical thermal analysis (“DMTA”) was performed using a Rheometric Scientific 3E apparatus in the rectangular tension/compression geometry. Free film of the cured coating was obtained on polysulfone substrate using razor blade. Sample size for testing was 10mm x 5 mm. The analysis was carried out from 0 to 250 0 C at a frequency of 10 rad/s and a ramp rate of 5°C/min.
• Tg was obtained from the maximum peak in the tan ⁇ curves.
• Hardness testing was performed with a BYK Gardener pendulum hardness tester in the K ⁇ nig mode on an aluminum panel .
• Cross-hatch adhesion test was performed on polysulfone substrate using a Gardco cross-hatch cutter which creates a 5 x 5 squares pattern; adhesive tape was then applied onto the pattern; and the adhesive tape was pulled off to examine coating loss.
• Methyl ethyl ketone (“MEK”) double rub experiment was used to assess the coating's solvent resistance. Coating samples were applied onto aluminum panels, UV cured, and placed at room temperature for 1 hour before test. A 26-ounce hammer with 5 layers of cheesecloth wrapped around the hammerhead was soaked in MEK for rubbing. After 100 double rubs, the cloth was rewet with MEK. The number of double rubs was reported once mar appeared on the film surface.
• MEK Methyl ethyl ketone
• UV laser ablation of cured coating films on polysulfone substrate was carried out using YAG laser.
• Laser parameters were: wavelength 355 nm, power 0.2 W, effective laser beam spot size 40 ⁇ m, beam spiral diameter 200 ⁇ m, velocity 125 mm/s, repetition rate 20 kHz.
• a 16-via array was generated (as shown in Figure 2. Nitrogen flow over the film surface was used to blow away ablation debris.
• Wyko NT3300 Optical Profiler from VEECO was used to obtain profile data of vias created by laser ablation.
• VSI vertical scanning interferometry
• a magnification of 50 x 0.5 were used.
• the NDC-OX is a white powder soluble in acetone and chloroform.
• the reaction product mixture contained about 71.8% NDC-OX.
• the ACA-EP is a brownish viscous liquid.
• the reaction product mixture contains about 56.2% ACA-EP. ' • ⁇
• the ACA-OL (MW 522) is a yellowish paste.
• GC- MS did not show any new product peaks except for the peaks of ACA and PCL.
• HPLC analysis there was indication of target product formation.
• the HPLC chromatogram showed two peaks at about 15 minutes, and these peaks were attributed to unreacted ACA. All the peaks in the HPLC chromatogram after 20 minutes have UV absorption spectra different from both ACA and PCL, indicating new product formation. All product peaks (except for two minor ones) have ACA' s characteristic UV absorption between 330-390 nm, indicating attachment of ACA to polyol .
• the reaction product mixture contains about 49.5% ACA-OL.
• the above synthesized products are expected to be "reactive" sensitizers since the epoxide or oxetane group in ACA-EP and NDC-OX can take part in the photopolymerization, and the polyol moiety in ACA-OL can be incorporated into the crosslink network via chain transfer reaction (Crivello et al . , J. Rad. Cur. , 13(4):2-6, 8-9 (1986) ("Crivello II”), which is hereby incorporated by reference) . Further separation/purification of the reaction product mixture was not carried out since decent amount of monomeric polyaromatic compounds had been modified according to the spectroscopic data, and the unreacted coating ingredients will still take part in photopolymerization as usual . The reaction product mixtures were put into formulation after removing the catalyst and solvent .
• the reactive sensitizers were added into the UV coating formula with the ratio of 0.1 mmol/5 g coating (about 1% wt) .
• Formulas with 0.1 mmol ACA-EP were named 3.8 -ACA-EP, 3.9-ACA-EP, and 3.10 -ACA-EP.
• the sensitizers dissolved in the coating after being heated at about 50°C for 15 minutes on hot plate. The resultant samples are clear liquid under room temperature, indicating good compatibility. Characterizations of these sensitized coatings were carried out to examine sensitizer's effect.
• the 3.9 system is a highly crosslinked system in which the vitrification point is earlier (compared to the 3.8 system) . Since an effective sensitization depends on collision, complex formation,
• the mono functional oxetane provides enough mobility so that sensitization is effective, even when the sensitizer is bound to the network earlier, as in the case of ACA- EP.
• the mobility provided by large amount of polyol is the greatest.
• the polyol helps to boost the monomer conversion rate (Crivello II; Koleske, Polym. Paint Colour J.. 179 (4249) -.796-798, 800, 802, 804 (1989) ("Koleske III”); and Goldberg et al . , Mod. Paint Coatings, 82(12):36, 39-40, 42 (1992) ("Goldberg”), which are hereby incorporated by reference) .
• the sensitizer's amount in the coating formula was varied to see its effect on UV curing.
• Formulas studied were based on 3.8-2 and 3.10-2 formulations.
• Formulas 3.X-2 half, double, and triple represent the NDC-OX's amount is half, double, and triple of 0.1 mmol (0.0328g)/5g respectively.
• RTIR study results was shown in Figures 4A-4C, from which it can be seen that there exists an optimum sensitizer amount in terms of UV curing acceleration. For example, for the 3.8 system, the amount is 0.1 mmol. For the 3.10 system, the amount is 0.2 mmol .
• the 3.9 system has the highest v e ; hence its curling is serious and the films formed are brittle, possibly reducing its potential in practical applications.
• One noticeable phenomenon is that almost all of the 3.10 samples exhibit two DMTA Tgs . This may be an indication of microphase separation of the cured coating.
• the inner average diameter was obtained by using the "data restore" function in the "processed options” first, then by measuring and averaging the x and y diameter below certain depth. Ablated vias ' dimension data are shown in Figures 5A-5E.
• the dash line arrow indicates that the sample is still in incubation stage at that pulse (Kunz; and Ortelli, which are hereby incorporated by reference) .
• a typical sign of incubation is the existence of a lump above the film plane.
• the solid line arrow in Figures 5A-5C indicates a through hole in the coating film at that pulse. From Figures 5A-5E, it is apparent to see that even addition of small amount of reactive sensitizers (about 1% in weight) greatly enhances laser ablation on the coating films. This is especially true at the initial several pulses (pulses 1, 2, and 4) .
• the depth improvement is less which can be explained by lower polymer molecular weight and higher mobility inside the cured film caused by a large amount of the polyol (Lippert I; Sasaki; Koleske III; and Goldberg, which are hereby incorporated by reference) ; thus even the blank sample can be ablated easily.
• the via ' s inner and outer diameter are larger. Since the laser beam's spiral diameter is 200 ⁇ m, a sample having an outer diameter closer to 200 ⁇ m is considered to be a better ablated one. After 4 pulses ablation on the 3.8 and 3.10 samples, such improvement is pronounced especially for samples with ACA-OL, for which the diameter is double that of the blank sample. When the films were ablated by more pulses, the difference between sensitized samples and original ones is less pronounced since the sensitizer's effect is overwhelmed by high laser energy input. Coatings sensitized by ACA- OL were found to have better performance in laser ablation at 355 nm. This can be explained by their broader and stronger absorption at around 355 nm. The UV absorption spectra for coating films containing the different sensitizers are shown in Figure 6.
• Kapton polyimide
• PEN poly (ethylene naphthalene)
• Kapton polyimide
• PEN poly (ethylene naphthalene)
• Film thickness for the Kapton reference material was 75 ⁇ m
• film thickness for the PEN reference material was 125 ⁇ m.
• Kapton is considered a standard commercial material for laser ablation, which ablation is mainly based on thermal mechanism (Ortelli; and Lippert I, which are hereby incorporated by reference) .
• PEN is expected to have good ablation performance due to a high content of naphthalene moieties in the polymer backbone.
• ACA-OL sensitized coating samples were used to compare with Kapton and PEN because of their better ablation performance.
• Tg is one of a polymer's key properties and is related to many polymer behaviors. It was found that polymers with crosslinked structure or with higher molecular weight are more difficult to ablate, probably due to their higher stability and viscosity (Lippert I, which is hereby incorporated by reference) . No report on the relationship between polymer's Tg and laser ablation behavior has been found.
• Tables 3A-3C (3.8-4, 3.8-5 and 3.10- 4, 3.10-5), with Tg variation in order to study the effect of Tg on laser ablation. In the 3.8 and 3.10 systems, Tg was varied by changing the percentage of difunctional monomers (DOX or ECC respectively) present. NDC-OX was added to the 3.8 system in order to further examine reactive sensitizer's effect. The basic thermal and mechanical properties of these formulations were tested, and the results are shown in Table 7.
• FIGS 8A- 8B show the relationship between Tg and laser ablation behavior of coating films. More particularly, Figures 0 8A- 8B reveal that the higher the Tg (also higher v e , since, here, the higher Tg is caused by denser network structure) , the later the ablation starts, and the smaller the via dimension. This phenomena can be explained by more energy needed to break the network to 5 liberate small molecules to create the via. Since thermal mechanism is inevitably involved in laser ablation process, it is likely that Tg, as one of polymer's most important thermal properties, will be a factor in the ablation process. The sensitizer's effect 0 on higher Tg coating formulations were also examined, and the thermal and mechanical properties of these coating formulations are given in Table 7. RTIR and ablation results are shown in Table 8 and in Figures 9A-9B. TABLE 8
• Novel reactive sensitizers were synthesized by reacting naphthalene or anthracene derivatives with ECC, EHMO, and PCL. These sensitizers have good compatibility in cycloaliphatic epoxide based cationic UV curable coatings, and, consequently the coatings sensitized with about 1 % wt sensitizers exhibit accelerated UV curing, resulting in higher Tg, hardness, and crosslink density. Profile and dimension data (depth and diameter) of vias created by YAG UV laser ablation on sensitized coating films and Kapton and PEN reference films were obtained. Larger depth and diameter were found for sensitized coatings than non sensitized ones.
• ACA-OL sensitized coatings have best laser ablation performance among the tested coating samples. This result can be explained by anthracene's stronger and broader absorption around 355 nm. These coatings even have greater laser ablation depths and diameters than Kapton, which is widely accepted as a standard laser ablation material. Moreover, the reactive sensitizers did not exhibit any adverse effect on coating performance. The effect of Tg on laser ablation behavior was investigated, and it was found that laser ablation becomes more difficult with higher Tg and v e .

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