Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Radiation sensitive composition or product or process of making
Reexamination Certificate
2002-09-27
2004-07-13
Huff, Mark F. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Radiation sensitive composition or product or process of making
C430S270100, C430S281100, C430S285100, C430S910000, C430S916000, C430S330000, C522S079000, C522S080000, C522S081000, C522S083000, C522S153000
Reexamination Certificate
active
06762009
ABSTRACT:
FIELD OF THE INVENTION
The invention is directed to a photoimageable thick film composition for use in photo-patterning methods, and more particularly, to a composition utilizing a photospeed enhancer.
BACKGROUND OF THE INVENTION
Since it is the trend in the industry to make smaller and cheaper electronic devices and provide higher resolution for performance, it has become necessary to develop new photoimageable materials to manufacture such devices. Photo-patterning technologies offer uniform finer lines and space resolution when compared to traditional screen-printing methods. A photo-patterning method, such as DuPont's FODEL® printing system, utilizes a photoimageable organic medium as found in patents U.S. Pat. Nos. 4,912,019; 4,925,771; and 5,049,480, whereby the substrate is first completely covered (printed, sprayed, coated or laminated) with the photoimageable thick film composition and dried. An image of the circuit pattern is generated by exposure of the photoimageable thick film composition with actinic radiation through a photomask bearing a circuit pattern. The exposed substrate is then developed. The unexposed portion of the circuit pattern is washed away leaving the photoimaged thick film composition on the substrate that, subsequently, is fired to remove all remaining organic materials and sinter inorganic materials. Such a photo-patterning method demonstrates line resolution of about 30 microns depending on the substrate smoothness, inorganic particle size distribution, exposure and development variables.
Despite the foregoing advances in such systems, manufacturers are continuously seeking compositions with improved photospeed and finer resolution of lines and spaces. Such materials will increase the speed of the manufacturing processes without compromising high resolutions in the lines and spaces of the circuit pattern. The present invention is directed to such a composition.
SUMMARY OF THE INVENTION
The invention is directed to a photoimageable composition comprising functional phase particles; finely divided particles of an inorganic binder having a glass transition temperature in the range of 325 to 600° C. a surface area to weight ratio of no greater than 10 m
2
/g and at least 85 wt. % of the particles having a size of 0.1-10 &mgr;m; aqueous developable photocrosslinkable polymer which is the copolymer, interpolymer or mixture thereof, wherein each copolymer or interpolymer comprises (1) nonacidic comonomers comprising C
1-10
alkyl methacrylate, C
1-10
alkyl acrylates, styrene, substituted styrene, or combinations thereof and (2) an acidic comonomer comprising ethylenically unsaturated carboxylic acid containing moiety, wherein 2-20% of the carboxylic acid containing moiety is reacted with a reactive molecule having a first and second functional unit wherein the first functional unit is a vinyl group and the second functional unit is capable of forming a chemical bond by reaction with the carboxylic acid moiety forming the copolymer, interpolymer or mixture having an acid content of at least 10 wt. % of the total polymer weight; and having a glass transition temperature in the range of 50-150° C. and a weight average molecular weight in the range of 2,000-250,000; photoinitiation system; and photospeed enhancer wherein the enhancer comprises a ratio in the range of 30/70 to 70/30 mixture selected from stearic acid and palmitic acid; salt of stearate and salt of palmitate; stearic acid and salt of palmitate; salt of stearate and palmitic acid.
The invention is further directed to a photoimageable composition comprising functional phase particles; inorganic binder having a glass transition temperature in the range of 325 to 600° C. a surface area to weight ratio of no greater than 10 m
2
/g and at least 85 wt. % of the particles having a size of; 0.1-10 micrometers; organic polymeric binder which is a copolymer, interpolymer or mixture thereof, wherein each copolymer or interpolymer comprises (1) nonacidic comonomers comprising C
1-10
alkyl methacrylate, C
1-10
alkyl acrylates, styrene, substituted styrenes, or combinations thereof, and (2) an acidic comonomer comprising ethylenically unsaturated carboxylic acid containing moiety, the copolymer, interpolymer or mixture having an acid content of at least 10 wt. % of the total polymer weight; and having a glass transition temperature of 50-150° C. and a weight average molecular weight in the range of 2,000-250,000; photohardenable monomer; photoinitiation system; photohardenable monomer; photoinitiation system; and photospeed enhancer wherein the enhancer comprises 30/70 to 70/30 mixture selected from stearic acid and palmitic acid; salt of stearate and salt of palmitate; stearic acid and salt of palmitate; salt of stearate and palmitic acid.
DETAILED DESCRIPTION
The photosensitive thick film compositions of the present invention have functional phase particles which impart conductive, resistive or dielectric properties to the composition. An organic medium along with other components of the photosensitive compositions comprises polymers that may or may not be photosensitive in themselves. Components of the composition are described herein below.
I. Inorganic Materials
A. Functional Phase
In conductor applications the functional phase is comprised of electrically functional conductor powder(s). The electrically functional powders in a given thick film composition may comprise a single type of powder, mixtures of powders, alloys or compounds of several elements. Examples of such powders include: gold, silver, copper, nickel, aluminum, platinum, palladium, molybdenum, tungsten, tantalum, tin, indium, lanthanum, gadolinium, boron, ruthenium, cobalt, titanium, yttrium, europium, gallium, sulfur, zinc, silicon, magnesium, barium, cerium, strontium, lead, antimony, conductive carbon, and combinations thereof and others common in the art of thick film compositions.
In resistor compositions, the functional phase is generally a conductive oxide. Examples of the functional phase in resistor compositions are Pd/Ag and RuO
2
. Other examples include ruthenium pyrochlore oxide which is a multi-component compound of RU
+4
, IR
+4
or a mixture of these (M″), said compound being expressed by the following general formula:
(M
x
Bi
2−x
)(M′
y
M″
2−y
)0
7−z
wherein
M is selected from the group consisting of yttrium, thallium, indium, cadmium, lead, copper and rare earth metals,
M′ is selected from the group consisting of platinum, titanium, chromium, rhodium and antimony,
M″ is ruthenium, iridium or a mixture thereof,
x denotes 0 to 2 with a proviso that x≦1 for monovalent copper,
y denotes 0 to 0.5 with the proviso that when M′ is rhodium or two or more of platinum, titanium, chromium, rhodium and antimony, y stands for 0 to 1, and
z denotes 0 to 1 with a proviso that when M is divalent lead or cadmium, z is at least equal to about x/2.
These ruthenium pyrochlore oxides are described in detail in the specification of U.S. Pat. No. 3,583,931. The preferred ruthenium pyrochlore oxides are bismuth ruthenate (Bi
2
Ru
2
O
7
) and lead ruthenate (Pb
2
Ru
2
O
6
).
In dielectric compositions, the functional phase is generally a glass or ceramic. Dielectric thick film compositions are nonconducting compositions or insulator compositions that separate electrical charges and may result in the storage of an electrical charge. Therefore, the thick film dielectric compositions typically contain ceramic powders, oxide and non-oxide frits, crystallization initiator or inhibitor, surfactants, colorants, organic mediums, and other components common in the art of such thick film dielectric compositions. Examples of ceramic solids include: alumina, titanates, zirconates and stannates, BaTiO
3
, CaTiO
3
, SrTiO
3
, PbTiO
3
, CaZrO
3
, BaZrO
3
, CaSnO
3
, BaSnO
3
and Al2O
3
, glass and glass-ceramic. It is also applicable to precursors of such materials, i.e., solid materials which upon firing are converted to dielectric solids, and to mixtures thereof.
B. Inorganic Bi
Glicksman Howard David
Yang Haixin
E. I. du Pont de Nemours and Company
Huff Mark F.
Lee Sin J.
LandOfFree
Aqueous developable photoimageable thick film compositions... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Aqueous developable photoimageable thick film compositions..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aqueous developable photoimageable thick film compositions... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3196077