U.S. patent application number 09/815059 was filed with the patent office on 2001-08-02 for molded resin composition exhibiting good adhesion to conductive material on a surface.
This patent application is currently assigned to NEC Corporation. Invention is credited to Funada, Yoshitsugu, Matsui, Koji.
Application Number | 20010011111 09/815059 |
Document ID | / |
Family ID | 18175294 |
Filed Date | 2001-08-02 |
United States Patent
Application |
20010011111 |
Kind Code |
A1 |
Funada, Yoshitsugu ; et
al. |
August 2, 2001 |
Molded resin composition exhibiting good adhesion to conductive
material on a surface
Abstract
A resin matrix with resistances to alkali and acid includes at
least any one of insulative organic particles and insulative
composite particles having an organic component and an inorganic
component with the total amount of these particles being in the
range of 5-50% by volume, wherein the insulative organic particles
and the organic component of the insulative composite particles are
allowed to be corroded by either alkali or acid, and wherein not
less than 90% by volume of the insulative organic particles and
insulative component particles have a particle diameter in the
range of 1-20 micrometers.
Inventors: |
Funada, Yoshitsugu; (Tokyo,
JP) ; Matsui, Koji; (Tokyo, JP) |
Correspondence
Address: |
YOUNG & THOMPSON
745 SOUTH 23RD STREET 2ND FLOOR
ARLINGTON
VA
22202
|
Assignee: |
NEC Corporation
Tokyo
JP
|
Family ID: |
18175294 |
Appl. No.: |
09/815059 |
Filed: |
March 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09815059 |
Mar 23, 2001 |
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08986104 |
Dec 5, 1997 |
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6232398 |
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Current U.S.
Class: |
523/434 ;
427/123 |
Current CPC
Class: |
C08L 63/00 20130101;
H05K 3/381 20130101; H05K 2201/0218 20130101; C08L 63/00 20130101;
C08L 63/00 20130101; H05K 2201/0209 20130101; H05K 3/181 20130101;
H05K 2201/0212 20130101; H05K 2201/0254 20130101; C08L 2666/04
20130101; H05K 1/0373 20130101; C08L 2666/02 20130101 |
Class at
Publication: |
523/434 ;
427/123 |
International
Class: |
C08L 001/00; B05D
005/12 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 5, 1996 |
JP |
08-325301 |
Claims
What is claimed is:
1. A method of forming a conductor on a surface of a resin
composition comprising the steps of: molding a resin which includes
at least any one of insulative organic particles and insulative
composite particles having an organic component and an inorganic
component at a total amount in the range of 5-50% by volume,
wherein the organic particles and the organic component of the
composite particles are allowed to be corroded by either alkali or
acid and wherein not less than 90% by volume of said at least any
one of said insulative organic particles and said insulative
composite particles has a particle diameter in the range of 1-20
micrometers; exposing the resin to at least any one of an acid
solution and an alkali solution to make a surface of the molded
resin rough; and subjecting the rough surface of the molded resin
to an electroless plating for subsequent heat treatment to the
resin.
2. The method as claimed in claim 1, wherein the acid solution and
the alkali solution are permanganate and neutralizing solution
thereof.
3. A resin with resistance to alkali and acid comprising: a resin
matrix comprising an epoxy-acrylate having a fluorine skeleton and
benzocyclobutene; and at least one of insulative organic particles
and insulative composite particles; wherein not less than 90
percent by volume of said organic particles and said composite
particles have a particle diameter in the range of 1-20
micrometers, and the volume of said at least one of said organic
particles and said composite particles is in the range of 5-50
percent of the resin volume, said composite particles having an
organic component and an inorganic component; said organic
particles and said organic component of said composite particles
being selected from the group consisting of a thermoplastic
amorphous polymer having a glass transition temperature of at least
90.degree. C., a thermoplastic crystalline polymer having a melting
point of at least 110.degree. C., and a thermosetting polymer, and
said organic particles and said organic component of said composite
particles being corrosible by one of an acid or an alkali; and
wherein said organic particles and said organic component of said
composite particles comprise a thermoplastic crystal polymer having
a melting point of at least 110.degree. C.
4. A resin with resistance to alkali and acid comprising: a resin
matrix comprising an epoxy-acrylate having a fluorine skeleton and
benzocyclobutene; and at least one of insulative organic particles
and insulative composite particles; wherein not less than 90
percent by volume of said organic particles and said composite
particles have a particle diameter in the range of 1-20
micrometers, and the volume of said at least one of said organic
particles aid said composite particles is in the range of 5-50
percent of the resin volume, said composite particles having an
organic component and an inorganic component; said organic
particles and said organic component of said composite particles
being selected from the group consisting of a thermoplastic
amorphous polymer having a glass transition temperature of at least
90.degree. C., a thermoplastic crystalline polymer having a melting
point of at least 110.degree. C., and a thermosetting polymer, and
said organic particles and said organic component of said composite
particles being corrosible by one of an acid or an alkali; and
wherein said organic particles and said organic component of said
composite particles comprise a thermosetting polymer.
5. A resin with resistance to alkali and acid comprising: a resin
matrix comprising an epoxy-acrylate having a fluorine skeleton and
benzocyclobutene; and at least one of insulative organic particles
and insulative composite particles; wherein not less than 90
percent by volume of said organic particles and said composite
particles have a particle diameter in the range of 1-20
micrometers, and the volume of said at least one of said organic
particles and said composite particles is in the range of 5-50
percent of the resin volume, said composite particles having an
organic component and an inorganic component; said organic
particles and said organic component of said composite particles
being selected from the group consisting of a thermoplastic
amorphous polymer having a glass transition temperature of at least
90.degree. C., a thermoplastic crystalline polymer having a melting
point of at least 110.degree. C., and a thermosetting polymer, and
said organic particles and said organic component of said composite
particles being corrosible by one of an acid or an alkali; and
wherein each of said composite particles comprise inorganic core
particles coated with a thermoplastic polymer layer.
6. A resin with resistance to alkali and acid comprising: a resin
matrix comprising an epoxy-acrylate having a fluorine skeleton and
benzocyclobutene; and at least one of insulative organic particles
and insulative composite particles; wherein not less than 90
percent by volume of said organic particles and said composite
particles have a particle diameter in the range of 1-20
micrometers, and the volume of said at least one of said organic
particles and said composite particles is in the range of 5-50
percent of the resin volume, said composite particles having an
organic component and an inorganic component; said organic
particles and said organic component of said composite particles
being selected from the group consisting of a thermoplastic
amorphous polymer having a glass transition temperature of at least
90.degree. C., a thermoplastic crystalline polymer having a melting
point of at least 110.degree. C., and a thermosetting polymer, and
said organic particles and said organic component of said composite
particles being corrosible by one of an acid or an alkali; and
wherein each of said composite particles comprise inorganic core
particles coated with a thermosetting polymer layer.
7. A resin with resistance to alkali and acid comprising: a resin
matrix comprising an epoxy-acrylate having a fluorine skeleton and
benzocyclobutene; and at least one of insulative organic particles
and insulative composite particles; wherein not less than 90
percent by volume of said organic particles and said composite
particles have a particle diameter in the range of 1-20
micrometers, and the volume of said at least one of said organic
particles and said composite particles is in the range of 5-50
percent of the resin volume, said composite particles having an
organic component and an inorganic component; said organic
particles and said organic component of said composite particles
being selected from the group consisting of a thermoplastic
amorphous polymer having a glass transition temperature of at least
90.degree. C., a thermoplastic crystalline polymer having a melting
point of at least 110.degree. C., and a thermosetting polymer, and
said organic particles and said organic component of said composite
particles being corrosible by one of an acid or an alkali; wherein
said organic particles and said composite particles comprise hollow
particles; wherein said hollow particles each have a coating of
calcium carbonate, the weight of said coating being 25 percent or
less of the weight of said hollow particle; and wherein said
organic particles and said organic component of said composite
particles are at least one thermosetting polymer selected from the
group consisting of epoxy resin, phenol resin, and diarylphthalate
resin.
Description
RELATED APPLICATION
[0001] This application is a divisional of co-pending Application
Ser. No. 08/986,104, filed on Dec. 5, 1997, the entire contents of
which are hereby incorporated by reference
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a resin composition, and
more particularly to a resin composition exhibiting a good adhesion
when a surface of the resin composition is subjected to a wet
processing for forming a conductor on a surface of the molded resin
composition.
[0003] A plating process has been developed for the purpose of
preventing static electricity on the surface of a molded resin
composition. This plating process is also made for forming a
patterned conductor on a predetermined part of the molded resin
composition surface, typically forming a printed wiring board. Such
plating processes may be isolated into two processes. The first one
is a dry process using thin film technologies of such as
evaporation and sputtering. The second one is a wet process,
wherein a catalyst core is adsorbed on the resin composition
surface, and the resin composition is subsequently immersed into an
electroless plating bath for precipitation of electroless plating.
If the dry process is used, then the maximum thickness of the
conducive film is only a few micrometers, namely it is difficult to
form a thin conductive film. This means that the thick conductive
film is formed in the wiring board, then the impedance of the
wiring is high, namely it is difficult to reduce the impedance of
the conductive film wiring on the wiring board. On the other hand,
the dry process allows a good adhesion of conductor with the resin
composition. However, the dry process is inferior in the
productivity and cost performance, for which reason the dry process
is not suitable for mass production at low cost.
[0004] Namely, the wet process is superior in cost performance but
inferior in adhesion between resin composition and conductor. In
order to improve the adhesion between resin composition and
conductor, it is required to provide a roughness to the surface of
the resin composition. Available methods for providing the
roughness to the resin composition surface would be isolated into
two typical ones. The first one is the mechanical and physical
method. The second one is the chemical method using wet etching by
chemical etchants. The mechanical and physical method is somewhat
inferior in uniformity of roughness and adhesion to the fine
patterns is not uniform. It is also difficult to obtain a
sufficiently high adhesion with a hard resin. On the other hand,
the chemical method is ineffective with chemical-resistant
resins.
[0005] Some typical electroless plating processes for resin surface
will be described.
EXAMPLE 1
Co-polymerization of resin matrix with components to be corroded by
chemicals
[0006] The following description will be made in the case of
acrylonitrile-butadiene-styrene resin (ABS resin). This resin has
an island structure wherein the rubber component of butadiene is
dispersed in the form of spherical particles in a body of
acrylonitrile-butadiene (AB). If this resin is immersed in an
oxidizing etchant, then the rubber component in the form of
spherical particles positioned in the vicinity of surfaces of the
body is selectively oxidized and dissolved into the etchant,
whereby the surface of the resin is made rough. The plated film of
conductor is securely engaged with the rough surface of the resin
by the anchor effect.
[0007] It is known in the art to make the adhesive layer rough. In
Japanese patent publication Nos. 63-10752 and Japanese laid-open
patent publication No. 3-18096, it is disclosed that the rubber
component of the acrylonitrile-butadiene-styrene rubbers is
introduced into the adhesive of epoxy resins to obtain the same
effect as described above.
[0008] Chromatic acid is used as an oxidizing etchant for selecting
etching the rubber component dispersed in the form of spherical
particles. The use of chromatic acid as the oxidizing etchant is
not preferable in the light of recently required reduction of
environmental pollution. Blending rubber component reduces heat
resistivity, stability in size, and insulation performance or
anti-migration performance.
EXAMPLE 2
Blending resin matrix with inorganic insulator to be dissolved into
chemicals
[0009] In Japanese laid-open patent publication No. 60-167492, it
is disclosed that an inorganic insulator is used to be selectively
etched by chemicals. Glass, magnesium oxide and calcium carbonate
are, for example, available to obtain a desired adhesion.
[0010] Since such inorganic insulators, however, include alkali
metals or alkali earth metals, there is raised a problem with
deterioration in moisture resistance of the resin. For this reason,
it is preferable to not include a large amount of such inorganic
insulators into the resin. Further, generally, the inorganic
insulator has a larger specific gravity than resins. Particularly
if liquid inorganic insulators such as varnish are used, then the
inorganic insulator is non-uniformly present in the resin matrix,
and the probability of the inorganic insulator existing in the
vicinity of the surface of the resin matrix is lower.
[0011] In the above circumstances, it was required to develop a
novel resin composition free from the above problems and a novel
method of forming a conductor on a surface of the resin
component.
SUMMARY OF THE INVENTION
[0012] Accordingly, it is an object of the present invention to
provide a novel resin composition free from the above problems.
[0013] It is a further object of the present invention to provide a
novel resin composition on which a conductor fine pattern is
adhered at a high adhesion.
[0014] It is a still further object of the present invention to
provide a novel resin composition having a surface allowing good
adhesion to a conductor.
[0015] It is yet a further object of the present invention to
provide a novel resin composition having good production yield.
[0016] It is a further more object of the present invention to
provide a novel resin composition which may be produced at a low
cost.
[0017] It is still more object of the present invention to provide
a novel method of forming a conductor on a surface of a resin
composition free form the above problems.
[0018] It is moreover object of the present invention to provide a
novel method of forming a conductor on a surface of a resin
composition with a good adhesion.
[0019] It is another object of the present invention to provide a
novel method of forming a conductor on a surface of a resin
composition at a low cost.
[0020] It is still another object of the present invention to
provide a novel high production yield method of forming a conductor
on a surface of a resin composition.
[0021] The above and other objects, features and advantages of the
present invention will be apparent from the following
descriptions.
[0022] In accordance with the present invention, a resin matrix
with resistances to alkali and acid includes at least any one of
insulative organic particles and insulative composite particles
having an organic component and an inorganic component at a total
amount in the range of 5-50% by volume, wherein the insulative
organic particles and the organic component of the insulative
composite particles are allowed to be corroded by either alkali or
acid, and wherein not less than 90% by volume of any one of the
insulative organic particles and insulative composite particles has
a particle diameter in the range of 1-20 micrometers.
[0023] It is preferable that the insulative organic particles and
the organic component of the insulative composite particles
comprise a thermoplastic amorphous polymer which has a glass
transition temperature of not less than 90.degree. C.
[0024] It is also preferable that the insulative organic particles
and the organic component of the insulative composite particles
comprise a thermoplastic crystal polymer which has a melting point
of not less than 110.degree. C.
[0025] It is also preferable that the insulative organic particles
and the organic component of the insulative composite particles
comprise a thermosetting polymer.
[0026] It is also preferable that parts of the insulative organic
particles and the insulative composite particles comprise hollow
particles.
[0027] It is also preferable that each of the insulative composite
particles comprise inorganic core particles coated with a
thermoplastic polymer layer.
[0028] It is also preferable that each of the insulative composite
particles comprise inorganic core particles coated with a
thermosetting polymer layer.
[0029] It is also preferable that each of the insulative composite
particles comprise a homogeneous organic particle coated with
calcium carbonate at an amount of 25% by weight or less.
[0030] It is also preferable that each of the insulative composite
particles comprise a hollow organic particle coated with calcium
carbonate at an amount of 25% by weight or less.
[0031] It is also preferable that the resin matrix has a
photosensitivity.
[0032] It is also preferable that the resin matrix with the
photosensitivity is any one of epoxy-acrylate having fluorene
skeleton and benzocyclobutene and the organic particles and the
organic component of the composite particles are at least one
thermoplastic polymer selected from the group consisting of
polymethylmethacrylate, polyacrylonitrile, polystyrene, nylon,
polycarbonate, and polyvinylidene chloride.
[0033] It is also preferable that the resin matrix with the
photosensitivity is any one of epoxy-acrylate having fluorene
skeleton and benzocyclobutene and the organic particles and the
organic component of the composite particles are at least one
thermosetting polymer selected from the group consisting of epoxy
resin, phenol resin, and diarylphthalate resin.
[0034] In accordance with the present invention, a method of
forming a conductor on a surface of a resin composition comprises
the steps of:
[0035] molding a resin which includes at least any one of
insulative organic particles and insulative composite particles
having an organic component and an inorganic component at a total
amount in the range of 5-50% by volume, wherein the organic
particles and the organic component of the composite particles are
allowed to be corroded by either alkali or acid and wherein not
less than 90% by volume of said at least any one of said insulative
organic particles and said insulative composite particles has a
particle diameter in the range of 1-20 micrometers;
[0036] exposing the resin to at least any one of an acid solution
and an alkali solution to make a surface of the molded resin rough;
and
[0037] subjecting the rough surface of the molded resin to an
electroless plating for subsequent heat treatment of the resin.
[0038] It is preferable that the acid solution and the alkali
solution are permanganate and a neutralizing solution thereof.
Permanganate is used as a chemical for desmear treatment.
DISCLOSURE OF THE INVENTION
[0039] In accordance with the present invention, a resin matrix has
at least any one of resistances to alkali and acid. The resins with
resistance to acid may, for example, be epoxy-acrylate, and
polyamide imide. The resins with resistance to alkali may, for
example, be polystyrene, and nylon. The resins with resistances to
both alkali and acid may, for example, be polypropylene, polyester,
epoxy resin, polyimide, and benzocyclobutene. Particularly,
epoxy-acrylate having fluorene skeleton and benzocyclobutene are
preferable due to those high glass transition temperature and high
hydrophobicity. The organic particles and the organic component of
the composite particles are allowed to be corroded by either alkali
or acid relative to the resin matrix. Thermoplastic polymers may,
for example, be selected from polymethylmethacrylate, acryl resins
such as polyacrylonitrile, polystyrene, polycarbonate, and acetal
resins.
[0040] It is preferable that the organic particles and the organic
component of the composite particles comprise a thermoplastic
amorphous polymer which has a glass transition temperature of not
less than 90.degree. C.
[0041] It is also preferable that the organic particles and the
organic component of the composite particles comprise a
thermoplastic crystal polymer which has a melting point of not less
than 110.degree. C.
[0042] In the method of forming the conductor on the surface of the
resin, after the rough surface of the molded resin is subjected to
the electroless plating, heat treatment of the resin is carried out
to remove moisture from the molded resin for improvement in the
adhesion of the surface of the resin. The heat treatment is
preferably carried out at not less than 90.degree. C. If the glass
transition temperature is less than 90.degree. C., or a melting
point is less than 110.degree. C., then any deformation such as
expansion may appear on the surface of the molded resin.
[0043] If the resin matrix comprises a thermoplastic polymer, then
the thermoplastic polymer has a glass transition temperature of not
less than 90.degree. C., and a melting point is less than
110.degree. C. If the glass transition and melting point
temperatures are lower than the above, then deformation may appear
due to heat treatment.
[0044] Generally, thermosetting resins have a bridge structure, for
which reason the thermosetting resins are superior in resistance to
chemicals. It is preferable to not roughen the surface of the resin
in a short time. However, if the high heat resistance and size
stability are required, then those thermosetting resins are
superior than the thermoplastic resins. It is, therefore,
preferable to blend the thermosetting resins, even if the time for
roughening the surface of the resin is somewhat long. The resin
matrix of epoxy-acrylate having fluorene skeleton and
benzocyclobutene having a high glass transition temperature is
blended with thermosetting resin such as epoxy resin, phenol resin,
and diarylphthalate resin to obtain higher properties than when the
thermosetting resin is used alone and obtain better adhesion.
[0045] On the other hand, the inorganic component of the composite
particles is not limited when used as core particles coated with an
organic component to be corroded by acid and alkali solutions. In
this case, the organic component is corroded, and the core particle
is also removed, thereby exhibiting roughness effects. If the
inorganic component is used for coating the core particles, then
calcium carbonate is preferable due to its high solubility. Since,
however, calcium carbonate includes alkali earth metals, the
moisture resistance might be dropped. It is preferable to not use a
large amount of calcium carbonate alone. It is preferable to reduce
the blending amount of calcium carbonate to 25% by weight or less.
The hollow particles are effective for shortening the corrosion
time and reducing the blending amount thereof. The hollow particles
have low specific gravity, and the particles are likely to be
localized on the surface region of the particles. This makes it
easy to obtain a rough surface on the resin. The blending amount of
the particles is in the range of 5-50% by volume. If the blending
amount is less than 5% by volume, then it is difficult to obtain
the desired rough surface o the resin necessary for good adhesion
to the conductor. If the blending amount is more than 50% by
volume, then the properties of the resin matrix are remarkably
changed. Not less than 90% by volume of the particles have a
particle diameter in the range of 1-20 micrometers. Preferably, not
less than 95% by volume of the particles have a particle diameter
in the range of 3-15 micrometers. More preferably, not less than
98% by volume of the particles have a particle diameter in the
range of 5-10 micrometers. If the diameter is less than 1
micrometer, then it is difficult to obtain a sufficiently rough
surface on the resin for required adhesion to the conductor. If the
diameter is more than 20 micrometers, then the surface roughness is
too great to form fine interconnections on the surface.
[0046] It is possible to add insulative particles to the resin
composition other than the particles to be corroded by alkali and
acid solutions. In order to reinforce the molded resin and obtain
dimension stability as well as improve heat conductivity, inorganic
particles such as silica, alumina, titanium oxide, and boron
nitride may be included. It is also possible to include additives
such as flame retardant, coloring agent, ultraviolet ray absorbent
agent, and an antistatic agent.
[0047] The chemicals to be used for corrosion are acid and alkali
solutions. In view of prevention of environmental pollution, it is
preferable to not use organic solvents. For example, mineral acids
such as sulfuric acid, and hydrochloric acid may be included, and
an oxidizing agent may also be included. As an alkali, sodium
hydroxide is generally used. Permanganate is used as a chemical for
desmear treatment to remove residual resin to obtain good adhesion
for deposition of the electroless plating. The desmear treatment
comprises three steps of swelling the resin with an alkali solution
containing a small amount of organic solvent, etching by an alkali
solution of permanganate, and neutralizing for removal of residual
manganese. Therefore, this process may be applicable to either
particles to be corroded by any one of acid and alkali solutions.
In accordance with the swelling and solubility, the immersion of
the resin in the chemicals is carried out for a few minutes to
several tens of minutes. In the interval between these immersion
processes, the resin needs to be washed by water. Further, it is
possible for pre-treatment or post-treatment with alkali solution,
before or after the desmear treatment.
[0048] The method of forming the conductor on the resin surface
will be described. The method comprises three steps of molding the
resin, making the surface of molded resin rough with at least one
of alkali and acid solutions, and subjecting the surface thereof to
electroless plating for subsequent heat treatment.
[0049] The method of molding is not limited. If the resin matrix is
thermoplastic polymer, then it is possible to melt the resin
composition to mold the resin in the desired shape. It is also
possible to dissolve the resin composition into the solvent to
apply on the substrate surface, or to inject into dies for
subsequent volatilization If the resin matrix is the thermosetting
polymer or non-thermoplastic polymer, it is possible to apply
precursor varnish on the substrate surface for subsequent
thermosetting by heat, light and radioactive ray.
[0050] The surface of the molded resin is made rough for good
adhesion with the electroless plated conductor by use of acid or
alkali solutions. Permanganate is used as a chemical for desmear
treatment. Further, prior to the desmear treatment, a mechanical
polishing such as buff polishing is preferably carried out for
obtaining the surface roughness. Particularly, if the surface is
hard and the resistance to chemicals is high, the resin thin film
is polished for removal thereof to show the particle surface.
[0051] The rough surface of the resin is subjected to the
electroless plating. In order to carry out the electroless plating,
it is required to add to the substrate surface a catalyst causing
plating reaction by various methods. As the catalyst, noble metals
such as palladium are available. Particularly, palladium of
colloidal type is often used. It is also possible to carry out the
sensitizing by immersion of the resin into stannic chloride
solution and subsequent activation by immersion into palladium
chloride. It is further possible to immerse the resin into metal
salt solution such as copper solution and nickel solution before
reduction thereof for deposition of the metal, and subsequent
palladium-replacement plating in the palladium chloride
solution.
[0052] After the catalyst is added, the electroless plating is
carried out. Materials for plating are not limited and are
selectable in accordance with various uses. If interconnections of
the printed wiring board are formed, copper is preferable due to
its low cost and low resistance. Nickel and gold are also
available. Since the electroless plating is inferior in deposition
rate, electroplating may be carried out following the electroless
plating.
[0053] If the conductive pattern is formed, photo-resist may be
used for selective etching of the conductive film. Alternatively,
only the necessary part of the conductive film is deposited after
addition of the catalyst.
[0054] Heat treatment is accomplished for improvement in adhesion
between the molded resin surface and the plated film by removal of
moisture from the interface between the molded resin surface and
the plated film. The heat treatment is preferably carried out at a
temperature of not less than 90.degree. C., but not rapidly to
prevent expansion of the plated film. Gradual heating is
preferable. If a relatively small area pattern is preliminary
formed, a rapid heating is also possible due to a sufficient pass
for removing moisture.
EXAMPLE 1
[0055] 100 parts by weight of a varnish available from Shin-Nihon
Seitetu and containing 50% by weight of epoxy-acrylate having
fluorene skeleton as resin solid component were blended with 20
parts by weight of bridged polymethylmethacrylate particles (M-305,
diameter; 5-20 micrometers) available from Matumoto Oils and Fats
Pharmaceutical for subsequent stirring in mixture for 20 minutes to
obtain a uniform dispersion of the particles. This varnish of 40
micrometers in thickness was then applied onto an FR-4 unclad plate
surface by curtain coater for subsequent pre-baking at 75.degree.
C. for 25 minutes before exposure at 500 mj/cm.sup.2 prior to a
thermosetting at 160.degree. C. for 30 minutes. A glass transition
temperature of the resin after thermosetting was 180.degree. C.
[0056] Subsequently, the resin surface was polished by #600 buff to
make the surface rough before desmear chemicals were used for
swelling, etching,. and neutralizing processes.
[0057] A solution containing 0.05 mol of copper nitrate was applied
to the rough surface for subsequent heat treatment at 150.degree.
C. for 3 hours, and oxygen-plasma treatment for 1 minute.
Thereafter, particle free epoxy-acrylate varnish having a fluorene
skeleton was treated in the same manner a described above until
accomplishment of pre-baking processes for exposure through mask
pattern and subsequent development with a solution containing 1% by
weight of sodium carbonate for 5 minutes.
[0058] This substrate was reduced in a solution containing 1 g/l of
boron sodium hydride for 10 minutes to deposit metals in the
patterns for subsequent washing by water before immersion into
electroless copper plating solution KC-500 (available from Japan
Energy) for 4 hours to deposit 20 micrometers-thick electroless
copper and subsequent heat treatment at 150.degree. C. for 1
hour.
[0059] 90 degree peel strength test was carried out to confirm a
strength of at least 1 kg/cm.
EXAMPLE 2
[0060] In place of bridged polymethylmethacrylate particles (M-305,
diameter; 5-20 micrometers), nylon 12 particles (orgasole 2001,
diameter; 8-12 micrometers, melting point: 175-179.degree. C.) was
used. Other conditions are the same as Example 1.
[0061] 90 degree peel strength test was carried out to confirm a
strength of at least 0.9 kg/cm.
EXAMPLE 3
[0062] In place of bridged polymethylmethacrylate particles (M-305,
diameter; 5-20 micrometers), composite particles of 7-10
micrometers in diameter comprising titanium oxide core particles of
3-5 micrometers in diameter coated with nylon 12 were blended by 25
parts by weight. Other conditions are the same as Example 1.
[0063] 90 degree peel strength test was carried out to confirm a
strength of at least 0.9 kg/cm.
EXAMPLE 4
[0064] In place of bridged polymethylmethacrylate particles (M-305,
diameter; 5-20 micrometers), phenol resin particles of 13-15
micrometers in diameter were used and the etching process is
carried out for twice as long. Other conditions are the same as
Example 1.
[0065] 90 degree peel strength test was carried out to confirm a
strength of at least 1 kg/cm.
EXAMPLE 5
[0066] 100 parts by weight of a photosensitive benzocyclobutene
varnish being available from Dow Chemicals was blended with 20
parts by weight of calcium carbonate-treated bridge
polymethylmethacrylate particles (M-305C, calcium
carbonate/polymethylmethacrylate; {fraction (2/8)} in percent by
weight) for subsequent stirring by mixture for 30 minutes to obtain
a uniform dispersion of the particles. An alumina ceramic substrate
is applied with 1 wt-% 3-aminopropyltriethoxysilane solution to
spin-coat this varnish to a thickness of 10 micrometers thereonto
for subsequent pre-baking at 75.degree. C. for 30 minutes before
exposure at 700 mj/cm.sup.2 prior to a thermosetting at 210.degree.
C. for 30 minutes. A glass transition temperature of the resin
after thermosetting was 250.degree. C.
[0067] Subsequently, the resin surface was polished by #320 buff to
make the surface rough for pre-immersion into 20 wt-% hydrochloric
acid solution for 15 minutes before desmear chemicals were used for
swelling, etching and neutralizing processes.
[0068] Palladium catalyst is adsorbed onto the rough surface for
activation in the THP process before particle free epoxy-acrylate
varnish having fluorene skeleton was treated in the same manner as
described above prior to accomplishment of pre-baking processes for
exposure through mask pattern, and subsequent development with
kerosine for 2 minutes prior to the thermosetting.
[0069] This substrate was returned to the THP process for reduction
in a solution containing 1 g/l of boron sodium hydride for 10
minutes to deposit metals in the patterns. Subsequent washing by
water is accomplished before immersion into electroless copper
plating solution KC-500 (available from Japan Energy) for 2 hours
to deposit 10 micrometers-thick electroless copper, and subsequent
heat treatment at 160.degree. C. for 1 hour.
[0070] 90 degree peel strength test was carried out to confirm a
strength of at least 0.9 kg/cm.
EXAMPLE 6
[0071] In place of calcium carbonate-treated bridge
polymethylmethacrylate particles (M-305C, diameter; 5-20
micrometers), hollow polyvinylidene particles (F-104E, diameter;
1-2 micrometers) were blended at 5 parts by weight to 15 parts by
weight of M-305C. The etching time is reduced by half. Other
conditions are the same as Example 5.
[0072] 90 degree peel strength test was carried out to confirm a
strength of at least 1 kg/cm.
EXAMPLE 7
[0073] 100 parts by weight of polypropylene resin dried at
90.degree. C. for 1 hour were blended with 40 parts by weight of
nylon 6/66 particles dried at 75.degree. C. for 4 hours (diameter;
10-20 micrometers) for subsequent mixing at 190.degree. C. by
biaxial extruder to form a chip. This chip was again dried at
90.degree. C. for 1 hour for subsequent injection molding at
190.degree. C. to form a 1.2 mm-thick plate.
[0074] Subsequently, the resin surface was polished by #320 buff to
make the surface rough before desmear chemicals were used for
swelling, etching and neutralizing processes.
[0075] Palladium catalyst is adsorbed onto the rough surface for
activation in the THP process before electroless plating for 15
minutes to increase the thickness up to 18 micrometers.
Hydrochloric acid is used to subsequently provide palladium to
deposit electroless nickel plating at 1 micrometer for further
flash gold plating. Heat treatment was carried out at 1000.degree.
C. for 1 hour.
[0076] 90 degree peel strength test was carried out to confirm a
strength of at least 0.9 kg/cm.
EXAMPLE 8
[0077] 100 parts by weight of polymethylpentene resin were solved
into 500 parts by weight of cyclohexane and then blended with nylon
12 particles (orgasole 2001, diameter; 8-12 micrometers, melting
point: 175-179.degree. C.). Other conditions are the same as
Example 7.
[0078] 90 degree peel strength test was carried out to confirm a
strength of at least 0.8 kg/cm.
[0079] Whereas modifications of the present invention will be
apparent to a person having ordinary skill in the art to which the
invention pertains, it is to be understood that embodiments as
shown and described by way of illustrations are by no means
intended to be considered in a limiting sense. Accordingly, it is
to be intended to cover by claims all modifications which fall
within the spirit and scope of the present invention.
* * * * *