U.S. patent application number 17/548788 was filed with the patent office on 2022-03-31 for electronic component package including stacked shield layers.
This patent application is currently assigned to DIC CORPORATION. The applicant listed for this patent is DIC CORPORATION. Invention is credited to Norimasa Fukazawa, Jun Shirakami.
Application Number | 20220102287 17/548788 |
Document ID | / |
Family ID | |
Filed Date | 2022-03-31 |
United States Patent
Application |
20220102287 |
Kind Code |
A1 |
Shirakami; Jun ; et
al. |
March 31, 2022 |
ELECTRONIC COMPONENT PACKAGE INCLUDING STACKED SHIELD LAYERS
Abstract
The present invention provides an electronic component package
including an electronic component mounted on a circuit board having
a ground pattern, a mold containing an epoxy resin that
encapsulates the electronic component, and a shield layer formed on
the mold. The shield layer is formed by stacking a metal particle
layer, a copper plating layer, and a nickel plating layer in this
order from the mold side, and the shield layer is grounded to the
ground pattern. The present invention also provides a method for
manufacturing the electronic component package. The electronic
component package is excellent in the adhesion of the shield
layer.
Inventors: |
Shirakami; Jun;
(Takaishi-shi, JP) ; Fukazawa; Norimasa;
(Takaishi-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DIC CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
DIC CORPORATION
Tokyo
JP
|
Appl. No.: |
17/548788 |
Filed: |
December 13, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16962300 |
Jul 15, 2020 |
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PCT/JP2019/006474 |
Feb 21, 2019 |
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17548788 |
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International
Class: |
H01L 23/552 20060101
H01L023/552; H01L 21/56 20060101 H01L021/56 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 2018 |
JP |
2018-033326 |
Claims
1. An electronic component package comprising: an electronic
component mounted on a circuit board having a ground pattern; a
mold containing an epoxy resin that encapsulates the electronic
component; a polymer layer formed on a surface of the mold; and a
shield layer formed on the polymer layer, the shield layer
comprising a metal particle layer, a copper plating layer, and a
nickel plating layer in this order from the polymer layer, wherein
the shield layer is grounded to the ground pattern, wherein metal
particles in the metal particle layer are coated with a polymer
dispersant having a functional group coordinates to the metal
particles.
2. The electronic component package according to claim 1, wherein
the polymer dispersant has a reactive functional group [Y], and the
polymer layer is a layer containing a polymer having a reactive
functional group [X], wherein the reactive functional group [Y] and
the reactive functional group [X] form a chemical bond.
3. The electronic component package according to claim 2, wherein
the reactive functional group [Y] is a basic nitrogen
atom-containing group.
4. The electronic component package according to claim 2, wherein
the polymer having the reactive functional group [Y] is at least
one selected from the group consisting of a polyalkyleneimine and a
polyalkyleneimine having a polyoxyalkylene structure including an
oxyethylene unit.
5. The electronic component package according to claim 2, wherein
the reactive functional group [X] is at least one selected from the
group consisting of a keto group, an acetoacetyl group, an epoxy
group, a carboxyl group, an N-alkylol group, an isocyanate group, a
vinyl group, a (meth)acryloyl group, and an allyl group.
6. The electronic component package according to claim 1, wherein
the metal particle layer comprises 80-99.9% by mass of metal
particles and 0.1 to 20% by mass of the polymer dispersant.
7. The electronic component package according to claim 1, wherein
the metal particle layer consists of 80-99.9% by mass of metal
particles and 0.1 to 20% by mass of the polymer dispersant.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 16/962,300, filed on Jul. 15, 2020, which is a 371 of
International Application No. PCT/JP2019/006474, filed on Feb. 21,
2019, which is based upon and claims the benefit of priority from
the prior Japanese Patent Application No. 2018-033326, filed on
Feb. 27, 2018.
TECHNICAL FIELD
[0002] The present invention relates to an electronic component
package and a method for manufacturing the same.
BACKGROUND ART
[0003] In recent years, in a portable information terminal such as
a smartphone, a semiconductor package called a system-in-package
(SiP), which operates as one functional block by mounting an IC and
a large number of electronic components on one semiconductor
package, has been widely used. Such a semiconductor package is
provided with a countermeasure against electromagnetic wave noise
so as to prevent malfunction due to external noise and prevent
itself from becoming a noise source. For example, although not
related to a system-in-package, PTL 1 discloses an electronic
component package including a plurality of plating layers as layers
for shielding electromagnetic wave noise.
[0004] However, in the above-described electronic component
package, although the plating layer is directly provided as a
shield layer on a mold in which the electronic component is
encapsulated, there is a disadvantage that the plating layer is
easily peeled off from the mold.
CITATION LIST
Patent Literature
[0005] PTL 1: JP-A-2005-109306
SUMMARY OF INVENTION
Technical Problem
[0006] An object of the present invention is to provide an
electronic component package in which a copper plating layer and a
nickel plating layer are provided as a shield layer on a mold in
which an electronic component is encapsulated, the electronic
component package having excellent adhesion between the shield
layer and the mold, and a method for manufacturing the electronic
component package.
Solution to Problem
[0007] As a result of intensive studies to solve the
above-mentioned problems, the present inventors have found that an
electronic component package including a mold containing an epoxy
resin for encapsulating an electronic component and a shield layer
formed on the mold, wherein the shield layer is formed by stacking
a metal particle layer, a copper plating layer and a nickel plating
layer in this order from the mold side, has remarkably excellent
adhesion between the shield layer and the mold and excellent
electromagnetic wave shielding properties, and thus the present
invention has been completed.
[0008] That is, the present invention provides an electronic
component package including: an electronic component mounted on a
circuit board having a ground pattern; a mold containing an epoxy
resin that encapsulates the electronic component; and a shield
layer formed on the mold, wherein the shield layer is formed by
stacking a metal particle layer, a copper plating layer, and a
nickel plating layer in this order from the mold side, and wherein
the shield layer is grounded to the ground pattern, and a method
for manufacturing the electronic component package.
Advantageous Effects of Invention
[0009] The electronic component package of the present invention
can be suitably used as, for example, a semiconductor package
provided with a shield layer for enhancing the shielding effect of
electromagnetic wave noise of a semiconductor device, or an
integrated module in which a plurality of modules are densely
mounted by integrating functions of a high-frequency module, a
front-end module including a filter, a communication module for
transmission and reception, and the like into one function.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 shows the entire electronic component package with a
shield layer.
[0011] FIG. 2 shows a cross section (A-A) of the electronic
component package of FIG. 1.
[0012] FIG. 3 shows a cross section of an electronic component
package in which a polymer layer is provided on the surface of a
mold.
[0013] FIG. 4 shows a cross section of a state in which a polymer
layer is provided on the surface of a mold, a slit portion is
formed along a scheduled division line, and a metal particle layer
is provided thereon. Finally, a copper plating layer and a nickel
plating layer are sequentially stacked on the metal particle layer
to form the electronic component package of the present
invention.
DESCRIPTION OF EMBODIMENTS
[0014] The electronic component package of the present invention is
an electronic component package including: an electronic component
mounted on a circuit board having a ground pattern; a mold
containing an epoxy resin that encapsulates the electronic
component; and a shield layer formed on the mold, wherein the
shield layer is formed by stacking a metal particle layer, a copper
plating layer, and a nickel plating layer in this order from the
mold side, and wherein the shield layer is grounded to the ground
pattern.
[0015] The circuit board having the ground pattern preferably has a
structure in which a part of the ground pattern is exposed on the
surface of the mold, and excellent electromagnetic wave shielding
properties can be obtained by connecting a shield layer described
later and the ground pattern.
[0016] In the circuit board having the ground pattern, the ground
pattern and a wiring pattern may be formed in at least two layers
on a substrate made of an insulating material such as glass epoxy
resin. In addition, when the circuit board is formed of two or more
layers, a structure in which the layers are electrically connected
by via holes is preferable.
[0017] As the circuit board having the ground pattern, a circuit
board for mounting at least two semiconductor devices in a planar
or three dimensional arrangement on a substrate made of an
insulating material, or a circuit board for an integrated module in
which a plurality of modules are densely mounted by integrating
functions of a high-frequency module, a front-end module including
a filter, a communication module for transmission and reception,
and the like into one function may be used.
[0018] Examples of the material of the circuit board having the
ground pattern include an insulating material such as a glass epoxy
resin, a liquid crystal polymer, a fluororesin represented by
polytetrafluoroethylene, a silicone resin, a polyimide resin, a
photosensitive insulating material such as a polyimide resin, or a
polybenzoxazole resin, a buildup film containing a thermosetting
epoxy resin, and a buildup film containing a glass cloth. These
materials may be used alone or in combination of two or more kinds
thereof as a substrate.
[0019] In the present invention, after an electronic component is
mounted on the circuit board having the ground pattern, a mold is
formed of a material containing an epoxy resin. As the material
containing the epoxy resin, a material obtained by curing a
thermosetting epoxy resin with a curing agent such as a
phenol-based curing agent, a cyanate ester-based curing agent, or
an active ester-based curing agent, or a material obtained by
adding an inorganic filler represented by silica particles to the
thermosetting epoxy resin, which is generally used as an
encapsulating material, can be used. Examples of the method of
molding the mold include a transfer molding method and a
compression molding method, and a method of encapsulating the mold
using an encapsulating resin sheet with a laminator or a press
apparatus.
[0020] In addition, the surface of the mold may be surface-treated
by, for example, a plasma discharge treatment method such as a
corona discharge treatment method; a dry treatment method such as
an ultraviolet treatment method; or a wet treatment method using
water, an acidic or alkaline chemical solution, an organic solvent,
or the like in order to further improve the adhesion to a metal
particle layer described later or a polymer layer described later.
Further, PTL 1 described above describes roughening treatment of
the surface of the mold with a chemical agent, but in the present
invention, it is preferable not to roughen the surface of the
mold.
[0021] Next, in the present invention, a metal particle layer is
provided to form a shield layer on the mold. The metal particle
layer functions as a plating seed layer for bringing the mold and a
copper plating layer described later into close contact with each
other and for forming the copper plating layer described later, and
is used as a catalyst for electroless copper plating or a seed
conductive layer for electrolytic copper plating.
[0022] In the present invention, a polymer layer is preferably
provided on the mold and between the mold and the metal particle
layer in order to further improve the adhesion between the mold and
the shield layer. Examples of the polymer forming the polymer layer
include various resins such as a urethane resin, a vinyl resin, an
acrylic resin, a urethane-acrylic composite resin, an epoxy resin,
an imide resin, an amide resin, a melamine resin, a phenol resin, a
polyvinyl alcohol, and a polyvinyl pyrrolidone.
[0023] Among the resins used as the polymer, a urethane resin, an
acrylic resin, a urethane-acrylic composite resin, and an epoxy
resin are preferable, and one or more resins selected from the
group consisting of a urethane resin having a polyether structure,
a urethane resin having a polycarbonate structure, a urethane resin
having a polyester structure, an acrylic resin, a urethane-acrylic
composite resin, and an epoxy resin are more preferable. Further,
the urethane-acrylic composite resin is still more preferable
because a wiring pattern excellent in adhesion and conductivity can
be obtained.
[0024] When the metal particle layer is composed of metal particles
dispersed by a polymer dispersant described later and the polymer
dispersant contains a compound (b1) having a reactive functional
group [Y] described later, the polymer forming the polymer layer is
preferably a compound (a1) having a functional group [X] having
reactivity with the reactive functional group [Y]. Examples of the
compound (a1) having the reactive functional group [X] include
compounds having an amino group, an amide group, an alkylolamide
group, a carboxyl group, an anhydrous carboxyl group, a carbonyl
group, an acetoacetyl group, an epoxy group, an alicyclic epoxy
group, an oxetane ring, a vinyl group, an allyl group, a
(meth)acryloyl group, a (blocked) isocyanate group, an (alkoxy)
silyl group or the like, and a silsesquioxane compound.
[0025] In particular, when the compound (b1) having a reactive
functional group [Y] in the polymer dispersant described later of
the metal particle layer is a compound having a basic nitrogen
atom-containing group described later, the polymer forming the
polymer layer preferably has a carboxyl group, a carbonyl group, an
acetoacetyl group, an epoxy group, an alicyclic epoxy group, an
alkylolamide group, an isocyanate group, a vinyl group, a
(meth)acryloyl group, or an allyl group as the reactive functional
group [X] because the adhesion between the finally obtained mold
and the shield layer can be further improved.
[0026] The polymer layer is preferably provided as a thin film on
the entire surface of the mold, but in order to connect the ground
pattern of the electronic component package and the shield layer,
the polymer layer is preferably provided avoiding the ground
pattern exposed from the mold. In addition, it is preferable that
the polymer layer is not formed in a portion where the shield layer
of the electronic component package is not formed. Examples of the
portion where the shield layer of the electronic component package
is not formed include a circuit board side opposite to the shield
layer of the electronic component package, a portion where a solder
ball is formed, and a portion where a solder ball is to be
formed.
[0027] When the polymer forming the polymer layer is applied to the
surface of the mold, a fluid in which the polymer is dissolved or
dispersed in a solvent is used. Examples of the application method
include a coating method, a dipping method, a roller coating
method, a spin coating method, a rotary method, a spray method, a
dispenser method, an inkjet printing method, a pad printing method,
a reverse printing method, a flexographic printing method, a screen
printing method, a gravure printing method, and a gravure offset
printing method.
[0028] Further, when the fluid containing the polymer is applied,
the fluid may be applied after a portion where the polymer layer is
not desired to be applied is protected by a masking tape or a
sealing material.
[0029] Next, the fluid containing the polymer is applied to form
the polymer layer and then dried. The drying is performed in order
to volatilize a solvent contained in the fluid containing the
polymer. The drying is preferably performed in a temperature range
of 80 to 300.degree. C. for about 1 to 200 minutes.
[0030] The thickness of the polymer layer formed using the polymer
is preferably in the range of 5 to 5,000 nm because the adhesion
between the mold and the metal particle layer described later can
be further improved, and more preferably in the range of 10 to 200
nm because the finally obtained shield layer has excellent adhesion
to the mold.
[0031] The metal particle layer forming the shield layer in the
present invention is preferably composed of metal particles
dispersed by a polymer dispersant because the metal particles have
excellent adhesion to the mold or the polymer layer.
[0032] The polymer dispersant is preferably a polymer having a
functional group that coordinates to the metal particles. Examples
of the functional group include a carboxyl group, an amino group, a
cyano group, an acetoacetyl group, a phosphorus atom-containing
group, a thiol group, a thiocyanato group, and a glycinato
group.
[0033] The polymer dispersant preferably contains the compound (b1)
having a reactive functional group [Y] in order to improve the
adhesion to the mold or the polymer layer.
[0034] The reactive functional group [Y] of the compound (b1) is
involved in bonding with an epoxy group, a phenolic hydroxy group,
or a hydroxy group present in the mold, or the reactive functional
group [X] in the polymer. Specific examples of the compound (b1)
include compounds having an amino group, an amide group, an
alkylolamide group, a carboxyl group, an anhydrous carboxyl group,
a carbonyl group, an acetoacetyl group, an epoxy group, an
alicyclic epoxy group, an oxetane ring, a vinyl group, an allyl
group, a (meth)acryloyl group, a (blocked) isocyanate group, an
(alkoxy) silyl group or the like, and a silsesquioxane
compound.
[0035] In particular, the reactive functional group [Y] is
preferably a basic nitrogen atom-containing group in order to
further improve the adhesion to the mold or the polymer layer.
[0036] Examples of the basic nitrogen atom-containing group include
an imino group, a primary amino group, and a secondary amino
group.
[0037] In addition, by using a compound having a plurality of basic
nitrogen atom-containing groups in one molecule as the compound
(b1), one of the basic nitrogen atom-containing groups is involved
in bonding with the epoxy group present in the mold or the reactive
functional group [X] of the polymer forming the polymer layer, and
the other contributes to interaction with the metal particles
contained in the metal particle layer, thereby further improving
the adhesion between the finally obtained metal plating layer
described later and the mold, which is preferable.
[0038] As the compound having a basic nitrogen atom-containing
group, a polyalkyleneimine or a polyalkyleneimine having a
polyoxyalkylene structure containing an oxyethylene unit is
preferable because the dispersion stability of the metal particles
and the adhesion to the polymer layer can be further improved.
[0039] The polyalkyleneimine having a polyoxyalkylene structure may
be a compound in which polyethyleneimine and polyoxyalkylene are
bonded in a linear form, or may be a compound in which the
polyoxyalkylene is grafted to a side chain of a main chain composed
of the polyethyleneimine.
[0040] Specific examples of the polyalkyleneimine having a
polyoxyalkylene structure include a block copolymer of
polyethyleneimine and polyoxyethylene, a compound in which a
polyoxyethylene structure is introduced by addition reaction of
ethylene oxide to a part of imino groups present in the main chain
of polyethyleneimine, and a compound in which an amino group of
polyalkyleneimine, a hydroxy group of polyoxyethylene glycol, and
an epoxy group of an epoxy resin are reacted.
[0041] Examples of commercially available products of the
polyalkyleneimineinclude"PAO2006 W", "PAO306", "PAO318", and
"PAO718" of "EPOMIN (registered trademark) PAO series" manufactured
by Nippon Shokubai Co., Ltd.
[0042] The number average molecular weight of the polyalkyleneimine
is preferably in the range of 3,000 to 30,000.
[0043] When the reactive functional group [Y] of the compound (b1)
is a carboxyl group, an amino group, a cyano group, an acetoacetyl
group, a phosphorus atom-containing group, a thiol group, a
thiocyanato group, a glycinato group or the like, the compound (b1)
can also be used as a polymer dispersant for metal particles
because these functional groups also function as functional groups
coordinating with metal particles.
[0044] Next, examples of the metal particles constituting the metal
layer include transition metals and compounds thereof, and among
the transition metals, ionic transition metals are preferable.
Examples of the ionic transition metal include metals such as
copper, silver, gold, nickel, palladium, platinum, and cobalt, and
complexes of these metals. These metal particles may be used alone
or in combination of two or more kinds thereof. Further, among
these metal particles, silver particles are particularly preferable
from the viewpoints of less problems in handling such as oxidation
deterioration and cost.
[0045] As the metal particles, it is preferable to use particulate
particles having an average particle diameter of about 1 to 20,000
nm, and it is more preferable to use metal nanoparticles having an
average particle diameter of 1 to 200 nm because the copper plating
deposition properties when used as a catalyst for electroless
copper plating and the electric resistance when used as a seed
layer for electrolytic copper plating can be further reduced in a
copper plating step described later, compared with the case of
using metal particles having an average particle diameter of
micrometer order. In the present invention, the average particle
diameter is a volume-average value measured by a dynamic light
scattering method after diluting the metal particle with a good
dispersion solvent. For this measurement, "Nanotrac UPA"
manufactured by MicrotracBEL Corp. can be used.
[0046] In order to form the metal particle layer, the mold is
preferably applied by various application methods described later,
and for this purpose, it is preferable to use a metal particle
dispersion liquid in which metal particles are dispersed in various
solvents. Examples of the solvent include aqueous media such as
distilled water, ion-exchanged water, pure water, and ultrapure
water; and organic solvents such as alcohol solvents, ether
solvents, ketone solvents, and ester solvents.
[0047] Examples of the alcohol solvent or ether solvent include
methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol,
isobutyl alcohol, sec-butanol, tert-butanol, heptanol, hexanol,
octanol, nonanol, decanol, undecanol, dodecanol, tridecanol,
tetradecanol, pentadecanol, stearyl alcohol, allyl alcohol,
cyclohexanol, terpineol, terpineol, dihydroterpineol,
2-ethyl-1,3-hexanediol, ethylene glycol, diethylene glycol,
triethylene glycol, polyethylene glycol, propylene glycol,
dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol,
2,3-butanediol, glycerin, ethylene glycol monomethyl ether,
ethylene glycol monoethyl ether, ethylene glycol monobutyl ether,
diethylene glycol monoethyl ether, diethylene glycol monomethyl
ether, diethylene glycol monobutyl ether, tetraethylene glycol
monobutyl ether, propylene glycol monomethyl ether, dipropylene
glycol monomethyl ether, tripropylene glycol monomethyl ether,
propylene glycol monopropyl ether, dipropylene glycol monopropyl
ether, propylene glycol monobutyl ether, dipropylene glycol
monobutyl ether, and tripropylene glycol monobutyl ether.
[0048] Examples of the ketone solvent include acetone,
cyclohexanone, and methyl ethyl ketone. In addition, examples of
the ester solvent include ethyl acetate, butyl acetate,
3-methoxybutyl acetate, and 3-methoxy-3-methyl-butyl acetate.
Further, examples of the other organic solvent include hydrocarbon
solvents such as toluene, particularly hydrocarbon solvents having
8 or more carbon atoms.
[0049] Examples of the hydrocarbon solvent having 8 or more carbon
atoms include nonpolar solvents such as octane, nonane, decane,
dodecane, tridecane, tetradecane, cyclooctane, xylene, mesitylene,
ethylbenzene, dodecylbenzene, tetralin, and
trimethylbenzenecyclohexane, which can be used in combination with
other solvents as necessary. Further, solvents such as mineral
spirits and solvent naphtha, which are mixed solvents, may be used
in combination.
[0050] The metal particle dispersion liquid can be produced, for
example, by mixing the polymer dispersant, the metal particles, and
if necessary, the solvent. Specifically, it can be produced by
adding a previously prepared ionic solution of the metal to a
medium in which a compound having a polyalkyleneimine chain, a
hydrophilic segment, and a hydrophobic segment is dispersed, and
reducing the metal ion.
[0051] In addition, in order to improve the dispersion stability of
the conductive material in a solvent such as an aqueous medium or
an organic solvent and the wettability to the surface to be
applied, a surfactant, an anti-foaming agent, a rheology modifier,
and the like may be added to the metal particle dispersion liquid
as necessary.
[0052] The metal particle layer may be provided as a thin film on
the entire surface and the side surface of the mold. However, in
order to connect the ground pattern of the electronic component
package and the shield layer, the metal particle layer needs to be
provided so as to be in contact with the ground pattern exposed
from the mold. In addition, it is preferable that the metal
particle layer is not formed in a portion where the shield layer of
the electronic component package is not formed. Examples of the
portion where the shield layer of the electronic component package
is not formed include a portion on the side opposite to the shield
layer of the electronic component package where a solder ball is
formed, a portion where the solder ball is to be formed, and the
like.
[0053] The metal particle layer may be provided on the entire
surface of a portion of the mold where the shield layer is to be
formed, or a pattern may be formed by applying the metal particle
dispersion liquid by an application method described later. When
the pattern is formed by the metal particle layer, a copper plating
layer and a nickel plating layer described later are formed only on
the pattern of the metal particle layer, and thus the shield layer
itself can be patterned. The pattern of the metal particle layer
may form a portion without the metal particle layer as long as the
electromagnetic wave shielding property is not impaired. For
example, a pattern in which holes are formed in a dot shape in the
metal particle layer, a pattern in which the metal particle layer
is arranged in a lattice shape, and other various patterns may be
formed.
[0054] When the metal particle dispersion liquid is applied to the
surface and the side surface of the mold, examples of the
application method include a coating method, a dipping method, a
roller coating method, a spin coating method, a rotary method, a
spray method, a dispenser method, an inkjet printing method, a pad
printing method, a reverse printing method, a flexographic printing
method, a screen printing method, a gravure printing method, and a
gravure offset printing method. When the pattern of the metal
particle layer is formed, it is preferable to use an inkjet
printing method, a pad printing method, a reverse printing method,
a flexographic printing method, a screen printing method, a gravure
printing method, or a gravure offset printing method.
[0055] Among the application methods, it is particularly preferable
to select an application method for uniformly forming a thin metal
particle layer, and it is preferable to select a dipping method, a
spin coating method, a spray method, an inkjet printing method, or
a flexographic printing method.
[0056] In addition, when the metal particle dispersion liquid is
applied, the metal particle dispersion liquid may be applied after
a portion where the metal particle layer is not formed is protected
by a masking tape or a sealing material. Examples of the masking
tape and the sealing material include masking pressure-sensitive
adhesive tapes for plating, masking tapes for printed circuit
boards, dicing tapes used in processing semiconductor wafers, and
thermal release sheets for electronic component processes, and it
is preferable to select a material capable of protecting the
portion where the shield layer is not formed even in the metal
plating step described later after the sealing material is laid on
the portion where the shield layer is not formed and the metal
particles are applied.
[0057] Next, the metal particle dispersion liquid is applied and
dried to form a metal particle layer. The drying is performed in
order to volatilize the solvent contained in the metal particle
dispersion liquid, or in order to form a metal particle layer
having conductivity by adhering and bonding the metal particles to
each other in the case of using as a conductive layer of
electrolytic copper plating described later. The drying is
preferably performed in a temperature range of 80 to 300.degree. C.
for about 1 to 200 minutes. Here, in order to obtain a metal
particle layer (plating seed layer) having excellent adhesion to
the mold or the polymer layer, the drying temperature is more
preferably set in the range of 100 to 200.degree. C.
[0058] The drying may be performed in the air, but in order to
prevent all of the metal particles from being oxidized, a part or
all of the drying step may be performed in a reducing
atmosphere.
[0059] In addition, the drying step may be performed using, for
example, an oven, a hot air drying furnace, an infrared drying
furnace, laser irradiation, microwave, light irradiation (flash
irradiation device), or the like.
[0060] It is preferable that the metal particle layer formed using
the metal particle dispersion liquid by the method as described
above contains a conductive material in the range of 80 to 99.9% by
mass and contains a polymer dispersant in the range of 0.1 to 20%
by mass in the pattern.
[0061] The thickness of the metal layer formed by using the metal
particle dispersion liquid is preferably in the range of 5 to 500
nm because the activity as a plating catalyst (plating deposition
property) in an electroless copper plating step described later and
the electric resistance as a conductive layer in an electrolytic
copper plating step can be reduced.
[0062] The copper plating layer constituting the shield layer of
the present invention is used for shielding electric field noise.
Examples of the method for forming the copper plating layer include
wet plating methods such as electroless copper plating and
electrolytic copper plating, and the copper plating layer may be
formed by combining these plating methods. For example, a method of
performing electroless copper plating using the metal particle
layer as an electroless copper plating catalyst and performing
electrolytic copper plating using the electroless copper plating
layer as a conductive layer, or electrolytic copper plating using
the metal particle layer as a conductive layer can be used.
[0063] Among the plating methods, an electrolytic copper plating
method is more preferable because the adhesion between the metal
particle layer and the copper plating layer formed by the plating
method is further improved and the productivity of the copper
plating step is excellent.
[0064] The electroless plating method is, for example, a method in
which an electroless copper plating solution is brought into
contact with the metal particle layer to deposit a copper metal
contained in the electroless copper plating solution, thereby
forming an electroless copper plating layer composed of a metal
film.
[0065] Examples of the electroless copper plating solution include
a solution containing copper, a reducing agent, and a solvent such
as an aqueous medium or an organic solvent.
[0066] Examples of the reducing agent include dimethylaminoborane,
hypophosphorous acid, sodium hypophosphite, dimethylamine borane,
hydrazine, formaldehyde, sodium borohydride, and phenol.
[0067] As the electroless copper plating solution, as necessary, it
is possible to use a complexing agent such as a monocarboxylic acid
such as acetic acid and formic acid; a dicarboxylic acid compound
such as malonic acid, succinic acid, adipic acid, maleic acid, and
fumaric acid; a hydroxycarboxylic acid compound such as malic acid,
lactic acid, glycolic acid, gluconic acid, and citric acid; an
amino acid compound such as glycine, alanine, iminodiacetic acid,
arginine, aspartic acid, and glutamic acid; an organic acid such as
an amino polycarboxylic acid compound such as iminodiacetic acid,
nitrilotriacetic acid, ethylenediaminediacetic acid,
ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic
acid, or a soluble salt (sodium salt, potassium salt, ammonium
salt, and the like) of the organic acid thereof; and an amine
compound such as ethylene diamine, diethylene triamine, and
triethylene tetramine.
[0068] The electroless copper plating solution is preferably used
in the range of 20 to 98.degree. C.
[0069] The electrolytic copper plating method is, for example, a
method of forming an electrolytic copper plating layer by causing a
metal such as copper contained in an electrolytic copper plating
solution to deposit on the surface of the metal particle layer
provided on a cathode or the electroless copper plating layer
formed by the electroless copper plating by applying an electric
current in a state where the electrolytic copper plating solution
is in contact with the surface of the metal constituting the metal
particle layer or the electroless copper plating layer formed by
the electroless copper plating.
[0070] Examples of the electrolytic copper plating solution include
a solution containing a sulfide of copper, sulfuric acid, and an
aqueous medium. Specific examples thereof include a solution
containing copper sulfate, sulfuric acid, and an aqueous
medium.
[0071] The electrolytic copper plating solution is preferably used
in the range of 20 to 98.degree. C.
[0072] As the method of the plating treatment, an electrolytic
copper plating method is preferable because a highly toxic
substance is not used and workability is good. In addition, the
electrolytic copper plating is preferable because the plating time
can be shortened and the control of the film thickness of the
plating is easy, as compared with the electroless copper
plating.
[0073] The thickness of the copper plating layer formed by the
copper plating method is preferably in the range of 0.5 to 30 .mu.m
because of excellent electric field shielding properties. When the
copper plating layer is formed by the electrolytic copper plating
method, the thickness of the layer can be adjusted by controlling
the treatment time, the current density, the amount of the plating
additive used, and the like in the plating treatment step.
[0074] The nickel plating layer constituting the shield layer of
the present invention is used for shielding magnetic field noise.
The nickel plating layer is also used to prevent oxidation
deterioration and corrosion of the surface of the copper plating
layer. Examples of the method for forming the nickel plating layer
include wet plating methods such as electroless nickel plating and
electrolytic nickel plating, and the nickel plating layer may be
formed by combining these plating methods. The nickel layer is
preferably formed by electrolytic nickel plating because of
excellent magnetic field shielding properties.
[0075] A plating layer of another metal may be stacked on the
nickel plating layer. For example, when a gold plating layer, a tin
plating layer, or a chromium plating layer is provided, corrosion
of the surface of the nickel plating layer can be prevented.
Further, the metal particle layer may be formed as a protective
film on the nickel plating layer. Examples of the metal particle
layer include a silver nanoparticle layer. Further, a resin film
may be formed as a protective film on the nickel plating layer.
Examples of the resin film include the resins exemplified as the
polymer layer.
[0076] The thickness of the nickel plating layer formed by the
nickel plating method is preferably in the range of 0.5 to 10 .mu.m
because of excellent magnetic field shielding properties.
[0077] Next, a method for manufacturing the electronic component
package of the present invention will be described. Examples of the
manufacturing method include a manufacturing method including:
applying a dispersion liquid having metal particles to a surface of
a mold of an electronic component package having an electronic
component mounted on a circuit board having a ground pattern and
the mold containing an epoxy resin that encapsulates the electronic
component and drying the dispersion liquid to form a metal particle
layer; forming a copper plating layer on the metal particle layer
by using at least one selected from the group consisting of
electroless copper plating and electrolytic copper plating; forming
a nickel plating layer by using at least one selected from the
group consisting of electroless nickel plating and electrolytic
nickel plating; and forming a shield layer having the metal
particle layer, the copper plating layer, and the nickel plating
layer.
[0078] Here, as the manufacturing method, a manufacturing method in
which a polymer layer is formed by applying and drying a fluid
containing a polymer on the surface of the mold, a metal particle
layer is formed by applying and drying a dispersion liquid
containing metal particles on the polymer layer, and then the
shield layer having the copper plating layer and the nickel plating
layer is formed is preferable because the adhesion between the mold
and the shield layer is excellent.
[0079] The polymer layer is preferably provided as a thin film on
the entire surface of the mold, but in order to connect the ground
pattern and the shield layer of the electronic component package,
the polymer layer is preferably provided avoiding the ground
pattern exposed from the mold. In addition, it is preferable that
the polymer layer is not formed in a portion where the shield layer
of the electronic component package is not formed. Examples of the
portion where the shield layer of the electronic component package
is not formed include a circuit board side opposite to the shield
layer of the electronic component package, a portion where a solder
ball is formed, and a portion where a solder ball is to be
formed.
[0080] As a method of forming the metal particle layer on the
surface of the mold or on the polymer layer, a method of applying
or printing a metal particle dispersion liquid and a method of
drying may be carried out by the above-exemplified methods, and in
the case where the metal particles are nanoparticles such as silver
nanoparticles, the above-described drying method can fuse the metal
particles to form a conductive layer which functions as a plating
seed layer in the electrolytic plating, which is preferable.
[0081] As a method of forming the polymer layer on the surface of
the mold, a method of applying or printing a fluid containing a
polymer and a method of drying may be carried out by the
above-exemplified methods, and the polymer layer may be formed by
heat-curing the polymer or curing the polymer with ultraviolet rays
as necessary.
[0082] In the method of manufacturing the electronic component
package, the method of forming the shield layer before singulating
the electronic component package may include forming the polymer
layer, dicing apart of the mold from above the polymer layer so as
to expose the ground pattern to form a slit portion in a scheduled
division line, forming the metal particle layer on a surface of the
polymer layer and a diced surface of the slit portion, stacking the
copper plating layer and the nickel plating layer to form the
shield layer, and singulating the electronic component using the
slit portion.
[0083] The above-described manufacturing method is preferable
because the shield layer can be efficiently manufactured on a large
number of electronic component packages and productivity is
excellent.
[0084] Here, the slit portion formed in the scheduled division line
is provided to connect the ground pattern included in the circuit
board of the electronic component package and the shield layer
formed of the metal particle layer, the copper plating layer, and
the nickel plating layer. When the metal particle layer is formed,
a fluid containing metal particles is preferably applied so as to
be in contact with the ground pattern to form the metal particle
layer.
[0085] The slit portion formed in the scheduled division line may
be formed after the electronic component package is fixed to a
support before or after the electronic component package is
encapsulated. The support may be the same as a temporary fixing
substrate described later.
[0086] In addition, in the method of manufacturing the electronic
component package, the method of forming the shield layer after
singulating the electronic component package may include forming
the polymer layer, singulating the electronic component
encapsulated with the mold by dicing from above the polymer layer,
temporarily fixing the singulated electronic component to a
temporary fixing substrate, forming the metal particle layer on a
surface of the polymer layer of the singulated electronic component
and a diced surface generated by dicing, stacking the copper
plating layer and the nickel plating layer to form the shield
layer, grounding the shield layer to the ground pattern, and then
taking out the singulated electronic component from the temporary
fixing substrate.
[0087] Here, examples of the temporary fixing substrate include, as
a pressure-sensitive adhesive sheet or a pressure-sensitive
adhesive film obtained by pressure-sensitive adhesive processing on
a support, fluororesin pressure-sensitive adhesive films using a
fluororesin film as a support, masking pressure-sensitive adhesive
tapes for plating, masking tapes for printed circuit boards, dicing
tapes used in processing semiconductor wafers, and thermal release
sheets for electronic component processes. The temporary fixing
substrate can also be used for the purpose of protecting the
portion where the shield layer is not formed.
[0088] Next, the method of forming a copper plating layer or a
nickel plating layer on a metal particle layer by electrolytic
plating or electroless plating can be carried out by the wet
plating method as exemplified above, and in particular, the
electrolytic plating method is preferably used from the viewpoints
of productivity, mechanical properties of the obtained metal film,
cost, and excellent magnetic field shielding properties in nickel
plating.
[0089] The electronic component package of the present invention
manufactured in this manner can be used as an electronic component
package in the applications as exemplified above.
EXAMPLES
[0090] Hereinafter, the present invention will be described in
detail with reference to examples.
Preparation Example 1: Preparation of Metal Particle Dispersion
Liquid
[0091] Silver particles having an average particle diameter of 30
nm were dispersed in a mixed solvent of 30 parts by mass of
ethylene glycol and 70 parts by mass of ion-exchanged water using a
compound obtained by adding polyoxyethylene to polyethylene imine
as a dispersant, and then ion-exchanged water, ethanol, and a
surfactant were added to adjust the viscosity to 10 mPas, thereby
preparing a metal particle dispersion liquid. The metal particle
dispersion liquid contains metal particles and a polymer dispersant
having a basic nitrogen atom-containing group as a reactive
functional group.
Production Example 1: Production of Resin for Polymer Layer
[0092] In a reaction vessel equipped with a stirrer, a reflux
condenser, a nitrogen inlet tube, and a thermometer, 100 parts by
mass of a polycarbonate polyol (polycarbonate diol having an acid
group equivalence of 1,000 g/equivalent obtained by reacting
1,4-cyclohexanedimethanol with a carbonate ester), 9.7 parts by
mass of 2,2-dimethylolpropionic acid, 5.5 parts by mass of
1,4-cyclohexanedimethanol, and 51.4 parts by mass of
dicyclohexylmethane diisocyanate were reacted in a mixed solvent of
111 parts by mass of methyl ethyl ketone, thereby obtaining an
organic solvent solution of a urethane prepolymer having an
isocyanate group at a molecular terminal.
[0093] Next, 7.3 parts by mass of triethylamine was added to the
organic solvent solution of a urethane resin to neutralize a part
or all of the carboxyl groups of the urethane resin, and 355 parts
by mass of water was further added and sufficiently stirred to
obtain an aqueous dispersion of the urethane resin.
[0094] Next, 4.3 parts by mass of a 25% by mass ethylenediamine
aqueous solution was added to the aqueous dispersion, stirred to
chain-extend the particulate polyurethane resin, followed by aging
and solvent removal to obtain an aqueous dispersion of a urethane
resin having a solid content concentration of 30% by mass.
[0095] A reaction vessel equipped with a stirrer, a reflux
condenser, a nitrogen inlet tube, a thermometer, a dropping funnel
for dropping the monomer mixture, and a dropping funnel for
dropping the polymerization catalyst was charged with 140 parts by
mass of deionized water and 100 parts by mass of the aqueous
dispersion of a urethane resin obtained above, and the temperature
was raised to 80.degree. C. while blowing nitrogen. Into the
reaction vessel heated to 80.degree. C., a monomer mixture
containing 60 parts by mass of methyl methacrylate, 10 parts by
mass of n-butyl acrylate, and 30 parts by mass of
N-n-butoxymethylacrylamide and 20 parts by mass of an aqueous
ammonium persulfate solution (concentration: 0.5% by mass) were
added dropwise with stirring from separate dropping funnels over
120 minutes while maintaining the temperature in the reaction
vessel at 80.+-.2.degree. C. to perform polymerization.
[0096] After completion of the dropwise addition, the mixture was
stirred at the same temperature for 60 minutes, and then the
temperature in the reaction vessel was cooled to 40.degree. C.,
deionized water was added so that the nonvolatile content became
20% by mass, and the mixture was filtered through a 200 mesh filter
cloth to obtain a resin for a polymer layer containing a carboxyl
group and an N-n-butoxymethylacrylamide group as reactive
functional groups.
Preparation Example 2: Preparation of Fluid Containing Resin for
Polymer Layer
[0097] To 10 parts by mass of the resin for a polymer layer
obtained in the "Production of Resin for Polymer Layer", 90 parts
by mass of ethanol was stirred and mixed to obtain a fluid
containing the resin for a polymer layer.
Example 1
[0098] An electronic component mounted on a circuit board having a
ground pattern is encapsulated with a semiconductor encapsulating
resin composition containing an epoxy resin, a phenol resin curing
agent, and a filler. The metal particle dispersion liquid prepared
in Preparation Example 1 was applied to the surface of the mold by
a spray device (a spray device equipped with a spray tip QTKA (flow
rate size: 0.1 L/min) of a spray nozzle manufactured by Spraying
Systems Co.) so that the film thickness of a metal particle layer
after drying became 150 nm. Thereafter, by drying at 180.degree. C.
for 10 minutes, a metal particle layer was formed. The surface
resistance value of the metal particle layer was
4.OMEGA./.quadrature..
[0099] Next, on the metal particle layer formed in the
above-described manner, a phosphorus-containing copper was set as
an anode, and electrolytic copper plating was performed for 10
minutes at a current density of 2.5 A/dm.sup.2 using an
electrolytic plating solution containing copper sulfate, whereby a
copper plating layer having a thickness of 5 .mu.m was stacked on
the surface of the metal particle layer. As the electrolytic copper
plating solution, 70 g/L of copper sulfate, 200 g/L of sulfuric
acid, 50 mg/L of chlorine ions, and 5 mL/L of an additive ("Top
Lucina SF-M" manufactured by Okuno Chemical Industries Co., Ltd.)
were used.
[0100] Next, a 2 .mu.m-thick nickel plating layer was stacked on
the copper plating layer formed in the above-described manner by
performing electrolytic nickel plating on the copper plating layer
at a current density of 2 A/dm.sup.2 for 5 minutes while supplying
nickel ions with nickel sulfate to form a shield layer.
Example 2
[0101] An electronic component mounted on a circuit board having a
ground pattern is encapsulated with a semiconductor encapsulating
resin composition containing an epoxy resin, a phenol resin curing
agent, and a filler. The fluid containing the resin for a polymer
layer prepared in Preparation Example 2 was applied to the surface
of the mold by a spray device (a spray device equipped with a spray
tip QTKA (flow rate size: 0.1 L/min) of a spray nozzle manufactured
by Spraying Systems Co.) so that the film thickness of a polymer
layer after drying became 200 nm. Thereafter, by drying at
150.degree. C. for 10 minutes, a polymer layer was formed.
[0102] Next, the metal particle dispersion liquid prepared in
Preparation Example 1 was applied onto the polymer layer formed in
the above-described manner by a spray device (a spray device
equipped with a spray tip QTKA (flow rate size: 0.1 L/min) of a
spray nozzle manufactured by Spraying Systems Co.) so that the film
thickness of a metal particle layer after drying became 150 nm.
Thereafter, by drying at 180.degree. C. for 10 minutes, a metal
particle layer was formed. The surface resistance value of the
metal particle layer was 4.OMEGA./.quadrature..
[0103] Next, electrolytic copper plating and electrolytic nickel
plating were performed on the metal particle layer which was formed
in the above-described manner in the same manner as in Example 1 to
form a shield layer formed of a copper plating layer having a
thickness of 5 .mu.m and a nickel plating layer having a thickness
of 2 .mu.m.
Example 3
[0104] An electronic component mounted on a circuit board having a
ground pattern is encapsulated with a semiconductor encapsulating
resin composition containing an epoxy resin, a phenol resin curing
agent, and a filler. Next, a masking pressure-sensitive adhesive
tape for plating was attached to the circuit board side of the mold
in which the electronic component was encapsulated, on which the
shield layer was not formed. Then, the fluid containing the resin
for a polymer layer prepared in Preparation Example 2 was applied
to the surface of the mold by a spray device (a spray device
equipped with a spray tip QTKA (flow rate size: 0.1 L/min) of a
spray nozzle manufactured by Spraying Systems Co.) so that the film
thickness of a polymer layer after drying became 200 nm.
Thereafter, by drying at 150.degree. C. for 10 minutes, a polymer
layer was formed.
[0105] Next, the surface of the polymer layer formed in the
above-described manner was subjected to half-dicing along the
scheduled division line with a diamond blade of a dicing apparatus
to form a slit portion. It was found that there was no polymer
layer in the slit portion and the ground line of the circuit board
was exposed.
[0106] Next, the metal particle dispersion liquid prepared in
Preparation Example 1 was printed on the mold obtained above, on
which the polymer layer was formed and the slit portion was formed
by half-dicing. The metal particle dispersion liquid was printed
using an ink jet printer (ink jet tester EB100, printer head KM512L
for evaluation, discharge amount 14 .mu.L, manufactured by Konica
Minolta IJ Inc.) first along the slit portion, and then the entire
surface of the mold was printed. Thereafter, by drying at
150.degree. C. for 10 minutes, a metal particle layer was formed.
The film thickness of the metal particle layer was 80 nm as an
average film thickness at each portion.
[0107] Next, electroless copper plating was performed on the metal
particle layer formed in the above-described manner to form an
electroless copper plating film having a thickness of 0.2 .mu.m.
The electroless copper plating was performed by preparing a bath of
ARG copper (manufactured by Okuno Chemical Industries Co., Ltd.)
under standard recommended conditions (ARG copper 1: 30 mL/L, ARG
copper 2: 15 mL/L, ARG copper 3: 200 mL/L), keeping the bath
temperature at 45.degree. C., and immersing the substrate having
the metal particle layer formed thereon for 15 minutes to deposit a
copper plating film.
[0108] Next, electrolytic copper plating and electrolytic nickel
plating were performed on the electroless copper plating layer
which was formed in the above-described manner in the same manner
as in Example 1 to form a shield layer formed of a copper plating
layer having a thickness of 5 .mu.m and a nickel plating layer
having a thickness of 2 .mu.m.
Example 4
[0109] An electronic component mounted on a circuit board having a
ground pattern is encapsulated with a semiconductor encapsulating
resin composition containing an epoxy resin, a phenol resin curing
agent, and a filler. Then, the fluid containing the resin for the
polymer layer prepared in Preparation Example 2 was applied to the
surface of the mold by a spray device (a spray device equipped with
a spray tip QTKA (flow rate size: 0.1 L/min) of a spray nozzle
manufactured by Spraying Systems Co.) so that the film thickness of
a polymer layer after drying became 200 nm. Thereafter, by drying
at 120.degree. C. for 10 minutes, a polymer layer was formed.
[0110] Next, the surface of the polymer layer formed in the
above-described manner was diced along the division line into
individual pieces each having a length of 10 mm and a width of 10
mm with a diamond blade of a dicing apparatus. It was found that
there was no polymer layer in the portion of the singulated mold in
contact with the diamond blade, and the ground line of the circuit
board was exposed. Next, 40 pieces of the singulated mold were
attached to the thermal release sheet for electronic component
process at a 2 mm interval.
[0111] Next, the metal particle dispersion liquid prepared in
Preparation Example 1 was printed on the surface of the mold
attached to the thermal release sheet for an electronic component
process in the above-described manner. The metal particle
dispersion liquid was also printed on the surface of the mold, the
side surface cut out by dicing, and the surface of the thermal
release sheet for the electronic component process to which the
mold was attached, using an ink jet printer (ink jet tester EB100,
printer head KM512L for evaluation, discharge amount 14 .mu.L,
manufactured by Konica Minolta IJ Inc.). Thereafter, by drying at
100.degree. C. for 10 minutes, a metal particle layer was formed.
The film thickness of the metal particle layer was 90 nm as an
average film thickness at each portion.
[0112] Next, electroless copper plating was performed on the metal
particle layer formed in the above-described manner in the same
manner as in Example 3 to form an electroless copper plating layer
having a thickness of 0.2 .mu.m.
[0113] Next, electrolytic copper plating and electrolytic nickel
plating were performed on the electroless copper plating layer
which was formed in the above-described manner in the same manner
as in Example 1 to form a shield layer formed of a copper plating
layer having a thickness of 5 .mu.m and a nickel plating layer
having a thickness of 2 .mu.m.
Comparative Example 1
[0114] An electronic component mounted on a circuit board having a
ground pattern is encapsulated with a semiconductor encapsulating
resin composition containing an epoxy resin, a phenol resin curing
agent, and a filler. In order to roughen the surface of the mold,
the filling material in the mold was dissolved using hydrofluoric
acid, and roughening treatment was performed on the surface of the
mold. For the roughening treatment, a chemical prepared by
dissolving 150 g/L of ammonium fluoride in 1000 mL/L of 62% nitric
acid was used. The roughening treatment temperature was 40.degree.
C., and the roughening treatment time was 20 minutes.
[0115] Next, the mold subjected to the roughening treatment in the
above-described manner was immersed in a catalyst liquid made of a
stannous chloride protective colloid solution of palladium as an
electroless copper plating catalyst (aqueous solution containing 40
mL/L of Catalyst C (trade name) manufactured by Okuno Chemical
Industries Co., Ltd. and 180 mL/L of 35% hydrochloric acid) at
30.degree. C. for 3 minutes. Next, the electroless copper plating
catalyst was activated by immersing in an aqueous solution
containing 100 mL/L of 98% sulfuric acid at 40.degree. C. for 3
minutes.
[0116] Next, the mold subjected to the roughening treatment, the
application of the electroless copper plating catalyst, and the
activation treatment in the above-described manner was subjected to
electroless copper plating in the same manner as in Example 3 to
form an electroless copper plating layer having a thickness of 0.2
.mu.m.
[0117] Next, electrolytic copper plating and electrolytic nickel
plating were performed on the electroless copper plating layer
which was formed in the above-described manner in the same manner
as in Example 1 to form a shield layer formed of a copper plating
layer having a thickness of 5 .mu.m and a nickel plating layer
having a thickness of 2 .mu.m.
Comparative Example 2
[0118] An electronic component mounted on a circuit board having a
ground pattern was encapsulated with a semiconductor encapsulating
resin composition containing an epoxy resin, a phenol resin curing
agent, and a filler. The surface of the mold was subjected to
sputtering process according to a film forming method of magnetron
sputtering. A copper film having a thickness of 0.2 .mu.m was
formed by this sputtering method.
[0119] Next, electrolytic copper plating and electrolytic nickel
plating were performed on the copper film formed in the
above-described manner in the same manner as in Example 1 to form a
shield layer formed of a copper plating layer having a thickness of
5 .mu.m and a nickel plating layer having a thickness of 2
.mu.m.
<Measurement of Adhesion (Peel Strength) of Shield Layer>
[0120] For each of the electronic component packages having the
shield layer formed thereon obtained as described above, the peel
strength between the mold and the shield layer was measured using
"Autograph AGS-X 500N" manufactured by Shimadzu Corporation. The
lead width used for the measurement was set to 1 mm, and the peel
angle was set to 90.degree.. In addition, the measurement of the
peel strength in the present invention was carried out on the basis
of the measured value when the thickness of the shield layer was 7
.mu.m.
<Measurement of Adhesion (Peel Test) of Shield Layer after
Heating>
[0121] Each of the electronic component packages having the shield
layer formed thereon obtained as described above was stored and
heated in a dryer set at 150.degree. C. for 168 hours. After
heating, the peel strength was measured in the same manner as
described above.
<Heat Resistance Evaluation>
[0122] Using the peel strength values before and after heating
measured above, retention rates before and after heating were
calculated, and heat resistance was evaluated according to the
following criteria.
[0123] A: The retention rate is 80% or more.
[0124] B: The retention rate is 70% or more and less than 80%.
[0125] C: The retention rate is 50% or more and less than 70%.
[0126] D: The retention rate is less than 50%.
[0127] Table 1 shows the measurement results of the peel strength
and the evaluation results of the heat resistance before and after
heating with respect to the shield layer of each of the electronic
component packages having a shield layer formed therein which were
obtained in Examples 1 to 4 and Comparative Examples 1 and 2.
TABLE-US-00001 TABLE 1 Comparative Example 1 Example 2 Example 3
Example 4 Example 1 Example 2 Roughening treatment of No No No No
Yes No mold Polymer layer No Yes Yes Yes No No Metal particle layer
Silver Silver Silver Silver No No particle particle particle
particle Sputtering layer No No No No No Copper sputtering
Evaluation Peel Before 350 560 600 610 180 150 results strength of
heating stacked After 280 460 520 480 30 50 layer (N/m) heating
Retention rate of 80 82 87 79 17 33 peel strength (%) Heat
resistance A A A B D D
[0128] From the results shown in Table 1, it was found that the
shield layers obtained in Examples 1 to 4, which are electronic
component packages in which the shield layer of the present
invention was formed, had a high peel strength between the mold and
the shield layer, a slight decrease in peel strength after heating,
a high retention rate of peel strength after heating, and an
excellent heat resistance.
[0129] On the other hand, the electronic component package having
the shield layer formed thereon obtained in Comparative Example 1
is an example in which the mold was subjected to roughening
treatment and then the metal plating film was formed, and it was
found that the peel strength was very low before and after
heating.
[0130] In addition, the electronic component package having the
shield layer formed thereon obtained in Comparative Example 2 is an
example in which a metal layer was formed on a support using a
sputtering method and then metal plating was performed, and it was
found that the peel strength was very low before and after
heating.
REFERENCE SIGNS LIST
[0131] 1: Circuit board [0132] 2: Shield layer [0133] 3: Metal
particle layer [0134] 4: Copper plating layer [0135] 5: Nickel
plating layer [0136] 6: Ground pattern [0137] 7: Wiring pattern
[0138] 8: Connection pad with another circuit board or the like
[0139] 9: Electronic component such as semiconductor device [0140]
10: Polymer layer [0141] 11: Mold
* * * * *