U.S. patent application number 12/678855 was filed with the patent office on 2010-08-12 for stacked mounting structure and method of manufacturing stacked mounting structure.
This patent application is currently assigned to OLYMPUS CORPORATION. Invention is credited to Yu Kondo, Mikio Nakamura.
Application Number | 20100202126 12/678855 |
Document ID | / |
Family ID | 40467856 |
Filed Date | 2010-08-12 |
United States Patent
Application |
20100202126 |
Kind Code |
A1 |
Nakamura; Mikio ; et
al. |
August 12, 2010 |
Stacked Mounting Structure and Method of Manufacturing Stacked
Mounting Structure
Abstract
There is provided a stacked mounting structure in which, it is
possible to realize a narrowing of pitch and to secure a height
which enables to mount components to be mounted, and a method of
manufacturing stacked mounting structure. The stacked mounting
structure includes a plurality of members provided with a mounting
area which is necessary for installing and operating components to
be mounted on at least one principal surface, and an area for
connections for signal transfer for operating the components to be
mounted, and an electroconductive member which is disposed on the
area for connections between the mutually facing members, and a
cross section of the electroconductive member is same as or smaller
than the area for connections, and an end portion of the
electroconductive member is extended from a principal surface of
one member up to a principal surface of the other member, and a
height of the electroconductive member regulates a distance of the
mounting area.
Inventors: |
Nakamura; Mikio; (Tokyo,
JP) ; Kondo; Yu; (Kanagawa, JP) |
Correspondence
Address: |
SCULLY SCOTT MURPHY & PRESSER, PC
400 GARDEN CITY PLAZA, SUITE 300
GARDEN CITY
NY
11530
US
|
Assignee: |
OLYMPUS CORPORATION
Tokyo
JP
|
Family ID: |
40467856 |
Appl. No.: |
12/678855 |
Filed: |
September 16, 2008 |
PCT Filed: |
September 16, 2008 |
PCT NO: |
PCT/JP2008/066655 |
371 Date: |
March 18, 2010 |
Current U.S.
Class: |
361/803 ;
29/825 |
Current CPC
Class: |
H01L 24/19 20130101;
H05K 3/4046 20130101; H05K 3/4647 20130101; Y10T 29/49147 20150115;
H01L 21/56 20130101; H01L 2224/04105 20130101; H01L 2224/274
20130101; H01L 2225/1023 20130101; H05K 3/284 20130101; H05K
2201/10318 20130101; H01L 25/105 20130101; H01L 2224/12105
20130101; Y10T 29/4913 20150115; H01L 2225/1058 20130101; H01L
2225/0652 20130101; H01L 2924/0002 20130101; H05K 3/3426 20130101;
H05K 3/3436 20130101; H01L 2924/0002 20130101; H01L 2924/01079
20130101; H05K 1/144 20130101; Y10T 29/49117 20150115; H01L 25/0657
20130101; H01L 2225/06541 20130101; H05K 3/368 20130101; H01L
2225/1035 20130101; H05K 2203/025 20130101; H05K 2203/1316
20130101; H05K 2201/10242 20130101; H01L 23/3121 20130101; H05K
2201/042 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
361/803 ;
29/825 |
International
Class: |
H05K 1/11 20060101
H05K001/11; H05K 13/00 20060101 H05K013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 18, 2007 |
JP |
JP 2007-240785 |
Mar 31, 2008 |
JP |
JP 2008-091636 |
Claims
1. A stacked mounting structure comprising: a plurality of members
provided with a mounting area, which is necessary for installing
and operating components to be mounted on at least one principal
surface, and an area for connections for signal transfer for
operating the components to be mounted; and an electroconductive
member which is disposed on the area for connections between the
mutually facing members, wherein a cross section of the
electroconductive member is same as or smaller than the area for
connections, and an end portion of the electroconductive member is
extended from a principal surface of one member up to a principal
surface of the other member, and a height of the electroconductive
member regulates a distance of the mounting area.
2. The stacked mounting structure according to claim 1, wherein a
reinforcing member is installed around the electroconductive
member.
3. The stacked mounting structure according to claim 1, wherein the
components to be mounted are mounted on the mounting area, and a
distance of the mounting area between the plurality of members is
more than a height of the components to be mounted.
4. The stacked mounting structure according to claim 1, wherein the
reinforcing member is filled in the mounting area between the
mutually facing members.
5. The stacked mounting structure according to claim 1, wherein the
electroconductive member is rod-shaped.
6. The stacked mounting structure according to claim 1, wherein the
electroconductive member, in a state of one end portion thereof
joined, the other end portion is mounted on the member, and is
formed by removing the portion joined after the other end portion
is mounted on the member.
7. The stacked mounting structure according to claim 1, wherein an
electroconductive pattern of which, at least a part is electrically
connected to the electroconductive member, is formed at one end
portion of the reinforcing member.
8. A method of manufacturing stacked mounting structure comprising
steps of: mounting components to be mounted, and mounting an
electroconductive member which is higher than a height of the
components to be mounted, on a first member; a reinforcing step of
forming a reinforcing member around the electroconductive member on
the first member by exposing an end portion of the
electroconductive member, at an opposite side of the first member,
wherein at the reinforcing step, a surface of the reinforcing
member, opposite to the first member is flattened by grinding, and
an end portion of the electroconductive member is exposed.
9. The method of manufacturing stacked mounting structure according
to claim 8, comprising: forming a metal film on an end-portion
surface of the electroconductive member which is exposed, after the
reinforcing member is formed by exposing the end portion of the
electroconductive member, on the opposite side of the first member;
and a step of forming a bump on the metal film of the end-portion
surface of the electro conductive member.
10. The method of manufacturing stacked mounting structure
according to claim 8, further comprising: a joining step of forming
one end portion of the electroconductive member, in a state of the
plurality of electroconductive member joined.
11. The method of manufacturing stacked mounting structure
according to claim 8, comprising: a separating step after an
insulating-material forming step, wherein the first member has a
size equivalent to a plurality of modules.
Description
TECHNICAL FIELD
[0001] The present invention relates to a stacked mounting
structure and a method of manufacturing stacked mounting
structure.
BACKGROUND ART
[0002] As a substrate connecting member which connects electronic
circuit boards which are stacked, a substrate connecting member
described in Patent Literature 1 (Japanese Patent Application
Laid-open Publication No. 2001-144399) is available. This substrate
connecting member is a member which covers a core body made of a
stiff conductor by an elastic body, and which covers the
surrounding of the elastic body by an electroconductive material.
By structuring the substrate connecting member in such manner,
there is an effect that heating is not necessary to separate the
electronic circuit board at the time of a repairing job.
[0003] Moreover; as another conventional example, for realizing a
small and a highly dense substrate in which electronic components
are built-in, a structure in which, electrodes of the electronic
components are exposed by carrying out a process of grinding and
perforating on a resin after the electronic components are fixed by
resin in a through hole in a circuit-board main body, and further,
a circuit layer is formed on a front and a rear surface of the
circuit-board main body, has been proposed.
[0004] Patent Literature 1: Japanese Patent Application Laid-open
Publication No. 2001-144399
DISCLOSURE OF INVENTION
Technical Problem
[0005] However, although narrowing of pitch was possible in the
substrate connecting member described in Patent Literature 1, there
were following problems. In other words, (1) stacked electronic
circuit boards were supposed to be attached and detached mutually,
(2) assembling and position adjustment in a recess in a case of
forming a plurality of connecting members have been difficult, (3)
stacking of a multiple number of electronic circuit boards has not
been taken into consideration, and (4) at least two members namely
the core body and the elastic body being necessary, small sizing
had been difficult.
[0006] Moreover, in the another conventional example mentioned
above, the electronic components which can be built-in in a
substrate thickness were restricted to components having a height
smaller than the substrate thickness, and also, the circuit layer
on the front and rear surface of the board main body had to be
connected via the electronic components, due to which there had
been substantial restrictions in designing of the circuit layer. In
a case of connecting the circuit layer on the front and rear
surface of the board main body upon bypassing the electronic
components, the connections can be made via a through hole, but it
is necessary to provide an electrode pad (land electrode) larger
than a through-hole diameter, and since the narrowing of pitch of
the board connecting portion was difficult, there had been
limitations on making small an area of a principal surface of the
substrate.
[0007] The present invention has been made in view of the
abovementioned circumstances, and an object of the present
invention is to provide a stacked mounting structure in which, it
is possible to realize the narrowing of pitch and to secure a
height which enables to mount components, and a method of
manufacturing stacked mounting structure. Moreover, another object
of the present invention is to provide a stacked mounting structure
in which, a degree of freedom of wiring of the substrate is high,
and the narrowing of pitch of the substrate connecting portions is
possible, and accordingly, the area of the principal surface of the
substrate is small.
Technical Solution
[0008] To solve the abovementioned problems and to achieve the
object, the stacked mounting structure of the present invention
includes
[0009] a plurality of members provided with a mounting area which
is necessary for installing an operating components to be mounted
on at least one principal surface, and an area for connections for
signal transfer for operating the components to be mounted, and
[0010] an electroconductive member which is disposed on the area
for connections between the mutually facing members, and
[0011] a cross-section of the electroconductive member is same as
or smaller than the area for connections, and an end portion of the
electroconductive member is extended from a principal surface of
one member up to a principal surface of the other member, and a
height of the electroconductive member regulates a distance of the
mounting area.
[0012] In the stacked mounting structure of the present invention,
it is preferable that a reinforcing member is installed around the
electroconductive member.
[0013] In the stacked mounting structure of the present invention,
it is desirable that the components to be mounted are mounted on
the mounting area, and a distance of the mounting area between the
plurality of members is more than a height of the components to be
mounted.
[0014] In the stacked mounting structure of the present invention,
it is preferable that the reinforcing member is filled in the
mounting area between the mutually facing members.
[0015] In the stacked mounting structure of the present invention,
it is preferable that the electroconductive member is
rod-shaped.
[0016] In the stacked mounting structure of the present invention,
it is desirable that the electroconductive member, in a state of
one end portion thereof joined, the other end portion is mounted on
the member, and is formed by removing the portion joined after the
other end portion is mounted on the member.
[0017] In the stacked mounting structure of the present invention,
it is preferable that an electroconductive pattern of which, at
least a part is electrically connected to the electroconductive
member, is formed at one end portion of the reinforcing member.
[0018] Moreover, a method of manufacturing stacked mounting
structure includes steps of:
[0019] mounting components to be mounted, and mounting an
electroconductive member which is higher than a height of the
components to be mounted, on a first member,
[0020] a reinforcing step of forming a reinforcing member around
the electroconductive member on the first member by exposing an end
portion of the electroconductive member, at an opposite side of the
first member, and
[0021] at the reinforcing step, a surface of the reinforcing
member, opposite to the first member is flattened by grinding, and
an end portion of the electroconductive member is exposed.
[0022] In the method of manufacturing stacked mounting structure of
the present invention, it is desirable that the method of
manufacturing stacked mounting structure further includes a joining
step of forming one end portion of the electroconductive member, in
a state of the plurality of electroconductive members joined.
[0023] In the method of manufacturing stacked mounting structure of
the present invention, it is preferable that the method of
manufacturing stacked mounting structure includes steps of: forming
a metal film on an end-portion surface of the electroconductive
member which is exposed, after the reinforcing member is formed by
exposing the end portion of the electroconductive member, on the
opposite side of the first member, and a step of forming a bump on
the metal film of the end-portion surface of the electroconductive
member.
[0024] In the method of manufacturing stacked mounting structure of
the present invention, it is preferable that the method of
manufacturing stacked mounting structure includes a separating step
after an insulating-material forming step, and that the first
member has a size equivalent to a plurality of modules.
[0025] According to the stacked mounting structure and the method
of manufacturing stacked mounting structure of the present
invention, there is shown an effect that it is possible to provide
a stacked mounting structure in which, it is possible to realize a
narrowing of pitch and to secure a height, which enables to mount
components to be mounted, and a method of manufacturing stacked
mounting structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is perspective view showing a structure of a stacked
mounting structure according to a first embodiment, by separating
into a first substrate and a second substrate.
[0027] FIG. 2 is a cross-sectional view showing a structure of the
stacked mounting structure according to the first embodiment;
[0028] FIG. 3 is a perspective view showing a structure of a
stacked mounting structure according to a second embodiment, by
separating into a first substrate and a second substrate;
[0029] FIG. 4 is an enlarged perspective view showing a
relationship of an electroconductive member and a reinforcing
member according to the second embodiment;
[0030] FIG. 5 is a perspective view showing a structure of a
stacked mounting structure according to a third embodiment;
[0031] FIG. 6 is a flowchart showing a flow of a method of
manufacturing stacked mounting structure according to a fourth
embodiment;
[0032] FIG. 7 is a flowchart showing a flow of a method of
manufacturing stacked mounting structure according to a fifth
embodiment;
[0033] FIG. 8 is a flowchart showing a flow of a method of
manufacturing stacked mounting structure according to a sixth
embodiment;
[0034] FIG. 9 is a diagram of which, a right side is an enlarged
perspective view showing a structure of a stacked mounting
structure corresponding to steps from step S1 to step S6 in FIG. 8,
and a left side is a perspective view showing an assembled state of
the stacked mounting structure separated into pieces in the
right-side diagram;
[0035] FIG. 10 is a side view showing a structure of the stacked
mounting structure corresponding to steps from step S1 to step S6
in FIG. 8;
[0036] FIG. 11A is a perspective view showing a structure of a
stacked mounting structure according to a modified embodiment;
[0037] FIG. 11B is another perspective view showing the structure
of the stacked mounting structure according to the modified
embodiment;
[0038] FIG. 11C is still another perspective view showing the
structure of the stacked mounting structure according to the
modified embodiment;
[0039] FIG. 11D is another perspective view showing the structure
of the stacked mounting structure according to the modified
embodiment; and
[0040] FIG. 12 is a flow chart showing a flow of a method of
manufacturing stacked mounting structure according to a modified
embodiment.
EXPLANATION OF REFERENCE
[0041] 10 stacked mounting structure [0042] 20 first substrate
[0043] 20a principal surface [0044] 21 electroconductive member
[0045] 21a end portion [0046] 22 electrode [0047] 23 insulating
layer [0048] 23a upper surface [0049] 24 circuit layer [0050] 26
electronic component [0051] 29 bump [0052] 30 second substrate
[0053] 32 electrode [0054] 34 circuit layer [0055] 36 electronic
component [0056] 40 stacked mounting structure [0057] 50 first
substrate [0058] 51 electroconductive member [0059] 52 electrode
[0060] 56 electronic component [0061] 57 reinforcing member [0062]
60 second substrate [0063] 66 electronic component [0064] 70
stacked mounting structure [0065] 80 first substrate [0066] 81
electroconductive member [0067] 83 insulating layer [0068] 88 wire
[0069] 90 module
BEST MODE FOR CARRYING OUT THE INVENTION
[0070] Exemplary embodiments of a stacked mounting structure and a
method of manufacturing stacked mounting structure according to the
present invention will be described below in detail by referring to
the accompanying diagrams. However, the present invention is not
restricted to the embodiments described below.
[0071] In the method of manufacturing stacked mounting structure
according to the present invention, components to be mounted are
mounted on a circuit board and at the same time, from among these
components to be mounted, an electroconductive member which is
longer than a component having the maximum height is connected upon
fixing in perpendicular with the substrate, to an electrode on the
circuit board, and after filling a resin in a gap between the
electroconductive member and the component to be mounted, only a
head portion of the electroconductive member is exposed by
grinding. By connecting a second substrate to the electroconductive
member exposed, or, by forming a circuit by printing on a ground
surface, the upper and the lower circuit boards are connected and
fixed electrically and mechanically, and accordingly, the stacked
mounting structure according to the present invention is formed.
Concrete embodiments will be described below.
First Embodiment
[0072] FIG. 1 is a perspective view showing a structure of a first
embodiment of a stacked mounting structure according to the present
invention, by separating into a first substrate 20 and a second
substrate 30.
[0073] As shown in FIG. 1, electronic components 26 are mounted on
a principal surface of the first substrate 20. Moreover, electronic
components 36 are mounted on the second substrate 30. The first
substrate 20 and the second substrate 30 are disposed face-to-face.
A multi-layer substrate or a substrate with built-in electronic
components may be used for the first substrate 20 and the second
substrate 30.
[0074] Electrodes 22 are provided between the electronic components
26 of the first substrate 20, and electroconductive members 21
having a substantially circular cylindrical shape are installed on
the electrodes 22. A length of all the electroconductive members 21
is substantially same, and is longer than the maximum height of the
electronic component 26 from among the electronic components 26
mounted on the first substrate 20. Moreover, an area of an
orthogonal cross-section perpendicular to a longitudinal direction
of the electroconductive member 21 is same as or less than an area
of the electrodes 22.
[0075] The electroconductive member 21 can be made easily by
cutting out from a wire, when a circular cylindrical shaped
component is used. At this time, when a diameter of an end portion
of a side of the electroconductive portion 21, to be mounted on the
first substrate 20 is made substantial, the mounting on the first
substrate 20 can be carried out easily and assuredly. Whereas, an
end portion of the electroconductive member, on the opposite side
of the first substrate 20 can also be mounted in a state of a
number of electroconductive members joined.
[0076] For the electroconductive member 21, it is preferable to use
a material having a lower electrical resistance (such as Cu
(copper)). Moreover, it is preferable to apply Au (gold) plating on
a surface of the electroconductive member 21 for preventing
oxidation of a base material. Furthermore, a surface treatment for
making soldering easy is carried out on the electroconductive
member 21, and one end portion of the electroconductive member 21,
and the electrode 22 are joined to be electroconductive by
soldering. Instead of soldering, it is possible to bring into
electrical conduction by contact conduction by a method such as an
ACP method in which, an anisotropic conductive material is used, an
ACF method, and an NCP method.
[0077] As shown in FIG. 2, circuit layers 24 and 34 are formed in
the first substrate 20 and the second substrate 30 respectively. An
insulating layer 23 is formed by filling and curing an insulating
material (reinforcing member) of a resin around the
electroconductive member 21 and the electronic components 26 on the
first substrate 20. In the insulating layer 23, only an end portion
21a of the electroconductive member 21, toward the second substrate
30 is exposed from a surface (an upper surface) 23a toward the
second substrate 30.
[0078] Electrodes 32 are installed on a surface 30a of the second
substrate 30, facing the first substrate 20, at positions facing
the electroconductive members 21. The second substrate 30 is joined
to a surface of the insulating surface 23 such that the end
portions 21a of the electroconductive members 21 of the first
substrate 20 and the electrodes 32 are connected electrically. The
number of stacked layers may be increased further by installing
electroconductive members (not shown in the diagram) on electrodes
(not shown in the diagram) on the exposed surface of the second
substrate 30.
[0079] In the first embodiment, since the electroconductive member
connecting the upper and the lower circuit boards can be installed
freely between the electronic components, a wiring design of each
substrate is not constrained. Furthermore, the electrode on which
the electroconductive member is mounted not being a through hole
electrode, a land electrode is not necessary, and the
electroconductive members can be disposed at a narrow pitch.
Therefore, it is possible to provide a stacked mounting structure
having a small area of a principal surface of a substrate.
Moreover, since processes such as cutting of through holes and
recesses in the substrate are not necessary, it is possible to
provide a stacked mounting structure at a low price and having a
small area of the principal surface of the substrate.
Second Embodiment
[0080] FIG. 3 is a perspective view showing a structure of a second
embodiment of a stacked mounting structure according to the present
invention, by separating into a first substrate 50 and a second
substrate 60. FIG. 4 is an enlarged perspective view showing a
relationship of an electroconductive member and a reinforcing
member according to the second embodiment.
[0081] The second embodiment differs from the first embodiment at a
point that, a reinforcing member 57 is formed in a state of a part
or whole of a mounting area exposed around an electroconductive
member 51. In other words, the first substrate 20, the electrode
22, the electronic component 26, the second substrate 30, the
electronic component 36 in the stacked mounting structure 10 of the
first embodiment correspond to the first substrate 50, the
electroconductive member 51, an electrode 52, an electronic
component 56, the second substrate 60, and an electronic component
66 respectively in a stacked mounting structure 40 of the second
embodiment. Moreover, although it is not shown in the diagram, even
in the stacked mounting structure of the second embodiment, a
circuit layer similar to the circuit layers 24 and 34 of the
stacked mounting structure 10 of the first embodiment is
formed.
[0082] In the second embodiment, the electronic components being
exposed after forming the reinforcing member, the electronic
components can be checked immediately before connecting the second
substrate, and the number of defective stacked mounting structures
can be reduced.
[0083] As shown in FIG. 4, the reinforcing member 57 is disposed
such that an end portion 51a toward the second substrate 60 is left
around the electroconductive member 51. As the reinforcing member
57, a material which is in a liquid format the time of disposing
around the electroconductive member 51, and which is hardened after
disposing is to be used.
Third Embodiment
[0084] FIG. 5 is a perspective view showing a structure of a third
embodiment of a stacked mounting structure according to the present
invention.
[0085] In a stacked mounting structure 70 of the third embodiment,
similarly as the insulating layer 23 of the first embodiment, an
insulating layer 83 by an insulating material of a resin is formed
around electronic components (not shown in the diagram) and
electroconductive members 81 on a first substrate 80, and on a
surface of the insulating layer 83, which is far from the first
substrate 80, wires 88 are formed to connect the electroconductive
members 81. In other words, in the third embodiment, without
placing a second substrate such as the second substrate 30 of the
first embodiment and the second substrate 60 of the second
embodiment, the wires 88 are formed directly on the insulating
layer 83. As a method for forming the wires 88, a method such as
plating, sputtering, vapor deposition, and printed wiring by an
ink-jet or dispensing may be used. By letting the structure to be
such structure, since a substrate portion of the second substrate
is not necessary, it is possible to improve a degree of freedom of
designing, and to provide a stacked mounting structure with a low
stacking height, and small area of a principal surface of the
substrate.
Modified Embodiments
[0086] Next, modified embodiments of the stacked mounting structure
will be described below. FIG. 11A, FIG. 118, FIG. 11C, and FIG. 11D
show structures of stacked mounting structures according to the
modified embodiments.
[0087] As it has been mentioned above, the end portion of the
electroconductive member 21 toward the opposite side of the first
substrate 20 can be mounted in the state of the number of
electroconductive members 21 joined. The state of the number of
electroconductive members 21 joined can be formed by forming the
electroconductive members 21 by plating of Cu on a substrate 100,
or by carrying out press working on a plate 100 of an
electroconductive material such as Cu (FIG. 11A).
[0088] In this embodiment, an electroconductive member 21 which is
connected is prepared separately from the first substrate 20, and
is connected to the first substrate 20. FIG. 11B shows a state of a
pin-substrate joining. Moreover, as shown in FIG. 11C, a resin is
applied between a portion where the first substrate 20 and the
electroconductive members 21 are joined, and cured. Here, a resin
may be applied in advance on the first substrate 20.
[0089] The portion at which, the first substrate 20 and the
electroconductive members 21 are joined is removed by grinding, and
each electroconductive member 21 is exposed. A metal film which
prevents oxidation of the electroconductive member 21 is formed at
the end portion of the exposed electroconductive members 21.
Finally, the second substrate 30 is stacked as shown in FIG. 118,
and the substrates 20 and 30 are connected. Accordingly, the
stacked mounting structure is formed. Therefore, in a case in
which, the height of the electronic component 26 is comparatively
high such as from 0.3 mm to 1 mm, by disposing freely the
electroconductive members 21 longer than the height of the
electronic component 26 on a principal surface 20a of the first
substrate 20, it is possible to connect the first substrate 20 and
the second substrate 30. Moreover, it is possible to narrow a pitch
of connections.
[0090] In such manner, the electroconductive members 21 are mounted
collectively on the first substrate 20 in the state of the
plurality of one end portions joined. Therefore, it is possible to
mount the electroconductive members 21 easily. Moreover, since
protruding electrodes can be prepared collectively, further
narrowing of pitch is possible. As a result, the stacked mounting
structure can be easily manufactured to be small.
[0091] Next, a method of manufacturing stacked mounting structure
according to the present invention will be described below by
citing embodiments from a fourth embodiment to a sixth
embodiment
Fourth Embodiment
[0092] FIG. 6 is a flowchart showing a flow of a method of
manufacturing stacked mounting structure according to the fourth
embodiment. The method of manufacturing of the fourth embodiment is
applicable to embodiments from the first embodiment to the third
embodiment, and the modified embodiments, and in the description of
the embodiments from the fourth embodiment to the sixth embodiment,
reference numerals of the first embodiment are used.
[0093] Firstly, the electronic components 26 are mounted on the
first substrate 20 (step S1), and at the same time, the
electroconductive members 21 are mounted on the electrodes 22 of
the first substrate 20 (step S2). For mounting the electronic
components 26, a prevalent surface mounting process may be used.
Moreover, in a case of mounting the electroconductive members 21 by
soldering, the electroconductive members 21 can be mounted by a
method in which, a cream solder and flux are supplied on the
electrodes 22 by a method such as printing, and the
electroconductive members are positioned and fixed on the
electrodes 22 by using a mounting instrument and jig, and heated.
For mounting the electronic components 26 and the electroconductive
members 21 on the first substrate 20, the electroconductive members
21 may be mounted after the electronic components 26 are mounted
(refer to the fifth embodiment or the sixth embodiment), or vice
versa.
[0094] Next, the insulating layer 23 is formed around the
electronic components 26 and the electroconductive members 21 on
the first substrate 20 by applying a liquid sealing resin on the
first substrate 20 on which the electronic components 26 and the
electroconductive members 21 are mounted such that, the end surface
21a on the opposite side of the first substrate 20 (toward the
second substrate 30) is exposed, and then curing the liquid sealing
resin. Accordingly, the electroconductive members 21 and the
electronic components 26 are sealed (step S3). As a curing method
of resin, methods such as a thermal curing and two-liquid mixing
are available. The shape of the resin after curing can be set
easily by using a mould which is matched with an outer shape of the
first substrate 20 or a desired shape after curing. In a case of
applying the fourth embodiment to the second embodiment, at step
S3, instead of sealing of a resin, a reinforcing member is to be
disposed around the electroconductive members.
[0095] Thereafter, the second substrate 30 is connected by stacking
on the first substrate 20 via the bump in the form of a metal film
formed on an end surface of the electroconductive member 21, on the
opposite side of the first substrate 20. In a case of applying the
fourth embodiment to the third embodiment, without stacking the
second substrate 30, wires are formed directly on a surface 23a of
the insulating layer 23, on the opposite side of the first
substrate 20.
[0096] The stacked mounting structure being manufactured by the
abovementioned steps, it is possible to provide the stacked
mounting structure having a small area of a principal surface of
the substrate by extremely less number of steps.
Fifth Embodiment
[0097] FIG. 7 is a flowchart showing a flow of a method of
manufacturing stacked mounting structure according to a fifth
embodiment. In the fifth embodiment, steps of mounting electronic
components (step S1), mounting electroconductive members (step S2),
and resin sealing (step S3) being same as in the fourth embodiment,
the description of these steps is omitted.
[0098] After the resin sealing (step S3), the upper surface 23a of
the insulating layer 23 is ground and flattened to be parallel to
the principal surface 20a of the first substrate 20, as well as,
each of the end surfaces 21a of the electroconductive members 21,
on the opposite side of the first substrate 20 is exposed (step
S4).
[0099] Next, a metal film (UBM layer) is formed on the end surface
21a of the exposed electroconductive member 21 (step S5). By
forming the metal layer, it is possible to prevent oxidation of the
electroconductive member 21, and the electric resistance at the
time of bump formation, which is the subsequent step, being low, it
is possible to form a bump having a high strength.
[0100] Next, the bump is formed on the metal film which is formed
on the end surface 21a of the exposed electroconductive member 21
(step S6). Solder or gold can be used as a material of bump.
[0101] Thereafter, the second substrate 30 is connected by stacking
via a bump 29 (FIG. 9 and FIG. 10) on the metal film which is
formed on the end surface 21a of the electroconductive member
21.
[0102] By manufacturing the stacked mounting structure by such
method, since the upper surface 23a of the insulating layer 23 is
flattened, and assuredly becomes parallel to the principal surface
20a of the first substrate 20, the end surface 21a of the
electroconductive member 21 has a structure which makes it easy to
connect the second substrate 30. Consequently, it is possible to
provide a stacked mounting structure having a high quality of
connection of the first substrate 20 and the second substrate 30,
and small area of the principal surface of the substrate.
Sixth Embodiment
[0103] FIG. 8 is a flowchart showing a flow of a method of
manufacturing stacked mounting structure according to a sixth
embodiment. FIG. 9 is a diagram of which, a right side is an
enlarged perspective view showing a structure of a stacked mounting
structure corresponding to steps from Step S1 to step S6 in FIG. 8,
and left side is a perspective view showing an assembled state of
the stacked mounting structure separated into pieces in the
right-side diagram. FIG. 10 is a side view showing a structure of
the stacked mounting structure corresponding to steps from step S1
to step S6 in FIG. 8.
[0104] In the sixth embodiment, steps of mounting electronic
components (step S1), mounting electroconductive members (step S2),
resin sealing (step S3), grinding (step S4), UBM layer formation
(step S5), and bump formation (step S6) are same as in the fifth
embodiment. After forming the bump 29, a plurality of modules 90 is
formed on the first substrate 20, and by a step of separating such
as dicing, the modules are turned to be individual modules (step
S7).
[0105] According to such method of manufacturing, since it is
possible to prepare a plurality of modules at a time, it is
possible to provide a stacked mounting structure in which, the cost
of manufacturing modules is low and the area of the principal
surface of the substrate is small.
Modified Embodiments
[0106] FIG. 12 is a flow chart showing a flow of a method of
manufacturing stacked mounting structure according to a modified
embodiment. Same reference numerals are assigned to contents which
are same as the steps of the embodiments described above, and
repeated description of such steps is omitted. To start with, in
this modified embodiment, firstly, the electronic components 26 are
mounted on the first substrate 20 (step S1).
[0107] Cu is grown by plating on a substrate 100, at positions
facing electrodes provided between the electronic components 26 of
the first substrate 20. Accordingly, a state in which, one end
portions of some of the electroconductive members 21 are connected
is formed (step S2a).
[0108] For the state in which, the one end portions of the
electroconductive members 21 are connected, various methods such as
forming Cu by plating on the substrate 10, furthermore, forming the
electroconductive members 21 by a method such as press working on a
plate 100 of an electroconductive material such as Cu, and plating
the end surfaces in a state of the rod-shaped electroconductive
members 21 arranged to be aligned on a jig, can be used. The
electroconductive members 21 are formed such that the height of the
electroconductive member 21 is more than the height of the
electronic component 26.
[0109] The end portion of the electroconductive member 21, on the
side which is not connected, is joined to the electrode of the
principal surface 20a of the first substrate 20 (step S2). In a
state of the one end portion of the electroconductive member 21
joined, when Au plating is applied on a surface thereof, oxidation
of Cu is prevented and the soldering can be carried out
assuredly.
[0110] A resin is applied between portions at which, the first
substrate 20 and the electroconductive members 21 are joined, and
cured (step S3). Here, the resin may be applied in advance on the
first substrate 20.
[0111] A portion at which the first substrate 20 and the
electroconductive members 21 are joined is removed by grinding, and
each electroconductive member 21 is exposed (step S4). Surrounding
of the electroconductive member 21 is reinforced by resin.
Therefore, the electroconductive member 21 can be ground stably.
Furthermore, the height (length) of the electroconductive members
21 can be arranged precisely by grinding. Therefore, a tolerance of
length of the electroconductive member 21 to be used can be
widened.
[0112] When the height of the electronic components 26 is
comparatively high such as from 0.3 mm to 1 mm, the
electroconductive member 21 longer than the height of the
electronic components 26 can be disposed freely on the principal
surface 20a of the first substrate 20, and the first substrate 20
and the second substrate 30 can be joined. Moreover, pitch of
connections can be narrowed.
[0113] Thereafter, a metal film which prevents oxidation of the
electroconductive member 21 is formed on the end portions of the
exposed electroconductive members 21. Next, by connecting the
second substrate 30, the stacked mounting structure is formed.
[0114] In such manner, the electroconductive members 21 are mounted
on the first substrate 20 in the state of the plurality of one end
portions joined. Therefore, the electroconductive members 21 can be
mounted easily. Moreover, since protruding electrodes can be
prepared collectively, further narrowing is possible. As a result,
the stacked mounting structure can be easily manufactured to be
small.
[0115] As it has been described above, according to the present
invention, since the electroconductive members, which connect the
upper and the lower circuit boards can be disposed freely between
the electronic components, wiring design of each substrate is not
constrained. Furthermore, the electrodes on which, the
electroconductive members are mounted not being through-hole
electrode, land electrodes are not required, and the
electroconductive members can be disposed with a narrow pitch.
Therefore, it is possible to provide a stacked mounting structure
having a small area of the principal surface of the substrate.
INDUSTRIAL APPLICABILITY
[0116] In such manner, the stacked mounting stricture and the
method of manufacturing stacked mounting structure according to the
present invention are useful for small sizing of a mounting
structure main body, and particularly, are appropriate for highly
dense mounting of an image picking unit at a front end of an
endoscope.
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