U.S. patent application number 09/842938 was filed with the patent office on 2002-11-14 for semiconductor device.
Invention is credited to Kondo, Yoichiro.
Application Number | 20020167081 09/842938 |
Document ID | / |
Family ID | 18634495 |
Filed Date | 2002-11-14 |
United States Patent
Application |
20020167081 |
Kind Code |
A1 |
Kondo, Yoichiro |
November 14, 2002 |
SEMICONDUCTOR DEVICE
Abstract
To provide a semiconductor device with a three-dimensional
mounting module using a flexible circuit substrate which is easy to
assemble a three-dimensional structure and is excellent in the
workability in repair work (or re-work). [MEANS FOR SOLUTION] A
flexible circuit substrate 11 has mounting regions 111, 112 and 113
on which electronic components 121, 122 and 123 are mainly mounted,
respectively, and other electronic components 124 and 125 are also
mounted. The flexible circuit substrate 11 is structured in such a
manner that the mounting regions 111.about.113 are folded on top of
the other over the base region 110 in a predetermined order
(f1.about.f3). An integrated spacer 13 has thick regions 131 and
thin regions 132, and is superposed and affixed to the flexible
circuit substrate 11 as indicated by arrows with broken lines, and
supports the electronic components 121.about.125 stacked in layers.
Fixing bosses 134 and aperture sections 14 to be coupled therewith
are provided to facilitate positioning.
Inventors: |
Kondo, Yoichiro;
(Nagano-ken, JP) |
Correspondence
Address: |
HOGAN & HARTSON L.L.P.
500 S. GRAND AVENUE
SUITE 1900
LOS ANGELES
CA
90071-2611
US
|
Family ID: |
18634495 |
Appl. No.: |
09/842938 |
Filed: |
April 25, 2001 |
Current U.S.
Class: |
257/686 ;
257/E23.171; 257/E23.177; 257/E25.013 |
Current CPC
Class: |
H01L 2225/06586
20130101; H01L 2224/16 20130101; H01L 2225/06579 20130101; H01L
23/5382 20130101; H01L 25/0657 20130101; H05K 1/189 20130101; H01L
23/5387 20130101; H01L 2225/06575 20130101 |
Class at
Publication: |
257/686 |
International
Class: |
H01L 023/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2000 |
JP |
2000-124353(P) |
Claims
1. A semiconductor device characterized in comprising: a flexible
circuit substrate having a base region and one or more mounting
region continuously provided at a peripheral edge of the base
region, wherein the mounting regions are folded over the base
region; electronic components mounted corresponding to the mounting
regions; a stacked layer support body including a thick first
region and a foldable thin second region that is formed with the
first region in one piece, each of the regions having a specified
outer frame provided in a manner to protect each of the electronic
components; a bonding member for integrating the stacked layer
support body and the flexible circuit substrate in one piece;
protruded sections provided at specified locations of the thick
first region of the stacked layered support body; and aperture
sections provided in at specified locations in a rear surface side
of the flexible circuit substrate to be coupled with the protruded
sections, wherein, when the mounting regions of the flexible
circuit substrate are folded together with the stacked layered
support body over the base region, the protruded sections and the
aperture sections are coupled and fixed together at an area where
the thick first regions are superposed on top of the other through
the flexible circuit substrate.
2. A semiconductor device according to claim 1 characterized in
that the flexible circuit substrate further includes an external
terminal region that is continuously provided along a periphery of
the base region.
3. A semiconductor device according to claim 1 characterized in
that the flexible circuit substrate further includes an external
terminal region that is provided on a surface of the base region on
its lower side.
4. A semiconductor device according to any one of claim 1 through
claim 3 characterized in that the stacked layer support body has a
structure that surrounds a periphery of the electronic component
with respect to the first region.
5. A semiconductor device according to any one of claim 1 through
claim 3 characterized in that the stacked layer support body has a
structure that partially follows along the periphery of the
electronic component with respect to the first region.
6. A semiconductor device according to any one of claim 1 through
claim 5 characterized in that the base region is further equipped
with a structure for mounting an electronic component, which is
provided with a thick first region of the stacked layer support
body corresponding to the electronic component to be mounted on the
base region, and aperture sections on the thick first region to be
engaged with the protruded sections.
Description
TECHNICAL FIELD
[0001] The present invention relates to a semiconductor device
using a flexible circuit substrate, and more particularly to a
semiconductor device composing a three-dimensional mounting module
that is required to be inexpensive, smaller in size, and lighter in
weight.
BACKGROUND TECHNOLOGY
[0002] Flexible circuit substrates have the advantage of being soft
and deformable unlike rigid circuit substrates. Accordingly, they
are advantageous in high-density mounting of ICs and size-reduction
of modules. In other words, flexible circuit substrates are used
for TCP (tape carrier packages), COF (Chip On Flexible or Film) and
the like, and particularly they are indispensable for reducing the
size of a variety of media apparatuses.
[0003] Also, the system LSI technology is important in the
realization of smaller, thinner and lighter media apparatuses.
System LSIs are steadily advancing the technology towards the
implementation of one-chip while incorporating LSIs of peripheral
circuits. However, the development of a system LSI requires a long
development time and results in an increased cost of the chip
because of mixing of processes of different types. For this reason,
requirements to be met by media apparatuses such as the short
delivery time and low cost cannot be currently met.
[0004] For the reasons described above, there are stronger demands
in a system function mounting mainly composed of a
three-dimensional mounting, and integration of a system LSI and the
mounting technology is becoming more important. Frequency (high
speed) and delivery (short-term delivery) determine the degree of
growth in the media apparatus industry. Accordingly, the connection
length and wiring length of an LSI to be built in must be shortened
as much as possible by utilizing the mounting and packaging
technologies. For this reason, three-dimensional mounting modules
have been subject to various contrivances and have come into the
stage of practical use.
[0005] For example, conventionally, a three-dimensional mounting
module has the following structure that has been placed in practice
or in the stage of being placed in practice First, (A): TCPs (Tape
Carrier Packages) are stacked in layers, and connection between the
stacked chip layers is achieved by outer leads of the TCPs. (B): A
frame body for wiring is disposed between layers of TCPs, and
connection between the layers of the TCPs is achieved by the frame
body. (C): Chips are stacked in layers, and the stacked chip layers
are connected by conduction material. Also, other techniques are
available.
[0006] According to the conventional technology, stacked chip
layers need to be electrically connected through certain
interposers. The interposers may have a connection structure in
which they are externally connected in a manner described above in
(A) or (C), or a connection structure in which they are internally
connected in a manner described above in (B). In any of the cases,
a structure as a three-dimensional mounting module needs to be
established first, then the electrical operation thereof as a
module product is confirmed, and measurement and examination
thereof can be conducted.
[0007] If a three-dimensional mounting module is determined to be
defective as a result of the measurement and examination, repair
work (or re-work) to correct the defect is conducted. In other
words, in a three-dimensional mounting module in the stage of
assembling into a three-dimensional structure, it is important to
provide a connection structure, which takes into consideration
processes of how common electrodes and non-common electrodes are
treated and how repair works (re-works) are conducted. In this
respect, the conventional technology has problems of longer
processing time and higher costs.
[0008] The present invention has been made in view of the problems
described above, and it is an object of the present invention to
provide a semiconductor device having a three-dimensional mounting
module structure using a flexible circuit substrate that is
excellent in the workability in repair (re-work) works and handling
readiness in the stage of assembling it into a three-dimensional
structure.
DESCRIPTION OF THE INVENTION
[0009] A semiconductor device in accordance with the present
invention is characterized in comprising: a flexible circuit
substrate having a base region and one or more mounting region
continuously provided at a peripheral edge of the base region,
wherein the mounting regions are folded over the base region;
electronic components mounted corresponding to the mounting
regions; a stacked layer support body including a thick first
region and a foldable thin second region that is formed with the
first region in one piece, each of the regions having a specified
outer frame provided in a manner to protect each of the electronic
components; a bonding member for integrating the stacked layer
support body and the flexible circuit substrate in one piece,
protruded sections provided at specified locations of the thick
first region of the stacked layered support body, and aperture
sections provided at specified locations in a rear surface side of
the flexible circuit substrate to be coupled with the protruded
sections, wherein, when the mounting regions of the flexible
circuit substrate are folded together with the stacked layered
support body over the base region, the protruded sections and the
aperture sections are coupled and fixed together at an area where
the thick first regions are superposed on top of the other through
the flexible circuit substrate.
[0010] In accordance with the semiconductor device of the present
invention, at the time when the electronic components are mounted
on the flexible circuit substrate, an operation as a module product
can be conducted. Accordingly, measurement and examination can be
conducted before they are assembled into a three-dimensional
mounting module.
[0011] Furthermore, the stacked layer support body for assembling a
three-dimensional mounting module is formed in one piece and
mounted on the flexible circuit substrate in one lot. Then, the
mounting regions are folded and affixed together with the stacked
layer support body on top of the other. As a result, a
three-dimensional mounting module is realized in a fewer number of
steps. In this instance, the protruded section and the aperture
section that are pre-installed are coupled together, whereby
positioning of the layers to be stacked is facilitated, and the
assembly accuracy is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows a prospective view of a structure of a
semiconductor device in accordance with a first embodiment of the
present invention.
[0013] FIG. 2 shows a perspective view of a characteristic
assembling configuration with the structure shown in FIG. 1.
[0014] FIG. 3 shows a cross-sectional view of an assembled
configuration of the semiconductor device of FIG. 1.
[0015] FIGS. 4(a) and (b) show a structure of a semiconductor
device in accordance with a second embodiment of the present
invention, respectively, wherein FIG. 4(a) shows a plan view before
assembly, and FIG. 4(b) schematically shows a cross-sectional view
of a characteristic general structure of a three-dimensional
mounting module after assembly.
[0016] FIGS. 5(a) and (b) show a structure of a semiconductor
device in accordance with a third embodiment of the present
invention, wherein FIG. 5(a) shows a plan view before assembly, and
FIG. 5(b) schematically shows a cross-sectional view of a
characteristic general structure of a three-dimensional mounting
module after assembly.
EMBODIMENTS OF THE PRESENT INVENTION IN BEST MODE
[0017] FIG. 1 shows a prospective view of a structure of a
semiconductor device in accordance with a first embodiment of the
present invention. FIG. 2 shows a perspective view of a
characteristic assembly configuration with the structure shown in
FIG. 1. As shown in FIG. 1, a flexible circuit substrate 11 has a
generally square base region 110 indicated by broken lines,
mounting regions 111, 112 and 113 that are continuously provided
along the periphery of the base region 110, and predetermined
conduction patterns (not shown) formed below a protection film.
Also, an external terminal section 115 is provided at the periphery
of the base region 110 in a region where the mounting regions are
not provided. The external terminal section 115 in this example is
a connector terminal.
[0018] In the flexible circuit substrate 11, electronic components
121, 122 and 123 respectively corresponding to the mounting regions
111, 112 and 113 are face-down mounted. The electronic components
121, 122 and 123 may be composed of any of various devices such as
memory chips, system LSI chips, control units and the like.
[0019] The face-down mounting of the electronic components 121, 122
and 123 can be conducted by, for example, solder-bonding bump
electrodes of each of the electronic components and predetermined
conduction patterns on the flexible circuit substrate 11. Also,
connection by an ACF (anisotropic conduction film) can be
considered. More specifically, an ACF (anisotropic conduction film)
is placed between the bump electrodes of each of the electronic
components and the predetermined conduction patterns on the
flexible circuit substrate 11 and they are heat-bonded together. As
a result, conduction particles in the ACF achieve electrical
connection between each of the electronic components 121, 122 and
123 and the conduction patterns on the flexible circuit substrate
11. In addition, a variety of other methods may be employed. For,
example, ACP (anisotropic conduction paste) bonding, NCP bonding
that attains electrical connection by the shrinking force of an
insulation resin, metal eutectic bonding of bumps between gold and
gold, gold and tin or the like. Also, in some cases, a face-up
mounting using the wire-bonding method can be applied. Furthermore,
extremely thin IC packages can also be mounted. Therefore,
electronic components are not limited to particular mounting
configurations.
[0020] Also, some electronic components (peripheral elements) in
small size relating to the electronic components 121, 122 and 123
are mounted. For example, electronic components 124 may be
capacitors, chip resistors or the like, and an electronic component
125 may be a crystal or the like.
[0021] The flexible circuit substrate 11 is formed from a soft
material such as polyimide that can be freely bent. The flexible
circuit substrate 11 is formed such that the mounting regions
111.about.113 can be folded on top of the other in a predetermined
order (f1.about.f3) over the base region 110. Therefore, distances
d1.about.d3 are set different from one another in consideration of
the bending distances required for bending the mounting regions
111.about.113.
[0022] An integrated spacer 13 is mounted on the flexible circuit
substrate 11. The integrated spacer 13 is superposed over and
affixed to the flexible circuit substrate as indicated by arrows
with broken lines, such that they can support stacked layers of the
electronic-components when the mounting regions 111.about.113 are
folded on top of the other. The integrated spacer 13 has thick
regions 131 and a thin region 132.
[0023] The thick regions 131 of the integrated spacer 13 are
provided to protect the stacked layers of the electronic components
121.about.123, and the other electronic components 124 and 125.
Each of the thick regions 131 has a configuration that surrounds,
for example, each of the corresponding electronic components
121.about.123, respectively. Also, with respect to an electronic
component in small size (e.g., 125) mounted adjacent to an edge,
the thick region can have a configuration that partially extends
along the periphery thereof. In any case, the thick regions 131 may
preferably have outer frame shapes that can be superposed over the
base region 110 since they are stacked over the base region
110.
[0024] The thin region 132 of the integrated spacer 13 extends over
the base region 110, and is formed in one piece with the thick
regions 131. The thin region 132 forms a region that can be bent at
least along the periphery of the base region 110. Also, an opening
section 133 may be provided such that mounting of the electronic
component 124 is not prevented.
[0025] The integrated spacer 13 can be composed of, for example, a
formed product of polyimide resin in consideration of heat
resistance. The thick regions 131 have a thickness to the extent
that the electronic components (121.about.123 and the like) to be
mounted are not prevented from being stacked in layers. Also, the
thin region 132 may preferably be as thin as possible because it
includes a bending section, and may preferably have a thickness of
about 0.1.about.0.2 mm, for example. If handling of the integrated
spacer 13 is not difficult, the thin region 132 can be much
thinner.
[0026] The integrated spacer 13 is affixed on its rear surface (not
shown) to the flexible circuit substrate 11 through a bonding
member such as a two-faced tape, adhesive or the like, such that it
forms an integrated structure with the flexible circuit substrate
11.
[0027] Fixing bosses 134 are pre-installed at specified locations
on the thick regions 131 of the integrated spacer 13. Also, as
shown in FIG. 2, aperture sections 14 to be coupled with the fixing
bosses 134 are provided in rear surface of the mounting regions 111
and 112 of the flexible circuit substrate 11 at locations
corresponding to the thick region 131 of the integrated spacer
13.
[0028] FIG. 2 shows the aperture sections 14 provided on the rear
surface side of the mounting region 111, which are coupled with the
fixing bosses 134 on the mounting region 112, as indicated by
arrows with broken lines. Although not shown, the aperture sections
14 to be coupled with the fixing bosses 134 on the mounting region
113 are provided on the rear surface side of the mounting region
112.
[0029] Each of the aperture sections 14 requires a depth in which
each of the fixing bosses 134 is inserted, and therefore it is
formed in a manner that it passes through the flexible circuit
substrate 11 (a through hole H shown in FIG. 1) and penetrates into
a part of the thick region 131 from its rear surface side.
Furthermore, bonding members such as adhesive, two-faced tapes or
the like are provided on stacking layer fixing sides (hatched
areas) of the thick regions 131. By these members, the electronic
components 121.about.123 (including the other small-sized
electronic components) are successively stacked in layers. In this
instance, the fixing bosses 134 and the aperture sections 14 are
coupled and affixed with one another in areas where the thick
regions 131 of the integrated spacer 13 are stacked on top of the
other through the flexible circuit substrate 11.
[0030] FIG. 3 shows a cross-sectional view of an assembled
configuration of the semiconductor device of FIG. 1. For ready
understanding of the assembled state, the flexible circuit
substrate folded at the front thereof is also shown by phantom
lines. More specifically, in an embodiment shown here, the mounting
regions 111, 112 and 113 are successively folded over the base
region 110 from the respective directions, such that the electronic
components 121, 122 and 123 and the other peripheral electronic
components 124 and 125 are stacked and affixed on top of the other
in a three-dimensional configuration.
[0031] The integrated spacer 13 is affixed to the flexible circuit
substrate 11 through, for example, a two-faced tape. Furthermore,
adhesive regions (for example, two-faced tapes) 20 provided on the
thick regions 131 contribute to affixing the stacked layers. As a
result, the electronic components 121, 122 and 123 and the other
peripheral electronic components 124 and 125 are surrounded and
protected by the respective thick regions 131.
[0032] A thin region 132 of the integrated spacer 13 supports
bending regions of the flexible circuit substrate 11, and plays a
role of protecting the flexible circuit substrate 11 particularly
with respect to its bending end regions 21 and 22 that can be
sharply bent.
[0033] Furthermore, the fixing bosses 134 and the aperture sections
14 engage with one another to thereby contribute to folding and
positioning of the mounting regions of the flexible circuit
substrate 11 with the integrated spacer 13. A bonding member may be
provided between the fixing bosses 134 and the aperture sections
14.
[0034] In accordance with the first embodiment of the present
invention, at the time when the electronic components
(121.about.123 and others) are mounted on the flexible circuit
substrate 11, an operation as a module product can be conducted.
Accordingly, measurement and examination can be conducted before
they are assembled into a three-dimensional mounting module.
[0035] Moreover, the integrated spacer 13 that can be assembled
into a three-dimensional mounting module can be mounted on the
flexible circuit substrate 11 in one lot. Then, the mounting
regions 111.about.113 together with the integrated spacer 13 are
folded and affixed on top of the other to realize a
three-dimensional mounting module of the electronic components
(121.about.123 and others).
[0036] It is noted that, in the first embodiment, the fixing bosses
134 are not provided on the thick regions 131 that are initially
folded over the base region 110. However, they may be provided. In
such an instance, apertures to be coupled with the fixing bosses
134 are needed in the thin region 132 of the integrated spacer 13
over the base region 110.
[0037] By doing so, the accuracy in assembly positions is improved
when the mounting regions are initially stacked. However, when a
three-dimensional module having such a structure is mounted on a
main substrate, it is important to make an arrangement so that the
fixing bosses 134 that are present on the base region 110 do no
prevent the mounting work. For example, as a countermeasure, the
bosses 134 are made to be low such that they do not protrude from
the base region 110. Alternatively, recesses (recesses) may be
provided in the main substrate at locations corresponding to the
bosses 134 to avoid (or alleviate) collision with the bosses
134.
[0038] Moreover, in the embodiment described above, apertures 14
are not provided on the thick regions 131 in the mounting region
113 that is lastly folded over the base region 110. However, they
may be provided in a manner to pass through the flexible circuit
substrate 11. In this case, they contribute to positioning when a
heat sink or the like is provided on the three-dimensional
module.
[0039] As a result, the assembly characteristic (readiness and
accuracy in assembly) of a three-dimensional mounting module is
substantially improved, and the number of work steps can be
reduced. This results in an excellent workability in repair work
(or re-work). The assembly characteristic is improved and the
number of parts is reduced compared to spacers of a separated type.
This contributes to the reduction of costs. Also, due to the
improved positioning accuracy attained by the engagement between
the fixing bosses 134 and the aperture sections 14, there is
provided an advantage in that a product can be designed with much
smaller clearances. As a result, a more compact three-dimensional
mounting module can be attained.
[0040] In the three-dimensional mounting module in accordance with
the present invention, the electronic components (121.about.123 and
others) are mounted on the flexible circuit substrate 11, and
folded over on top of the other together with the flexible circuit
substrate 11 and the integrated spacer 13. This configuration
substantially loosens the restrictions on the size of ICs and
placements of the pads, compared to a stacked package in which IC
chips are stacked on top of the other. In a stacked package, there
are a variety of restrictions on the size of ICs that are combined,
IC terminal positions and the like. In contrast, a
three-dimensional mounting module in accordance with the present
invention has a greater degree of freedom in selection and
combination of different types of ICs, and provides an electrically
most optimized module in view of the fact that a plurality of
peripheral elements can also be mounted.
[0041] FIGS. 4(a) and (b) show a structure of a semiconductor
device in accordance with a second embodiment of the present
invention, respectively, wherein FIG. 4(a) shows a plan view before
assembly, and FIG. 4(b) schematically shows a cross-sectional view
of a characteristic general structure of a three-dimensional
mounting module after assembly.
[0042] For ready understanding of the assembled state, the flexible
circuit substrate folded at the front thereof is also shown by
phantom lines. Elements that are the same as those of the first
embodiment are referred to by the same reference numbers and the
description thereof is omitted.
[0043] In the second embodiment of the present invention, a
flexible circuit substrate 41 is different from that of the first
embodiment. As shown in the figure, an electronic component 126 is
also mounted on the base region 110 of the flexible circuit
substrate 41. Accordingly, the integrated spacer 13 is also
provided with a thick region 131 on the base region 110
corresponding to the electronic component 126.
[0044] Also, in view of the fact that the electronic components
121.about.123 are successively stacked over the electronic
component 126 in layers, in the integrated spacer 13, distances
d11.about.d13 between the thick region 131 on the base region 110
and the thick regions 131 on the mounting regions 111.about.113,
respectively are made different from one another.
[0045] Furthermore, fixing bosses 134 are provided at specified
locations on the thick region 131 of the integrated spacer 13 over
the mounting region 111. Also, aperture sections 14 to be coupled
to the fixing bosses 134 are provided in the thick region 131 of
the integrated spacer 13 provided on the base region 110.
[0046] With this structure, the flexible circuit substrate 41 is
folded over in a predetermined order together with the integrated
spacer 13 (the thick regions 131). In other words, the electronic
components 121.about.125 are stacked and fixed in layers in a
similar manner as described in the first embodiment (see FIG.
4(b)).
[0047] FIGS. 5(a) and (b) show a structure of a semiconductor
device in accordance with a third embodiment of the present
invention, wherein FIG. 5(a) shows a plan view before assembly, and
FIG. 5(b) schematically shows a cross-sectional view of a
characteristic general structure of a three-dimensional mounting
module after assembly. For ready understanding of the assembled
state, the flexible circuit substrate folded at the front thereof
is also shown by phantom lines. Elements that are the same as those
of the second embodiment are referred to by the same reference
numbers and the description thereof is omitted.
[0048] In the third embodiment of the present invention, a flexible
circuit substrate 51 is different from that of the first
embodiment. As shown in the figure, external terminal sections (for
example, ball electrodes) 52 indicated by broken lines are provided
on the rear surface of the base region 110 of the flexible circuit
substrate 51. In other words, in this structure, the external
terminal section 115 described in the first embodiment (in FIG. 1),
which is a connector terminal, is replaced with an array type
electrode (52).
[0049] End sections of the conduction patterns, which are
equivalent to external terminals (not shown), are connected to the
external terminal sections (ball electrodes) 52 through via
patterns (not shown) in the main surface of the flexible circuit
substrate 61 in which the mounting regions (111.about.113) are
provided.
[0050] Also, an electronic component 125 is a crystal, which is an
SMD (Surface Mount Device) type instead of a cylinder type
described above. An SMD type can be subject to a reflow when a
three-dimensional module is mounted on a main substrate by solder
and therefore is reliable.
[0051] The integrated spacer 13 is provided with thick regions 131
in accordance with the electronic components 121.about.125.
Accordingly, the flexible circuit substrate 51 is folded over on
top of the other in a predetermined order together with the
integrated spacer 13 (with the thick regions 131). Namely, the
fixing bosses 134 and the aperture sections 14 are coupled together
and the electronic components 121.about.125 are stacked and affixed
in layers in a similar manner as described in the first embodiment
(see FIG. 5(b)).
[0052] The electronic components 121.about.125 may be affixed in
advance to the flexible circuit substrate 61 by an adhesive means
such as a thermosetting type adhesive depending on the
requirements. This would contribute toward preventing, for example,
the electronic components 124 and 125 that are solder-bonded from
falling off, when they are mounted on a main substrate by a reflow
solder-bonding as a three-dimensional module. The adhesive means is
not necessarily required because it depends on the temperature
condition and the specific gravity of each electronic component. In
any case, specified electronic components are preferably be bonded
without interfering with the spacer 13.
[0053] In one possible structure, mounting regions may be provided
along all of the four edges of the periphery of the base region
110. In such a case, electronic components are stacked in layers in
a predetermined order together with an integrated spacer including
thick regions and a thin region and affixed together in the same
manner as described in the first embodiment.
[0054] Both of the second and third embodiments described above are
made in pursuit of a high-density mounting structure. In accordance
with these embodiments, at the time when the electronic components
are mounted on the flexible circuit substrate 41 or 51, an
operation as a module product can likewise be conducted.
Accordingly, measurement and examination can be conducted before
they are assembled into a three-dimensional mounting module.
[0055] Moreover, the integrated spacer 13 that can be assembled
into a three-dimensional mounting module can be mounted on the
flexible circuit substrate 41 or 51 in one lot. Then, the mounting
regions are folded together with the integrated spacer 13 and
affixed on top of the other. In this instance, since the fixing
bosses 134 and the aperture sections 14 that are pre-installed
engage one another, the positioning work becomes substantially
easy.
[0056] It is noted that the number and locations of the fixing
bosses 134 and the aperture sections 14 are not particularly
limited, and they can be provided at any locations necessary for
positioning or affixing. As described above in the first
embodiment, fixing bosses for aligning the positions thereof with
respect to the base region 110 may be provided on the thick region
131 that is initially folded over the base region 110, and aperture
sections may be provided on the base region. However, as described
above, it is important to provide a structure in which the fixing
bosses 134 existing on the base region 110 do not hinder the
mounting work.
[0057] Furthermore, apertures that pass through the flexible
circuit substrate 11 may be provided on the thick regions 131 in
the mounting region that is lastly folded over the base region 110.
As a result, they contribute to positioning when a heat sink or the
like is provided on the three-dimensional module.
[0058] In accordance with the embodiments described above, due to
the integrated spacer together with engagement of the fixing bosses
and the aperture sections, the assembly characteristic (readiness
and accuracy in assembly) is substantially improved, and a product
can be designed with much smaller clearances. This provides a
three-dimensional mounting module having an excellent workability
in repair work (or re-work). The assembly characteristic is
improved and the number of parts is reduced compared to spacers of
a separated type This contributes to the reduction of costs.
Furthermore, a greater degree of freedom in combining different
types of ICs is available and a most electrically optimized module
can be obtained in view of the fact that a plurality of peripheral
elements can be mounted.
[0059] As a result, there is provided a most electrically optimum
semiconductor device with the high degree of freedom can be
provided with a highly reliable three-dimensional mounting module
using a flexible circuit substrate, in which the readiness and
controllability are attained in assembling the high density
three-dimensional mounting module, and an excellent workability in
repair work (or re-work).
* * * * *