U.S. patent application number 11/631635 was filed with the patent office on 2008-03-20 for interposer and manufacturing method for the same.
Invention is credited to Tomohisa Hoshino, Kenichi Kagawa, Masami Yakabe.
Application Number | 20080067073 11/631635 |
Document ID | / |
Family ID | 35782926 |
Filed Date | 2008-03-20 |
United States Patent
Application |
20080067073 |
Kind Code |
A1 |
Kagawa; Kenichi ; et
al. |
March 20, 2008 |
Interposer And Manufacturing Method For The Same
Abstract
In a manufacturing method for an interposer, a seed layer is
formed at an opening portion in a through hole on back surface side
of a substrate, an electrode layer for electroplated coating is
formed based on the seed layer, and an electroplated coating layer
is formed to fill the through hole from the electrode layer for
electroplated coating layer to a front surface side. As a result, a
manufacturing method for an interposer is provided in which the
manufacturing process is simple and the void is not generated
inside of the through hole.
Inventors: |
Kagawa; Kenichi; (Kanagawa,
JP) ; Hoshino; Tomohisa; (Hyogo, JP) ; Yakabe;
Masami; (Tokyo, JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER;LLP
901 NEW YORK AVENUE, NW
WASHINGTON
DC
20001-4413
US
|
Family ID: |
35782926 |
Appl. No.: |
11/631635 |
Filed: |
July 5, 2005 |
PCT Filed: |
July 5, 2005 |
PCT NO: |
PCT/JP05/12424 |
371 Date: |
January 5, 2007 |
Current U.S.
Class: |
205/125 ;
257/E23.067 |
Current CPC
Class: |
H01L 21/486 20130101;
H01L 2924/0002 20130101; H01L 23/49827 20130101; H01L 2924/00
20130101; H01L 2924/0002 20130101 |
Class at
Publication: |
205/125 |
International
Class: |
C25D 5/02 20060101
C25D005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 6, 2004 |
JP |
2004-199785 |
Jul 6, 2004 |
JP |
2004-199870 |
Claims
1. An interposer comprising: a substrate which has one surface,
another surface opposed to said one surface, and a through hole
passing through from said one surface to said another surface; a
seed layer which is formed at an opening portion of said through
hole on said one surface side of said substrate; an electrode layer
for electroplated coating which is formed by covering said seed
layer; and an electroplated coating layer which extends from said
electrode layer for electroplated coating to said another surface
side to fill said through hole.
2. The interposer according to claim 1, wherein said through hole
has a shape whose center portion is concave.
3. The interposer according to claim 1, wherein said seed layer,
said electrode layer for electroplated coating and said
electroplated coating layer are made out of the same material.
4. The interposer according to claim 1, wherein at least two of
said seed layer, said electrode layer for electroplated coating and
said electroplated coating layer are made out of different
materials.
5. A method for manufacturing an interposer comprising steps of:
preparing a substrate which has one surface and another surface
opposed to said one surface; forming a through hole on said
substrate; forming a seed layer at an opening portion of said
through hole on said one surface side; and filling said through
hole by forming an electroplated coating layer from said seed layer
on said one surface side to said another surface side.
6. The method for manufacturing an interposer according to claim 5,
wherein said step of filling said through hole by forming an
electroplated coating layer from said seed layer on said one
surface side to said another surface side includes steps of:
forming an electrode layer for electroplated coating to close said
through hole at said one surface side; and forming said
electroplated coating layer utilizing said electrode layer.
7. The method for manufacturing an interposer according to claim 5,
wherein said step of forming the through hole includes a step of
forming a through hole whose center portion becomes concave.
8. The method for manufacturing an interposer according to claim 6,
wherein said seed layer, said electrode layer for electroplated
coating and said electroplated coating layer are made out of the
same material.
9. The method for manufacturing an interposer according to claim 6,
wherein at least two of said seed layer, said electrode layer for
electroplated coating and said electroplated coating layer are made
out of different materials.
10. An interposer having a through hole wherein: said through hole
is made from a surface of one side of said substrate to a surface
of another side; said through hole has a first opening area at said
surface of said one side and the opening area becomes smaller in
succession as the hole goes from said surface to inside and has a
second opening area at said surface of said another side and the
opening area becomes smaller in succession as the hole goes from
said surface of another side to inside; and a conducting layer is
formed on said through hole.
11. The interposer according to claim 10, wherein the first opening
area and the second opening area are different.
12. The manufacturing method for the interposer according to claim
10, wherein said through hole has a cylindrical hole part having
the same opening area between said surfaces of said one side and
said another side.
13. The interposer according to claim 1, wherein said through hole
has a smaller opening area in succession as it goes from said
surface of said one side to said surface of said another side.
14. A method for manufacturing an interposer comprising steps of:
preparing a substrate which has one surface and another surface
opposed to the one surface; forming a through hole by performing an
etching such that an opening area of said through hole becomes
smaller in succession as the hole goes from said surface of said
one side and from said surface of said another side to inside; and
forming a conducting layer in said through hole.
15. The method for manufacturing an interposer according to claim
14, wherein said etching is performed such that said opening area
of said surface on said one side and said opening area of said
surface on said another side are different.
16. The method for manufacturing an interposer according to claim
14 further comprising a step of forming a through hole whose
opening area at said surface of said one side is the same as that
at said surface of said another side.
17. The method for manufacturing the interposer according to claim
5, wherein said step of forming said through hole on said substrate
is performed utilizing etching such that an opening area of said
through hole becomes smaller in succession as the hole goes from
one side of the substrate to another side.
18. The method for manufacturing an interposer according to claim
14, wherein said etching is performed utilizing dry etching.
19. The method for manufacturing an interposer according to claim
14, wherein said step of forming said conducting layer is performed
utilizing evaporation, electroplated coating or electroless
plating.
Description
TECHNICAL FIELD
[0001] The present invention relates to an interposer and a
manufacturing method for the same, and more particularly, relates
to an interposer and a manufacturing method for the same in which a
pinch-off is not generated in a through hole.
BACKGROUND ART
[0002] An interposer in which a conducting hole is prepared on a
substrate in the prior art technology, is disclosed, for example,
in Japanese Unexamined Patent Publication 2004-165291.
[0003] According to the above described Unexamined Patent
Publication, a structure is disclosed wherein a conducting member
is formed such that a diameter of the conducting member becomes
larger or smaller in succession or in incremental steps from one
side to another side in the ceramic substrate which has laminated
greensheets of a plurality of through holes arranged in a
predetermined pattern and filled with the conducting member, and a
plurality of another through holes arranged in the same pattern
having different diameters.
[0004] FIG. 9 is a cross sectional view to show a silicon substrate
80 explaining a problem in the prior art technology when an
interposer is manufactured by arranging a conducting hole on the
silicon substrate 80. Referring to FIG. 9, in the prior art
technology, firstly a through hole 91 is formed on the silicon
substrate 80. At this point, the through hole 91 becomes a
cylindrical shape whose center portion is concave as shown in FIG.
9 rather than straight.
[0005] For the through hole 91, seed layers 83, 84 are formed by
sputtering around the through hole 91 from both of a front surface
81 and a back surface 82. Then, conducting layers 85, 86 are formed
by electroplated coating and the like utilizing the seed layers 83,
84 as a seed.
[0006] The interposer in the prior art technology is constituted as
described above. According to the Unexamined Japanese Patent
Publication 2004-165291, because the ceramic substrate is utilized
and drilling or sand blasting is employed to open holes on the
substrate, there is a problem that a diameter of the through hole
cannot be made small. Moreover, because it is necessary to
agglutinate two ceramic substrates, there is a problem that a
manufacturing process becomes complicated.
[0007] Further, when the through hole is formed on the silicon
substrate, because the center portion of the through hole has the
concave shape and diameter of the through hole becomes larger as it
goes inside from the front surface or the back surface, the seed
layer cannot be formed well inside even when the seed layer is
intended to be formed inside of the through hole. As a result, even
when the conducting layer is grown from the seed layer by the
electroplated coating and the like, because the conducting layer is
not grown enough, so called "void" 92 is formed inside of the
through hole 91, in which the conducting layer does not exist. This
causes a problem that the through hole 91 is not conductive and the
manufacturing precision is poor.
DISCLOSURE OF THE INVENTION
[0008] The present invention is made to solve the above described
problems and it is an object of the present invention to provide an
interposer and manufacturing method for the same in which the
manufacturing process is simple and the void is not generated
inside of the through hole.
[0009] In accordance with one aspect of the present invention an
interposer includes: a substrate which has one surface and another
surface opposed to the one surface; a through hole being formed
from the one surface to the another surface; a seed layer which is
formed at an opening portion of the through hole on the one surface
side of the substrate; an electrode layer for electroplated coating
which is formed by covering the seed layer; and an electroplated
coating layer which extends from the electrode layer for
electroplated coating to the another surface side to fill the
through hole.
[0010] Because the interposer according to the present invention
includes the seed layer which is formed at the opening portion of
the through hole on the one surface side of the substrate, the
electrode layer for electroplated coating which is formed by
covering the seed layer, and the electroplated coating layer which
extends from the electrode layer for electroplated coating to the
another surface side to fill the through hole, the electroplated
coating layer can be surely formed from the seed layer on the one
surface side of the substrate to the another surface side.
[0011] As a result, an interposer can be provided in which the
manufacturing process is simple and the void is not generated
inside of the through hole.
[0012] The through hole may have a shape whose center portion is
concave. Further, the seed layer, the electrode layer for
electroplated coating and the electroplated coating layer may be
made out of the same material, or may be different materials.
[0013] In accordance with another aspect of the present invention,
a manufacturing method for interposer includes steps of: preparing
a substrate which has one surface and another surface; forming a
through hole on the substrate; forming a seed layer at an opening
portion of the through hole on the one surface side; and filling
the through hole by forming an electroplated coating layer from the
seed layer on the one surface side to the another surface side.
[0014] The manufacturing method for the interposer according to the
present invention includes steps of forming a seed layer at an
opening portion of the through hole on the one surface side and
filling the through hole by forming an electroplated coating layer
from the seed layer on the one surface side to the another surface
side. Because the conducting layer is surely formed by the
electroplating from the one surface side of the through hole on the
substrate to another surface side, the void is not generated inside
of the through hole.
[0015] As a result, a method for manufacturing the interposer can
be provided that is simple and the void is not generated inside of
the through hole.
[0016] Preferably, the step of filling the through hole by forming
an electroplated coating layer from the seed layer on the one
surface side to the another surface side includes steps of forming
an electrode layer for electroplated coating to close the through
hole at the one surface side, and forming the electroplated coating
layer utilizing the electrode layer.
[0017] More preferably, the step of forming the through hole
includes a step of forming a through hole whose center portion
becomes concave.
[0018] At this point, the seed layer, the electrode layer for
electroplated coating and the electroplated coating layer may be
made out of the same material, or different materials.
[0019] In accordance with still another aspect of the present
invention, an interposer includes a through hole which is made from
a surface of one side of the substrate to a surface of another
side, the through hole has a first opening area at the surface of
the one side, and has a second opening area at the surface of the
another side, and both of the first opening area and the second
opening area become smaller in succession as they go from the
surfaces to inside, and the interposer also includes a conducting
layer which is formed in the through hole.
[0020] Because the interposer has the through hole whose opening
area becomes smaller in succession as they go from the surfaces to
inside, the through hole can be easily filled by the conducting
layer.
[0021] As a result of this, an interposer whose manufacturing
process is simple and the void is not generated inside of the
through hole, can be provided.
[0022] Preferably, areas of the first opening and the second
opening are different.
[0023] Because the values of the opening area on one surface side
and another surface side are different, the wiring rules for the
both surfaces can be independently settled, and wider degree of
freedom for designing a wiring width and a wiring layout can be
obtained.
[0024] More preferably, the through hole has a cylindrical portion
between the surface of the one side and the surface of another side
of the substrate.
[0025] In accordance with still another aspect of the present
invention, an interposer has a through hole, in which the through
hole is made from a surface of one side of the substrate to a
surface of another side; the through hole has a first opening area
at the surface of the one side, and the first opening area becomes
smaller in succession as the hole goes from the surface of the one
side to the surface of the another side; and a conducting layer is
formed in the through hole.
[0026] In accordance with still another aspect of the present
invention, a manufacturing method for the interposer including
steps of: preparing a substrate which has one surface and another
surface opposed to the one surface; forming a through hole by
performing an etching such that an opening area of the through hole
becomes smaller in succession as the hole goes from the surface of
the one side and from the surface of the another side to inside;
and forming a conducting layer in the through hole.
[0027] Because in this manufacturing method for interposer the
through hole is formed by performing an etching such that an
opening area of the through hole becomes smaller in succession as
it goes from the surface of the one side and from the surface of
the another side to inside, the conducting layer can be formed
without any discontinuity inside of the through hole when the
conducting layer is formed in the through hole.
[0028] As a result, a manufacturing method for the interposer which
is simple and the void is not generated inside of the through hole,
can be provided.
[0029] Preferably, the etching is performed such that the area of
the opening of the surface on the one side and the area of the
opening of the surface on another side are different.
[0030] More preferably, the manufacturing method further includes a
step of forming a through hole whose opening area is constant from
the surface of the one side to the surface of another side.
[0031] In accordance with still another aspect of the present
invention, a manufacturing method for interposer including steps
of: preparing a substrate which has one surface and another surface
opposed to the one surface; forming a through hole by performing an
etching such that an opening area of the through hole becomes
smaller in succession as the hole goes from the surface of the one
side to the surface of the another side; and forming a conducting
layer in the through hole.
[0032] At this point, it is preferable that the etching is
performed utilizing dry etching. The conducting layer may be formed
utilizing evaporation, electroplated coating or electroless
plating.
BRIEF DESCRIPTION OF DRAWINGS
[0033] FIG. 1A is a diagram showing a manufacturing process of an
interposer according to the first embodiment of the present
invention step by step;
[0034] FIG. 1B is a diagram showing a manufacturing process of the
interposer according to the first embodiment of the present
invention step by step;
[0035] FIG. 1C is a diagram showing a manufacturing process of the
interposer according to the first embodiment of the present
invention step by step;
[0036] FIG. 1D is a diagram showing a manufacturing process of the
interposer according to the first embodiment of the present
invention step by step;
[0037] FIG. 2 is a diagram showing a manufacturing process of an
interposer according to the second embodiment of the present
invention;
[0038] FIG. 3A is a diagram to show a shape of a through hole to
which the third embodiment of the present invention is applied;
[0039] FIG. 3B is a diagram showing a shape of the through hole to
which the third embodiment of the present invention is applied;
[0040] FIG. 4A is a diagram showing a manufacturing process of an
interposer according to the forth embodiment of the present
invention step by step;
[0041] FIG. 4B is a diagram showing a manufacturing process of the
interposer according to the fourth embodiment of the present
invention step by step;
[0042] FIG. 4C is a diagram showing a manufacturing process of the
interposer according to the forth embodiment of the present
invention step by step;
[0043] FIG. 4D is a diagram showing a manufacturing process of the
interposer according to the forth embodiment of the present
invention step by step;
[0044] FIG. 5 is a cross sectional view showing a through hole on a
substrate of an interposer according to the fifth embodiment of the
present invention;
[0045] FIG. 6 is a cross sectional view showing a through hole on a
substrate of an interposer according to the sixth embodiment of the
present invention;
[0046] FIG. 7 is a perspective view showing a substrate of the
interposer which has the cross sectional structure shown in FIG.
6;
[0047] FIG. 8A is a cross sectional view showing a through hole of
an interposer according to the seventh embodiment of the present
invention;
[0048] FIG. 8B is a diagram showing a manufacturing process of the
through hole for the interposer according to the seventh embodiment
of the present invention; and
[0049] FIG. 9 is a diagram to explain a problem of an interposer in
the prior art technology.
BEST MODE FOR CARRYING OUT THE INVENTION
(1) First Embodiment
[0050] Hereinafter, the first embodiment according to the present
invention will be described with reference to the accompanying
drawings. FIG. 1A-FIG. 1D are diagrams to show step by step a
manufacturing process of an interposer according to the first
embodiment of the present invention. Referring to FIG. 1A-FIG. 1D,
firstly a silicon substrate 10 having a front surface 11 and a back
surface 12 is prepared, and a through hole 13 is opened on the
substrate (FIG. 1A). At this point, the through hole 13 may be
formed having a shape whose center portion is concave as shown in
FIG. 1A as the interposer in the prior art. In this state, then, an
insulating film which is not shown in the drawing, is formed on the
substrate 10 including inside of the through hole 13. This
insulating film may be made of SiO2, SiN and the like and is formed
by sputtering, CVD or oxidization.
[0051] Next, Ti layer (not shown) as a barrier layer is formed by
sputtering and the like around the through hole 13 where the
insulating layer is formed on the back surface 12 of the substrate
10. Then, a seed layer 14 (a base layer for an electrode to flow
current for electroplating) made out of Cu is formed on the barrier
layer by sputtering and the like (FIG. 1B). An electroplated
coating is performed from the back surface 12 based on the Cu seed
layer 14. This electroplated coating is performed till an edge
surface of the electroplating meets to close the through hole 13 at
the back surface 12 so as to form an electrode layer for the
electroplated coating of the electroplated coating layer 15 made
out of Cu (FIG. 1C).
[0052] Next, an electroplated coating of Cu is performed to the
front surface 11 utilizing the electroplated coating layer 15 of Cu
as an electrode. By these steps, an electroplated coating layer of
Cu grows in a direction shown by an arrow in FIG. 1D, and an
electroplated coating layer 16 is prepared (FIG. 1D).
[0053] As described above, according to this embodiment, the
through hole 13 can be made as the conducting layer of Cu without
generating the void inside of the through hole even when the
concave shaped hole is formed inside of the through hole 13.
[0054] At this point in the embodiment described above, though Ti
is utilized as the barrier layer, this layer can be omitted.
(2) Second Embodiment
[0055] Next, an explanation will be given on the second embodiment.
FIG. 2 is a diagram to show a manufacturing process of an
interposer according to the second embodiment corresponding to FIG.
1D of the first embodiment, and the interposer has basically the
same structure as shown in FIG. 1. Referring to FIG. 2, in this
second embodiment, a through hole 23 is formed on a silicon
substrate 20, and the through hole 23 is filled with a seed layer
24, an electrode layer 25 for electroplated coating and
electroplated coating layer 26.
[0056] Though in the first embodiment, the seed layer and the
electroplated coating layer made out of Cu are formed on the
silicon substrate, in this embodiment the seed layer 24, the
electrode layer 25 for electroplating and the electroplated coating
layer 26 are made out of not only Cu but any material such as Ni,
Cr, Au, Ag and the like as far as the electroplated coating can be
performed. The material for the seed layer 24, the electrode layer
25 for electroplated coating and the electroplated coating layer 26
may be different from one another. For example, the seed layer may
be made out of Cu and the electroplating of Au may be performed
utilizing the seed layer as the electrode layer for electroplated
coating.
(3) Third Embodiment
[0057] Next, an explanation will be given on the third embodiment
of the present invention. FIG. 3 is a diagram to show a shape of
the through hole to which an interposer according to the third
embodiment of the present invention is applied. Though in the first
and the second embodiments, the present invention is applied to the
through holes having the shape whose center portion becomes
concave, the present invention can be applied to the substrate 30
with the through hole 31 having a cylindrical shape (FIG. 3A) and
the through hole 32 having a diameter which becomes smaller in
succession as the hole goes from the front surface to the back
surface (FIG. 3B).
[0058] Though in the above described embodiments, the explanation
is made on the embodiments utilizing the silicon substrate as a
material for the substrate, these embodiments should not be
considered as the restricted examples, and the present invention is
applicable to the insulating substrate made out of such as glass
and sapphire. In these cases, forming of the insulating layer
described above is not necessary.
[0059] Though in the embodiments described above, the explanation
is made on the cases in which filling of the conducting material
into the through hole is performed by electroplated coating, the
present invention should not be restricted to these examples, the
filling may be performed by electroless plated coating.
(4) Fourth Embodiment
[0060] Next, an explanation will be given on the fourth embodiment
of the present invention. FIG. 4A-FIG. 4D are diagrams to show step
by step a manufacturing process of an interposer according to the
fourth embodiment of the present invention. Referring to FIG.
4A-FIG. 4D, in this embodiment firstly, a silicon substrate 40
having a front surface 41 and a back surface 45 is prepared (FIG.
4A). Then, a front surface hole 42 is formed which has a diameter
that becomes smaller in succession as it goes into inside at a
predetermined position on the front surface 41 of the substrate 40
by dry etching from the front surface 41. To be more specific, the
etching is performed with appropriate combination of etching
conditions of the isotropic etching and the anisotropic
etching.
[0061] Next, a back surface hole 46 is formed which has diameter
that becomes smaller in succession as it goes into inside on the
back surface 45 of the substrate 40 by the same manner from the
back surface 45, and center axis of the both holes are made
substantially into a line at the center portion of the substrate
40. As described above, a through hole 49 is formed having a
diameter that becomes smaller in succession as it goes into inside
from the front surface 41 and the back surface 45 on the substrate
40 (FIG. 4B).
[0062] In this state, then, an insulating film which is not shown
in the drawing, is formed on the substrate 40 including inside of
the through hole 49. This insulating film may be made out of SiO2,
SiN and the like and is formed by sputtering, CVD or
oxidization.
[0063] Then the seed layers 43, 47 to be seeds of the electroplated
coating layers are formed inside of the through hole 46, 49 and at
an adjoining area of the front surface 41 and the back surface 45
around the through hole 46, 49 on the insulating film by sputtering
(FIG. 4C). At this point, because the through hole 46, 49 has not
the shape whose center portion becomes concave as in the prior art
technology, the seed layers 43, 47 can be formed easily inside of
the through hole 46, 49 and around the opening of the through hole
46, 49 of the front surface 41 and the back surface 45 continuing
from inside.
[0064] Next, the electroplated coating or the electroless-plated
coating is performed on the through hole 46, 49 based on the seed
layer 43, 47, and the conducting layer 44 made of Cu and the like
is formed (FIG. 4D). As a result, the interposer which has the
conducting layer without any generation of the void inside of the
through hole 46, 49 can be formed utilizing simple manufacturing
process.
[0065] Though the explanation is made about the case in which only
one through hole 46, 49 is made in the above described embodiment,
a plurality of through holes 46, 49 may be formed.
[0066] At this point, it is contemplated that the similar through
hole having slopes inside may be formed by the wet etching. However
by the wet etching, there may be a problem that a slope of the
through hole becomes too broad to get a predetermined shape of the
through hole. To the contrary, by the dry etching, the through hole
with a predetermined shape can be formed because the manufacturing
control of the slope of the through hole is easy.
(5) Fifth Embodiment
[0067] Next, an explanation will be given on the fifth embodiment
of the present invention. FIG. 5 is a cross sectional view to show
a through hole on the substrate of an interposer according to the
fifth embodiment of the present invention corresponding to FIG. 4B
of the fourth embodiment. In the fourth embodiment, the explanation
is made in a case in which etching is performed from both sides of
the silicon substrate 40. In this embodiment a through hole 51
whose diameter becomes smaller as it goes inside from only one
surface of the front surface or the back surface of the substrate
50, is formed as shown in FIG. 5 by performing the etching only
from the front surface of the silicon substrate 50. Further, the
through hole 51 is made to be conductive by filling a conductive
material inside of the through hole 51 by the same method as shown
in FIG. 4A to FIG. 4D.
[0068] Even in this embodiment, the seed layer and the conductive
layer based on the seed layer, can be formed easily as in the
fourth embodiment, and the same effect can be obtained as the
fourth embodiment.
(6) Sixth Embodiment
[0069] Next, an explanation will be given on the further different
embodiment of the present invention. FIG. 6 is a cross sectional
view to show a through hole on the substrate 60 of an interposer
according to the sixth embodiment of the present invention
corresponding to FIG. 4B of the fourth embodiment.
[0070] In this embodiment, the holes 63, 64 are formed whose
diameters become respectively smaller as they go inside from the
front surface 61 and the back surface 62 on the substrate 60
similar to the fourth embodiment, however, the diameters of them
are different at the front surface 61 and the back surface 62. In
other words, referring to FIG. 6, the substrate 60 has a thickness
"t", the hole on the front surface 61 has a diameter "a" and the
hole on the back surface 62 has a diameter "b" where a<b. The
hole 63 on the front surface 61 has a depth "t1" and the hole 64 on
the back surface 62 has a depth "t2" to the inside of the hole. As
a result, a step portion 68 is formed inside of the substrate 60.
At this point, etching for different diameters may be performed
from both of the front surface 61 and the back surface 62 similar
to the fourth embodiment so as to form the front side hole 63 and
the back side hole 64 with different diameters and to form the
through hole 69 at any position whereby a structure without the
step portion 68 may be formed as shown by the dotted line in the
drawing. After manufacturing as described above, the inside of the
through hole 69 is filled with the conducting layer.
[0071] FIG. 7 is a perspective view to show the substrate 60 of the
interposer which has the cross sectional structure shown in FIG. 6.
Referring to FIG. 7 in this embodiment, because diameters of the
through hole 69 are determined at the front surface 61 and the back
surface 62 as described above, wiring area 67 can be made wider at
the front surface 61 than at the back surface 62. By this
arrangement, wiring rules for the front surface 61 and the back
surface 62 can be independently settled, and wider degree of
freedom for designing a wiring width and a wiring layout can be
obtained on the front surface 61. Moreover, because size of the
opening portion of the through hole 69 is designed larger at the
back surface 62, process window for a through wiring can be
expanded such that electroplating liquid penetrates well, the
aspect ratio of the through hole becomes small, and the like.
[0072] At this point, the wiring 65 in FIG. 7 is performed via
terminals 66b, 66c which are formed in the pads 63b, 63c formed on
the surface of the conducting layer filled in the hole 63.
(7) Seventh Embodiment
[0073] Next, an explanation will be given on the seventh embodiment
of the present invention. FIG. 8A is a diagram to show a cross
sectional structure of the substrate 70 in this embodiment of the
present invention. Referring to FIG. 8A in this embodiment, the
through hole 76 has semispherical opening portions 72, 74 on the
front surface 71 and the back surface 75 of the substrate 70 and a
cylindrical hole 73 is formed at the central portion of the through
hole 76.
[0074] By forming the through hole 76 with the above described
shape, penetration of the electroplating liquid is improved and
improvement of adhesion of the electroplated coating can be
expected. Further, suppression of peeling of the adhered
electroplated coating can be expected.
[0075] Next, the conducting hole is completed by filling of the
through hole 76 with the conductive material utilizing the
electroplated coating and the like similar to the embodiments
described above.
[0076] Next, explanation will be made how to manufacture the
through hole 76 in this embodiment. FIG. 8B is a diagram to show a
manufacturing process of the through hole 76 shown in FIG. 8A.
Referring to FIG. 8B, a resist 77 is located on the surface 71 of
the substrate 70, and the opening portion is formed on a
predetermined position to perform isotropic etching. By this, the
semispherical opening portion 72 is formed on the front surface 71
side. Similarly, the semispherical opening portion 74 on the back
surface 75 side is also formed. Then, the anisotropic etching is
performed to form the cylindrical hole 73.
[0077] At this point, forming of the cylindrical hole in this
embodiment may be applied to the above described respective
embodiments.
[0078] Though in the above described embodiments explanation is
made on cases that circular or cylindrical through holes are
utilized, the present invention should not be restricted to these
embodiments, and a rectangular or a polygonal through hole may be
used.
[0079] Though in the above described embodiments, explanation is
made on cases that the conducting layers are formed utilizing the
electroplated coating based on the seed layer, the present
invention should not be restricted to these embodiments, and the
conducting layer may be formed only by the seed layer.
[0080] Though in the above described embodiments, explanation is
made on cases that filling of the conducting material into the
through hole is performed by the electroplated coating, the present
invention should not be restricted to these embodiments, and the
filling may be performed by the electroless plating or the
evaporation.
[0081] Though in the above described embodiments, explanation is
made on cases that forming of the through hole is performed by
utilizing the dry etching, the present invention should not be
restricted to these embodiments, and the forming may be performed
by utilizing the wet etching.
INDUSTRIAL APPLICABILITY
[0082] The manufacturing method of the interposer in accordance
with the present invention can be utilized advantageously as a
manufacturing method of the interposer in which the void is not
generated in the through hole because the conducting layer by the
electroplated coating is surely formed at the through hole from one
side of the substrate to another side.
* * * * *