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Patent Application Titled "Interposer Substrate, Electronic Device Package, and Electronic Component" Published Online

January 28, 2014



By a News Reporter-Staff News Editor at China Weekly News -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventor YAMAMOTO, Satoshi (Sakura-shi, JP), filed on August 27, 2013, was made available online on January 16, 2014.

The assignee for this patent application is Fujikura Ltd.

Reporters obtained the following quote from the background information supplied by the inventors: "The present invention relates to an interposer substrate, an electronic device package using this, and an electronic component, which are provided with through-hole interconnections realizing a SiP (system in package) in which a high-density package such as an integrated circuit device, an optical device, a MEMS device, or the like or such devices are systemized in a single package.

"In recent years, with the higher performance of electronic devices such as portable telephones or the like, higher speed and higher performance are required for electronic devices or the like used therein.

"In order to achieve this, technological development is necessary for realizing not only a higher-speed and higher-performance device but also a higher-speed and higher-performance device package.

"As a technique of high-density packaging, a SiP is proposed which uses a three-dimensional packaging technique of stacking and packaging chips by use of microscopic through-hole interconnections or uses an interposer substrate in which through-hole interconnections are formed.

"Formation techniques of through-hole interconnections or an interposer substrate used for realizing a SiP have been actively researched and developed.

"An interposer substrate, in which a through-hole interconnection is formed so as to be inclined to the direction perpendicular to a main surface of a substrate, is disclosed in, for example, Japanese Unexamined Patent Application, First Publication No. 2003-347502.

"By applying the above-described forming technique of the through-hole interconnection, an interposer substrate can be obtained in which electrodes formed at different pitches on a top face and a back face of the substrate are connected to each other with through-hole interconnections.

"However, there is a technical problem in the case of realizing higher-density three-dimensional packaging in the above-described interposer substrate.

"For example, since a through-hole interconnection disclosed in Japanese Unexamined Patent Application, First Publication No. 2003-347502 is a through-hole interconnection extending in a straight line, positional limitation of the through-hole interconnection may occur.

"In the case where, for example, a device is formed inside a substrate, it is necessary to form the through-hole interconnection so as to avoid the device.

"In the interposer substrate in which the through-hole interconnection extending as straight as an arrow is formed, it is difficult to solve the foregoing problem.

"Additionally, since a through-hole interconnection disclosed in Japanese Unexamined Patent Application, First Publication No. 2003-347502 is a through-hole interconnection extending in a straight line, and since the layout or pitches of the terminals are different from each other for each device depending on the kinds of devices mounted onto a top face and a back face of the interposer substrate, there is a significant difference in the lengths of through-hole interconnections to be manufactured.

"Here, FIGS. 12 and 13 are views schematically showing a configuration example of an interposer substrate which is manufactured by applying Japanese Unexamined Patent Application, First Publication No. 2003-347502.

"Here, FIG. 12 is a plan view illustrating a state where a plurality of terminal groups are arranged on the surface of a conventional interposer substrate.

"Moreover, FIG. 13 is a cross-sectional view taken along the line M7-M7 shown in FIG. 12.

"As a structure, it is thought that, for example, a plurality of terminals 130A, 130B, and 130C arranged at equal distance on the first main surface 110a of the substrate 110 are electrically connected to a plurality of terminals 130A', 130B', and 130C' arranged at equal distance on the second main surface 110b of the substrate 110 through the through-hole interconnections 120A, 120B, and 120C, respectively, so that the terminal numbers thereof correspond to each other as shown in FIGS. 12 and 13.

"Specifically, the terminals 130A', 130B', and 130C' are arranged on the second main surface 110b of the substrate 110 with the same layout as that of the terminals 130A, 130B, and 130C, and the positions of the terminals 130A', 130B', and 130C' on the second main surface 110b are different from the positions of the terminals 130A, 130B, and 130C in the X direction.

"Here, the distance between the adjacent through-hole interconnections (between the edges) is constant and represented as P1 on the first main surface 110a, and is constant and represented as P2 on the second main surface 110b. Relationship of P1
"At this time, it is apparent from FIG. 13 that the length of the through-hole interconnections between the terminals provided on the first main surface 110a is different from that of the second main surface 110b.

"If the lengths of the through-hole interconnections are varied as mentioned above, there is variations in interconnection resistances of the through-hole interconnections, and it is difficult to control a voltage in signal transmission.

"In addition, in a case of high-speed signal transmission from one end to the other end of the through-hole interconnections, there is a concern that variations in the wiring delay of the through-hole interconnections occurs depending on variations in the lengths of the through-hole interconnections.

"Consequently, transmission of signals through the through-hole interconnections with synchronization becomes difficult.

"Under circumstances as described above, there are problems in that performance of the interposer substrate degrades or performance of the electronic device using the interposer substrate degrades."

In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventor's summary information for this patent application: "The invention was conceived in view of the above-described circumstances and has an object thereof to provide an interposer substrate, an electronic device package, and an electronic component which reduce the interconnection resistance of a through-hole interconnection or difference in the wiring delay (variations).

"In order to achieve the object, an interposer substrate of a first aspect of the invention includes: a single substrate having a first main surface (one of the main surfaces) and a second main surface (the other of the main surfaces); a plurality of through-hole interconnections having at least a first portion formed so as to extend in a direction different from the thickness direction of the substrate, a second portion constituting one of end portions of a through-hole interconnection, and a third portion constituting the other of the end portions of the through-hole interconnection, the through-hole interconnections being provided inside the substrate so as to connect the first main surface to the second main surface, wherein the second portion is substantially perpendicular to the first main surface and is exposed to the first main surface, the third portion is substantially perpendicular to the second main surface and is exposed to the second main surface, and lengths of the through-hole interconnections are the same as each other.

"In the interposer substrate of the first aspect of the invention, it is preferable that a longitudinal direction of the first portion be substantially parallel to a main surface of the substrate.

"According to the interposer substrate of the first aspect of the invention, the lengths of the through-hole interconnections are the same as each other.

"Consequently, difference (variations) in the interconnection resistance values which is caused by difference in the lengths of the wirings in the through-hole interconnections eases.

"Furthermore, it is possible to reduce variations in the wiring delay in case of transmitting signal from one end to the other end of the through-hole interconnections.

"In addition, since the second portion and the third portion extend substantially perpendicular to a first main surface and a second main surface, respectively, even where the thickness of the substrate varies, the overall length of each through-hole interconnection (the total of the length of the first portion, the length of the second portion, and the length of the third portion) does not vary.

"For this reason, the interconnection resistance values and the variations in the wiring delay of a plurality of through-hole interconnections does not vary.

"As a result, the invention can realize an interposer substrate with excellent transmission characteristics.

"In the interposer substrate of the first aspect of the invention, it is preferable that a longitudinal direction of the first portion be oblique to a main surface of the substrate.

"According to such interposer substrate, the length of the through-hole interconnection connecting two predetermined surfaces of the substrate is shortened, contributing to a reduction in an interconnection resistance value.

"It is preferable that the interposer substrate of the first aspect of the invention further include: a pad provided on the first main surface so as to be electrically connected to the second portion constituting the through-hole interconnection; and a pad provided on the second main surface so as to be electrically connected to the third portion constituting the through-hole interconnection.

"When a device is mounted onto both faces of the interposer substrate, electrodes of the device are electrically connected to the pads without front wirings interposed therebetween.

"Because of this, the through-hole interconnections can be directly connected to the device, even in cases where a downsized device in which the electrodes are densely arranged with any layout is used, it is possible to easily connect the downsized device to the interposer substrate.

"In the interposer substrate of the first aspect of the invention, it is preferable that the substrate include a cooling unit cooling the substrate.

"Therefore, even in cases where a device having a large amount of heat generation is packaged into the interposer substrate, since the cooling unit can effectively cool the device, increases in temperature of the entire package is reduced, and the performance of the device can be maintained.

"An electronic device package of a second aspect of the invention includes: the interposer substrate of the aforementioned first aspect and an electronic device mounted onto at least one of the first main surface and the second main surface of the interposer substrate.

"As a result, the invention is to contribute to the provision of an electronic device package with excellent transmission characteristics.

"In the electronic device package of the second aspect of the invention, it is preferable that at least one end portion of the second portion and the third portion be located at a position facing a terminal of the electronic device and be electrically connected to the terminal of the electronic device.

"When a device is mounted onto both faces of the interposer substrate, an electrode of the device is electrically connected to at least one of the end portion of the second portion and the end portion of the third portion without front wirings interposed therebetween.

"Accordingly, even in cases where a downsized device in which the electrodes are densely arranged with any layout is used, it is possible to easily connect the downsized device to the interposer substrate.

"An electronic component of a third aspect of the invention includes the electronic device package of the aforementioned second aspect.

"As a result, the invention is to contribute to the provision of an electronic component with excellent signal transmission therein.

"Effects of the Invention

"According to the invention, since the lengths of the through-hole interconnections are substantially the same as each other, it is possible to reduce the interconnection resistances of the through-hole interconnections or differences in the wiring delay (variations).

"For this reason, it is possible to provide an interposer substrate, an electronic device package, and an electronic component which have excellent signal transmission characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 is a plan view schematically showing an interposer substrate of a first embodiment of the invention.

"FIG. 2 is a cross-sectional view taken along the line M1-M1 shown in FIG. 1.

"FIG. 3 is a cross-sectional view schematically showing the interposer substrate of the first embodiment of the invention.

"FIG. 4 is a cross-sectional view schematically showing the interposer substrate of the first embodiment of the invention.

"FIG. 5 is a cross-sectional view schematically showing an interposer substrate of a modified example of the first embodiment of the invention.

"FIG. 6A is a plan view schematically showing an interposer substrate of a second embodiment of the invention.

"FIG. 6B schematically shows the interposer substrate of the second embodiment of the invention and is a cross-sectional view taken along the line M2-M2 shown in FIG. 6A.

"FIG. 7A is a plan view schematically showing an interposer substrate of a third embodiment of the invention.

"FIG. 7B schematically shows the interposer substrate of the third embodiment of the invention and is a cross-sectional view taken along the line M3-M3 shown in FIG. 7A.

"FIG. 7C schematically shows the interposer substrate of the third embodiment of the invention and is a cross-sectional view taken along the line N-N shown in FIG. 7A.

"FIG. 8A is a plan view schematically showing an interposer substrate of a fourth embodiment of the invention.

"FIG. 8B schematically shows the interposer substrate of the fourth embodiment of the invention and is a cross-sectional view taken along the line M4-M4 shown in FIG. 8A.

"FIG. 8C schematically shows the interposer substrate of the fourth embodiment of the invention and is a cross-sectional view taken along the line M5-M5 shown in FIG. 8A.

"FIG. 9A is a schematic cross-sectional view illustrating a step of a method of manufacturing an interposer substrate.

"FIG. 9B is a schematic cross-sectional view illustrating a step of a method of manufacturing an interposer substrate.

"FIG. 9C is a schematic cross-sectional view illustrating a step of a method of manufacturing an interposer substrate.

"FIG. 9D is a schematic cross-sectional view illustrating a step of a method of manufacturing an interposer substrate.

"FIG. 10 is a plan view schematically showing an electronic device package of an embodiment of the invention.

"FIG. 11 is a cross-sectional view taken along the line M6-M6 shown in FIG. 10.

"FIG. 12 is a plan view schematically showing an example of a conventional interposer substrate.

"FIG. 13 is a cross-sectional view taken along the line M7-M7 shown in FIG. 12."

For more information, see this patent application: YAMAMOTO, Satoshi. Interposer Substrate, Electronic Device Package, and Electronic Component. Filed August 27, 2013 and posted January 16, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=3579&p=72&f=G&l=50&d=PG01&S1=20140109.PD.&OS=PD/20140109&RS=PD/20140109

Keywords for this news article include: Asia, Fujikura Ltd.

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Source: China Weekly News


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