Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W70/00—Package substrates; Interposers; Redistribution layers [RDL]
  • H10W70/01—Manufacture or treatment
  • H10W70/05—Manufacture or treatment of insulating or insulated package substrates, or of interposers, or of redistribution layers
  • H10W70/08—Manufacture or treatment of insulating or insulated package substrates, or of interposers, or of redistribution layers by depositing layers on the chip or wafer, e.g. "chip-first" RDLs
  • H10W70/09—Manufacture or treatment of insulating or insulated package substrates, or of interposers, or of redistribution layers by depositing layers on the chip or wafer, e.g. "chip-first" RDLs extending onto an encapsulation that laterally surrounds the chip or wafer, e.g. fan-out wafer level package [FOWLP] RDLs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B81—MICROSTRUCTURAL TECHNOLOGY
  • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
  • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
  • B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
  • B81C1/00222—Integrating an electronic processing unit with a micromechanical structure
  • B81C1/0023—Packaging together an electronic processing unit die and a micromechanical structure die
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B81—MICROSTRUCTURAL TECHNOLOGY
  • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
  • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
  • B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
  • B81C1/00261—Processes for packaging MEMS devices
  • B81C1/00333—Aspects relating to packaging of MEMS devices, not covered by groups B81C1/00269 - B81C1/00325
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P72/00—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof
  • H10P72/70—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping
  • H10P72/74—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping using temporarily an auxiliary support
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W70/00—Package substrates; Interposers; Redistribution layers [RDL]
  • H10W70/60—Insulating or insulated package substrates; Interposers; Redistribution layers
  • H10W70/611—Insulating or insulated package substrates; Interposers; Redistribution layers for connecting multiple chips together
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W70/00—Package substrates; Interposers; Redistribution layers [RDL]
  • H10W70/60—Insulating or insulated package substrates; Interposers; Redistribution layers
  • H10W70/611—Insulating or insulated package substrates; Interposers; Redistribution layers for connecting multiple chips together
  • H10W70/614—Insulating or insulated package substrates; Interposers; Redistribution layers for connecting multiple chips together the multiple chips being integrally enclosed
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W70/00—Package substrates; Interposers; Redistribution layers [RDL]
  • H10W70/60—Insulating or insulated package substrates; Interposers; Redistribution layers
  • H10W70/67—Insulating or insulated package substrates; Interposers; Redistribution layers characterised by their insulating layers or insulating parts
  • H10W70/688—Flexible insulating substrates
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W74/00—Encapsulations, e.g. protective coatings
  • H10W74/01—Manufacture or treatment
  • H10W74/014—Manufacture or treatment using batch processing
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W74/00—Encapsulations, e.g. protective coatings
  • H10W74/01—Manufacture or treatment
  • H10W74/019—Manufacture or treatment using temporary auxiliary substrates
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W74/00—Encapsulations, e.g. protective coatings
  • H10W74/10—Encapsulations, e.g. protective coatings characterised by their shape or disposition
  • H10W74/131—Encapsulations, e.g. protective coatings characterised by their shape or disposition the semiconductor body being only partially enclosed
  • H10W74/137—Encapsulations, e.g. protective coatings characterised by their shape or disposition the semiconductor body being only partially enclosed the encapsulations being directly on the semiconductor body
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W74/00—Encapsulations, e.g. protective coatings
  • H10W74/10—Encapsulations, e.g. protective coatings characterised by their shape or disposition
  • H10W74/131—Encapsulations, e.g. protective coatings characterised by their shape or disposition the semiconductor body being only partially enclosed
  • H10W74/141—Encapsulations, e.g. protective coatings characterised by their shape or disposition the semiconductor body being only partially enclosed the encapsulations being on at least the sidewalls of the semiconductor body
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P72/00—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof
  • H10P72/70—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping
  • H10P72/74—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping using temporarily an auxiliary support
  • H10P72/7424—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof for supporting or gripping using temporarily an auxiliary support used as a support during the manufacture of self-supporting substrates
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W70/00—Package substrates; Interposers; Redistribution layers [RDL]
  • H10W70/60—Insulating or insulated package substrates; Interposers; Redistribution layers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/01—Manufacture or treatment
  • H10W72/0198—Manufacture or treatment batch processes
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W72/00—Interconnections or connectors in packages
  • H10W72/90—Bond pads, in general
  • H10W72/941—Dispositions of bond pads
  • H10W72/9413—Dispositions of bond pads on encapsulations
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W74/00—Encapsulations, e.g. protective coatings
  • H10W74/10—Encapsulations, e.g. protective coatings characterised by their shape or disposition
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W90/00—Package configurations
  • H10W90/10—Configurations of laterally-adjacent chips

Definitions

• the present invention is directed to manufacturing objects. More particularly, the invention provides a method and resulting structure for integrating a chip structure onto a film of flexible material.
• the invention has been applied to integrated circuit chips provided on polymer based structures such as a film of parylene material. But it would be recognized that the invention has a much broader range of applicability.
• the invention can be applied to other chip structures including discrete electronic components, micro-electrical mechanical systems (MEMS), nano- electrical mechanical systems (NEMS), displays, power supplies, biological chips, medical chips, and biomedical chips.
• the integrated chip and film structures can be applied to the fields of electronics, life sciences, publishing, medicine, business, finance, and/or other areas of commerce and/or lifestyle.
• An integrated circuit or chip fabrication facility can cost hundreds of millions, or even billions, of U.S. dollars. Each fabrication facility will have a certain throughput of wafers, and each wafer will have a certain number of integrated circuits on it. Therefore, by making the individual devices of an integrated circuit smaller, more devices maybe fabricated on each wafer, thus increasing the output of the fabrication facility. Making devices smaller is very challenging, as each process used in integrated fabrication has a limit. That is to say, a given process typically only works down to a certain feature size, and then either the process or the device layout needs to be changed. Additionally, as devices require faster and faster designs, process limitations exist with certain conventional processes and materials.
• An example of such a process is packaging of such integrated circuit chip using molding and/or encapsulation techniques. More particularly, conventional integrated circuits are often diced into individual integrated circuit chips. Such chips are individually packaged mounted on lead frames using die attach and/or bonding techniques. The chip and lead frames are then encapsulated using injection molding processes. Such molding processes use epoxy based plastic materials that are often very durable, but hard and rigid. Lead frames must also often be bonded using wire bonding techniques to connect the individual integrated circuits to leads and/or connectors. Plastic encapsulating packages are often cumbersome, difficult to integrate with other devices, and are limited due to size and shape. Other limitations include lack of biocompatibility, hermeticity, and general degradation in salt/water environments, among others. These and other limitations will be described in further detail throughout the present specification and more particularly below.
• the invention provides a method and resulting structure for integrating a chip structure onto a film of flexible material.
• the invention has been applied to integrated circuit chips provided on polymer based structures such as a film of parylene material. But it would be recognized that the invention has a much broader range of applicability.
• the invention can be applied to other chip structures including discrete electronic components, micro-electrical mechanical systems (MEMS), nano-electrical mechanical systems (NEMS), displays, power supplies, biological chips, medical chips, and biomedical chips.
• the integrated chip and film structures can be applied to the fields of electronics, life sciences, publishing, medicine, business, clothing, finance, and other areas of commerce and/or lifestyle.
• the present invention provides a method for manufacturing integrated objects, e.g., electronic devices, biomedical devices, and sensors.
• the method includes providing a holder substrate, which has at least one recessed region, the recessed region having a predetermined shape.
• the holder substrate has a selected thickness and is characterized as being substantially rigid in shape.
• the method includes aligning a chip comprising a face and a backside into the predetermined shape of the recessed region and disposing the chip into the recessed region. The chip is secured into the recessed region.
• the method includes providing a first film of insulating material having a first thickness overlying the face and portions of the holder substrate to attach the chip to a portion of the first film of insulating material and patterning the first film of insulating material to form at least one opening through a portion of the first thickness to a contact region on the face of the chip.
• the method includes forming a metallization layer overlying the first film of insulating material to couple to the contact region through the one opening and fonning a protective layer overlying the metallization layer.
• the method includes releasing the chip from the holder substrate while maintaining attachment of the chip to the first film of insulating material.
• the present invention provides an alternative method for manufacturing integrated objects, e.g., electronic devices, biomedical devices, and sensors.
• the method includes providing a holder substrate, which has at least one recessed region, the recessed region having a predetermined shape.
• the holder substrate has a selected thickness and is characterized as being substantially rigid in shape.
• the method includes aligning a chip comprising a face and a backside into the predetermined shape of the recessed region and disposing the chip into the recessed region. The chip is secured into the recessed region.
• the method includes providing a first film of insulating material having a first thickness overlying the face and portions of the holder substrate to attach the chip to a portion of the first film of insulating material and patterning the first film of insulating material to form at least one opening through a portion of the first thickness to a contact region on the face of the chip.
• the method includes fonning a metallization layer overlying the first film of insulating material to couple to the contact region through the one opening and forming a protective layer overlying the metallization layer.
• the method includes releasing the chip from the holder substrate while maintaining attachment of the chip to the first film of insulating material.
• the present invention provides a method for manufacturing integrated electronic devices onto flexible substrate structures.
• the method includes providing a holder substrate, which has at least one recessed region smrounded by a peripheral region.
• the recessed region has a predetermined shape and the peripheral region has a surface portion.
• the holder substrate has a selected thickness and is characterized as being substantially rigid in shape.
• the method aligns an integrated circuit chip comprising a face and a backside into the predetermined shape of the recessed region surrounded by the peripheral region and disposes the integrated circuit chip into the recessed region.
• the method secures the integrated circuit chip into the recessed region using a release layer, which is formed overlying portions of the peripheral region.
• the method provides a first flexible film of insulating material having a first thickness overlying the face and portions of the release layer formed on the peripheral region of the holder substrate to attach the integrated circuit chip to a portion of the first film of insulating material.
• the method patterns the first flexible film of insulating material to form at least one opening through a portion of the first thickness to a contact region on the face of the integrated circuit chip and forms a metallization layer overlying the first flexible film of insulating material to couple to the contact region through the at least one opening in the first flexible film of insulating material.
• the method forms a flexible protective layer overlying the metallization layer and then patterns a portion of the flexible protective layer.
• the present invention provides an integrated chip and a flexible substrate device.
• the device has a chip (e.g., solid substrate structure) comprising a face and a backside.
• the device has a first flexible film of insulating material having a first thickness overlying the face of the chip.
• At least one opening is formed through a portion of the first thickness to a contact region on the face of the chip.
• a metallization layer is overlying the first flexible film of insulating material to couple to the contact region through the at least one opening in the first flexible film of insulating material.
• the device has a flexible protective layer overlying the metallization layer.
• a flexible sandwich str ⁇ cture is formed by a portion of the first flexible film of insulating material, a portion of the metallization layer, and a portion of the flexible protective layer.
• a surface area region is characterized by the flexible sandwich structure. In a specific embodiment, , the surface area region has a size of at least 1.1 times greater than a face surface region of the face of the chip or even larger depending upon the specific embodiment.
• the present technique provides an easy to use process that relies upon conventional technology.
• the method provides higher device yields.
• the method provides a process that is compatible with conventional process technology without substantial modifications to conventional equipment and processes.
• the invention provides for a method and device that can provide a flexible film of material having electronic chips thereon.
• the present invention provides a film of flexible material that is generally easy to use, inert, light weight, and has other desirable characteristics. Using Parylene rather than conventional substrate materials allows for improvements in performance due to its mechanical and thermal properties.
• Additional features and/or benefits may include, but are not limited to:
• Devices resulting from this process are flexible, e.g., flexibility equivalent to plastic wrap for food products; 5. Overall device is well sealed from external environment/biocompatible;
• an impediment to the fabrication of complex electronics is the difficulty inherent in fabrication from scratch of an entire device that include chips such as integrated circuits (ICs). This is because IC fabrication often requires very high precision, and usually uses processes that are not easily compatible with sensor fabrication modalities. As such, these ICs are usually fabricated on a wafer at foundries throughout the country, are diced into chips, and are wire-bonded or sometimes bump-bonded to separately fabricated devices. If, however, computing circuits and driving electronics are fabricated at a foundry and can be easily integrated into the fabrication process of a flexible sensor or electrode stimulator, rather than using wire-bonding for attacliment, these devices would be more robust according to a preferred embodiment. What is more, if separately fabricated chips could be connected to one another using a flexible substrate, or skin, we can effectively make concatenated circuits that are more complex and also flexible.
• Figure 1 is a simplified diagram of an integrated chip and flexible substrate according to an embodiment of the present invention.
• Figure 1 A is a simplified cross-sectional view diagram of the integrated chip and flexible substrate according to an embodiment of the present invention
• Figures IB-ID are simplified diagrams of alternative views of the integrated chip and substrate according to embodiments of the present invention.
• Figure 2 is a simplified diagram illustrating a method of fabricating an integrated chip and flexible substrate according to an embodiment of the present invention.
• Figure 3 is a simplified diagram illustrating details of a method of fabricating an integrated chip and flexible substrate according to an embodiment of the present invention
• Figure 4 is a simplified diagram illustrating an alternative method of fabricating an integrated chip and flexible substrate according to an embodiment of the present invention
• Figure 5 is a simplified diagram illustrating yet an alternative method of fabricating an integrated chip and flexible substrate according to an embodiment of the present invention
• Figure 6 is a simplified diagram illustrating still an alternative method of fabricating an integrated chip and flexible substrate according to an embodiment of the present invention.
• FIGs 7-15 are simplified diagrams of experimental results according to embodiments of the present invention.
• the invention provides a method and resulting structure for integrating a chip structure onto a film of flexible material.
• the invention has been applied to integrated circuit chips provided on polymer based structures such as a film of parylene material. But it would be recognized that the invention has a much broader range of applicability.
• the invention can be applied to other chip structures including discrete electronic components, micro-electrical mechanical systems (MEMS), nano-electrical mechanical systems (NEMS), displays, power supplies, biological chips, medical chips, and biomedical chips.
• the integrated chip and film structures can be applied to the fields of electronics, life sciences, publishing, medicine, business, finance clothing, other areas of commerce and/or lifestyle, and the like.
• FIG. 1 is a simplified diagram of an integrated chip and flexible substrate 100 according to an embodiment of the present invention.
• the device has a chip (e.g., solid substrate structure) 101 comprising a face and a backside.
• the device also has a thickness.
• the chip can be any substrate structure such as an integrated circuit chip, a MEMS and/or NEMS device, a discrete device or devices, a power supply, a biological chip, a medical chip, a display chip, a battery, a light, any combination of these, and others.
• a chip e.g., solid substrate structure
• the chip can be any substrate structure such as an integrated circuit chip, a MEMS and/or NEMS device, a discrete device or devices, a power supply, a biological chip, a medical chip, a display chip, a battery, a light, any combination of these, and others.
• the device has a first flexible film of insulating material 103 having a first thickness overlying the face of the chip according to a specific embodiment.
• the first flexible material is on and in contact with the face of the chip.
• the first flexible film of insulating material comprises a Parylene Material and/or other like material.
• the parylene material has a thickness ranging from about 0.1 microns to about 100 microns and less than 1mm.
• At least one opening 105 is formed tlirough a portion of the first thickness to a contact region on the face of the chip.
• the contact region is often a bonding pad or other contact structure.
• the bonding pad has a surface dimension of 100 microns or less or 80 microns or less or 50 microns or less depending upon the embodiment.
• a metallization layer 109 is overlying the first flexible film of insulating material to couple to the contact region through at least one opening in the first flexible film of insulating material.
• the metallization layer is selected from aluminum, gold, copper, silver, platinum, titanium, iridium, titanium, tungsten, doped silicon, conductive polymers, any combination of these, including alloys, multi-layered structures, and the like.
• the metallization layer has been patterned to form conductive traces from the chip to various other elements.
• the contact region can be a via structure that connects the metallization layer to the chip and other outside circuit elements, depending upon the specific embodiment.
• the elements may include electrodes 111 or other like structures.
• the elements can also include discrete electronic components, micro-electrical mechanical systems (MEMS), nano-electrical mechanical systems (NEMS), displays, power supplies, biological chips, medical chips, and biomedical chips depending upon the specific embodiment.
• the device also has a flexible protective layer 113 overlying the metallization layer according to a specific embodiment.
• the flexible protective layer comprises a Parylene material and/or other like structure.
• a flexible sandwich structure is formed by a portion of the first flexible film of insulating material, a portion of the metallization layer, and a portion of the flexible protective layer.
• a surface area region is characterized by the flexible sandwich structure, the surface area region having a size of at least 1.1 times greater than a face surface region of the face of the chip according to a specific embodiment.
• the packaged chip and flexible film have certain desirable characteristics. That is, the packaged chip and film are flexible and can be bent while the chip is maintained in the film.
• the packaged chip is generally inert and can be bio- compatible according to a specific embodiment.
• the integrated chip also has an overall thickness ranging from about 1 micron to about lmillimeter and could be less than 1 centimeter depending upon the specific embodiment.
• the integrated chip has a rigid or flexible region capable of having a line density of 50-1000 lines per millimeter and greater depending upon the embodiment. Refer also to Figures IB-ID.
• Figures IB-ID See also to Figures IB-ID.
• one of ordinary skill in the art would recognize many other variations, modifications, and alternatives. Further details of certain methods for fabricating the present integrated substrate structure can be found throughout the present specification and more particularly below.
• a method according to an embodiment of the present invention for fabricating an integrated substrate structure is briefly outlined below.
• Pattern metallization 10. Treat parylene surface;
• the above sequence of steps provides a method according to an embodiment of the present invention.
• the method uses a combination of steps including a way of forming an integrated chip and flexible film structure using a parylene bearing material or the like.
• trenches are etched in a pure single-crystal silicon wafer using DRIE (deep- reactive ion etching) or wet-etching that match (within certain tolerances) the dimensions of foundry or otherwise fabricated chips.
• Photoresist is spun on the wafer and in the trenches, and the chips (most likely with a pre-coating of parylene) are placed in the locations etched in the wafer.
• parylene Poly-para-xylylene
• Parylene C, parylene N, or parylene D are deposited on the wafer by vapor deposition. Because the deposition of parylene is conformal to any exposed surfaces, the chips are effectively sealed in their locations on the wafer and the surface of the wafer has now been effectively planarized to facilitate easy fabrication of the rest of the device.
• the parylene surface is at some time etched in the locations where electricafcontact to the underlying IC chips is desired using standard photoresist patterning and O 2 plasma etching.
• Metal is deposited on the wafer and patterned using liftoff or chemical etching.
• a second layer of parylene is deposited on the first layer after a short surface treatment. The metal has thus been sealed between either two layers of parylene or between the chip and the overlying parylene layer. Further fabrication is possible, including but not limited to creation of contact areas in the overlying parylene.
• a solvent e.g., acetone or resist stripper
• FIG. 2 is a simplified diagram illustrating a method of fabricating an integrated chip and flexible substrate according to an embodiment of the present invention. This diagram is merely an example, which should not unduly limit the scope of the claims herein. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.
• the present invention provides a method 200 for manufacturing integrated objects, e.g., chip and flexible substrate. The method includes providing a holder substrate 201.
• the holder substrate is made of a material selected from an insulating material, a conductive material, or a semiconductor material.
• the insulating material can be selected from glass, quartz, plastic, or polymers or any combination of these materials.
• the conductive material can be selected from a metal, conducting polymers, doped semiconductor materials, any combination of these conductive materials.
• the semiconductor material can be selected from silicon, glass, Group III/V compound semiconductors, Group II/VI compound semiconductors, and any combination of these semiconductor materials.
• the holder substrate can be homogeneous, multilayered, or graded depending upon the specific embodiment.
• the holder substrate 201 has at least one recessed region 203, which has a predetermined shape.
• the holder substrate can also include a plurality of recessed regions. Each of such recessed regions has a depth, length, and width according to a specific embodiment. The recessed regions may be formed using etching, deep reactive ion etching, or other techniques combined with photo masking depending upon the specific embodiment.
• the holder substrate has a selected thickness and is characterized as being substantially rigid in shape.
• the holder substrate also has an upper surface region 202, which is preferably flat, surrounding the periphery of each of the recessed regions. The method forms a release layer overlying exposed portions of the recessed regions.
• photo-resist is spun on the wafer and in the trenches, and the chips (most likely with a pre-coating of parylene are placed (which will be described in more detail below) in the locations etched in the wafer.
• the chips most likely with a pre-coating of parylene are placed (which will be described in more detail below) in the locations etched in the wafer.
• the method aligns a chip comprising a face and a backside into the predetennined shape of the recessed region.
• the method also disposes the chip into the recessed region.
• the chip is held using a transfer material during at least the aligning and disposing.
• the transfer material comprises a tape material, e.g., Nitto tape, which can be attached to the face of the chip and easily removed from the face of the chip once it has been disposed into the recessed region.
• the tape is used with the recessed region is a through hole or other configuration, which would not support the chip in a selected location.
• the transfer material can hold multiple chips to be aligned and disposed into each of the respective recessed regions.
• the method secures the chip into the recessed region using a glue layer 205 or other suitable material, which holds the chip into the recessed region for further processing.
• the method includes providing a first film of insulating material 207 having a first thickness overlying the face and portions of the holder substrate to attach the chip to a portion of the first film of insulating material.
• the insulating material is a parylene or other like polymer material.
• the entire substrate including chip and recessed regions is placed in a parylene (Poly-para-xylylene) deposition system.
• An example of such deposition system is the PDS 2010 manufactured by Specialty Coating Systems, but can be others.
• Parylene C, parylene N, or parylene D are deposited on the wafer by vapor deposition. Because the deposition of parylene is conformal to any exposed surfaces, the chips are effectively sealed in their locations on the wafer and the surface of the wafer has now been effectively planarized to facilitate easy fabrication of the rest of the device.
• the method patterns the first film of insulating material to form at least one opening 208 through a portion of the first thickness to a contact region on the face of the chip.
• the parylene surface is etched in specific locations where electrical contact to the underlying IC chips is desired using standard photoresist patterning and O 2 plasma etching as well as other suitable techniques.
• the opening can even be 10 microns and less depending upon the specific embodiment. Of course, there can be other variations, modifications, and alternatives.
• the method forms a metallization layer 24 overlying the first film of insulating material to couple to the contact region through the one opening.
• Metal is deposited on the wafer and patterned using liftoff or chemical etching.
• the metallization is selected from aluminum, gold, copper, silver, platinum, titanium, iridium, and any combination of these metals.
• the metallization is gold, which is relatively inert, for certain biological chips.
• the metallization has a thickness of about 0.1 to 10 microns and can be patterned having a density of 50 - 1000 lines per mm depending upon the specific embodiment. Of course, there can be other variations, modifications, and alternatives.
• the method forms a protective layer 213 overlying the metallization layer in a specific embodiment.
• a second layer of parylene is deposited on the first layer after a short surface treatment.
• the patterned metal has thus been sealed between either two layers of parylene or between the chip and the overlying parylene layer.
• Further fabrication is possible, including but not limited to, creation of contact areas in the overlying parylene according to a specific embodiment.
• Other protective layers such as oxide, nitride, metal, ceramics, and polymers and/or any combination of these can also be used depending upon the specific embodiment.
• the method then releases 215 the chip from the holder substrate while maintaining attachment of the chip to the first film of insulating material.
• a solvent e.g., acetone or resist stripper
• Other release techniques such as heating, other chemical, mechanical, ultrasonic, or other techniques may also be used according to the specific embodiment.
• the method uses a combination of steps including a way of forming an integrated chip and flexible film structure using a parylene bearing material or the like.
• steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein. Further details of alternative methods and structures can be found throughout the present specification and more particularly below.
• a method according to an alternative embodiment of the present invention for fabricating an integrated substrate structure is briefly outlined below. Such method has also been illustrated in the simplified diagrams 300 of Figure 3. As shown, the method performs the following sequence of steps, which are numbered numerically from 1 through 15 in Figure 3 (see reference numeral 300), which should not unduly limit the scope of the claims herein.
• the method uses a combination of steps including a way of forming an integrated chip and flexible film structure using a parylene bearing material or the like.
• steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein. Further details of alternative methods and structures can be found throughout the present specification and more particularly below.
• a method according to yet an alternative embodiment of the present invention for fabricating an integrated substrate structure is briefly outlined below. Such method has also been illustrated in the simplified diagrams 300, 350 of Figure 3. As shown, the method performs the following sequence of steps, which are numbered numerically from 1-8, 9A- 11 A, and 12-15 in Figure 3 (see reference numerals 300, 350 ), which should not unduly limit the scope of the claims herein. As noted, steps 9-11 are substituted with the illustrations in steps 9A-11 A also in Figure 3. 1. Spin photoresist on surfaces of the substrate;
• the method uses a combination of steps including a way of forming an integrated chip and flexible film structure using a parylene bearing material or the like.
• steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein. Further details of alternative methods and structures can be found throughout the present specification and more particularly below.
• a method according to an alternative embodiment of the present invention for fabricating an integrated substrate structure is briefly outlined below. Such method has also been illustrated in the simplified diagrams 400 of Figure 4. As shown, the method performs the following sequence of steps, which are numbered numerically from 1 through 16 in Figure 4 (see reference numeral 400), which should not unduly limit the scope of the claims herein.
• the method uses a combination of steps including a way of forming an integrated chip and flexible film structure using a parylene bearing material or the like.
• Other alternatives can also be provided where steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein. Further details of alternative methods and structures can be found throughout the present specification and more particularly below.
• a method according to yet an alternative embodiment of the present invention for fabricating an integrated substrate structure is briefly outlined below. Such method has also been illustrated in the simplified diagrams 500 of Figure 5. As shown, the method performs the following sequence of steps, which are numbered numerically from 1 through 15 in Figure 5 (see reference numeral 500), which should not unduly limit the scope of the claims herein.
• the method uses a combination of steps including a way of forming an integrated chip and flexible film stracture using a parylene bearing material or the like.
• steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein. Further details of alternative methods and structures can be found throughout the present specification and more particularly below.
• a method according to yet an alternative embodiment of the present invention for fabricating an integrated substrate structure is briefly outlined below. Such method has also been illustrated in the simplified diagrams 600 of Figure 6. As shown, the method performs the following sequence of steps, which are numbered numerically from 1 through 15 in Figure 6 (see reference numeral 600), which should not unduly limit the scope of the claims herein.
• the method uses a combination of steps including a way of forming an integrated chip and flexible film stracture using a parylene bearing material or the like.
• steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein. Further details of alternative methods and structures can be found throughout the present specification and more particularly below.
• FIGs 7-15 are simplified diagrams of experimental results according to embodiments of the present invention. These diagrams are merely examples, which should not unduly limit the scope of the claims herein.
• a video-capture and data- encoding mechanism for power and data transmission and recovery
• a radio-frequency (RF) coil system for power and data transmission and recovery
• IC analog/digital driving integrated circuit
• a flexible retinal electrode array for neural stimulation.
• the overall goal for the test bed is to complete a 1,000 electrode system, far more than the 16 electrode device currently in use. Because of the complexity of the driver circuitry necessary for such high-lead-count devices, these circuits typically are off fabricated at a foundry. As yet, there is no cost-effective method for high-density interconnection of foundry-fabricated driver circuitry with the RF coil and retinal stimulator.
• Parylene is a USP Class VI biocompatible polymer that is deposited through a highly conformal vapor- deposition process. Of the three most common parylenes (See Figure 7), parylene C is the most widely used in industry. The advantages of the use of parylene include its proven biocompatibility, its strength and flexibility (Young's Modulus ⁇ 4 GPa), its pinhole-free, conformal deposition, and its ease of manipulation using standard microfabrication techniques. Several research groups use parylene as a method for sealing fabricated electrode anays.
• Chips simulating foundry-fabricated chips were first used to demonstrate the technology. The only properties of these prefabricated chips known a priori were the electrical pad dimensions and locations as well as the overall length, width, and height dimensions of the chip.
• the simulated chip consisting of simple electrical shorts and intrinsic resistors, was embedded in a standard silicon wafer using backside mechanical anchoring with parylene. The entire wafer then underwent standard processing as though the circuitry had been prefabricated on the wafer itself, with electrical connections to regions far from the chip being demonstrated.
• Figure 10 shows the chip integration and interconnection concept in terms of an abridged process flow. Briefly, trenches are etched in a standard silicon wafer using the Bosch process (ensuring accurate chip alignment to within built-in tolerances). The chips are then self-aligned in these trenches (to within 10 ⁇ m lateral displacement) and sealed from the backside with photoresist and parylene. Fabrication is then performed on this wafer as though it were a whole wafer with integrated circuitry. Metallization is performed using an e-beam evaporation process with optimized step coverage. The photoresist sacrificial layer is then removed, leaving a flexible skin with embedded circuitry.
• the end result can be a stimulation system which is completely enclosed in parylene, where parylene' s pinhole-free coating would make it impermeable to saline. If the need arises, other hermetic coatings can be deposited on the entire stracture to increase device longevity.
• Figure 11 shows an overhead view of the parylene "skin" with the simulated IC chip embedded in this manner, and demonstrates the system's size relative to a penny which is seen through the transparent parylene.
• Figure 12 shows the backside of the same device. As can be clearly seen from this picture, the entire system is extremely flexible, a feature which facilitates implantation, and, because parylene is the main substrate, the system is also mechanically robust.
• Figures 13 and 14 show a magnified view of the interconnects from the perimeter contacting the circuits on the chip, and the metallization continuity over the perimeter to chip junction, respectively. Table 1 summarizes the electrical data verifying the efficacy of this interconnection scheme. Resistances between the perimeter pads connected to the quadrant of the chip shown in Fig.
• this package also adds flexibility because individual chips can now be strung together into larger conglomerate circuits post-fabrication and can be directly integrated with the stimulating electrode anay. For instance, one team can work on the design of a multiplexer chip, and another can work on a 256 electrode driver chip. In addition to the possibility of fabrication of a 256 electrode array for testing, the multiplexer can be strung together with four of these driver chips to create a 1024 electrode driver circuit without the need for a complete overhaul of the design and expensive fabrication of an entirely new chip.

Landscapes

• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Manufacturing & Machinery (AREA)
• Micromachines (AREA)
• Wire Bonding (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (2)

Family

ID=34590158

Family Applications (1)

Country Status (4)

Cited By (11)

Families Citing this family (37)

Citations (3)

Family Cites Families (20)

• 2004
  • 2004-10-25 US US10/974,006 patent/US7338836B2/en not_active Expired - Lifetime
  • 2004-10-29 JP JP2006539568A patent/JP4854514B2/ja not_active Expired - Lifetime
  • 2004-10-29 EP EP04810125.7A patent/EP1680803B1/en not_active Expired - Lifetime
  • 2004-10-29 WO PCT/US2004/036048 patent/WO2005048302A2/en not_active Ceased
• 2007
  • 2007-10-31 US US11/933,222 patent/US7706887B2/en not_active Expired - Lifetime

Patent Citations (3)

Non-Patent Citations (3)

Also Published As

Similar Documents

Legal Events