WO1994029897A1 - Method for providing electrical interconnections between adjacent circuit board layers of a multi-layer circuit board - Google Patents

Method for providing electrical interconnections between adjacent circuit board layers of a multi-layer circuit board Download PDF

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Publication number
WO1994029897A1
WO1994029897A1 PCT/US1994/006387 US9406387W WO9429897A1 WO 1994029897 A1 WO1994029897 A1 WO 1994029897A1 US 9406387 W US9406387 W US 9406387W WO 9429897 A1 WO9429897 A1 WO 9429897A1
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WO
WIPO (PCT)
Prior art keywords
circuit board
layer
board layer
electrical contact
layers
Prior art date
Application number
PCT/US1994/006387
Other languages
French (fr)
Inventor
Joel A. Gerber
Peter A. Gits
Original Assignee
Minnesota Mining And Manufacturing Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Minnesota Mining And Manufacturing Company filed Critical Minnesota Mining And Manufacturing Company
Priority to EP94919395A priority Critical patent/EP0702847A1/en
Priority to JP7502035A priority patent/JPH08510868A/en
Publication of WO1994029897A1 publication Critical patent/WO1994029897A1/en
Priority to KR1019950705493A priority patent/KR960702938A/en

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/46—Manufacturing multilayer circuits
    • H05K3/4611—Manufacturing multilayer circuits by laminating two or more circuit boards
    • H05K3/4614—Manufacturing multilayer circuits by laminating two or more circuit boards the electrical connections between the circuit boards being made during lamination
    • H05K3/4617—Manufacturing multilayer circuits by laminating two or more circuit boards the electrical connections between the circuit boards being made during lamination characterized by laminating only or mainly similar single-sided circuit boards
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/48—Manufacture or treatment of parts, e.g. containers, prior to assembly of the devices, using processes not provided for in a single one of the subgroups H01L21/06 - H01L21/326
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/52—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames
    • H01L23/538—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames the interconnection structure between a plurality of semiconductor chips being formed on, or in, insulating substrates
    • H01L23/5385—Assembly of a plurality of insulating substrates
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/46—Manufacturing multilayer circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001—Technical content checked by a classifier
    • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/01—Dielectrics
    • H05K2201/0183—Dielectric layers
    • H05K2201/0195—Dielectric or adhesive layers comprising a plurality of layers, e.g. in a multilayer structure
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/03—Conductive materials
    • H05K2201/0302—Properties and characteristics in general
    • H05K2201/0305—Solder used for other purposes than connections between PCB or components, e.g. for filling vias or for programmable patterns
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/03—Conductive materials
    • H05K2201/0332—Structure of the conductor
    • H05K2201/0388—Other aspects of conductors
    • H05K2201/0394—Conductor crossing over a hole in the substrate or a gap between two separate substrate parts
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/09—Shape and layout
    • H05K2201/09209—Shape and layout details of conductors
    • H05K2201/095—Conductive through-holes or vias
    • H05K2201/09563—Metal filled via
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/11—Treatments characterised by their effect, e.g. heating, cooling, roughening
    • H05K2203/1189—Pressing leads, bumps or a die through an insulating layer
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H05K3/4038—Through-connections; Vertical interconnect access [VIA] connections
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H05K3/42—Plated through-holes or plated via connections
    • H05K3/423—Plated through-holes or plated via connections characterised by electroplating method
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49117—Conductor or circuit manufacturing
    • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/49126—Assembling bases
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49117—Conductor or circuit manufacturing
    • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/49155—Manufacturing circuit on or in base
    • Y10T29/49165—Manufacturing circuit on or in base by forming conductive walled aperture in base

Definitions

  • the present invention relates to multi-layer circuit boards.
  • the invention relates to improved electrical interconnections for circuit board layers of a multi-layer circuit board, and to a method of making those interconnections.
  • Multi-layer printed circuit boards are known in the art, and are used to make complex electrical circuits.
  • a circuit board consists of a pattern of conductive traces which are used to interconnect electric components.
  • the conductive traces are bonded to or otherwise incorporated into an insulating substrate which mechanically supports the components. This includes single and double sided boards, multi layer constructions, hybrids, multi-chip modules, chip on board assemblies and the like.
  • the conductive traces may be formed using any number of techniques, for example electroplating, etching, sputtering, mechanical attachment using adhesives and others.
  • the substrate can be flexible or rigid and can be fabricated of any suitable material, for example polymers, ceramics, glasses, silicon etc.) Electrical connections between components of the electrical circuits are provided on the circuit board layers of the multi ⁇ layer circuit board. Using multiple circuit board layers allows the circuit designer to lay out complex circuit designs using many components in which those components require numerous interconnections. Multi-layer circuit boards increase component density and functionality per unit volume. Each circuit board layer of a multi-layer circuit board carries electrical connections, or electrical traces, which act as wires and are used to interconnect the various components of the circuit. Electrical connection between adjacent circuit board layers is achieved using "vias." A via is created by forming a hole between adjacent layers. The hole is filled with conductive material to form an electrical connection between the two adjacent layers.
  • PCB printed circuit board
  • the circuit board layers of the multi ⁇ layer circuit board are then stacked and aligned to each other with an electrically insulating bonding layer between adjacent layers.
  • the assembled layers are then subjected to heat and pressure to provide a bond between adjacent layers.
  • Via holes are then drilled in the appropriate locations which interconnect pads on successive layers.
  • the electrical interconnect is achieved by applying a conductive material to the side walls of the via holes.
  • the prior art requires the metal via contact pads to have sufficient area on the circuit board to accommodate the drill cross section and/or any misalignment. These large pad areas limit the component density of the circuit board.
  • To form buried vias additional processing is required. Namely, the above structure is treated as a sub-assembly several of which can be laminated together to form the full board.
  • MCMs multi-chip modules
  • MCM-Ds The D refers to deposition where a circuit is built up upon an inorganic non ⁇ conducting substrate using thin film approaches with copper or aluminum traces and organic or inorganic dielectrics.
  • This technology is capable of fabricating very fine lines and vias (blind, stacked, and buried) resulting in very much higher circuit densities than traditional plated through hole technology described above.
  • this increased density comes at the cost of much more expensive processing which is usually accomplished in sequential batch processing. Batch processing does not lend itself to high volume production and the sequential fabrication results in lower yield as the deposition of one defective layer ruins an entire part.
  • the present invention provides an improved process for assembling a multi-layer circuit board with an improved wiring density.
  • the invention provides an improved method of forming interconnections between adjacent layers in a multi-layer circuit board where stacked, buried and blind vias which occupy areas smaller than those occupied by plated through hole technology can be fabricated routinely.
  • the invention does not rely on high cost low volume fabrication methods such as is common in the fabrication of MCMs.
  • a parallel process for assembling a multi-layer circuit board that reduces the number of manufacturing sequences and increases the yield of completed parts in comparison to sequential processing is provided.
  • Each circuit board layer is fabricated separately allowing inspection of each layer prior to incorporation in the final part.
  • a circuit board layer is formed by depositing electrically conductive material which forms electrical circuit traces as well as interconnect pads on one side of an electrically insulating material.
  • the electrically conductive traces are then exposed on the uncircuitized side of the circuit board layer by forming holes in the electrically insulating material at locations where a via is desired.
  • the interconnection is fabricated by the formation of rigid bumps of a conductive material in the holes formed in the electrically insulating material which protrude above the surface of the electrically insulating material.
  • An electrically conducting metal which is capable of forming an electrically sound metal to metal bond between the bump and the corresponding pad on an adjacent layer is then deposited on the surface of the bumps or the pads, more frequently on both.
  • a layer of electrically insulating bonding material is deposited over at least one of the surfaces of the circuit board layer fabricated as described above. A plurality of these layers are then aligned and fused together by the application of heat and pressure in a single lamination step to form a multi-layer circuit board.
  • the metal on the surfaces of the bumps bonds with the metal on the pads providing the electrical interconnect between layers and the insulating bonding material forms the mechanical bond that holds the layers together and isolates the via connections.
  • the above fabrication method can be carried out in a batch process, a continuous process or in a combination of the two. Fabrication using a continuous process enables large volume production of the circuit board layers a clear advantage over the batch type process practiced in both PCB and MCM manufacturing. The ability to perform the majority of the fabrication in a continuous process is an important aspect of this invention.
  • the circuit board layers are fabricated in the method described above and laminated under heat and pressure as described above however, the insulating bonding material is substituted with an anisotropically conductive adhesive which by design is an electrical insulator in the plane of the circuit layer but permits electrical conduction in the out of plane direction.
  • Figure 1 is a side cross sectional view of a dielectric film circuit board layer.
  • Figure 2 is a side cross sectional view of the circuit board layer of Figure 1 including an adhesion and seed metal layer.
  • Figure 3 is a side cross sectional view of the circuit board layer of Figure 2 including patterned photoresists.
  • Figure 4 is a side cross sectional view of the circuit board layer of Figure 3 including a layer of trace metal.
  • Figure 5 is a side cross sectional view of the circuit board layer of Figure 4 including a via hole extending through the circuit board.
  • Figure 6 is a side cross sectional view of the circuit board layer of Figure 5 following removal of the photoresist and plating of a solid via.
  • Figure 7 is a side cross sectional view of the circuit board layer of Figure 6 following removal of the adhesion and seed metal layer.
  • Figure 8 is a side cross sectional view of the circuit board layer of Figure 7 following deposition of a cover metal layer.
  • Figure 9 is a side cross sectional view of the circuit board layer of Figure 8 including an adhesive film and a plurality of spaced apart circuit board layers.
  • Figure 10 is a side cross sectional view of the circuit board layers of Figure 9 following lamination to form a multi-layer circuit board in accordance with the present invention.
  • Figure 11 is a side cross sectional view of a test sample.
  • Figures 1 through 11 are cross sectional views. For clarity, cross hatching has been omitted.
  • Figure 1 shows a cross-sectional view of a circuit board layer 10.
  • circuit board layer 10 comprises a precast polymeric dielectric film.
  • the particular dielectric film used is a matter of choice however, web polyimide is an example of one that works well.
  • a conductive metal layer, and an adhesion layer is deposited if needed, on the first side of circuit layer 10.
  • the adhesion layer helps bond the metal layer to the dielectric film.
  • the composition of the adhesive layer is a matter of choice depending on the metal and dielectric materials used.
  • the outer metal layer portion of layer 12 can be comprised of copper or other appropriate conductive metal and can be deposited by any appropriate method. Electrodeposition is one process that works well.
  • Photoresist 14 is deposited, as shown in Figure 3.
  • Photoresist 14 is a standard photoresist deposited on circuit board 10 using conventional techniques. The photoresist is exposed to radiation through a mask. The photoresist is then developed, which causes portions of the photoresist to be removed exposing material and forming a patterned layer 14 as shown in Figure 3.
  • trace metal layer 16 is deposited on the exposed adhesion and conductive metal layer 12 as shown in Figure 4.
  • trace metal layer 16 comprises copper and is deposited through electrodeposition techniques so that it is only formed on the exposed portions of layer 12.
  • Trace metal layer 16 forms an electrical circuit carried on circuit board layer 10.
  • Trace metal layer 16 provides the electrical traces which will interconnect components when they are placed in the completed multi-layer circuit board. Additionally, the trace metal provides electrical "pads" which are used to interconnect adjacent circuit board layers.
  • circuitization of the dielectric illustrates one method of depositing circuit traces on the dielectric however, other methods can be used to deposit the circuit traces on the dielectric without changing the invention, for example both additive and subtractive process including sputtering, electroless plating, dry etching and the like.
  • via hole 18 is formed in circuit board layer 10 as shown in Figure 5.
  • via hole 18 is formed using a wet milling technique. This may include application of a hot fluid etch such as potassium hydroxide. Photoresist layer 14 and trace metal layer 16 protect portions of circuit board layer 10. The wet milling is of sufficient duration to ensure that via hole 18 extends all the way through circuit board layer 10 to layer 12.
  • the invention described in the above paragraphs eliminates the necessity of using the annular ring characteristic of plated through hole technology and thus allows for increased circuit density.
  • the via holes can be formed using any applicable wet or dry milling process.
  • dry milling processes include laser ablation, ion milling, reactive ion etching, mechanical punching and the like, some of which provide for the formation of holes that are much smaller than those produced by mechanical drilling. This yields even smaller vias and a further increase in circuit density.
  • Via metal 20 can be deposited separately or simultaneously with trace metal layer 16 on the opposite side. Via metal 20 electrically contacts trace metal layer 16 through layer 12 and forms a "bump" or “crown” that extends above the top surface of circuit board 10. This bump is used to electrically interconnect adjacent circuit board layers in accordance with the present invention. Via metal 20 should have good electrical conductivity and a high melting temperature relative to a solder. Preferably via metal 20 melts at a temperature greater than 500 C. The trace metal layer 16 forms electrical "pads" which contact the via metal bumps of adjacent circuit board layers. The adhesion and seed metal layer 12 is etched and removed from the circuit side of circuit board layer 10. This removes a small portion of trace metal layer 16. This is shown in the cross sectional view of Figure 7.
  • the second cover metal layer 22 is composed of a low melting point metal (low relative to the other metal layers) which is used to fuse with the pad on the adjacent circuit board layer to form electrically stable interconnections between layers.
  • the bump and pads can have the same or different metallurgies and the quantity of metal must be sufficient to provide a stable electrical bond but not so much that reflow causes shorting with adjacent interconnections.
  • Suitable metals for this cover layer include tin-lead, solder, tin, gold-tin alloys or other metals.
  • Layer 22 can be deposited by electroplating, electroless plating, spraying or other process.
  • Tin deposited on both the bump and the pad by an electroless process is one example of a metallurgy that works well.
  • the melting temperature of the cover metal layer has an upper limit which cannot exceed the degradation temperature of the polymeric film, layer 10, or the adhesive layers 58, 24, 60, and 62. While it is desirable in this embodiment to have reflow of the interfacial metallurgy, it is not necessary that the metals melt. Other embodiments include bonding using other means for example cold welding, ultrasonic welding, and the like.
  • the interconnect has been made with just a contact bond as well. It is desirable but not compulsory to accomplish all of the fabrication steps discussed above in a continuous web roll to roll process which amendable to high volume low cost production.
  • Figure 9 shows circuit board layer 10 including an electrically insulating bonding film 24 placed between adjacent layers. Additionally, Figure 9 shows circuit board layers 26, 28, 30, and 32 which have been prepared in accordance with the present invention, as set forth above. Circuit board layers 26-32 include trace metal layers 34, 36, 38, and 40, respectively. Via metal 42, 44, 46, and 48 is deposited in via holes of circuit board layers 26, 28, 30, and 32, respectively. Cover metal layers 50, 52, 54, and 56 are deposited on trace metal layers 34, 36, 38, and 40 and via metal 42, 44, 46, and 48 of circuit boards 26, 28, 30, and 32, respectively.
  • the present invention is well suited for forming blind and buried vias, as well as stacked vias as shown by vias 44 46, and 42 and 20.
  • the electrically insulating bonding film layers 58, 24, 60, and 62 are deposited on circuit board layers 26, 10, 28, and 30 and separate adjacent circuit board layers.
  • the particular polymer used is a matter of choice although epoxy compounds have been found to work well.
  • Figure 9 shows only five layers, it will be understood that the invention allows for lamination of a plurality of circuit board layers to be assembled as shown to form an interconnected structure. It should be noted as well that such an interconnect could be used to attach a single or multiplicity of layers to a rigid substrate.
  • a flex circuit could be attached to a printed circuit board by putting bumps on the flex and pads on the board.
  • circuit board layers 10, 26, 28, 30, and 32 are stacked and aligned as shown in Figure 9. Specifically, the via metal bump layer of one layer is aligned with its corresponding electrical pad on an adjacent layer.
  • the alignment can be performed by any suitable means. Mechanical alignment using alignment pins is one method that works well.
  • circuit board layers 10 and 26-32 are aligned as shown in Figure 9, they are laminated together under heat and pressure to form the structure shown in Figure 10. The lamination causes an electrical contact where the "bump" of the via metal of one layer contacts an electrical pad of an adjacent layer and the low melting point metal fuses together. Simultaneously, the adhesive layers fuse together forming a mechanical bond that holds the circuit board layers together and isolates the electrical contacts.
  • the lamination conditions are a matter of choice and depend on the polymers and metallurgies involved. Applicable pressure ranges include 0.15 MPa - 5 MPa, more preferably 0.3 MPa - 3.5 MPa, and more preferably 0.7 - 1.7 MPa. Temperature ranges for lamination are 80°C-425°C, more preferable 130-350°C, and more preferably 175-280°C.
  • the metal- metal bond is formed instantly and thus the lamination time is dependant on the chosen adhesive bonding material and the temperature at which the bonding takes place.
  • circuit board layers are fabricated as described above.
  • the bumps and circuitry are then plated with at thin conductive metallurgy for example gold, tin, nickel, palladium and the like.
  • the electrically insulating bonding material 58, 24, 60, and 62, used to bond the layers shown in Figure 9 is an anisotropically conductive adhesive.
  • These adhesives are capable of conducting electricity in one direction while insulating in the other two directions. In this embodiment, there is no direct metallic bonding of the metal pad and bump. Electrical contact is made through a very thin layer of adhesive pressed between a given bump and its corresponding pad.
  • An example of one type of anisotropically conductive adhesive is described in U.S.
  • Patent 5,143,785 issued September 1, 1992 held by 3M.
  • This adhesive is structured such that when the adhesive is compressed under heat and pressure to form a bond, small conductive particles dispersed in the resin are trapped between the bump and the contact pd and are compressed forming electrical contacts between the bump and the contact pad. The adhesive cures trapping the particles in place. No metal reflow is needed for such a bond and thus laminations can be performed at temperatures below the melting point of the interface metallurgy.
  • Figure 11 shows a test sample 70 having circuit board layers 72 and 74.
  • Circuit board layer 72 carries copper layer 76 and circuit board layer 74 carries copper layer 78.
  • "Bumps" 80, 82, 84, and 86 extend between copper layer 76 and copper layer 78 and contact copper layer 78 in accordance with the present invention.
  • An insulating dielectric adhesive layer 88 separates circuit board 72 from circuit board 74.
  • each sample had a total of 16 "bumps.” Electrical resistance measurements were made between copper layer 76 and copper layer 78. All six samples showed a resistance of less than 0.10 Ohms. Circuit boards 72 and 74 were pulled apart so that the individual "bumps" could be examined. As the samples were pulled apart, most of the bumps were transferred to copper layer 78 so that the individual bumps could be tested. Using a four point test probe, each bump had an electrical resistance of less than 0.10 Ohms. Resistance measurements as low as 0.5 milli-Ohms have been observed.
  • edges may be sealed by allowing the adhesive to overlap the edges. This improves the reliability of the electrical interconnections under conditions of high humidity and temperature. Samples fabricated in the manner of these examples have survived humidity aging tests for over 1000 hours at 85°C and 85% relative humidity.
  • the present invention provides an improved electrical interconnection between adjacent circuit board layers in a multi-layer circuit board.
  • the fabrication process for the circuit layers of the present invention is based on the enhancement of the processing of fine pitched metallized circuit layers which are already produced in high volume for use in TAB and flex circuitry.
  • the lamination technology used to assemble the circuit boards of the current invention is based on the enhancement of conventional high volume printed circuit board production.
  • the invention includes a simple improved method of electrical interconnection which allows the combining of these two well developed technologies to produce a circuit board that has interconnect densities in the range of high density circuits but is manufactured using conventional techniques and materials at significantly lower cost. Since all of the circuitry is fabricated prior to lamination, each circuit layer can be inspected prior to lamination into the full multi-layer structure thereby increasing yield. Furthermore, fabricating the circuit board in a single lamination step, so called parallel processing, results in significant cost savings over the prior art.
  • the invention provides for a via formation process that yields vias which are much smaller than the prior PCB art and can be buried, blind and stacked without additional processing. The smaller vias provide for the resulting increase in circuit density achieved using the current invention.
  • the invention also provides for a substrate with some inherent flexibility.
  • the present invention can be employed with a wide range of dielectric films which are used to form individual circuit board layers. Although a description of a "bump” contacting an electrical pad has been shown, the present invention can also be used where a "bump” contacts another "bump.”
  • via holes can be formed by any wet or dry process such as laser ablation, reactive ion etching, mechanical punching, photo imaging, chemical milling, mechanical forming, casting etc.
  • adhesives and dielectrics than those described can be used.
  • the adhesive layer can be removed altogether replacing the dielectric substrate film with a conformable film that bonds to the adjacent layers.
  • conformable polyamide and the like can be used.
  • the present invention can be used in forming multi-chip modules, tape automated bonding of double metal (ground plane) tape, and other microelectronic interconnect devices.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Power Engineering (AREA)
  • Production Of Multi-Layered Print Wiring Board (AREA)

Abstract

A multi-layer circuit board includes electrical interconnections between adjacent circuit board layers of the multi-layer board. A via hole is provided through a circuit board layer. The via hole is filled with a via metal. The via metal is plated with a low melting point metal. An adhesive film is deposited over the circuit board layer. Adjacent layers of the multi-layer circuit board are stacked and aligned together. The layers are laminated under heat and pressure. The low melting point metal provides an electrical interconnection between adjacent layers.

Description

METHOD FOR PROVIDING ELECTRICAL
INTERCONNECTIONS BETWEEN ADJACENT CIRCUIT BOARD
LAYERS OP A MULTI-LAYER CIRCUIT BOARD
BACKGROUND OF THE INVENTION
The present invention relates to multi-layer circuit boards. In particular, the invention relates to improved electrical interconnections for circuit board layers of a multi-layer circuit board, and to a method of making those interconnections.
Multi-layer printed circuit boards are known in the art, and are used to make complex electrical circuits. (As used herein, a circuit board consists of a pattern of conductive traces which are used to interconnect electric components. The conductive traces are bonded to or otherwise incorporated into an insulating substrate which mechanically supports the components. This includes single and double sided boards, multi layer constructions, hybrids, multi-chip modules, chip on board assemblies and the like. The conductive traces may be formed using any number of techniques, for example electroplating, etching, sputtering, mechanical attachment using adhesives and others. The substrate can be flexible or rigid and can be fabricated of any suitable material, for example polymers, ceramics, glasses, silicon etc.) Electrical connections between components of the electrical circuits are provided on the circuit board layers of the multi¬ layer circuit board. Using multiple circuit board layers allows the circuit designer to lay out complex circuit designs using many components in which those components require numerous interconnections. Multi-layer circuit boards increase component density and functionality per unit volume. Each circuit board layer of a multi-layer circuit board carries electrical connections, or electrical traces, which act as wires and are used to interconnect the various components of the circuit. Electrical connection between adjacent circuit board layers is achieved using "vias." A via is created by forming a hole between adjacent layers. The hole is filled with conductive material to form an electrical connection between the two adjacent layers.
Typically in printed circuit board (PCB) fabrication (otherwise known as printed wiring board or plated through hole technology) , the electrical traces are formed separately on each layer of the multi layer circuit board. The circuit board layers of the multi¬ layer circuit board are then stacked and aligned to each other with an electrically insulating bonding layer between adjacent layers. The assembled layers are then subjected to heat and pressure to provide a bond between adjacent layers. Via holes are then drilled in the appropriate locations which interconnect pads on successive layers. The electrical interconnect is achieved by applying a conductive material to the side walls of the via holes. The prior art requires the metal via contact pads to have sufficient area on the circuit board to accommodate the drill cross section and/or any misalignment. These large pad areas limit the component density of the circuit board. To form buried vias additional processing is required. Namely, the above structure is treated as a sub-assembly several of which can be laminated together to form the full board.
The advent of semiconductor processing and advanced materials has permitted the fabrication of circuit boards on a much finer scale than the printed circuit boards described above. Examples of these include hybrids, multi-chip modules (MCMs) and the like. Typically, MCMs are manufactured in small numbers of aerospace, military and supercomputer applications. An example would be MCM-Ds. The D refers to deposition where a circuit is built up upon an inorganic non¬ conducting substrate using thin film approaches with copper or aluminum traces and organic or inorganic dielectrics. Using these technologies a multi layer circuit is built up by a sequential process. This technology is capable of fabricating very fine lines and vias (blind, stacked, and buried) resulting in very much higher circuit densities than traditional plated through hole technology described above. However, this increased density comes at the cost of much more expensive processing which is usually accomplished in sequential batch processing. Batch processing does not lend itself to high volume production and the sequential fabrication results in lower yield as the deposition of one defective layer ruins an entire part.
U.S. Patent 5,046,238 issued September 10, 1991 to Daigle et al. entitled METHOD OF MANUFACTURING A MULTILAYER CIRCUIT BOARD describes a method for providing interconnections between layers of a multi-layer circuit board and is hereby incorporated by reference. The technology is practiced using fluoropolymers which are expensive and are traditionally difficult to process. Processing difficulties include adhesion problems and the requirement of high temperatures for processing laminates (700°F and above) . In addition, the process is practiced in batch form which is not easily amendable to high volume production.
SUMMARY OF THE INVENTION The present invention provides an improved process for assembling a multi-layer circuit board with an improved wiring density. The invention provides an improved method of forming interconnections between adjacent layers in a multi-layer circuit board where stacked, buried and blind vias which occupy areas smaller than those occupied by plated through hole technology can be fabricated routinely. The invention does not rely on high cost low volume fabrication methods such as is common in the fabrication of MCMs. In addition, a parallel process for assembling a multi-layer circuit board that reduces the number of manufacturing sequences and increases the yield of completed parts in comparison to sequential processing is provided. Each circuit board layer is fabricated separately allowing inspection of each layer prior to incorporation in the final part.
In one embodiment of the invention, a circuit board layer is formed by depositing electrically conductive material which forms electrical circuit traces as well as interconnect pads on one side of an electrically insulating material. The electrically conductive traces are then exposed on the uncircuitized side of the circuit board layer by forming holes in the electrically insulating material at locations where a via is desired.
The interconnection is fabricated by the formation of rigid bumps of a conductive material in the holes formed in the electrically insulating material which protrude above the surface of the electrically insulating material. An electrically conducting metal which is capable of forming an electrically sound metal to metal bond between the bump and the corresponding pad on an adjacent layer is then deposited on the surface of the bumps or the pads, more frequently on both. In accordance with another aspect of the invention, a layer of electrically insulating bonding material is deposited over at least one of the surfaces of the circuit board layer fabricated as described above. A plurality of these layers are then aligned and fused together by the application of heat and pressure in a single lamination step to form a multi-layer circuit board. The metal on the surfaces of the bumps bonds with the metal on the pads providing the electrical interconnect between layers and the insulating bonding material forms the mechanical bond that holds the layers together and isolates the via connections. The above fabrication method can be carried out in a batch process, a continuous process or in a combination of the two. Fabrication using a continuous process enables large volume production of the circuit board layers a clear advantage over the batch type process practiced in both PCB and MCM manufacturing. The ability to perform the majority of the fabrication in a continuous process is an important aspect of this invention. In another embodiment, the circuit board layers are fabricated in the method described above and laminated under heat and pressure as described above however, the insulating bonding material is substituted with an anisotropically conductive adhesive which by design is an electrical insulator in the plane of the circuit layer but permits electrical conduction in the out of plane direction.
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side cross sectional view of a dielectric film circuit board layer.
Figure 2 is a side cross sectional view of the circuit board layer of Figure 1 including an adhesion and seed metal layer. Figure 3 is a side cross sectional view of the circuit board layer of Figure 2 including patterned photoresists.
Figure 4 is a side cross sectional view of the circuit board layer of Figure 3 including a layer of trace metal.
Figure 5 is a side cross sectional view of the circuit board layer of Figure 4 including a via hole extending through the circuit board.
Figure 6 is a side cross sectional view of the circuit board layer of Figure 5 following removal of the photoresist and plating of a solid via. Figure 7 is a side cross sectional view of the circuit board layer of Figure 6 following removal of the adhesion and seed metal layer.
Figure 8 is a side cross sectional view of the circuit board layer of Figure 7 following deposition of a cover metal layer.
Figure 9 is a side cross sectional view of the circuit board layer of Figure 8 including an adhesive film and a plurality of spaced apart circuit board layers.
Figure 10 is a side cross sectional view of the circuit board layers of Figure 9 following lamination to form a multi-layer circuit board in accordance with the present invention. Figure 11 is a side cross sectional view of a test sample.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Figures 1 through 11 are cross sectional views. For clarity, cross hatching has been omitted.
Figure 1 shows a cross-sectional view of a circuit board layer 10. In a preferred embodiment, circuit board layer 10 comprises a precast polymeric dielectric film. The particular dielectric film used is a matter of choice however, web polyimide is an example of one that works well. As shown in Figure 2, a conductive metal layer, and an adhesion layer is deposited if needed, on the first side of circuit layer 10. The adhesion layer helps bond the metal layer to the dielectric film. The composition of the adhesive layer is a matter of choice depending on the metal and dielectric materials used. The outer metal layer portion of layer 12 can be comprised of copper or other appropriate conductive metal and can be deposited by any appropriate method. Electrodeposition is one process that works well. The resulting metal layer 12 acts as a seed layer for later deposition. Next, photoresist 14 is deposited, as shown in Figure 3. Photoresist 14 is a standard photoresist deposited on circuit board 10 using conventional techniques. The photoresist is exposed to radiation through a mask. The photoresist is then developed, which causes portions of the photoresist to be removed exposing material and forming a patterned layer 14 as shown in Figure 3.
After photoresist layer 14 has been patterned, a trace metal layer 16 is deposited on the exposed adhesion and conductive metal layer 12 as shown in Figure 4. In a preferred embodiment, trace metal layer 16 comprises copper and is deposited through electrodeposition techniques so that it is only formed on the exposed portions of layer 12. Trace metal layer 16 forms an electrical circuit carried on circuit board layer 10. Trace metal layer 16 provides the electrical traces which will interconnect components when they are placed in the completed multi-layer circuit board. Additionally, the trace metal provides electrical "pads" which are used to interconnect adjacent circuit board layers. The above discussion of circuitization of the dielectric illustrates one method of depositing circuit traces on the dielectric however, other methods can be used to deposit the circuit traces on the dielectric without changing the invention, for example both additive and subtractive process including sputtering, electroless plating, dry etching and the like.
Next, a via hole 18 is formed in circuit board layer 10 as shown in Figure 5. In a preferred embodiment, via hole 18 is formed using a wet milling technique. This may include application of a hot fluid etch such as potassium hydroxide. Photoresist layer 14 and trace metal layer 16 protect portions of circuit board layer 10. The wet milling is of sufficient duration to ensure that via hole 18 extends all the way through circuit board layer 10 to layer 12. The invention described in the above paragraphs eliminates the necessity of using the annular ring characteristic of plated through hole technology and thus allows for increased circuit density. In other embodiments, the via holes can be formed using any applicable wet or dry milling process. Examples of dry milling processes include laser ablation, ion milling, reactive ion etching, mechanical punching and the like, some of which provide for the formation of holes that are much smaller than those produced by mechanical drilling. This yields even smaller vias and a further increase in circuit density.
Once the via holes have been formed, photoresist layer 14 carried on both sides of circuit board 10 is stripped, and circuit board 10 is plated with via metal 20, as shown in Figure 6. Via metal 20 can be deposited separately or simultaneously with trace metal layer 16 on the opposite side. Via metal 20 electrically contacts trace metal layer 16 through layer 12 and forms a "bump" or "crown" that extends above the top surface of circuit board 10. This bump is used to electrically interconnect adjacent circuit board layers in accordance with the present invention. Via metal 20 should have good electrical conductivity and a high melting temperature relative to a solder. Preferably via metal 20 melts at a temperature greater than 500 C.The trace metal layer 16 forms electrical "pads" which contact the via metal bumps of adjacent circuit board layers. The adhesion and seed metal layer 12 is etched and removed from the circuit side of circuit board layer 10. This removes a small portion of trace metal layer 16. This is shown in the cross sectional view of Figure 7.
Next, a second metal layer 22 is deposited on via metal 20 and on the trace metal layer 16 as shown in Figure 9. In one embodiment, the second cover metal layer 22 is composed of a low melting point metal (low relative to the other metal layers) which is used to fuse with the pad on the adjacent circuit board layer to form electrically stable interconnections between layers. The bump and pads can have the same or different metallurgies and the quantity of metal must be sufficient to provide a stable electrical bond but not so much that reflow causes shorting with adjacent interconnections. Suitable metals for this cover layer include tin-lead, solder, tin, gold-tin alloys or other metals. Layer 22 can be deposited by electroplating, electroless plating, spraying or other process. Tin deposited on both the bump and the pad by an electroless process is one example of a metallurgy that works well. The melting temperature of the cover metal layer has an upper limit which cannot exceed the degradation temperature of the polymeric film, layer 10, or the adhesive layers 58, 24, 60, and 62. While it is desirable in this embodiment to have reflow of the interfacial metallurgy, it is not necessary that the metals melt. Other embodiments include bonding using other means for example cold welding, ultrasonic welding, and the like. The interconnect has been made with just a contact bond as well. It is desirable but not compulsory to accomplish all of the fabrication steps discussed above in a continuous web roll to roll process which amendable to high volume low cost production. Figure 9 shows circuit board layer 10 including an electrically insulating bonding film 24 placed between adjacent layers. Additionally, Figure 9 shows circuit board layers 26, 28, 30, and 32 which have been prepared in accordance with the present invention, as set forth above. Circuit board layers 26-32 include trace metal layers 34, 36, 38, and 40, respectively. Via metal 42, 44, 46, and 48 is deposited in via holes of circuit board layers 26, 28, 30, and 32, respectively. Cover metal layers 50, 52, 54, and 56 are deposited on trace metal layers 34, 36, 38, and 40 and via metal 42, 44, 46, and 48 of circuit boards 26, 28, 30, and 32, respectively. As shown in Figure 9, the present invention is well suited for forming blind and buried vias, as well as stacked vias as shown by vias 44 46, and 42 and 20. The electrically insulating bonding film layers 58, 24, 60, and 62 are deposited on circuit board layers 26, 10, 28, and 30 and separate adjacent circuit board layers. The particular polymer used is a matter of choice although epoxy compounds have been found to work well. While Figure 9 shows only five layers, it will be understood that the invention allows for lamination of a plurality of circuit board layers to be assembled as shown to form an interconnected structure. It should be noted as well that such an interconnect could be used to attach a single or multiplicity of layers to a rigid substrate. For example, a flex circuit could be attached to a printed circuit board by putting bumps on the flex and pads on the board.
Following completion of the formation of circuit board layers 10, 26, 28, 30, and 32, the circuit board layers are stacked and aligned as shown in Figure 9. Specifically, the via metal bump layer of one layer is aligned with its corresponding electrical pad on an adjacent layer. The alignment can be performed by any suitable means. Mechanical alignment using alignment pins is one method that works well. Once circuit board layers 10 and 26-32 are aligned as shown in Figure 9, they are laminated together under heat and pressure to form the structure shown in Figure 10. The lamination causes an electrical contact where the "bump" of the via metal of one layer contacts an electrical pad of an adjacent layer and the low melting point metal fuses together. Simultaneously, the adhesive layers fuse together forming a mechanical bond that holds the circuit board layers together and isolates the electrical contacts. The lamination conditions are a matter of choice and depend on the polymers and metallurgies involved. Applicable pressure ranges include 0.15 MPa - 5 MPa, more preferably 0.3 MPa - 3.5 MPa, and more preferably 0.7 - 1.7 MPa. Temperature ranges for lamination are 80°C-425°C, more preferable 130-350°C, and more preferably 175-280°C. The metal- metal bond is formed instantly and thus the lamination time is dependant on the chosen adhesive bonding material and the temperature at which the bonding takes place.
In another embodiment of the present invention, circuit board layers are fabricated as described above. The bumps and circuitry are then plated with at thin conductive metallurgy for example gold, tin, nickel, palladium and the like. In this embodiment of the invention, the electrically insulating bonding material 58, 24, 60, and 62, used to bond the layers shown in Figure 9 is an anisotropically conductive adhesive. These adhesives are capable of conducting electricity in one direction while insulating in the other two directions. In this embodiment, there is no direct metallic bonding of the metal pad and bump. Electrical contact is made through a very thin layer of adhesive pressed between a given bump and its corresponding pad. An example of one type of anisotropically conductive adhesive is described in U.S. Patent 5,143,785 issued September 1, 1992 held by 3M. This adhesive is structured such that when the adhesive is compressed under heat and pressure to form a bond, small conductive particles dispersed in the resin are trapped between the bump and the contact pd and are compressed forming electrical contacts between the bump and the contact pad. The adhesive cures trapping the particles in place. No metal reflow is needed for such a bond and thus laminations can be performed at temperatures below the melting point of the interface metallurgy.
Figure 11 shows a test sample 70 having circuit board layers 72 and 74. Circuit board layer 72 carries copper layer 76 and circuit board layer 74 carries copper layer 78. "Bumps" 80, 82, 84, and 86 extend between copper layer 76 and copper layer 78 and contact copper layer 78 in accordance with the present invention. An insulating dielectric adhesive layer 88 separates circuit board 72 from circuit board 74.
Six samples similar to sample 70 were made. Each sample had a total of 16 "bumps." Electrical resistance measurements were made between copper layer 76 and copper layer 78. All six samples showed a resistance of less than 0.10 Ohms. Circuit boards 72 and 74 were pulled apart so that the individual "bumps" could be examined. As the samples were pulled apart, most of the bumps were transferred to copper layer 78 so that the individual bumps could be tested. Using a four point test probe, each bump had an electrical resistance of less than 0.10 Ohms. Resistance measurements as low as 0.5 milli-Ohms have been observed.
When laminating circuit board layers of the present invention, the edges may be sealed by allowing the adhesive to overlap the edges. This improves the reliability of the electrical interconnections under conditions of high humidity and temperature. Samples fabricated in the manner of these examples have survived humidity aging tests for over 1000 hours at 85°C and 85% relative humidity.
In another example, many samples fabricated from flexible Kapton polyimide substrate similar to that of Figure 11 with 4 by 5 inch arrays of bumps with a pitch of 40 mils and bump diameter and heights of less than 200 and 25 μm respectively and a tin cover metallurgy were bonded to a tin plated copper substrate. A high performance 9900 epoxy adhesive film available from Minnesota Mining and Manufacturing Company of Saint Paul, Minnesota was used as the bonding adhesive Laminations were executed at 450°F and 500 Psi for 30 minutes. Individual vias were isolated by etching the surrounding copper after bonding and single via resistances of less than 10 milli-Ohms were measured. Examination of sectioned samples using optical and scanning electron microscopy revealed reflow of the tin at the bump-pad interface indicating good electrical contact. Samples with a plurality of such layers have been fabricated as well. The present invention provides an improved electrical interconnection between adjacent circuit board layers in a multi-layer circuit board. The fabrication process for the circuit layers of the present invention is based on the enhancement of the processing of fine pitched metallized circuit layers which are already produced in high volume for use in TAB and flex circuitry. The lamination technology used to assemble the circuit boards of the current invention is based on the enhancement of conventional high volume printed circuit board production. The invention includes a simple improved method of electrical interconnection which allows the combining of these two well developed technologies to produce a circuit board that has interconnect densities in the range of high density circuits but is manufactured using conventional techniques and materials at significantly lower cost. Since all of the circuitry is fabricated prior to lamination, each circuit layer can be inspected prior to lamination into the full multi-layer structure thereby increasing yield. Furthermore, fabricating the circuit board in a single lamination step, so called parallel processing, results in significant cost savings over the prior art. The invention provides for a via formation process that yields vias which are much smaller than the prior PCB art and can be buried, blind and stacked without additional processing. The smaller vias provide for the resulting increase in circuit density achieved using the current invention. The invention also provides for a substrate with some inherent flexibility. The present invention can be employed with a wide range of dielectric films which are used to form individual circuit board layers. Although a description of a "bump" contacting an electrical pad has been shown, the present invention can also be used where a "bump" contacts another "bump."
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example via holes can be formed by any wet or dry process such as laser ablation, reactive ion etching, mechanical punching, photo imaging, chemical milling, mechanical forming, casting etc. Different adhesives and dielectrics than those described can be used. The adhesive layer can be removed altogether replacing the dielectric substrate film with a conformable film that bonds to the adjacent layers. For example, conformable polyamide and the like. The present invention can be used in forming multi-chip modules, tape automated bonding of double metal (ground plane) tape, and other microelectronic interconnect devices.

Claims

WHAT IS CLAIMED IS:
1. A method of making a multi-layer interconnect, comprising: depositing a trace metal layer on a first side of a first circuit board layer; forming a via hole extending between the first side and a second side of the first circuit board layer, wherein the via hole extends to the trace metal layer; depositing a via metal in the via hole such that said via metal forms a crown outward from said via hole on said second side of said first circuit board layer; depositing an electrical contact on a first side of a second circuit board layer; aligning the first circuit board layer with a second circuit board layer, wherein an adhesive is between the first and second circuit board layers and the electrical contact of the second circuit board layer is generally aligned with a via of the first circuit board layer; and laminating the first circuit board layer to the second circuit board layer wherein the via metal of the first circuit board layer electrically contacts the electrical contact of the second circuit board layer.
2. The method of Claim 1 wherein forming a via comprises wet or dry milling the first circuit board layer.
3. The method of Claim 2 wherein dry milling comprises using laser ablation to fabricate the holes in the first circuit board layer.
4. The method of Claim 1 further comprising overplating the via metal with a low melting temperature metal.
5. The method of Claim 1 wherein depositing an electrical contact comprises depositing a trace metal layer, the trace metal layer forming an electrical pad as the electrical contact.
6. The method of Claim 1 including laminating at least a third circuit board layer to the first and second circuit board layers.
7. A multi-layer interconnect, comprising: a first circuit board layer having a first side and a second side, the first circuit board layer including a via hole extending through the first circuit board layer from the first side to the second side; a trace metal layer deposited on the first side of the first circuit board layer; conductive via metal carried in the via hole of the first circuit board layer, the conductive via material in electrical contact with the trace metal and forming a crown exterior to the via hole on the second side of the first circuit board layer; a second circuit board layer having a first side; an adhesive between the first side of the first circuit board layer and the first side of the second circuit board layer; and an electrical contact on the first side of the second circuit board layer, the electrical contact generally aligned with the via hole and the conductive via material, wherein the conductive via material provides an electrical conduction path between the trace metal and the electrical contact.
8. The multi-layer interconnect of Claim 7 wherein the first and second circuit board layers comprise polymeric film.
9. A method of making a multi-layer interconnect, comprising: forming a first circuit board layer having a via hole extending between a first side to a second side, the via hole extending to a trace metal layer carried on the first side, the via hole carrying a conductive via material in electrical contact with the trace metal layer and forming a crown exterior to the via hole on the second side of the first circuit board layer; forming a second circuit board layer having an electrical contact carried on a first side; aligning the first circuit board layer with the second circuit board layer wherein the via hole of the first circuit board is substantially aligned with the electrical contact of the second circuit board layer; and laminating the first circuit board layer to the second circuit board layer wherein the conductive via material of the first circuit board layer electrically contacts the electrical contact of the second circuit board layer.
10. The method of Claim 9 including laminating at least a third circuit board layer to the first and second circuit board layers.
PCT/US1994/006387 1993-06-08 1994-06-07 Method for providing electrical interconnections between adjacent circuit board layers of a multi-layer circuit board WO1994029897A1 (en)

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EP94919395A EP0702847A1 (en) 1993-06-08 1994-06-07 Method for providing electrical interconnections between adjacent circuit board layers of a multi-layer circuit board
JP7502035A JPH08510868A (en) 1993-06-08 1994-06-07 Method for forming an electrical interconnection between adjacent circuit board layers of a multilayer circuit board
KR1019950705493A KR960702938A (en) 1993-06-08 1995-12-05 METHOD FOR PROVIDING ELECTRICAL INTERCONNECTIONS BETWEEN ADJACENT CIRCUIT BOARD LAYERS OF A MULTI-LAYER CIRCUIT BOARD

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0851725A1 (en) * 1996-12-27 1998-07-01 Shinko Electric Industries Co. Ltd. Multi-layer wiring board
US6638378B2 (en) 1999-02-01 2003-10-28 3M Innovative Properties Company Passive electrical article, circuit articles thereof, and circuit articles comprising a passive electrical article
US6812060B1 (en) 1999-10-18 2004-11-02 Sony Chemicals Corporation Multilayer flexible wiring boards and processes for manufacturing multilayer flexible wiring boards
DE19681758B4 (en) * 1996-06-14 2006-09-14 Ibiden Co., Ltd. Single-sided circuit substrate for multi-layer circuit board, multi-layer circuit board and method of making the same
US7721427B2 (en) 1997-06-06 2010-05-25 Ibiden Co., Ltd. Method for manufacturing single sided substrate

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Publication number Priority date Publication date Assignee Title
US5736681A (en) * 1993-09-03 1998-04-07 Kabushiki Kaisha Toshiba Printed wiring board having an interconnection penetrating an insulating layer
US5745987A (en) * 1995-10-20 1998-05-05 Lucent Technologies Inc. Method for bonding circuit boards to pallets
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US6147870A (en) * 1996-01-05 2000-11-14 Honeywell International Inc. Printed circuit assembly having locally enhanced wiring density
US5839188A (en) * 1996-01-05 1998-11-24 Alliedsignal Inc. Method of manufacturing a printed circuit assembly
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US5819401A (en) * 1996-06-06 1998-10-13 Texas Instruments Incorporated Metal constrained circuit board side to side interconnection technique
US6112407A (en) * 1996-06-24 2000-09-05 Circuitronics, Inc. Latticework with plurality of overlying lines
US5829127A (en) * 1996-06-24 1998-11-03 Circuitronics, Inc. Latticework with plurality of overlying lines
US5873161A (en) * 1996-07-23 1999-02-23 Minnesota Mining And Manufacturing Company Method of making a Z axis interconnect circuit
US6375871B1 (en) 1998-06-18 2002-04-23 3M Innovative Properties Company Methods of manufacturing microfluidic articles
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US6071597A (en) * 1997-08-28 2000-06-06 3M Innovative Properties Company Flexible circuits and carriers and process for manufacture
US6156484A (en) * 1997-11-07 2000-12-05 International Business Machines Corporation Gray scale etching for thin flexible interposer
US6038133A (en) * 1997-11-25 2000-03-14 Matsushita Electric Industrial Co., Ltd. Circuit component built-in module and method for producing the same
US6063647A (en) 1997-12-08 2000-05-16 3M Innovative Properties Company Method for making circuit elements for a z-axis interconnect
US6294407B1 (en) * 1998-05-06 2001-09-25 Virtual Integration, Inc. Microelectronic packages including thin film decal and dielectric adhesive layer having conductive vias therein, and methods of fabricating the same
US6140707A (en) * 1998-05-07 2000-10-31 3M Innovative Properties Co. Laminated integrated circuit package
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US6400018B2 (en) 1998-08-27 2002-06-04 3M Innovative Properties Company Via plug adapter
US6163957A (en) * 1998-11-13 2000-12-26 Fujitsu Limited Multilayer laminated substrates with high density interconnects and methods of making the same
US6246010B1 (en) * 1998-11-25 2001-06-12 3M Innovative Properties Company High density electronic package
JP2000332369A (en) * 1999-05-25 2000-11-30 Mitsui Mining & Smelting Co Ltd Printed-circuit board and its manufacture
US6326555B1 (en) 1999-02-26 2001-12-04 Fujitsu Limited Method and structure of z-connected laminated substrate for high density electronic packaging
US6462414B1 (en) 1999-03-05 2002-10-08 Altera Corporation Integrated circuit package utilizing a conductive structure for interlocking a conductive ball to a ball pad
US6492600B1 (en) * 1999-06-28 2002-12-10 International Business Machines Corporation Laminate having plated microvia interconnects and method for forming the same
US7223364B1 (en) 1999-07-07 2007-05-29 3M Innovative Properties Company Detection article having fluid control film
US6583364B1 (en) * 1999-08-26 2003-06-24 Sony Chemicals Corp. Ultrasonic manufacturing apparatuses, multilayer flexible wiring boards and processes for manufacturing multilayer flexible wiring boards
JP3183653B2 (en) * 1999-08-26 2001-07-09 ソニーケミカル株式会社 Flexible board
SE521704C2 (en) * 1999-10-29 2003-11-25 Ericsson Telefon Ab L M Method for arranging coupling between different layers of a circuit board and circuit board
US6451191B1 (en) * 1999-11-18 2002-09-17 3M Innovative Properties Company Film based addressable programmable electronic matrix articles and methods of manufacturing and using the same
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US6316734B1 (en) 2000-03-07 2001-11-13 3M Innovative Properties Company Flexible circuits with static discharge protection and process for manufacture
US6377433B1 (en) * 2000-03-17 2002-04-23 The Boeing Company Electrical fuse/support assembly
JP2001320167A (en) * 2000-05-10 2001-11-16 Ibiden Co Ltd Method of manufacturing multilayer circuit board
JP3951091B2 (en) * 2000-08-04 2007-08-01 セイコーエプソン株式会社 Manufacturing method of semiconductor device
US6624383B1 (en) * 2000-08-30 2003-09-23 Parker-Hannifin Corporation Using laser etching to improve surface contact resistance of conductive fiber filler polymer composites
US7331502B2 (en) * 2001-03-19 2008-02-19 Sumitomo Bakelite Company, Ltd. Method of manufacturing electronic part and electronic part obtained by the method
US6879492B2 (en) * 2001-03-28 2005-04-12 International Business Machines Corporation Hyperbga buildup laminate
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US6459043B1 (en) 2001-03-29 2002-10-01 3M Innovative Properties Company Flexible circuit with electrostatic damage limiting feature and method of manufacture
JP3826731B2 (en) * 2001-05-07 2006-09-27 ソニー株式会社 Multilayer printed wiring board and method for manufacturing multilayer printed wiring board
US6995954B1 (en) 2001-07-13 2006-02-07 Magnecomp Corporation ESD protected suspension interconnect
US6558560B2 (en) * 2001-07-27 2003-05-06 Hewlett-Packard Company Method for the fabrication of electrical contacts
TWI312166B (en) * 2001-09-28 2009-07-11 Toppan Printing Co Ltd Multi-layer circuit board, integrated circuit package, and manufacturing method for multi-layer circuit board
US6818464B2 (en) * 2001-10-17 2004-11-16 Hymite A/S Double-sided etching technique for providing a semiconductor structure with through-holes, and a feed-through metalization process for sealing the through-holes
US7080445B2 (en) * 2001-10-31 2006-07-25 Denso Corporation Method for connecting printed circuit boards and connected printed circuit boards
US6805280B2 (en) * 2002-01-08 2004-10-19 International Business Machines Corporation Z interconnect structure and method
JP3807312B2 (en) * 2002-01-18 2006-08-09 富士通株式会社 Printed circuit board and manufacturing method thereof
US7514045B2 (en) * 2002-01-18 2009-04-07 Avery Dennison Corporation Covered microchamber structures
US20030155656A1 (en) * 2002-01-18 2003-08-21 Chiu Cindy Chia-Wen Anisotropically conductive film
WO2003061949A1 (en) * 2002-01-18 2003-07-31 Avery Dennison Corporation Sheet having microsized architecture
US6596384B1 (en) * 2002-04-09 2003-07-22 International Business Machines Corporation Selectively roughening conductors for high frequency printed wiring boards
TW530377B (en) * 2002-05-28 2003-05-01 Via Tech Inc Structure of laminated substrate with high integration and method of production thereof
US7260890B2 (en) * 2002-06-26 2007-08-28 Georgia Tech Research Corporation Methods for fabricating three-dimensional all organic interconnect structures
US6900708B2 (en) * 2002-06-26 2005-05-31 Georgia Tech Research Corporation Integrated passive devices fabricated utilizing multi-layer, organic laminates
US7576288B2 (en) * 2002-11-27 2009-08-18 Sumitomo Bakelite Company Limited Circuit board, multi-layer wiring boards, method of producing circuit boards and method of producing multilayer wiring boards
JP3981026B2 (en) * 2003-01-30 2007-09-26 株式会社東芝 Semiconductor device having multilayer wiring layer and method for manufacturing the same
US7489914B2 (en) * 2003-03-28 2009-02-10 Georgia Tech Research Corporation Multi-band RF transceiver with passive reuse in organic substrates
JP3933094B2 (en) * 2003-05-27 2007-06-20 セイコーエプソン株式会社 Electronic component mounting method
WO2005008733A2 (en) * 2003-07-14 2005-01-27 Avx Corporation Modular electronic assembly and method of making
US20050098605A1 (en) * 2003-11-06 2005-05-12 International Business Machines Corporation Apparatus and method for low pressure wirebond
US7489493B2 (en) * 2003-12-01 2009-02-10 Magnecomp Corporation Method to form electrostatic discharge protection on flexible circuits using a diamond-like carbon material
US7828736B2 (en) * 2004-01-27 2010-11-09 Fujinon Corporation Electronic scan type ultrasound diagnostic instrument
US7012017B2 (en) * 2004-01-29 2006-03-14 3M Innovative Properties Company Partially etched dielectric film with conductive features
US7772164B2 (en) * 2004-06-02 2010-08-10 Rhodia, Inc. Multicomponent viscoelastic surfactant fluid and method of using as a fracturing fluid
US8345433B2 (en) * 2004-07-08 2013-01-01 Avx Corporation Heterogeneous organic laminate stack ups for high frequency applications
US7446399B1 (en) 2004-08-04 2008-11-04 Altera Corporation Pad structures to improve board-level reliability of solder-on-pad BGA structures
JP4595471B2 (en) * 2004-09-30 2010-12-08 住友電気工業株式会社 Conductive paste and method for producing multilayer printed wiring board using the same
JP2007141956A (en) * 2005-11-15 2007-06-07 Three M Innovative Properties Co Printed-circuit board connection method
KR101150116B1 (en) * 2006-04-12 2012-06-08 히다치 가세고교 가부시끼가이샤 Circuit connecting adhesive film, circuit member connecting structure and circuit member connecting method
US7439840B2 (en) 2006-06-27 2008-10-21 Jacket Micro Devices, Inc. Methods and apparatuses for high-performing multi-layer inductors
US7808434B2 (en) * 2006-08-09 2010-10-05 Avx Corporation Systems and methods for integrated antennae structures in multilayer organic-based printed circuit devices
US7989895B2 (en) * 2006-11-15 2011-08-02 Avx Corporation Integration using package stacking with multi-layer organic substrates
CN100454669C (en) * 2007-07-26 2009-01-21 友达光电股份有限公司 Electric connection device, electronic device and electric product including the same
JP2009059814A (en) * 2007-08-30 2009-03-19 Denso Corp Manufacturing method of multilayer printed board
JP5306634B2 (en) * 2007-11-22 2013-10-02 新光電気工業株式会社 WIRING BOARD, SEMICONDUCTOR DEVICE, AND WIRING BOARD MANUFACTURING METHOD
US8179639B2 (en) * 2009-03-02 2012-05-15 Seagate Technology Llc Head gimbal assembly without bus traces for plating
JP5621311B2 (en) * 2010-05-11 2014-11-12 富士通株式会社 Circuit board manufacturing method
CN105101674A (en) * 2015-07-20 2015-11-25 惠州绿草电子科技有限公司 Manufacturing method of stacked circuit board and stacked circuit board
CN105578738B (en) * 2015-12-21 2019-01-25 上海交通大学 The preparation method of stretchable circuit board based on elastic substrate and stretchable circuit board
US10068851B1 (en) * 2017-05-30 2018-09-04 Advanced Semiconductor Engineering, Inc. Semiconductor package structure and method for manufacturing the same
CN108322997A (en) * 2018-03-07 2018-07-24 苏州诺莱声科技有限公司 A kind of flexible printed circuit board and the enhanced ultrasonic transducer that absorbs sound
WO2020060837A1 (en) 2018-09-20 2020-03-26 Applied Materials, Inc. Systems and methods for improving within die co-planarity uniformity

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02137293A (en) * 1988-11-17 1990-05-25 Toshiba Lighting & Technol Corp Multilayer circuit board
JPH0410696A (en) * 1990-04-27 1992-01-14 Nitto Denko Corp Multilayer wiring board
EP0494668A2 (en) * 1991-01-09 1992-07-15 Nec Corporation Polyimide multilayer wiring board and method of producing same
US5146674A (en) * 1991-07-01 1992-09-15 International Business Machines Corporation Manufacturing process of a high density substrate design
JPH04312998A (en) * 1991-01-09 1992-11-04 Nec Corp Polyimide multilayer wiring board and manufacture thereof
JPH04350993A (en) * 1991-05-29 1992-12-04 Fujitsu Ltd Via for heat dissipation and its forming method
EP0543364A2 (en) * 1991-11-21 1993-05-26 Nec Corporation Method for manufacturing polyimide multilayer wiring substrate
JPH05144973A (en) * 1991-11-20 1993-06-11 Nec Corp Polyimide multilayer circuit board and manufacture thereof

Family Cites Families (51)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3562009A (en) * 1967-02-14 1971-02-09 Western Electric Co Method of providing electrically conductive substrate through-holes
US3471631A (en) * 1968-04-03 1969-10-07 Us Air Force Fabrication of microminiature multilayer circuit boards
US3646670A (en) * 1968-07-19 1972-03-07 Hitachi Chemical Co Ltd Method for connecting conductors
GB1353671A (en) * 1971-06-10 1974-05-22 Int Computers Ltd Methods of forming circuit interconnections
US3795047A (en) * 1972-06-15 1974-03-05 Ibm Electrical interconnect structuring for laminate assemblies and fabricating methods therefor
FR2204940B1 (en) * 1972-10-27 1976-01-30 Thomson Csf Fr
US3888639A (en) * 1974-01-02 1975-06-10 Teledyne Electro Mechanisms Method for connecting printed circuits
US3953924A (en) * 1975-06-30 1976-05-04 Rockwell International Corporation Process for making a multilayer interconnect system
JPS5357481A (en) * 1976-11-04 1978-05-24 Canon Inc Connecting process
FR2402996A1 (en) * 1977-09-12 1979-04-06 Labo Electronique Physique PROCESS FOR MAKING METAL BUBBLES ON A SUBSTRATE PUNCHED, SUBSTRATE THUS TREATED AND USE
US4184729A (en) * 1977-10-13 1980-01-22 Bunker Ramo Corporation Flexible connector cable
DE2858153C2 (en) * 1978-05-10 1984-10-18 Siemens AG, 1000 Berlin und 8000 München Method for gluing an electrical component with a sheet-like electrode to a carrier plate
US4219708A (en) * 1979-02-12 1980-08-26 Detectors, Inc. Shockswitch
US4466184A (en) * 1981-04-21 1984-08-21 General Dynamics, Pomona Division Method of making pressure point contact system
US4396457A (en) * 1982-03-17 1983-08-02 E. I. Du Pont De Nemours And Company Method of making bumped-beam tape
US4627565A (en) * 1982-03-18 1986-12-09 Lomerson Robert B Mechanical bonding of surface conductive layers
JPS60227496A (en) * 1984-04-26 1985-11-12 日本電気株式会社 Method of producing multilayer printed circuit board
US4554033A (en) * 1984-10-04 1985-11-19 Amp Incorporated Method of forming an electrical interconnection means
US4572764A (en) * 1984-12-13 1986-02-25 E. I. Du Pont De Nemours And Company Preparation of photoformed plastic multistrate by via formation first
US4685210A (en) * 1985-03-13 1987-08-11 The Boeing Company Multi-layer circuit board bonding method utilizing noble metal coated surfaces
JPS6284973U (en) * 1985-11-19 1987-05-30
US4635073A (en) * 1985-11-22 1987-01-06 Hewlett Packard Company Replaceable thermal ink jet component and thermosonic beam bonding process for fabricating same
US4681654A (en) * 1986-05-21 1987-07-21 International Business Machines Corporation Flexible film semiconductor chip carrier
EP0260490A1 (en) * 1986-08-27 1988-03-23 Kabushiki Kaisha Toshiba Bonding sheet for electronic component and method of bonding electronic component using the same
US4912020A (en) * 1986-10-21 1990-03-27 Westinghouse Electric Corp. Printed circuit boards and method for manufacturing printed circuit boards
JPH07112041B2 (en) * 1986-12-03 1995-11-29 シャープ株式会社 Method for manufacturing semiconductor device
US4824521A (en) * 1987-04-01 1989-04-25 Fairchild Semiconductor Corporation Planarization of metal pillars on uneven substrates
JPS63249393A (en) * 1987-04-03 1988-10-17 シャープ株式会社 Method of connecting electronic component
US4788766A (en) * 1987-05-20 1988-12-06 Loral Corporation Method of fabricating a multilayer circuit board assembly
JPH0754872B2 (en) * 1987-06-22 1995-06-07 古河電気工業株式会社 Method for manufacturing double-layer printed circuit sheet
US4857482A (en) * 1987-06-30 1989-08-15 Kabushiki Kaisha Toshiba Method of forming bump electrode and electronic circuit device
US4867839A (en) * 1987-09-04 1989-09-19 Shinko Electric Industries Co., Ltd. Process for forming a circuit substrate
US4803450A (en) * 1987-12-14 1989-02-07 General Electric Company Multilayer circuit board fabricated from silicon
US4868350A (en) * 1988-03-07 1989-09-19 International Business Machines Corporation High performance circuit boards
US4854038A (en) * 1988-03-16 1989-08-08 International Business Machines Corporation Modularized fabrication of high performance printed circuit boards
US4864722A (en) * 1988-03-16 1989-09-12 International Business Machines Corporation Low dielectric printed circuit boards
US4935584A (en) * 1988-05-24 1990-06-19 Tektronix, Inc. Method of fabricating a printed circuit board and the PCB produced
US5008997A (en) * 1988-09-16 1991-04-23 National Semiconductor Gold/tin eutectic bonding for tape automated bonding process
US4925723A (en) * 1988-09-29 1990-05-15 Microwave Power, Inc. Microwave integrated circuit substrate including metal filled via holes and method of manufacture
GB8823537D0 (en) * 1988-10-06 1988-11-16 Telco Int Ltd Circuit board manufacture
US5031308A (en) * 1988-12-29 1991-07-16 Japan Radio Co., Ltd. Method of manufacturing multilayered printed-wiring-board
JPH0740496B2 (en) * 1989-03-01 1995-05-01 シャープ株式会社 Method of placing conductive particles on electrode
US4933045A (en) * 1989-06-02 1990-06-12 International Business Machines Corporation Thin film multilayer laminate interconnection board assembly method
US4970106A (en) * 1989-06-02 1990-11-13 International Business Machines Corporation Thin film multilayer laminate interconnection board
US5014162A (en) * 1989-06-27 1991-05-07 At&T Bell Laboratories Solder assembly of components
US5056216A (en) * 1990-01-26 1991-10-15 Sri International Method of forming a plurality of solder connections
US5046238A (en) * 1990-03-15 1991-09-10 Rogers Corporation Method of manufacturing a multilayer circuit board
US5060844A (en) * 1990-07-18 1991-10-29 International Business Machines Corporation Interconnection structure and test method
US5129142A (en) * 1990-10-30 1992-07-14 International Business Machines Corporation Encapsulated circuitized power core alignment and lamination
US5245135A (en) * 1992-04-20 1993-09-14 Hughes Aircraft Company Stackable high density interconnection mechanism (SHIM)
US5329423A (en) * 1993-04-13 1994-07-12 Scholz Kenneth D Compressive bump-and-socket interconnection scheme for integrated circuits

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02137293A (en) * 1988-11-17 1990-05-25 Toshiba Lighting & Technol Corp Multilayer circuit board
JPH0410696A (en) * 1990-04-27 1992-01-14 Nitto Denko Corp Multilayer wiring board
EP0494668A2 (en) * 1991-01-09 1992-07-15 Nec Corporation Polyimide multilayer wiring board and method of producing same
JPH04312998A (en) * 1991-01-09 1992-11-04 Nec Corp Polyimide multilayer wiring board and manufacture thereof
JPH04350993A (en) * 1991-05-29 1992-12-04 Fujitsu Ltd Via for heat dissipation and its forming method
US5146674A (en) * 1991-07-01 1992-09-15 International Business Machines Corporation Manufacturing process of a high density substrate design
JPH05144973A (en) * 1991-11-20 1993-06-11 Nec Corp Polyimide multilayer circuit board and manufacture thereof
EP0543364A2 (en) * 1991-11-21 1993-05-26 Nec Corporation Method for manufacturing polyimide multilayer wiring substrate

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 14, no. 380 (E - 0965) 16 August 1990 (1990-08-16) *
PATENT ABSTRACTS OF JAPAN vol. 16, no. 158 (E - 1191) 17 April 1992 (1992-04-17) *
PATENT ABSTRACTS OF JAPAN vol. 17, no. 148 (E - 1338) 24 March 1993 (1993-03-24) *
PATENT ABSTRACTS OF JAPAN vol. 17, no. 213 (E - 1356) 26 April 1993 (1993-04-26) *
PATENT ABSTRACTS OF JAPAN vol. 17, no. 528 (E - 1437) 22 September 1993 (1993-09-22) *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19681758B4 (en) * 1996-06-14 2006-09-14 Ibiden Co., Ltd. Single-sided circuit substrate for multi-layer circuit board, multi-layer circuit board and method of making the same
EP0851725A1 (en) * 1996-12-27 1998-07-01 Shinko Electric Industries Co. Ltd. Multi-layer wiring board
US7721427B2 (en) 1997-06-06 2010-05-25 Ibiden Co., Ltd. Method for manufacturing single sided substrate
US6638378B2 (en) 1999-02-01 2003-10-28 3M Innovative Properties Company Passive electrical article, circuit articles thereof, and circuit articles comprising a passive electrical article
US6812060B1 (en) 1999-10-18 2004-11-02 Sony Chemicals Corporation Multilayer flexible wiring boards and processes for manufacturing multilayer flexible wiring boards

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US5601678A (en) 1997-02-11
CA2162499A1 (en) 1994-12-22
US5401913A (en) 1995-03-28
CN1125998A (en) 1996-07-03
JPH08510868A (en) 1996-11-12
KR960702938A (en) 1996-05-23

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