WO2018031186A1

WO2018031186A1 - Printed circuit board fabrication methods programs and libraries

Info

Publication number: WO2018031186A1
Application number: PCT/US2017/042193
Authority: WO
Inventors: Marom LEVINER; Sharon Fima; Simon FRIED
Original assignee: Nano-Dimension Technologies, Ltd.; The IP Law Firm of Guy Levi, LLC
Priority date: 2016-08-08
Filing date: 2017-07-14
Publication date: 2018-02-15

Abstract

The disclosure relates to methods, programs and libraries for fabricating printed circuit boards (PCBs) using three-dimensional printers. Specifically, the disclosure relates to the 3D printing of conductive leads and insulating portions of printed circuit boards using inkjet printing based on converted CAD/CAM data packages.

Description

PRINTED CIRCUIT BOARD FABRICATION METHODS PROGRAMS AND LIBRARIES

BACKGROUND

[0001] The disclosure is directed to methods programs and libraries for fabricating printed circuit boards (PCBs) and/or flexible printed circuits (FPCs) using three-dimensional printers. Specifically, the disclosure is directed to the printing of conductive leads and insulating portions of printed circuit boards using inkjet printing based on converted CAD/CAM data packages.

[0002] Printed circuit boards (PCBs) are designed with the aid of computers and so-called printed circuit board CAD systems that enable a two-dimensional representation of the printed circuit board. Three-dimensional representations are possible, but they typically relate to the three- dimensional representation of flat printed circuit layers. The printed circuit board CAD systems are tailored to the design of electrical and/or electronic circuits, that is to say the design may enable, inter alia, the routing of the connecting traces, the spacing of components, space optimization and the like.

[0003] Although some CAD/CAM systems that enable three-dimensional structures to be designed are available; these systems are incapable of accounting for the logic and electrical aspects of electronic components and modules. In addition, in order to improve components' integration, multi-layered printed circuit boards, and/or double sided printed circuit boards may be required - that introduce further complication to the CAD/CAM systems.

[0004] Current fabrication of multi-layered printed circuit boards (PCBs) require complicated processes including drilling to form plated through (PTH) or via holes in order to enable conduction between multilayer boards and limit electromagnetic interference, laminating the boards and soldering to adhere elements to the printed circuit board. When soldering is performed in order to adhere elements to the printed circuit board, a region, where a solder is melted and spread, is further required and the elements are thus located in an area wider than the size of elements, themselves, thus limiting miniaturization and causing waste.

[0005] Some of the vias provided in a PCB may not need to interconnect all of the layers of the PCB. Thus, some of the conductive material provided in such vias may be removed (e.g., to create what is referred to as "via stubs") using a variety of removal techniques. For example, the conductive material may be removed using mechanical removal techniques (e.g., back drilling or front drilling), optical removal techniques (e.g., laser drilling), or chemical removal techniques (e.g., etching). However, the removal techniques may not effectively remove all of the conductive material from the particular PCB vias, which may result in improper functioning or complete inoperability of the PCB. In addition, these methods create breaks in the fabrication process which may affect lead times and ultimately costs.

[0006] Thus there is a need for methods enabling efficient and precise fabrication of complex circuit boards.

SUMMARY

[0007] Disclosed, in various embodiments, are methods of fabricating printed circuit boards (PCB's) using inkjet printing, using CAD/CAM data packages. More particularly, disclosed herein are embodiments of methods, programs and libraries for using converted CAD/CAM data packages, to fabricate PCBs using drop-on-demand three dimensional printing.

[0008] In an embodiment provided herein is method of fabricating a printed circuit board (PCB) using a 3D inkjet printer comprising: providing a 3D inkjet printer, the printer including: a bitmap library to store printer operation parameters; a processor in communication with the bitmap library; a memory device storing a set of operational instructions for execution by the processor; a micromechanical inkjet print head or heads in communication with the processor and with the bitmap library; and a print head or, heads' interface circuit in communication with the bitmap library, the memory and the micromechanical inkjet print head or heads, the bitmap library configured to provide printer operation parameters specific for a layer; pre-processing Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, thereby obtaining a plurality of vector data models and/or bitmaps, each vector data model and/or bitmap specific for a predetermined layer or their interface and/or cross section; loading the plurality of bitmaps and/or vector data models processed in the step of pre-processing onto the bitmap library and applying relevant print heads' calibration factors; and using the bitmap library, instructing the processor to print the predetermined layer, its interface and/or a portion thereof in a predetermined order.

[0009] In another embodiment, provided herein is a computer program product for fabricating one or more printed circuit board (PCB), the computer program product comprising: a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code when executed by a processor (microprocessor, CPU or GPU) in a digital computing device causes a three-dimensional inkjet printing unit to perform the steps of: preprocessing Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, thereby obtaining a plurality of bitmaps and/or vector data models, each bitmap/vector data model (VDM) (and accompanying metadata) specific for a predetermined layer, or a portion thereof, in a specific order; loading the plurality of bitmaps and/or VDMs processed in the step of pre-processing onto a bitmap library; directing a stream of droplets of a first material from a first inkjet print head of the three-dimensional inkjet printing unit at a surface of a substrate, wherein the first material is associated with a first predetermined layer or portion thereof, directing a stream of droplets of a second material from a second inkjet print head of the three-dimensional inkjet printing unit at the surface of the substrate, wherein the second material is associated with a sequentially following predetermined layer; moving the first and second inkjet heads relative to the substrate in an x-y plane of the substrate, wherein the step of moving the first and second inkjet heads relative to the substrate in the x-y plane of the substrate, for each of a plurality of layers in a layer-by-layer (or portion of each layer) fabrication of the printed circuit board on the substrate.

[00010] In yet another embodiment, provided herein is a bitmap library comprising a plurality of bitmaps and/or VDMs of layers or portions thereof for three dimensional inkjet printing, wherein each bitmap defines a f layer or a portion thereof in a printed circuit board.

[00011] Further, provided herein are embodiments of double sided and multi-layered printed circuit boards fabricated using the method programs and libraries described herein.

[00012] These and other features of the methods, programs and libraries for using inkjet printing based on converted CAD/CAM data packages, will become apparent from the following detailed description when read in conjunction with the figures and examples, which are exemplary, not limiting.

BRIEF DESCRIPTION OF THE FIGURES

[00013] For a better understanding of the methods, programs and libraries for using inkjet printing based on converted CAD/CAM data packages, with regard to the embodiments thereof, reference is made to the accompanying examples and figures, in which:

[00014] FIG. 1, illustrates a typical structure of a typical layer composition of a multi-layered printed circuit board (PCB); [00015] FIG. 2, illustrates a plan view of a typical circuit board showing insulating and conducting components;

[00016] FIG. 3, illustrates an embodiment of a printing procedure of a single insulating layer using 3 separate forward and backward passes;

[00017] FIG. 4, illustrates an embodiment of a printing procedure of a single conductive layer using 3 separate forward and backward passes;

[00018] FIG. 5, illustrates the structure of several vias drills in a PCB;

[00019] FIG. 6, is a schematic of an embodiment of vias connecting different layers on and/or in the board;

[00020] FIG. 7, illustrates drill holes in a PCB ;

[00021] FIG. 8, illustrates a non-rectangular PCB shape;

[00022] FIG. 9, illustrates an embodiment of a PCB with blank areas automatically detected and marked as a non-printable areas; and

[00023] FIG. 10, illustrates a schematic overview of an embodiment of the pre-processing procedure.

DETAILED DESCRIPTION

[00024] Provided herein are embodiments of methods, programs and libraries for using converted CAD/CAM data packages, to fabricate PCBs and/or FPCs using drop-on-demand three dimensional printing.

[00025] The methods, programs and libraries described herein can be used to fabricate the printed circuit board (PCB) in a single pass using the inkjet printing device, or using several passes. Using the methods described herein, the PCB printer is based on a "drop-on-demand", direct deposition 3D printing technology. The printing process can make use of a series of ink-jet print heads to deposit several liquid materials on a printing surface. The resulting layer of liquid is subsequently dried or cured or otherwise solidified using, for example a combination of heaters and UV light sources optionally before or after each subsequent layer is printed on top of the previous one. Many such layers can be combined to construct a complete multi-layered PCB. In addition, the methods programs and libraries described herein can be used to fabricate PCB(s) including resistors and capacitors embedded therein, using the same or different materials with the same, different or additional print heads or heads. [00026] Accordingly and in an embodiment, provided herein is a method of fabricating a printed circuit board (PCB) using a 3D inkjet printer comprising: providing a 3D inkjet printer, the printer comprising: a bitmap library; a processor (e.g., central processing unit, or CPU or, in another embodiment graphic processing unit (GPU), referring to a processor configured to perform rapid mathematical calculations, primarily for the purpose of rendering images) in communication with the bitmap library; a memory device storing a set of operational or executable instructions for execution by the processor; a micromechanical inkjet print head (or heads) in communication with the processor and with the bitmap library; and a print head's (or, heads') interface circuit in communication with the bitmap library, the memory and the micromechanical inkjet print head or heads , the bitmap library configured to provide printer operation parameters specific to a layer; pre-processing Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, thereby obtaining a plurality of bitmaps, each bitmap specific for a predetermined layer; loading the plurality of bitmaps processed in the step of pre-processing onto the bitmap library; and using the bitmap library, instructing the processor to print the predetermined layer in a predetermined order.

[00027] As used herein, the term "interface circuit" is used to refer to the electronics of an integrated circuit that is coupled to one or more pins of the print head; and is used to effectuate communications with other integrated circuit devices (e.g., the bitmap library). An interface circuit can include a single receiver circuit or a single transmitter circuit coupled to a pin, or both a receiver and transmitter circuit (e.g., a transceiver) coupled to that pin. Interface circuitry may also share circuitry that is used for communications via a plurality of pins. Other circuitry may be included in the interface circuit, for example, pipeline stages, or on-chip termination (e.g., a resistive, capacitive or inductive element).

[00028] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as "processing," "loading," "in communication," "detecting," "calculating," "determining", "analyzing," or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulate and/or transform data represented as physical, such as PCB architecture into other data similarly represented as physical layers.

[00029] In general, "printed circuit board," "PCB" or "electrical interconnect systems" as disclosed are interchangeable and are broadly defined and comprise, without limitation, any and all systems that provide, among others, mechanical support to electrical components, electrical connection to and between these electrical components, or the like. PCBs can therefore comprise systems that generally include a base platform to support the electrical components (for example, a thin board of insulating material) and conductors such as conductive pathways, surfaces, solderable attachments, and the like interconnect the electrical components. Likewise, PCBs can employ a broad range of technologies to support the electrical components (for example, through-hole, surface-mount, mixed-technology, component mounted on one or both sides, etc.) and can comprise a wide range of single or multi-layer constructions (for example, single-sided, double-sided, multilayer, flexible, rigid-flex, stripline, etc). Also, the terms may be used throughout the description to broadly describe PCBs at any stage of the manufacturing process, including, for example, multiple PCBs configured into a stack structure to be printed using three-dimensional printing (3D).

[00030] As used in this disclosure, "bitmap library" refers to a given set of bitmaps that define a single PCB, or a plurality of PCBs used for a given purpose. The term can also be used to refer to a set of bitmaps or any other raster graphic file format (the representation of images as a collection of pixels, generally in the form of a rectangular grid, e.g., BMP, PNG, TIFF, GIF), or vector data model (VDM) capable of being digitized, indexed, searched, and reassembled to provide the layers or their portion, of a given PCB or PCBs - whether the search is for the PCB, PCBs, a given specific layer or a portion of a specific layer or interface between layers. While the term bitmap library is used in this disclosure, the bitmap data and/or VDM may be stored in any suitable facility for the storage of data such as a look up table. Also, the term "fabricating" (and its variants) refers in an embodiment to pumping, injecting, pouring, releasing, displacing, spotting, circulating, or otherwise placing a fluid or material (e.g., the conductive ink material) in contact with another material (e.g., the substrate, or another layer) using any suitable manner known in the art. Furthermore, the bitmap library does not need to be physically located with the printer, but can reside on a remote server and database in communication with the printer central processing unit.

[00031] The method of fabricating the PCB's can further comprise a step of providing a removable substrate. The print head (and derivatives thereof; are to be understood to refer to any device or technique that deposits, transfers or creates material on a surface in a controlled manner) depositing the first ink can be configured to provide the ink droplet(s) upon demand, in other words, as a function of various process parameters such as conveyor speed, desired conductive layer thickness, layer type and the like. The removable substrate can also be a relatively rigid material, for example, glass or crystal (e.g., sapphire).

[00032] As illustrated in FIG. 1, a typical PCB layer to be printed can be an electrical pattern layer, or the main type of layer used to create the electrical connection of the circuit board. Another layer can be soldermask layer; referring to, for example, a top or bottom layer used primarily for protecting conductors against corrosion, as well as aiding in the soldering process. Likewise, silkscreen layer can exist, referring to the top or bottom overlay layer, allowing text or graphics to be placed on the board for informational purposes.

[00033] As illustrated in FIG. 1, PCB 10 can typically comprise conductive material 100 and insulating material 200, where conductive material 100 form traces 101 on top layer 210 and bottom layer 250. Also shown, are vias 300 illustrated herein as plated through holes (PTH). The terms via hole and PTH are used interchangeably in the description. A PTH should however be seen as a via hole that traverses the entire PCB.

[00034] In addition to the layers, additional information may be required during the fabrication of a PCB, for example, vias structures; referring to a set of small holes used to provide conductivity between the electrical pattern layers including for example plated-through-hole (PTH) and/or Castellated PTH and whether the PCB needs to be a part of a stack. Also, location and size of drills, referring to apertures defined in the PCB, typically used for screws and other fixtures. In addition the route, or outer shape of the PCB may also be required. The information can be stored as metadata to bitmap library, accompanying each substantially 2D layer and be retrieved with the bitmap layer, or separately. The bitmap and/or vector data model metadata can be any additional information needed to effectively and efficiently fabricate the layer or the whole PCB and/or FPC.

[00035] Using the inkjet printer described herein, it is possible to recreate an exact facsimile of a PCB layer's digital image by depositing several types of material into a flat layer (or substrate). After the deposition of the "ink" material, each layer is dried using a combination of different curing and/or sintering techniques. In an embodiment, information on the curing and/or sintering process to be used, conditions and durations can be stored as part of the bitmap image metadata in the library.

[00036] As used herein, "curing" or "cured" or "cure" broadly defines the process of polymerizing, toughening, solidifying and/or hardening the deposited ink material by, for example; combining polymers such as epoxies with curing agents, or by subjecting the deposited "ink" to other curing processes such as heat, pressure, radiation, evaporation, or the like. "Curing agents" or "curing materials" broadly defines substances or mixtures of substances added to ink materials to promote or control the curing process. Curing agents may comprise non-curing substances. Ink material can be uncured, partially cured in which the hardening process has begun but is not complete, or fully cured wherein, for example, for an insulating ink, the epoxy resin in the ink material has substantially or completely hardened. Further, the terms cure or curing also include processes such as drying, absorption of fluids by an ink media, and evaporation, which do not require a separate means for curing the inks. In addition or as an alternative, the disclosed technology may employ other inks and their respective curing processes are not specifically described above.

[00037] Likewise, sintering, generally refers to superficial fusion of particles to one another or together, for example, the fusion of metallic nanoparticles in the fabrication of PTH vias, conductive traces and the like.

[00038] Turning to FIG. 2, illustrating a "bare" PCB, or a layer that has yet to have components attached, and is generally constructed of alternating layers of conductive material 100 and non- conductive insulating material 200. By depositing and drying consecutive layers one on top of each other, a multi-layered 3-dimensional PCB can be fabricated. After the print heads complete the deposition of the material for each layer, the print heads can be modulated in the z-direction (vertically), normal to the printing area to ensure a constant distance to the printing surface is maintained, thus ensuring consistency of layer thickness. Maintaining constant distance between the print heads and the printing surface area can be done by elevating the platform holding the print head (s) or, alternatively, lowering the substrate with each layer deposited.

[00039] Accordingly, by combining multiple layers together, it is possible to create complex 3D structures; such structures may be internal to the PCB (e.g. a middle layer) or external (a connector socket - plugs and sockets that directly connect signal and power between PCBs). Further, any given layer may be printed several times in order to build thickness and to achieve the required electrical characteristics.

[00040] The Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the PCB to be fabricated used in the methods, programs and libraries for using inkjet printing based on converted CAD/CAM data packages can be, for example, IGES, DXF, DMIS, NC files, GERBER® files, EXCELLON®, STL, EPRT files or a package comprising one or more of the foregoing. For example, a Gerber file, referring to the file format used as the standard for printed circuit board (PCB) image data transfer. In an embodiment, a single file can describe one single image. Additionally, attributes attached to the graphics objects transfer the meta-information needed for fabrication and can precisely define the PCB image and the function of the image (e.g., insulating or conducting), resulting in an efficient and effective transfer of PCB fabrication data from design (CAD e.g.,) to fabrication (CAM e.g.,). Similarly, EXCELLON^® files can be used to drive CAM for drilling and can be used in conjunction with the GERBER^® files to define the location of vias (PTH, Blind, Buried etc.) as well as drills for fasteners and other purposes. Likewise DXF (CAD drawing exchange format, commonly representing the route data), can be the only design software available when mechanical CAD software such as AutoCAD. However, the DXF or DWG format can require extra time to interpret files and introduce potential for errors to occur. Accordingly and in an embodiment, using pre-processing algorithm, GERBER®, EXCELLON®, DWG, DXF, STL, EPRT and the like as described herein, are converted to bitmap files. The term "bitmap" is used herein in its generic sense referring in an embodiment, to a set of bits that represents a graphic image, with each bit or group of bits corresponding to a drop in the bitmap image.

[00041] In certain embodiments, the obtained image will be manipulated and converted to vector data models (VDMs), where the captured image is converted and captured as points, lines, and polygons and their combination; and only at the last stage will the image be converted into raster data model. At that point a high resolution raster will be obtained for computation (e.g., to remove unnecessary blank areas) and a lower resolution image that can be used for the print heads. In another embodiment, a vector data model refers to an abstraction of the obtained image in which various elements are represented in the form of points, lines, and polygons. Objects can be displayed along with (e.g., can overlay) vector and raster data. "Object" can refer to anything with object attributes, where object attributes are attributes characterizing at least part of an object to be displayed, such as area of a surface or footprint, longest single dimension, or a volume. An object can be a blind via, for example. A blind via can have overlaid raster (e.g. to provide width of pad), diameters, or height data. An object can also include vector data representing, for example, a trace, a capacitor, a transistor, a CPU, a GPU, etc.

[00042] In the methods, programs and libraries described herein, each of the ink-jet print heads in a given printer may only have partial coverage of the desired print area, and thus can require multiple forward and backward (in other words, on an X-Y plane, the reciprocating motion is in a single axis x-direction or y-direction, but not both) printing passes. The conducting and insulating ink materials may be printed in alternation (in other words in altering manner, such that the second (n+1) layer is the same) using multiple different print passes for each type of material. As illustrated in FIG.'s 3 and 4, starting at the top right corner, first print head 501 with coverage width Wi can travel along path 511, depositing insulating ink. As indicated, the route (outer perimeter of the PCB, see e.g., FIG. 8), can be printed based on the bitmap conversion of the input files, namely the , GERBER®, EXCELLON®, DWG, DXF and the like as described herein. Since each bitmap translates to a single layer with a given thickness, or in embodiments where higher resolution is required, a single bitmap can provide a portion of a layer.

[00043] Accordingly and in an embodiment; in order to improve resolution of the printing and the various layers, more than single bitmap will be produced, assigned and used per layer. Likewise, each layer may be printed using two or more materials together (e.g., dielectric and conductive materials), using few printer heads simultaneously. The term "dielectric" or "dielectric material" refers in an embodiment to a substance that is resistant to the flow of an electric current and has relatively (to the conductive material) high dielectric constant. For example, an electrical insulator is considered to be a dielectric material. The term dielectric constant refers to a measure of the extent to which a substance concentrates the electrostatic lines of flux. More specifically, it is the ratio of the amount of electrical energy stored in an insulator, when a static electric field is imposed across it, relative to vacuum (which has a dielectric constant of 1). Thus, the dielectric constant is also known as the static permittivity.

[00044] Moreover, voids (in other words, unprinted areas) can be defined for subsequent passage with the conducting ink material, can be formed, for example, for traces 201, drills 202, or vias 203. Upon reaching the end of the layer, a chuck carrying the substrate can move 512 in the Y direction and printing can continue in the "reverse" X-direction 513, followed by subsequent progress in the Y-direction 514 and again in the original X direction 515 and so on, until the functional layer defined by the bitmap is printed entirely. Following the printing of the insulating layer in an embodiment, the layer can be cured (in other words, fully or partially hardened, solidified or viscosified) as described herein, at which point, depending on the characteristics of the conducting ink material (see e.g., FIG. 4), the layer can be printed over with another insulating layer or, alternatively and as shown in FIG. 4, be deposited with conductive ink material 100.

[00045] As illustrated in FIG. 4, following curing of the insulating layer and starting at either the top right corner as illustrated, or where the first inkjet print head or head terminated (e.g, end of printing 515 stage), second print head or head 502 with coverage width Wc can travel along path 521, depositing conductive ink material 200. As indicated, traces and pads, can be printed based on the bitmap conversion of the input files, namely the , GERBER®, EXCELLON®, DWG, DXF and the like as described herein. Since each bitmap translates to a single layer with a given thickness, traces and pads can be printed, for example, traces 101, contact pads 102, or via pads 103 in the voids left by the printing of the insulating material. Upon reaching the end of the layer, a chuck carrying the substrate can move 522 in the Y direction and printing can continue in the "reverse" X- direction 523, followed by subsequent progress in the Y-direction 524 and again in the original X direction 525 and so on, until the conductive layer (or functional layer) defined by the properly ordered bitmap is printed entirely. Similar to the insulating functional layer, upon termination conductive ink material can be cured by solvent removal, followed by sintering, referring in an embodiment to define a process of fusing or welding or affecting growth of adjacent surfaces of particles in a powder by heating the powder to a temperature that is less than or equal to the temperature corresponding to the melting-point T_m of the particles. For example, conductive ink material 100 can be comprised of low melting point (LMP) metallurgies, and can be mixed with the primary metal (e.g., silver or a silver-copper mixture) nano-particles. For example, tin-lead, bismuth-tin, bismuth-tin-iron, tin, tin-silver, tin-gold, tin- silver-zinc, tin-silver-zinc-copper, tin- bismuth- silver, tin-copper, tin-copper- silver, tin-indium- silver, tin-antimony, tin-zinc, tin-zinc- indium, copper-based solders, and alloys mixtures and combinations comprising one or more of the foregoing. These secondary LMP metallurgies can have melting points (T_m) greater than that of the primary metal and thereby melt, once the primary metal has effectively sintered, or these LMP metallurgies may begin melting during the sintering, depending on how close the melting point of the secondary metallurgies is relative to the corresponding melting point of the primary metal.

[00046] Turning now to FIG.s 5 and 6, illustrating 3D printing of vias. As illustrated in FIG. 5, vias, which can be small drills coated (e.g., plated) in conductive materials and can be used to connect multiple conductor layers in PCB 10 (not shown, see FIG. 1). In a typical PCB fabrication process, vias 300 are drilled after the copper traces 101 have been created. Using the methods, programs and libraries described herein, it is possible to print the Vias by directly creating

"columns" (or stubs) of conductive ink material 100 that traverse multiple layers. The data defining Vias 300 can be parsed (in other words, sliced to the proper thickness per fiunctional layer printed), then merged into the bitmap image of each layer and be printed using the same conductive material that is used to print circuit traces 101. [00047] As illustrated in FIG. 6, it is possible, when using the methods, programs and libraries described herein, to directly fabricate complex vias directly. As illustrated, 3 vias 310, 320, 330 are shown in an embodiment of 4 layer PCB. As illustrated, via 310 represents (plated) thru- hole via or fullstack via with trace 101 leading a top layer 210 (not shown), culminating at via pad 103. Also shown are intermediate traces 104i, and intermediate layer via pads 105_m, I 5_n coupled to through hole via stub 310 as well as bottom layer 250 (not shown, see e.g., FIG. 1) traces 106 and bottom via pad 107. Via 320 begins at top layer 210 and ends at the second inner layer, illustrating a blind via. Via 330 begins at intermediate layer 220 (not shown) and ends at third layer 230, illustrating a buried via. All vias defined can be directly fabricated using the 3D printer provided herein

[00048] FIG. 7, illustrates drills in various diameters used in a PCB for various purposes can be fabricated using the methods, programs and libraries described herein. For example, "through hole" devices typically require a drill for each pin on the device. Wide drills may be used to enable the connection of screws or other fixtures. A drill can further be coated with a conductive material, all of which can be defined by the files processed by the programs in the methods described herein, to produce bitmaps of "slices" of functional layers to be printed.

[00049] In an embodiment, the thickness of a functional layer, or "slice" described by a single bitmap, can be a determined based on the average drop size of the insulating ink material 200 or conductive ink material 100 and their physico-chemical properties (e.g., density, viscosity, type, curing type time and temperature etc.), for example a drop size of between about 2picoLitre (pL) and about 12 pL, or between about 2 pL and about 80 pL, will affect slice or functional layer size, the number of bitmaps per layer and the order by which the layers are to be printed. Moreover, the number of passes as described in reference to FIG.s 3 and 4, can be a determined based on the curing process used per layer. Furthermore, the desired printing resolution can influence the number of passes and thickness created by single slice/2D layer image.

[00050] As illustrated in FIG. 8, the shape of a PCB is determined by a "route layer" that defines the contour of the board and can be part of, for example the GERBER® or DXF files. In a traditional PCB manufacturing process, this data is used by a cutting or milling machine, which removes any excess material from the board. Using the inkjet printer described herein and utilizing the methods, programs and libraries described, the shape of the PCB is directly incorporated into the printing (fabrication) run and can determine the extents to which the insulator material is printed in order to create the final shape with high precision.

[00051] Using the methods, programs and libraries provided herein, it is possible to implement a set of instruction that based on a plurality of predetermined factors, can automatically detects and avoids the printing of areas in the PCB that do not have any meaningful features, in other words, "blank" areas, (e.g areas with no traces, no Vias, no drills). These blank areas (see e.g., 260_P, FIG. 9) will be incorporated into the bitmap and will therefore NOT be printed or otherwise fabricated. By avoiding printing of blank areas, cost saving in ink materials can be realized, as well as assist in thermal and electrostatic insulation.

[00052] Automatically detecting the blank areas, refers in an embodiment to an action or operation performed by a computer system (e.g., software executed by the computer system), without user input directly specifying or performing the action or operation, for example, using the necessary algorithms to determine the size and shape of the blank areas based on the predetermined factors selected. Thus the term "automatically" is in contrast to an operation being manually performed or specified by the user, where the user provides input to directly perform the operation. An automatic procedure may be initiated by input provided by the user (for example, the loading of the GERBER^®, EXCELLON^®, DXF files, but the subsequent actions that are performed

"automatically" are not specified by the user, i.e., are not performed "manually", where the user specifies each action to perform. For example, print head calibration data, referring to the alignment of the print heads relative to the substrate and/or relative to other print heads, as well as real-time data such as temperature of the substrate, inks, soldering etc. can be loaded as part of the data loaded before printing commences. While calibration data (degrees of pitch (relative to the substrate), azimuth (relative to the printing direction and adjacent print head(s), and yaw (relative to adjacent print head(s)) can be done by the user, temperatures, flow rate and the like can be loaded not by the user, but by sensors disposed within the printing chamber or on various printer components.

[00053] The factors used to determine the size and shape of the blank areas can be, for example, guaranteed distance between meaningful features (e.g., vias (hy, FIG. 9), contact pads, traces 101 (hr, FIG. 9), other soldered components) and the edges (HE, FIG. 9) of the PCB, insulating ink material rigidity after curing, desired thermal expansion and electric properties of the PCB or a combination of factors comprising the foregoing. [00054] In addition, provided herein is a computer program, comprising program code means for carrying out the steps of the methods described herein, as well as a computer program product (e.g., a micro -controller) comprising program code means stored on a medium that can be read by a computer, such as a floppy disk, a hard disk, CD-ROM, DVD, USB memory stick, or a storage medium that can be accessed via a data network, such as the Internet or Intranet, when the computer program product is loaded in the main memory of a computer [or micro-controller] and is carried out by the computer [or micro controller] . Accordingly and in an embodiment, provided herein is a computer program product for fabricating one or more printed circuit board (PCB), the computer program product can comprise: a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code, when executed by a processor in a digital computing device, can cause a three-dimensional (3D) inkjet printing unit to perform the steps of: pre-processing Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) generated information that is associated with the printed circuit board to be fabricated, the pre-processing configured to generate (in other words yield) a plurality of bitmaps. Each bitmap generated by the pre-processing is specific for a predetermined layer (in other words, insulating layer or conductive layer or any other material later developed) in a specific order (determined by the program); loading the plurality of bitmaps processed in the step of pre-processing onto a bitmap library; directing a stream of droplets of a first material from a first inkjet print head of the three- dimensional inkjet printing unit at a surface of a substrate, wherein the first material is associated with a first predetermined layer; directing a stream of droplets of a second material from a second inkjet print head of the three-dimensional inkjet printing unit at the surface of the substrate, wherein the second material is associated with a sequentially following predetermined functional layer; moving the first and second inkjet heads relative to the substrate in an x-y plane of the substrate, wherein the step of moving the first and second inkjet heads relative to the substrate in the x-y plane of the substrate, for each of a plurality of layers in a layer-by-layer fabrication of the printed circuit board on the substrate.

[00055] As illustrated schematically in FIG. 10, the methods and programs disclosed comprise a step of pre-processing 700 Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, thereby obtaining a plurality of bitmaps, each bitmap(s), or a few bitmaps per layer for higher resolution specific for a predetermined layer. Typically, PCB CAM (Computer Aided Manufacturing) data is provided as a package containing several types of file formats, for example; GERBER® files for traces, contact pads, EXCELLON® files for vias and drills, and DXF files for route shape. The CAD/CAM data package is loaded 701 (in other words, data is provided from a non-printer system or data source to the printer system) onto the processor. Typically, the operating system "loads" the CAD/CAM data file when an application or other executing process requests to use it. The application can be a self-contained program that performs a specific function or duty, typically for the user. Examples include a word processor, graphic design package, electronic mail program, etc. In an embodiment, pre-processing 700 is an application residing in a non-volatile memory in the computer [or micro controller] being in communication with the three-dimensional printer provided herein. Likewise, the program to automatically detect and define the blank areas can be an application that is either separate or combined with the pre-processing application.

[00056] Following the loading of the CAD/CAM files, the program determines the print plan 702. In other words, the program determines the order in which the bitmaps generated are to be printed. As disclosed hereinabove, bitmap refers to a set of bits that represents a graphic image of the layer, with each bit or group of bits corresponding to a physical aspect of the printing process. For example, a bit can be a single drop of insulating ink material 200 or a single conductive ink material, either immediately post expulsion from the printing nozzle, immediately before curing or after curing. Likewise, the plan or bit can be determined based on the desired thickness of the layer, or desired print resolution. In another embodiment, when drop size on the substrate is NOT the limiting factor, a bit can be the smallest feature in a PCB layer, and can be for example a quadrilateral polygon representing the shortest distance allowed between adjacent features.

Furthermore, bitmaps and/or VDMs generated per layer or a portion thereof, can have the same or different bit size representing a physical property of the three dimensional inkjet printing system or the PCB. In addition, each bitmap can be associated with a unique set of executable instructions configured to instruct a processor (or microprocessor) to print the bitmap.

[00057] Following the ordering of the print plan 702, the data reflecting the drills and route is integrated and merged with the trace data 703, where the external shape of the PCB (the route) is incorporated and the drills are integrated to the printed area (see e.g., FIG. 3). In an embodiment, there can be overlap between the head movements. For example there can be more than 3 separate forward and backward passes. In an embodiment multiplication of 2 or 8 back-and-forth movements are used to improve resolution. Next, rendering of the data to yield the bitmap of the layer (insulating or conductive or other material) as disclosed herein can be done 704. Finally data concerning the vias is merged 705 to each bitmap, and the full complement of bitmaps are loaded 706 onto the bitmap library.

[00058] In an embodiment, the bitmaps representing the functional layers can be loaded onto a bitmap file library. In another embodiment, the term "bitmap library" can also generally be defined as a collection of subroutines, images, vector data models and functions, and can be used to link programs together. The libraries can be stored, for example, in one or more files and be in a compiled format. A library can defines a way of organizing the reusability of printing of the layer for additional printing of additional PCBs. Further, the bitmap libraries can be supplied by an operating system or software environment developer, and can be used with many different programs. Furthermore, routines in a library (for example, 3D printing instructions, curing type and time and the like) may be general purpose or designed for some specific function such as, for example, three dimensional printing, etc. In addition, libraries can be linked with programs to form a complete executable set of instruction. This linking may be static linking or, in some systems, dynamic linking.

[00059] Furthermore, provided herein is a computer-readable medium comprising the bitmap libraries provided herein. The term "computer-readable medium" as used herein, in addition to having its ordinary meaning, refers to any medium that participates in providing instructions to a processor for execution. Such a medium may take many forms, including but not limited to, nonvolatile media and volatile media. Non-volatile media can be, for example, optical or magnetic disks, such as a storage device. Volatile media includes dynamic memory, such as main memory.

[00060] Memory device as used in the methods, programs and libraries described herein can be any of various types of memory devices or storage devices. The term "memory device" is intended to encompass an installation medium, e.g., a CD-ROM, floppy disks, or tape device; a computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; or a non-volatile memory such as a magnetic media, e.g., a hard drive, optical storage, or ROM, EPROM, FLASH, etc. The memory device may comprise other types of memory as well, or combinations thereof. In addition, the memory medium may be located in a first computer in which the programs are executed (e.g., the 3D inkjet printer provided), and/or may be located in a second different computer [or micro controller] which connects to the first computer over a network, such as the Internet [remark: they might be even not connected and information will be transferred using USB stick]. In the latter instance, the second computer may further provide program instructions to the first computer for execution. The term "memory device" can also include two or more memory devices which may reside in different locations, e.g., in different computers that are connected over a network. Accordingly, for example, the bitmap library can reside on a memory device that is remote from the 3D inkjet printer provided, and be accessible by the 3D inkjet printer provided.

[00061] Accordingly and in an embodiment, provided herein is a bitmap library comprising a plurality of bitmaps of functional layers for three dimensional inkjet printing, wherein each bitmap defines a functional layer in a printed circuit board.

[00062] The term "comprising" and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, "including", "having" and their derivatives.

[00063] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. "Combination" is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms "a", "an" and "the" herein do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The suffix "(s)" as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the film(s) includes one or more films). Reference throughout the specification to "one embodiment", "another embodiment", "an embodiment", and so forth, when present, means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

[00064] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. Furthermore, the terms "first," "second," and the like, herein do not denote any order, quantity, or importance, but rather are used to denote one element from another. [00065] Likewise, the term "about" means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, size, formulation, parameter or other quantity or characteristic is "about" or "approximate" whether or not expressly stated to be such.

[00066] Although the foregoing disclosure for 3D printing of conductive leads and insulating portions of printed circuit boards using inkjet printing based on converted CAD/CAM data packages has been described in terms of some embodiments, other embodiments will be apparent to those of ordinary skill in the art from the disclosure herein. Moreover, the described embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods, programs, libraries and systems described herein may be embodied in a variety of other forms without departing from the spirit thereof. Accordingly, other combinations, omissions, substitutions and modifications will be apparent to the skilled artisan in view of the disclosure herein.

[00067] Accordingly, provided herein is a method of fabricating a printed circuit board (PCB) using a 3D inkjet printer comprising: providing a 3D inkjet printer, the printer including: a bitmap library to store printer operation parameters; a processor in communication with the bitmap library; a memory device storing a set of operational instructions for execution by the processor; a micromechanical inkjet print head or heads in communication with the processor and with the bitmap library; and a print head or, heads' interface circuit in communication with the bitmap library, the memory and the micromechanical inkjet print head or heads, the bitmap library configured to provide printer operation parameters specific for a layer; pre-processing Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, thereby obtaining a plurality of vector data models and/or bitmaps, each vector data model and/or bitmap specific for a predetermined layer or their interface and/or cross section; loading the plurality of bitmaps and/or vector data models processed in the step of pre-processing onto the bitmap library and applying relevant print heads' calibration factors; and using the bitmap library, instructing the processor to print the predetermined layer, its interface and/or a portion thereof in a predetermined order, wherein (i) the Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated comprises IGES, DXF, DMIS, NC files, Gerber files, Excellon files, a vector data model file, (e.g., VPF) or a package comprising one or more of the foregoing, wherein (ii) the layer comprises a single printed material, wherein (iii) the material is a conductive material, or an insulating (e.g., dielectric) material, wherein (iv) the step of pre-processing comprises: loading a data package comprising the Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated; determining print layer order; merging drills and route layer for each printed layer; rendering each printed layer in a bitmap; adding vias data to the rendered bitmap; and incorporating print head calibration factors, (v) further comprising: detecting blank areas having a size equal to or larger than a predetermined threshold; and clearing the detected area from the bitmap or marking the area with "do not print" flag, wherein the blank area does not comprise traces, vias, or drills, and is within a predetermined distance from the edge of the printed circuit board, wherein (vi) the print layer order is determined based on rendering resolution (e.g., of the bitmap and/or the VDM), required print resolution, drop size, layer thickness or portion thereof, or a combination comprising one or more of the foregoing, wherein (vii) the step of merging drills and route layers comprises providing the route layer and adding the layer specific drill data, wherein (viii) the step of rendering each printed layer (or portion thereof) in a bitmap comprises rendering each conductive and insulating layer into a separate bitmap, and (ix) further comprising rendering the conductive ink around a drill hole defined in an insulating bitmap.

[00068] In another embodiment, provided herein is a computer program product for fabricating one or more printed circuit board (PCB), the computer program product comprising: a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code when executed by a processor in a digital computing device causes a three- dimensional inkjet printing unit to perform the steps of: pre-processing Computer-Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, thereby obtaining a plurality of bitmaps and/or vector data models, each bitmap or vector data model specific for a predetermined layer or portion thereof in a specific order; adding meta data for each of the bitmaps and/or vector data model; loading the plurality of bitmaps processed in the step of pre-processing onto a bitmap library; directing a stream of droplets of a first material from a first inkjet print head of the three-dimensional inkjet printing unit at a surface of a substrate, wherein the first material is associated with a first predetermined layer or portion thereof; directing a stream of droplets of a second material from a second inkjet print head of the three-dimensional inkjet printing unit at the surface of the substrate, wherein the second material is associated with a sequentially following predetermined layer or portion thereof; moving the first and second inkjet heads relative to the substrate in an x-y plane of the substrate, wherein the step of moving the first and second inkjet heads relative to the substrate in the x-y plane of the substrate, for each of a plurality of layers or portions thereof in a layer-by-layer fabrication of the printed circuit board on the substrate, wherein (x) the first inkjet material is an insulating (e.g., dielectric) material or a conducting material and wherein the second inkjet material is different than the first material and is an insulating material or a conducting material, wherein (xi) the computer readable program code when executed by a processor (or microprocessor) in a digital computing device that causes a three- dimensional inkjet printing unit to perform the step of pre-processing, Computer-Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, is configured to: load a data package comprising the Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated; determine print layer order (or portion of the print layer order); merge drills and route layer for each printed layer or portion thereof); render each printed layer (or portion thereof) in a bitmap; add vias data to the rendered bitmap; and incorporate print head calibration data, and (xii) further configured to: detect blank areas having a size equal to or larger than a predetermined threshold; and clear the detected area from the bitmap or mark it as no print, wherein each of the blank areas detected does not comprise traces, vias, or drills, and is within a predetermined distance from the edge of the printed circuit board, and is (xiii) further configured to render each conductive and insulating layer in a separate bitmap.

[00069] In yet another embodiment, provided herein is a bitmap library comprising a plurality of bitmaps and/or vector data model of layers or portions of layers for three dimensional inkjet printing, wherein each bitmap defines a layer or portion thereof in a printed circuit board, wherein (xiv) the bitmaps are generated by pre-processing Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, wherein (xv) the layer or portion thereof is a conducting layer or an insulating layer, wherein (xvi) each bitmap, and/or vector data model and/or or structural data and metadata further defines a blank area having a size equal to or larger than a predetermined threshold and wherein each of the blank areas defined does not comprise traces, vias, or drills, and is within a predetermined distance from an edge of the printed circuit board, as well as a computer readable medium comprising the libraries described herein. [00070] While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one of ordinary skill in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Accordingly, it is intended that the present disclosure covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

What is claimed:

1. A method of fabricating a printed circuit board (PCB) using a 3D inkjet printer comprising: a. providing a 3D inkjet printer, the printer including: a bitmap library to store printer operation parameters; a processor in communication with the bitmap library; a memory device storing a set of operational instructions for execution by the processor; a micromechanical inkjet print head or heads in communication with the processor and with the bitmap library; and a print head or, heads' interface circuit in communication with the bitmap library, the memory and the micromechanical inkjet print head or heads, the bitmap library configured to provide printer operation parameters specific for a layer; b. pre-processing Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, thereby obtaining a plurality of vector data models and/or bitmaps, each vector data model and/or bitmap specific for a predetermined layer or their interface and/or cross section; c. loading the plurality of bitmaps and/or vector data models processed in the step of preprocessing onto the bitmap library and applying relevant print heads' calibration factors; and d. using the bitmap library, instructing the processor to print the predetermined layer, its interface and/or a portion thereof in a predetermined order.

2. The method of claim 1, wherein the Computer- Aided Design/Computer- Aided

Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated comprises IGES, DXF, DMIS, NC files, Gerber files, Excellon files or a package comprising one or more of the foregoing.

3. The method of claim 2, wherein the layer comprises a single printed material.

4. The method of claim 3, wherein the material is a conductive material, or an insulating material.

5. The method of claim 4, wherein the step of pre-processing comprises: a. loading a data package comprising the Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated; b. determining print layer order; c. merging drills and route layer for each printed layer; d. rendering each printed layer in a bitmap; e. adding vias data to the rendered bitmap; and . f. incorporating print head calibration factors.

6. The method of claim 5, further comprising: detecting blank areas having a size equal to or larger than a predetermined threshold; and clearing the detected area from the bitmap or mark the area with do not print flag, wherein the blank area does not comprise traces, vias, or drills, and is within a predetermined distance from the edge of the printed circuit board.

7. The method of claim 5, wherein the print layer order is determined based on rendering resolution, print resolution, drop size, layer thickness or a combination comprising one or more of the foregoing.

8. The method of claim 7, wherein the step of merging drills and route layers comprises providing the route layer and adding the layer specific drill data.

9. The method of claim 8, wherein the step of rendering each printed layer in a bitmap comprises rendering each conductive and insulating layer into a separate bitmap.

10. The method of claim 8, further comprising rendering the conductive ink around a drill hole defined in an insulating bitmap.

11. A computer program product for fabricating one or more printed circuit board (PCB), the computer program product comprising: a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code when executed by a processor in a digital computing device causes a three-dimensional inkjet printing unit to perform the steps of: a. pre-processing Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, thereby obtaining a plurality of bitmaps and/or vector data models, each bitmap or vector data model specific for a predetermined layer or portion thereof in a specific order; b. adding meta data; c. loading the plurality of bitmaps processed in the step of pre-processing onto a bitmap library; d. directing a stream of droplets of a first material from a first inkjet print head of the three-dimensional inkjet printing unit at a surface of a substrate, wherein the first material is associated with a first predetermined layer or portion thereof; e. directing a stream of droplets of a second material from a second inkjet print head of the three-dimensional inkjet printing unit at the surface of the substrate, wherein the second material is associated with a sequentially following predetermined layer or portion thereof; f. moving the first and second inkjet heads relative to the substrate in an x-y plane of the substrate, wherein the step of moving the first and second inkjet heads relative to the substrate in the x-y plane of the substrate, for each of a plurality of layers in a layer-by-layer or portion thereof fabrication of the printed circuit board on the substrate.

12. The method of claim 11, wherein the first inkjet material is an insulating material or a conducting material and wherein the second inkjet material is different than the first material and is an insulating material or a conducting material.

13. The program of claim 11, wherein the computer readable program code when executed by a processor in a digital computing device that causes a three-dimensional inkjet printing unit to perform the step of pre-processing Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated, is configured to: a. load a data package comprising the Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated; b. determine print layer order; c. merge drills and route layer for each printed layer; d. render each printed layer in a bitmap; e. add vias data to the rendered bitmap; and f . incorporate print head calibration data .

14. The program of claim 13, wherein the computer readable program code when executed further configured to: detect blank areas having a size equal to or larger than a predetermined threshold; and clear the detected area from the bitmap or mark it as no print, wherein each of the blank areas detected does not comprise traces, vias, or drills, and is within a predetermined distance from the edge of the printed circuit board.

15. The program of claim 14, wherein the computer readable program code when executed by a processor in a digital computing device that causes a three-dimensional inkjet printing unit to perform the step of rendering each printed layer in a bitmap is configured to render each conductive and insulating layer in a separate bitmap.

16. A bitmap library comprising a plurality of bitmaps and/or vector data model of layers for three dimensional inkjet printing, wherein each bitmap defines a layer in a printed circuit board.

17. The library of claim 16, wherein the bitmaps are generated by pre-processing Computer- Aided Design/Computer- Aided Manufacturing (CAD/CAM) generated information associated with the printed circuit board to be fabricated.

18. The library of claim 17, wherein the layer or portion thereof is a conducting layer or an insulating layer.

19. The library of claim 18, wherein each bitmap, and/or vector data model and/or or structural data further defines a blank area having a size equal to or larger than a predetermined threshold and wherein each of the blank areas defined does not comprise traces, vias, or drills, and is within a predetermined distance from an edge of the printed circuit board.

20. A computer readable medium comprising the library of claim 19.