Patent Description:
<CIT> discloses a way of electrically connecting a substrate and a semiconductor device via a female connection element provided on a contact pad of the substrate and a cor-responding male connection element provided on a contact pad of the semiconductor device. Each of the male and female con-nection elements include an outer dielectric jacket that sur-rounds a conductive center portion which is in contact with the respective contact pad. Upon connection of the connection elements, their conductive center portions enable a conductive connection between corresponding contact pads of the semicon-ductor device and the substrate. The dielectric jackets and the conductive centers of the connection elements may be formed by stereolithography.

<CIT> discloses an interposer for electrically connecting an integrated circuit to a printed circuit board. The interposer comprises a microspring which, in use, enables electrical connection between contact pads of the integrated circuit and the printed circuit board.

<CIT> discloses connecting chips or chip packages to a printed circuit board. One of the printed circuit board and the chip package comprises a connection protrusion and the other one comprises a corresponding recess for receiving the protrusion. When connected, the protrusion is engaged to the recess to electrically connect the chip package with the printed circuit board.

<CIT> discloses a method for forming connection elements on a substrate, which may be used for establishing a flip-chip connection between the substrate and semiconductor elements. The connection elements are formed on top of the substrate by a sequence of layer deposition and etching steps.

Consumers are frequently demanding smaller, portable devices. Additionally, many devices, such as missiles and aircraft, are restricted in size. As a result, circuit boards are also becoming smaller thereby decreasing the available space on the circuit boards for connections.

Therefore, it is an object of the invention to provide a printed circuit board having an interconnect and being suitable to fit within devices having limited space and a method for forming such a printed circuit board.

This object is achieved by the method according to claim <NUM> and by the apparatus according to claim <NUM>. The dependent claims describe advantageous embodiments of the invention.

For a more complete understanding of the present disclosure, and for further features and advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:.

As consumer devices are being reduced in size, printed circuit boards used within the devices are also being reduced in size. Additionally, some devices are necessarily limited in their size, such as a missile. As a result, the devices may not have space for printed circuit boards with bulky interconnects. Moreover, traditional manufacturing techniques typically involve solder joints between the printed circuit board and the interconnect, which may cause a loss in signal integrity.

Accordingly, aspects of the present disclosure include, in one embodiment, forming a printed circuit board by depositing a first plurality of layers and forming an interconnect integral to the printed circuit board by depositing a second plurality of layers on at least a portion of the first plurality of layers. The interconnect includes a stabilizing structure and a contact positioned within the stabilizing structure. The stabilizing structure is made of a first material and the contact is made of a second material that is different than the first material.

Board integrated interconnect apparatus <NUM> of the present disclosure provides numerous advantages. As one advantage, some embodiments may reduce the profile of printed circuit board <NUM> thereby allowing one or more printed circuit boards <NUM> to fit within a small device. As another advantage, certain embodiments may improve the yield in the manufacturing process by reducing the need for soldering techniques. As another advantage, some embodiments may reduce the need for electrical connections by utilizing optical connections. As another advantage, some embodiments may improve signal quality by reducing the usage of solder joints between printed circuit board <NUM> and interconnects <NUM>.

Additional details are discussed in <FIG>. <FIG> illustrates an example board integrated interconnect apparatus <NUM>. <FIG> show an example printed circuit board <NUM> with interconnects <NUM> before, during, and after reorientation of interconnects <NUM>. <FIG> shows an example method of forming printed circuit board <NUM> with interconnect <NUM> integral to printed circuit board <NUM>.

<FIG> illustrates an example board integrated interconnect apparatus <NUM>. Board integrated interconnect apparatus <NUM> comprises printed circuit board <NUM> with one or more interconnects <NUM> formed integrally with printed circuit board <NUM>. Board integrated interconnect apparatus <NUM> may include printed circuit board <NUM>, first plurality of layers <NUM>, interconnects <NUM>, second plurality of layers <NUM>, stabilizing structures <NUM>, non-zero lengths <NUM>, and contacts <NUM> in an embodiment.

Printed circuit board <NUM> may be any component configured to support and connect components in some embodiments. Printed circuit board <NUM> may reside within a device in some embodiments. For example, printed circuit board <NUM> may reside within a missile. As another example, printed circuit board <NUM> may reside in a cellular device. Printed circuit board <NUM> may support electrical components in some embodiments. For example, printed circuit board <NUM> may support capacitors, resistors, or other electronic components. Printed circuit board <NUM> may support optical components in some embodiments. Printed circuit board <NUM> may also support interconnect <NUM> in some embodiments. Printed circuit board <NUM> may be coupled to another printed circuit board using interconnect <NUM> in certain embodiments. Printed circuit board <NUM> may be coupled to any electrical or optical component using interconnect <NUM> in some embodiments. Printed circuit board <NUM> may be single sided, double sided, or multilayer in some embodiments.

Printed circuit board <NUM> may be manufactured using a variety of different manufacturing process. Printed circuit board <NUM> may be manufactured using a laminating process in an embodiment. In the laminating process, printed circuit board <NUM> may have various layers of laminates with etched copper connecting electronic components. Etched copper may join different layers of printed circuit board <NUM> in some embodiments. Printed circuit board <NUM> may be formed using a three-dimensional printing process in certain embodiments. Three-dimensional printing may include laying successive layers of material to form printed circuit board <NUM>. These layers may be joined or fused to create the final shape of printed circuit board <NUM>. In either manufacturing method, printed circuit board <NUM> may include first plurality of layers <NUM>.

First plurality of layers <NUM> may include two or more layers forming printed circuit board <NUM> in an embodiment. First plurality of layers <NUM> may be made of any type of material. For example, first plurality of layers <NUM> may be made of a woven glass epoxy. First plurality of layers <NUM> may be made of a non-conductive material in certain embodiments. As noted above, first plurality of layers <NUM> may be formed using a laminating process or a three-dimensional printing process in certain embodiments. First plurality of layers <NUM>, which form printed circuit board <NUM>, may support interconnects <NUM> in certain embodiments.

Interconnect <NUM> may be any component configured to interface with an electronic or optical component in certain embodiments. For example, interconnect <NUM> may be a component that connects another component, such as a graphics card, to printed circuit board <NUM>. As another example, interconnect <NUM> may be a structure that couples printed circuit board <NUM> to another printed circuit board. As another example, interconnect <NUM> may be a socket for an integrated circuit, such as a microprocessor. Interconnect <NUM> is formed integrally with printed circuit board <NUM>. For example, interconnect <NUM> may be formed together with printed circuit board <NUM> during the laminating or three-dimensional printing process. Because interconnect <NUM> may be integrally formed with printed circuit board <NUM>, interconnect <NUM> need not be soldered to printed circuit board <NUM> in certain embodiments. Forming interconnect <NUM> integrally with printed circuit board <NUM> rather than soldering interconnect <NUM> to printed circuit board <NUM> may improve signal quality. Interconnect <NUM> may include second plurality of layers <NUM>, stabilizing structures <NUM>, non-zero length <NUM>, and contacts <NUM> in an embodiment.

Second plurality of layers <NUM> may be two or more layers forming stabilizing structure <NUM> of interconnect <NUM>. Second plurality of layers <NUM> may be made of any material in some embodiments. For example, second plurality of layers <NUM> may be a woven glass epoxy. Second plurality of layers <NUM> may be a non-conductive material in certain embodiments. Second plurality of layers <NUM> may be made of a material different than the material used for first plurality of layers <NUM> in an embodiment. Second plurality of layers <NUM> may be formed in any shape in some embodiments. For example, second plurality of layers <NUM> may be formed in a rectangular, square, or circular shape. Second plurality of layers <NUM> may be formed using a laminating process or a three-dimension printing process. For example, second plurality of layers <NUM> may be built up on top of first plurality of layers <NUM> using three-dimensional printing in an embodiment. As another example, first plurality of layers <NUM> may be built up around second plurality of layers <NUM> so that second plurality of layers <NUM> may be recessed within printed circuit board <NUM>. As another example, second plurality of layers <NUM> may be deposited on an already-existing printed circuit board <NUM>. Second plurality of layers <NUM> is integral to printed circuit board <NUM>. As will be discussed in <FIG>, second plurality of layers <NUM> is formed in plane with printed circuit board <NUM> and reoriented in a direction normal to printed circuit board <NUM>. Second plurality of layers <NUM> forms stabilizing structure <NUM>.

Stabilizing structure <NUM> may be any structure configured to support contact <NUM> in some embodiments. Stabilizing structure <NUM> may be formed in any shape. For example, stabilizing structure <NUM> may be rectangular, square, or circular in shape. Stabilizing structure <NUM> may be made of any material in some embodiments. For example, stabilizing structure may be made of a woven glass epoxy. Stabilizing structure <NUM> may be made of a non-conductive material in certain embodiments. Stabilizing structure <NUM> may be flexible during the manufacturing process to facilitate reorientation of stabilizing structure <NUM> from a position in plane with printed circuit board <NUM> to a position normal to printed circuit board <NUM> in certain embodiments. A stabilizing agent, such as an epoxy, glue, or molded thermal plastic, may be applied to stabilizing structure <NUM> to harden stabilizing structure <NUM> after reorientation in some embodiments. Stabilizing structure <NUM> may be made of a different material than printed circuit board <NUM> to ensure that stabilizing structure <NUM> remains flexible during the manufacturing process in an embodiment. For example, stabilizing structure <NUM> may be made of a material with a higher glass transition temperature than the material used for printed circuit board <NUM>. As another example, stabilizing structure <NUM> may be made of a highly porous material that is subsequently soaked in epoxy to harden stabilizing structure <NUM>. Stabilizing structure <NUM> may be made of a thinner material than printed circuit board <NUM> to facilitate the flexibility of stabilizing structure <NUM>. Stabilizing structure <NUM> of interconnect <NUM> may extend non-zero length <NUM> in a direction normal to a surface of printed circuit board <NUM>.

Non-zero length <NUM> may be any distance normal to a surface of printed circuit board <NUM> in some embodiments. Non-zero length <NUM> may be a distance above the top layer of printed circuit board <NUM> in certain embodiments. Non-zero length <NUM> may be a distance below the top layer of printed circuit board <NUM> in some embodiments. For example, non-zero length <NUM> may be a distance from the top layer of printed circuit board <NUM> to an internal layer of printed circuit board <NUM> so that interconnect <NUM> is recessed within printed circuit board <NUM>. Such a recessed interconnect <NUM> reduces the profile of printed circuit board <NUM> thereby allowing printed circuit board <NUM> to fit within devices having limited volumes.

Contact <NUM> may be any component configured to provide a link between components of printed circuit board <NUM> and other electronic components in an embodiment. For example, contact <NUM> may provide a link between an attached graphics card and a microprocessor attached to printed circuit board <NUM>. Contact <NUM> may be made of a conductive material in certain embodiments. Contact <NUM> may be an electrical contact in certain embodiments. In other embodiments, contact <NUM> may be an optical contact. For example, contact <NUM> may be a fiber optic connector. Contact <NUM> may be configured to interface with any component coupled to printed circuit board <NUM>, such as a graphics card, in certain embodiments. Contact <NUM> may be formed in any shape in some embodiments. For example, contact <NUM> may be rectangular, square, or circular in shape.

Contact <NUM> may be formed using a variety of different manufacturing processes. Contact <NUM> may be formed during the laminating or three-dimensional printing process in an embodiment. In either the laminating process or the three-dimensional printing process, contact <NUM> may be formed subsequent to stabilizing structure <NUM> in an embodiment. For example, contact <NUM> may be "flowed" into a channel formed by stabilizing structure <NUM>. That is, the material forming contact <NUM> may be heated to a liquid state so that it may be flowed into the channel formed by stabilizing structure <NUM>. As another example, contact <NUM> may be printed into the channel formed by stabilizing structure <NUM> using a three-dimensional printing process. Contact <NUM> may be formed prior to stabilizing structure <NUM> in certain embodiments. For example, contact <NUM> may be built up on printed circuit board <NUM> and then stabilizing structure <NUM> may be formed around contact <NUM>. In that scenario, at least a portion of contact <NUM> must be left exposed to interface with an external component.

<FIG> illustrates an example printed circuit board <NUM> with interconnects <NUM> before reorientation of interconnects <NUM>, according to certain embodiments of the present disclosure. As noted above, printed circuit board <NUM> and interconnects <NUM> may be formed using a laminating process or a three-dimensional printing process in some embodiments. In either of those processes, interconnects <NUM> are formed in a plane of printed circuit board <NUM> and reoriented to a position normal to printed circuit board <NUM>. As shown in <FIG>, interconnects <NUM> are positioned in plane with printed circuit board <NUM>. Interconnects <NUM> may be initially flexible to allow for subsequent reorientation in some embodiments. For example, interconnects <NUM> may be initially flexible, but subsequently hardened during or after reorientation using a stabilizing agent, such as an epoxy, glue, or molded thermal plastic, in an embodiment. Interconnects <NUM> may be reoriented by force <NUM> in some embodiments.

Force <NUM> may be any force sufficient to reorient interconnects <NUM> from a position in plane with printed circuit board <NUM> to a position normal to printed circuit board <NUM>. Force <NUM> may be applied by a human or a mechanical device in certain embodiments. For example, a human may use a finger to reorient interconnects <NUM>. As another example, a machine may use a tool to reorient interconnects <NUM>. Force <NUM> may reorient interconnects <NUM> to a direction normal to printed circuit board <NUM> as shown in <FIG> in an embodiment.

<FIG> illustrates the example printed circuit board <NUM> with interconnects <NUM> of <FIG> during reorientation of interconnects <NUM>, according to certain embodiments of the present disclosure. As force <NUM> is applied to interconnects <NUM>, interconnects <NUM> are reoriented from an initial position in plane with circuit board <NUM> towards a position normal to circuit board <NUM> in an embodiment.

<FIG> illustrates the example printed circuit board <NUM> with interconnects <NUM> of <FIG> after reorientation of interconnects <NUM>, according to certain embodiments of the present disclosure. After or during reorientation, interconnects <NUM> may be hardened from their prior flexible state. For example, a material, such as an epoxy, glue, or molded thermal plastic, may be applied to interconnects <NUM> to cause interconnects <NUM> to harden. Hardening interconnects <NUM> may allow interconnects <NUM> to support external components, such as another printed circuit board. Once force <NUM> reorients interconnects <NUM> from a direction in plane with printed circuit board <NUM> to a direction normal to printed circuit board <NUM>, interconnects <NUM> may be coupled to an external component, such as an electrical, optical, or any other type of component.

<FIG> illustrates steps of an example method <NUM> of forming printed circuit board <NUM> with interconnect <NUM> integral to printed circuit board <NUM>, according to certain embodiments of the present disclosure. Method <NUM> begins at step <NUM> where printed circuit board <NUM> may be formed by depositing first plurality of layers <NUM>. First plurality of layers <NUM> may be formed using a laminating process in some embodiments. In other embodiments, first plurality of layers <NUM> may be formed using a three-dimensional printing process.

At step <NUM>, interconnect <NUM> is formed integral to printed circuit board <NUM> by depositing second plurality of layers <NUM> on at least a portion of first plurality of layers <NUM>. For example, second plurality of layers <NUM> may be formed on a square portion of the top surface of first plurality of layers <NUM>. Interconnect <NUM> may be formed using a laminating process in an embodiment. Interconnect <NUM> may be formed using a three-dimensional printing process in some embodiments. Interconnect <NUM> includes stabilizing structure <NUM> and contact <NUM>. Contact <NUM> is positioned within stabilizing structure <NUM>. Stabilizing structure <NUM> is made of a first material and contact <NUM> si made of a second material that is different than the first material. As discussed above with reference to <FIG>, interconnect <NUM> is formed in plane with printed circuit board <NUM>. In the method according to the invention, in a step not shown in <FIG> interconnect <NUM> is reoriented to a direction normal to printed circuit board <NUM>.

As an example embodiment of operation, first plurality of layers <NUM> may be deposited to form a portion or all of printed circuit board <NUM> using a variety of different manufacturing processes, such as a laminating process or a three-dimensional printing process. Interconnect <NUM> may be formed integrally with printed circuit board <NUM> by depositing second plurality of layers <NUM> on at least a portion of first plurality of layers <NUM> using a variety of different manufacturing processes, such as a laminating process or a three-dimensional printing process.

Claim 1:
A method, comprising:
forming a printed circuit board (<NUM>) by depositing a first plurality of layers (<NUM>); and
forming an interconnect (<NUM>) integral to the printed circuit board (<NUM>) by depositing a second plurality of layers (<NUM>) on at least a portion of the first plurality of layers (<NUM>), the interconnect (<NUM>) comprising a stabilizing structure (<NUM>) and a contact (<NUM>) positioned within the stabilizing structure (<NUM>), the stabilizing structure (<NUM>) being made of a first material and the contact (<NUM>) being made of a second material that is different than the first material, wherein
the second plurality of layers (<NUM>) are deposited on the first plurality of layers (<NUM>) such that the interconnect (<NUM>) is positioned in-plane with the printed circuit board (<NUM>),
characterized in that
the method further comprises reorienting the interconnect (<NUM>) in a direction normal to a surface of the printed circuit board (<NUM>).