Circuit board structure of integrated optoelectronic component

A circuit board structure of an optoelectronic component is proposed. A supporting structure has a first surface and a second surface. At least one optical transceiver has an active surface and an inactive surface. The inactive surface of the optical transceiver is mounted on the first surface of the supporting structure, and the active surface of the optical transceiver has an optical active region and a plurality of electrode pads. A dielectric layer is formed on the first surface of the supporting structure and the active surface of the optical transceiver. A circuit layer is formed on the dielectric layer and is electrically connected to the electrode pads on the active surface of the optical transceiver through the conductive structure in the dielectric layer. At least one hole, which penetrates the dielectric layer, is used to expose the optical active region on the active surface of the optical transceiver. Therefore, the transmission quality of the optical transceiver is improved and the dimension of the circuit board structure is shrunken.

FIELD OF THE INVENTION

The present invention is related to circuit board structures of integrated optoelectronic component, and more particularly, to a circuit board structure that has been integrated with optical transmitting and receiving components and circuit structures.

BACKGROUND OF THE INVENTION

As the technological development of semiconductors advances, demands for miniaturized packaging and larger data storage capacity have also intensified along the way. In addition to that, because the data processing capacity is constantly increasing, if data units of the same size can be processed at the fastest speed possible in a given unit of time, then data can be processed more efficiently. The most straightforward method for raising the processing speed of semiconductors is to increase its operating frequency, but when the data transfer rate exceeds one gigabyte per second, problems like heat dissipation caused by high wattage, signal time delay, and electromagnetic interference (EMI) also arise, which will impede the production of semiconductors with high performance. This problem has been made even more severe because the traditional medium for data signal transmission is copper circuit, which cannot achieve higher conductivity due to its intrinsically limited conducting property, thus its signal transmission rate cannot be elevated by the method of increasing its conductivity.

Moreover, the signal transmission structure made of metal circuits is more susceptible to the interference of external noises or internal circuits during signal transmission, which in turn leads to erroneous signals being transferred. Therefore, the signal transmission structure has to be equipped with adequate protective measures to prevent the interference mentioned above from affecting signals, and this phenomenon is especially obvious in high-frequency signal transmission. The protective measures will result in increased difficulty to the designs of circuit and additional structures, which will in turn raise the costs of design and production, and cannot improve the current situation.

The traditional method of signal transmission is analog signal transmission, which works by charging conductor with electrical currents, but the current method for processing signals inside circuits is the digital processing method, which can easily distort signals when one type of signal is converted to the other during signal transmission.

In order to resolve the disadvantages resulted from the traditional method of analog signal transmission, the new technology uses optical signal to replace electrical signal for signal transmission, and the most obvious advantage by such change is better quality in signal transmission, since the optical signal is almost unsusceptible to interference of electromagnetic waves and is thus not distorted as much. As a result, there is no need to design a structure for preventing the interference of electromagnetic waves, and this helps reduce the costs of design and production. Therefore, using optical signal for signal transmission has become the main aim for future development.

In the prior arts, the optical transmission structure is designed to be disposed inside the printed circuit board; the process begins by adding a layer of optical conductive layer with organic waveguide film into the printed circuit board, then followed by the integration and packaging of optoelectronic and driving components onto the circuit board; the optical conductive layer can serve as the pathway for optical signal transmission, thereby achieving the aim of high-speed transfer.FIG. 1shows the invention of U.S. Pat. No. 6,839,476, wherein a core layer12is formed on the bottom layer11, and a plurality of grooves12aare also formed on core layer12; an optical fiber13is disposed into groove12a, followed by the formation of a top layer14on top of core layer12, so that optical fiber13is embedded within core layer12; optical fiber13is made by enclosing a layer of cladding13baround a core13a. The two ends of optical fiber13can be fitted with optical transmitting and receiving modules, along with passive optical components, so that the disadvantages of electrical signal transmission can be avoided by sending optical signal via optical fiber13.

However, because optical fiber13needs to be embedded in groove12aof core layer12, the core layer12has to undergo the grooving process in prior to the above step, followed by the disposition of optical fiber13into groove12ato complete the overall production process. But the disposition of optical fiber13into groove12ais carried out mechanically is similar to the mechanically process of electronic components inserted into the circuit board. As a result, the speed of production is slower and cannot reach the goal of fast production.

Moreover, optical fiber13needs to be cut in accordance with the length of groove12athat it faces beforehand, so that it can then be disposed into groove12a; this adds an additional step in the overall production process, and hence raises the difficulty of the production process. On the other hand, the uneven length of optical fiber13also makes the classification step in the production process more complicated, thereby increasing overall production steps and raising its complication, which in turn results in increased production costs.

Because grooves12ahas to be formed on core layer12in order to accept optical fiber13, it is necessary to leave adequate interval spaces between each of the groove12awhile designing their size, so that optical fiber13can be disposed into core layer12. But under the double influences of the size of interval space and the diameter of optical fiber13, the optical fiber13layout density cannot be elevated.

Furthermore, the optical fiber13used to transfer optical signal is made by enclosing a layer of cladding13baround a core13a, wherein the inner layer of cladding13bcan serve as a reflecting surface that allows the optical signals to be reflected forwardly and thereby achieving the goal of transmitting signals. On the other hand, optical fiber13and circuit board are two different structures and need to be produced independently; afterwards, the two separately produced products also needs to be integrated. Both steps described above increase the difficulty of the overall production process; impede the attainment of mass production, and thus the production cost cannot be lowered further.

Because optical fiber13needs to be embedded with core layer12, the difficulty and cost of the production are increased as a result; on the other hand, the demand of high optical fiber13layout density cannot be satisfied either, and all of the above issues require immediate attention and solution from the industry.

Therefore, it is urgent for the industry to provide a circuit board structure of integrated optoelectronic component that can meet the demand of miniaturization for electronic devices, reduce signal loss during signal transmission, shorten conductive pathway, decrease noises, and enhance the quality of optoelectronic signal transmission.

SUMMARY OF THE INVENTION

Bearing the shortcomings of the prior arts in mind, the major objective of the present invention is to provide a circuit board structure of integrated optoelectronic component that can reduce signal loss during signal transmission, shorten conductive pathway, decrease noises, and enhance the quality of optoelectronic signal transmission.

Another objective of the present invention is to provide a circuit board structure of integrated optoelectronic component that can meet the demand of miniaturization of electronic devices.

A further objective of the present invention is to provide a circuit board structure of integrated optoelectronic component that has heat slug or heat dissipation board that can raise the overall heat dissipation efficiency of the circuit board.

To achieve the above and other objectives, the circuit board structure of integrated optoelectronic component is composed of: a supporting structure that has a first surface and a second surface; at least one optical transceiver that has an active surface and an inactive surface opposite to the active surface; the inactive surface of the optical transceiver is mounted on the supporting structure, and the active surface of the optical transceiver has an optical active region and a plurality of electrode pads; a dielectric layer that is formed on the first surface of the supporting structure and the active surface of the optical transceiver; a circuit layer that is formed on the dielectric layer and is electrically connected to the electrode pads on the active surface of the optical transceiver through the conductive structure in the dielectric layer; as well as at least one hole that penetrates the dielectric layer in order to expose the optical active region on the active surface of the optical transceiver.

The supporting structure can either be metal boards, ceramic boards, insulating boards, organic circuit boards, or the randomly stacked structure made of the previous materials; the organic circuit board can be a printed circuit board or an IC package substrate.

The optical transceiver can either be laser diode (LD), light emitting diode (LED), vertical cavity surface emitting laser (VCSEL), photodiode (PD) or photo sensor.

The circuit board structure of integrated optoelectronic component described above is further comprised of a semiconductor component that is either an active component or a passive component, and the semiconductor component is disposed in the opening of the supporting structure, so that the circuit layer is electrically connected to the semiconductor component by the conductive structure formed in the dielectric layer.

In addition to that, an insulating protective layer is formed on the circuit layer, and a plurality of openings are formed in the insulating protective layer to expose the parts of the circuit layer that serve as electrical connecting pads, while another optical transceiver is disposed on the electrical connecting pad of the circuit board, so that the optical transceiver is electrically connected to the electrical connecting pad; the optical active region on the active surface of another optical transceiver is opposite to the dielectric layer and the hole of the insulating protective layer, so that the optical transceivers can transmit optical signal directly.

Moreover, a built-up circuit layer structure that is electrically connected to the circuit layer can be further formed on the circuit layer, and at least one through hole can be formed in the dielectric layer and the built-up circuit layer structure to expose the optical active region on the active surface of the optical transceiver. Additionally, an insulating protective layer can also be formed on the outer surface of the built-up circuit layer structure, so that the circuits located on the outer surface of the built-up circuit layer structure are protected. The insulating protective layer also possess a plurality of openings that are used to expose the electrical connecting pads located on the outer surface of the built-up circuit layer structure, and another optical transceiver is disposed on and electrically connected to the electrical connecting pads, so that through holes are formed in the dielectric layer and the built-up circuit layer structure, and the through holes are opposite to the optical active region on the active surface of another optical transceiver, and the optical transceivers can transmit and receive optical signal directly as a result.

Therefore, according to the present invention, the circuit board structure of integrated optoelectronic component is mainly consisted of a supporting structure and the optical transceiver thereof, and a single-layer or a multi-layer circuit structure that possess optical transceivers with holes on their active surfaces, so that the circuits in the single-layer or multi-layer circuit structure can be electrically connected to the electrode pads of the optical transceivers directly, and the optical active region of the optical transceivers is made face the position of the holes, thereby giving rise to the circuit board structure that meet the demand of miniaturization for electronic devices. On the other hand, the integration of the optoelectronic components also reduces signal loss during signal transmission, shortens the conductive pathway, and decreases noises, thereby enhancing the quality of optoelectronic signal transmission.

Furthermore, in the circuit board structure of integrated optoelectronic component in accordance with the present invention, the two ends of a hole in the single-layer or multi-layer circuit structure can be connected to an optical transceiver, thereby making the optical active regions on the active surfaces of the two optical transceivers face each other, thereby forming a modularized circuit board structure integrated with optoelectronic components, which in turn satisfies the constantly rising demands regarding the quality of electronic products.

Furthermore, in the circuit board structure of integrated optoelectronic component in accordance with the present invention, the supporting structure is composed of a first and a second supporting board, and the first and the second supporting boards can either be metal boards, ceramic boards, insulating boards, organic circuit boards, or the randomly stacked structure made of the previous materials; the organic circuit board can be a printed circuit board or an IC package substrate.

In addition, a heat slug can be formed in the supporting structure or the second supporting board described before, so as to connect to the optical transceiver or the semiconductor component, so that the heat generated from running the optical transceiver or the semiconductor component can be directly dispelled outwards. As a result, the heat dissipation efficiency of the circuit board structure of integrated optoelectronic component can be elevated, thereby protecting the components from being damaged.

The circuit board structure of integrated optoelectronic component of the present invention can also be disposed with organic circuit boards, so that other electronic components can be connected to the circuit board and thereby raising its electrical functionality.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention has been described using exemplary preferred embodiments; anyone who is familiar with the arts can easily comprehend other advantages and effects of the present invention by reading the disclosed content in this claim. Moreover, the present invention can also be implemented or applied by using other embodiments, and anyone can modify and adjust the details in this claim on the basis of different considerations or applications, provided that he or she does not depart from the purpose and scope of the present invention.

The First Preferred Embodiment

FIGS. 2A and 2Bshow the cross-sectional views of the circuit board structure of integrated optoelectronic component of the present invention according to the first embodiment of the present invention.

As shown inFIG. 2A, the circuit board structure of integrated optoelectronic component in this embodiment is composed of: a supporting structure21that has a first surface21aand a second surface21bopposite to the first surface; an optical transceiver22that has at least one active surface22aand an inactive surface22bopposite to22a; the inactive surface22bof optical transceiver22is disposed on the first surface21aof supporting structure21, an optical active region221and a plurality of electrode pads222are formed on active surface22aof optical transceiver22; a dielectric layer23that is formed on the first surface21aof supporting structure21and on active surface22aof optical transceiver22; a circuit layer24that is formed on the surface of dielectric layer23, and circuit layer24is electrically connected to the electrode pads222on active surface22aof optical transceiver22by the conductive structure241formed in dielectric layer23; as well as a hole25that penetrates dielectric layer23.

The supporting structure21can either be metal boards, ceramic boards, insulating boards, organic circuit boards, or the randomly stacked structure made of the previous materials; in addition, the surface of supporting structure21can be further disposed with a semiconductor component26such as an active component or a passive component; dielectric layer23and circuit layer24can be formed on the surface of supporting structure21, on the active surface22aof optical transceiver22, and on the active surface26aof semiconductor component26, and circuit layer24is electrically connected to the electrode pads222on active surface22aof optical transceiver22, as well as to the electrode pads261on active surface26aof semiconductor component26by the conductive structure241formed in dielectric layer23.

The optical transceiver22is disposed on the first surface21aof supporting structure21, and an optical active region221and a plurality of electrode pads222are formed on active surface22aof optical transceiver22, wherein the optical transceiver is either LD, LED, VCSEL, PD or photo sensor.

The dielectric layer23is formed on the first surface21aof supporting structure21and on active surface22aof optical transceiver22, and the dielectric layer23can be made of photosensitive or non-photosensitive resins like ABF (Ajinomoto Build-up Film), BCB (Benzocyclo-buthene), ICP (liquid Crystal Polymer), PI (Poly-imide), PPE (Poly(phenylene ether)), PTFE (Poly(tetra-fluoroethylene)), FR4, FR5, BT (Bismaleimide Triazine), Aramide; or made of substances mixed with epoxy resin and glass fiber.

An additional built-up circuit layer structure20can be formed on the surface of dielectric layer23and circuit layer24, in which hole25penetrates the positions of dielectric layer23and built-up circuit layer structure20that are opposite to optical active region221on active surface22aof optical transceiver22, so that optical active region221is exposed and thereby allowing optical transceiver22to transmit optical signal.

The built-up circuit layer structure20is consisted of: a dielectric layer200, a circuit layer202formed on the surface of dielectric layer200, and a conductive structure203formed in dielectric layer200that allows circuit layer202to electrically connect to circuit layer24. A plurality of electrical connecting pads204are formed on the circuit layer on the outer surface of built-up circuit layer structure20, wherein hole25penetrates the positions of dielectric layer23and built-up circuit layer structure20that are opposite to optical active region221on active surface22aof optical transceiver22, so that optical active region221of optical transceiver22is exposed.

An insulating protective layer27can be further formed on the outer surface of the built-up circuit layer structure20described above in order to protect the circuit layer underneath it, and a plurality of openings271are formed in insulating protective layer27to expose the electrical connecting pads204on the outer surface of the built-up circuit layer structure.

Referring toFIG. 2B, the circuit board structure of integrated optoelectronic component of the present invention can further comprise another optical transceiver28formed on the surface of the built-up circuit layer structure20, and optical transceiver28is disposed on electrical connecting pad204of built-up circuit layer structure20by conductive element29; the optical active region281on active surface28aof optical transceiver28is opposite to hole25, hence it is facing optical active region221of optical transceiver22, so that the signals from optical transceivers22and28can be directly transmitted and received, thereby raising the electrical functionality of the circuit board structure.

The hole25can be filled with air or optical conductive material to prevent external noises from interfering with the transmission of optical signal, and to protect optical active region221of optical transceiver22.

The Second Preferred Embodiment

FIG. 3is a cross-sectional view showing the circuit board structure of integrated optoelectronic component of the present invention according to the second embodiment of the present invention; it differs from the previous embodiment in that the supporting structure31can be either a circuit board or an insulating board, and an opening310is formed in supporting structure31, with a heat slug312formed in opening310. The optical transceivers22and28, as well as semiconductor component26are disposed on heat slug312, so that the heat generated from running optical transceivers22and28or semiconductor component26can be dispelled outwards, thereby raising the heat dissipation function of the circuit board structure of integrated optoelectronic component and protecting the components from getting damaged.

The Third Preferred Embodiment

FIGS. 4A and 4Bare schematic cross-sectional views illustrating the circuit board structure of integrated optoelectronic component of the present invention according to the third embodiment of the present invention.

As shown inFIG. 4A, the circuit board structure of integrated optoelectronic component in this embodiment is composed of: a supporting structure41that has a first surface41aand a second surface41b, the supporting structure41can either be metal boards, ceramic boards, insulating boards, organic circuit boards, or the randomly stacked structure made of the previous materials; an opening410that penetrates the first surface41abut not the second surface41bis formed in supporting structure41; at least one optical transceiver22that has an active surface22aand an inactive surface22bopposite to22a, and the inactive surface22bof optical transceiver22is disposed in opening410of supporting structure41by an adhesive layer (not shown in the figure); at least a semiconductor component26, which can be an active component or a passive component; the semiconductor component26can be formed in another opening411of supporting structure41; the semiconductor component26has an active surface26aand an inactive surface26bopposite to26a, and a plurality of electrode pads261are located on active surface26a; a dielectric layer23that is formed on the first surface41aof supporting structure41, on active surface22aof optical transceiver22, and on active surface26aof semiconductor component26; a circuit layer24formed on the surface of dielectric layer23, and circuit layer24is electrically connected to the electrode pads222on active surface22aof optical transceiver22and to the electrode pads261on active surface26aof semiconductor component26by the conductive structure241formed in dielectric layer23; as well as a hole25that penetrates dielectric layer23, so that optical active region221on active surface22aof optical transceiver22is exposed, thereby enabling optical transceiver22to transmit optical signal.

A built-up circuit layer structure20can be further formed on the circuit layer24described above, the built-up circuit layer structure20is formed on the surface of dielectric layer23and circuit layer24, and the built-up circuit layer structure20is electrically connected to circuit layer24; an insulating protective layer27is formed on the surface of built-up circuit layer structure20in order to protect the circuit layer under its cover, a plurality of openings271are also formed in the insulating protective layer27to expose the parts of circuit layer that serve as electrical connecting pads204. At least a through hole25is formed in dielectric layer23and built-up circuit layer structure20as well, in order to expose optical active region221on active surface22aof optical transceiver22.

Referring toFIG. 4B, an additional optical transceiver28is disposed on the surface of built-up circuit layer structure20, and optical transceiver28is disposed on electrical connecting pad204of built-up circuit layer structure20by conductive element29; optical active region281on active surface28aof optical transceiver28is opposite to hole25, in other words, it is facing optical active region221of optical transceiver22, which allows optical signals from optical transceivers22and28to be transmitted and received directly, thereby raising the electrical functionality of the circuit board structure.

The Fourth Preferred Embodiment

FIGS. 5A and 5Bare schematic cross-sectional views illustrating the circuit board structure of integrated optoelectronic component of the present invention according to the fourth embodiment of the present invention. This embodiment differs from the previous one in that the supporting structure51has a first surface51aand a second surface51b, and openings510and511are formed in supporting structure51, which penetrate the first and the second surface,51aand51brespectively; the optical transceiver22and semiconductor component26are disposed in openings510and511of supporting structure51respectively.

A dielectric layer23and a circuit layer24are successively formed on the surface of supporting structure51, on active surface22aof optical transceiver22, and on active surface26aof semiconductor component26; a built-up circuit layer structure20is formed on the surfaces of dielectric layer23and circuit layer24, and an insulating protective27that functions as a soldermask layer is formed on the surface of built-up circuit layer structure20as well; another optical transceiver28is formed on the surface built-up circuit layer structure20, and optical transceiver28is disposed on electrical connecting pad204of built-up circuit layer structure20by conductive element29; optical active region281on active surface28aof optical transceiver28is opposite to hole25, in other words, it is facing optical active region221of optical transceiver22, which allows optical signals from optical transceivers22and28to be transmitted and received directly, thereby raising the electrical functionality of the circuit board structure.

The Fifth Preferred Embodiment

FIGS. 6A and 6Bare schematic cross-sectional views illustrating the circuit board structure of integrated optoelectronic component of the present invention according to the fifth embodiment of the present invention.

As shown inFIG. 6A, this embodiment is basically identical to the embodiments mentioned before, the only difference is that in this embodiment, the supporting structure61is consisted of a first supporting board610and a second supporting board612, wherein the first and the second supporting boards610and612can either be metal boards, ceramic boards, insulating boards, organic circuit boards, or the randomly stacked structure made of the previous materials. The first supporting board610has a plurality of through openings610aand610b, and the second supporting board612seals the other end of openings610aand610b, thereby making the inactive surface22bof optical transceiver22and the inactive surface26bof semiconductor component26dispose on the second supporting board612by an adhesive layer (not shown in the figure), so that optical transceiver22and semiconductor component26are disposed in openings610aand610bof the first supporting board610respectively. This is then followed by the formation of a dielectric layer23on the surface of the first supporting board610, and the formation of circuit layer24in dielectric layer23; circuit layer24is electrically connected to electrode pads222of optical transceiver22and electrode pads261of semiconductor component26, and a through holes25is also formed in dielectric layer23.

A built-up circuit layer structure20is formed on the surfaces of dielectric layer23and circuit layer24, and an additional insulating protective layer27is formed on the outer surface of built-up circuit layer structure20in order to protect the circuit layer under its cover, a plurality of openings271are also formed in insulating protective layer27to expose the electrical connecting pads204on the outer surface of built-up circuit layer structure, wherein a hole25that penetrates dielectric layer23and built-up circuit layer structure20is formed in the position that faces the optical active region221on active surface22aof optical transceiver22, thereby exposing optical active region221.

Referring toFIG. 6B, the surface of built-up circuit layer structure20is disposed with another optical transceiver28, and optical transceiver28is disposed on electrical connecting pad204of built-up circuit layer structure20by conductive element29; optical active region281on active surface28aof optical transceiver28is opposite to hole25, in other words, it is facing optical active region221of optical transceiver22, which allows optical signals from optical transceivers22and28to be transmitted and received directly, thereby raising the electrical functionality of the circuit board structure.

The Sixth Preferred Embodiment

FIG. 7is a schematic cross-sectional view illustrating the circuit board structure of integrated optoelectronic component of the present invention according to the sixth embodiment of the present invention. It differs from the previous embodiment in that the first and the second supporting boards are either circuit boards or insulating boards, and an opening612ais formed in the second supporting board612, a heat slug613is also formed in opening612a; the optical transceivers22and28, as well as semiconductor component26are disposed on heat slug613, so that the heat generated from running optical transceivers22and28or semiconductor component26can be dispelled outwards by heat slug613, thereby raising the heat dissipation function of the circuit board structure of integrated optoelectronic component and protecting the components from getting damaged.

Therefore, in the circuit board structure of integrated optoelectronic component of the present invention, a supporting structure is integrated with optical transceiver first, then a single-layer or multi-layer circuit structure with holes is formed on the active surface of the optical transceiver, so that the circuits in the single-layer or multi-layer circuit structure can be electrically connected to the electrode pads of optical transceiver directly, and thus the optical active region of the optical transceiver is made opposite to the hole. As a result, a circuit board structure of integrated optoelectronic component that meets the demand of miniaturization regarding electronic devices can be produced, thus the integration of optoelectronic components can reduce signal loss during signal transmission, shorten conductive pathway, and decrease noises, thereby elevating the quality of optical and electrical signal transmission.

Moreover, in the circuit board structure of integrated optoelectronic component of the present invention, the two ends of a hole in single-layer or multi-layer circuit structure can be connected to two optical transceivers respectively, so that the optical active regions on the active surfaces of the two optical transceivers can face each other, thereby forming a modularized circuit board structure integrated with optoelectronic components, which in turn satisfies the constantly rising demands regarding the quality of electronic products.

In addition to that, in the circuit board structure of integrated optoelectronic component of the present invention, additional heat slugs or heat dissipation boards can be formed, so that optical transceivers or semiconductor components can be disposed on it, hence the heat generated from running the optical transceivers or semiconductor components can be directly dispelled outwards, thereby raising the heat dissipation efficiency of the circuit board structure of integrated optoelectronic component and protecting components from getting damaged.

The preferred embodiments described above only serve the purpose of explaining the principle and effects of the present invention, and are not to be used to limit the scope of the present invention. Anyone who is familiar with the art may modify and adjust the above-mentioned embodiments provided that he or she does not depart from the purpose and scope of the present invention. Therefore, the scope of the present invention should be covered by the claims listed in the following pages.