Patent Description:
Octal Small Formfactor Pluggable (OSFP) is a module and interconnect system with a pluggable form factor with eight high speed electrical lanes. OSFP was designed to initially support <NUM> Gbps (<NUM> lanes x <NUM> per lane) optical data links. Compared to other form factors, such as QSFP, OSFP is slightly wider and deeper but still supports <NUM> ports per 1U front panel, which enables a theoretical <NUM> bitrate through an OSFP module. The OSFP has several advantages, including that it is reverse compatible with QSFP formats through simple adapters. The OSFP continues to become more common in supporting optics technologies for datacenter and other data transfer applications.

Current OSFP modules consume roughly <NUM>-<NUM> watts to achieve a <NUM> bitrate. However, as the throughput requirements on the OSFP module increase, the wattage requirements also increase. This in turn increases the thermal load and electromagnetic interference on the OSFP. With the current standard OSFP form factor, these effects lead to issues in operating the OSFP modules at higher bit rates or throughputs due to thermal and electrical effects.

Further, as the OSFP Module specifications define specific mechanical form factors and electric parameters for compliance with the standard, the above problems cannot be addressed by changing the mechanical form factors of the modules. There is a need for solutions to enable OSFP modules to operate at higher bitrates while maintaining compliance with the OSFP module specification. <INSERT DESCRIPTION PAGE 1A HERE>.

The presently claimed subject-matter is defined in independent claim <NUM>. There are provided systems for thermal and electrical optimizations for OSFP optical transceiver modules. Document <CIT> relates to an electronics module including a housing enclosing a printed circuit board, a first and a second heat sink and one or more notches or apertures enabling airflow through the electronics module.

This disclosure generally relates to methods, systems, and apparatuses for thermal and electrical optimizations in Octal Small Form factor Pluggable (OSFP) optical transceiver modules.

<FIG> illustrates an exploded view of OSFP modules and improvements according to aspects of this disclosure. <NUM> illustrates a block or group of OSFP modules, such as modules <NUM>-<NUM>. The block of OSFP modules are configured such that they are compatible with a cage, such as cage <NUM>. Cage <NUM> is a 1x4 cage meaning that it can house <NUM> OSFP modules arranged in one row. Cage <NUM> has four openings and each opening can be configured to house a single OSFP module. Other configurations of cages are possible. In some examples, a 1x1 cage can house a single OSFP module, while in other examples, other arbitrary M x N modules are possible. An OSFP module can contain other components such as opticals, optical receivers, optical transceivers, lasers, and processors to enable the transmission of data. Modules <NUM>-<NUM> and cage <NUM> can be part of or installed within a larger enclosure. For example, the larger enclosure can have electronics, fans, cooling, or other systems to enable operation of OSFP modules. Cage <NUM> can have a top surface <NUM>, a bottom surface <NUM>, vertical walls separating OSFP modules, such as separator <NUM>, and a back side or back portion of the separator, rear edge <NUM>.

Module <NUM> is for example an OSFP compliant transceiver module which meets the parameters of the OSFP form factor and/or OSFP specifications. Module <NUM> is also an OSFP transceiver module with a connector on one side, connector <NUM>, and a heatsink <NUM> on the top of the module. In some examples, heatsink <NUM> can be the top surface of module <NUM>. An inlet can be formed above or near connector <NUM>. Module <NUM> is intended to be mounted within a rack or cage, as further discussed below with reference to <FIG>. Connectors <NUM> can make one end or be formed towards one end of module <NUM>. Module <NUM> can have a throughput across the number of lanes. For example, the throughput of module <NUM> may be <NUM> Gbps or <NUM> per lane across the <NUM> lanes. In other examples, a higher throughput of module <NUM> may exist and correspondingly be higher across the lanes.

Module <NUM> may also be in communication with a computing device. The computing device can be any type of computing device such as a server, cluster of servers, virtual machine, laptop, desktop, mobile device, or custom-designed hardware device. The computing device may contain a processor, volatile memory, non-volatile memory, a user interface, a display, communication interface(s), and instructions.

Although not illustrated in <FIG>, modules <NUM>-<NUM> may contain processors or application specific integrated circuits (ASIC). The processor or ASIC of modules <NUM> may be configured to enable signals to be transmitted through the module. Module <NUM> may be configured in various modes to enable both high-speed signals, such as those described in the electric specifications of IEEE802.3bs, IEEE802.3cd, or low-speed signals, such as those using the I2C or I3C protocols, which can be used for configuration and control of module <NUM> by a host. The encoding or specific implementation of the signals may depend on the capability of the ASIC or processor within module <NUM>. Similarly, although not illustrated in <FIG>, module <NUM> may contain a laser.

Connector <NUM> can support various types of communication interfaces. In some examples, connector <NUM> can be a duplex LC connector, which is a type of fiber connector developed by Lucent Technologies. In some examples, connector <NUM> can be a multi-fiber push on (MPO) type of optical connector. In other examples, connector <NUM> can be any known or compatible communication interface capable of enabling transfer of data.

Heatsink <NUM> is also illustrated in <FIG>. Heatsink <NUM> can be made of a base section, such as base <NUM>, and various fins, such as fins <NUM>-<NUM>. The absolute dimensions of the fins and the position of the fins relative to one another is constrained by the size of cage <NUM>, as well as OSFP guidelines and restrictions. In addition, the shape, relative location or position, or absolute position of the fins are optimized to enable better airflow which in turn, can enable the OSFP to remain operable despite the higher amount of heat generated due to the higher wattage requirements associated with an increased throughput. Heatsink <NUM> can be mechanically attached to cage <NUM> or make contact with modules <NUM>-<NUM> through the use of springs, screws, clips, or another mechanism to allow the heatsink to easily attach to cage <NUM> and form a secure connection. Although heatsink <NUM> is shown as one unit, heatsink <NUM> can be formed or made in multiple configurations or parts.

Each module can have a plurality of openings or inlets which allow air to enter into the internal volume of the module. For example, <FIG> illustrates an inlet <NUM> of module <NUM> and inlet <NUM> of module <NUM>, as well as a surface <NUM> overlying the inlet <NUM>. Air entering the inlet can cool the module and exit from the back of the module, outlet <NUM>-B. Surface <NUM> can also cool heat generated within the modules. Surface <NUM> can couple with base <NUM> of the heatsink in order to create a thermal connection and allow heat to further dissipate. In some examples, surface <NUM> can form part of a heatsink or a vapor chamber. Two air-paths are thus formed for cooling the modules.

<FIG> illustrates a view of assembled OSFP modules and improvements according to aspects of this disclosure. As illustrated in <FIG>, base <NUM> may be directly adjacent and contact heatsink <NUM> to allow heat generated within the module to dissipate and be conducted away from the module. Fins <NUM>-<NUM> can divert heat away from the OSFP modules <NUM>-<NUM> and allow cooling.

The fins can extend longitudinally across the length of cage <NUM> parallel to the top surface <NUM>, perpendicular to the top surface <NUM>, or longitudinally across or parallel bottom surface <NUM> of cage <NUM> between an edge of the cage adjacent separators <NUM> and an opposite and rear edge <NUM> of the cage. In the example shown in <FIG>, fins <NUM>-<NUM> extend along a majority of a length of the cage. Any number of fins may be provided across a width of cage <NUM>. In the example shown, <NUM> fins extend across the width of the cage, but the number of fins can vary widely.

In some examples, fins may have a length ranging up to the length of cage <NUM>, such as <NUM>, a height of <NUM>, and a thickness of <NUM>. In other examples, the height may range between <NUM> and <NUM>, the length may range between <NUM> and <NUM>, and the thickness may range between <NUM> and <NUM>. Fin pitch may range between <NUM> and <NUM>. But in other examples, fins may have length less than <NUM> or greater than <NUM>.

The relationship between air velocity and air pressure drop is roughly quadratic. The power required to move air is roughly a cubic function of the air velocity. The relationships between the fins, the length of the fins, thickness, and contact points with heatsink <NUM> are optimized to maximize cooling while ensuring that a pressure drop from the front of the OSFP compliant modules is not excessive.

<FIG> illustrates an additional view of assembled OSFP modules and improvements according to aspects of this disclosure. Visible in <FIG> are outlets for the various modules, such as outlet <NUM><NUM>-B. Outlets allow airflow to move from one end of the modules to the other. The airflow through the modules can additionally assist in cooling the modules in conjunction with the heatsinks and fins.

In some examples, one or more components illustrated with reference to <FIG>, can be partially or fully made from diamond composites, such as silver-diamond, aluminum-diamond, or copper-diamond. In some examples, the diamond-composite material can consist of a surface layer which is pure metal surrounding an internal layer or internal core made of diamond or diamond-metal hybrid. The surface layer which has a higher conductivity will allow heat to be transferred more quickly while the internal core, which is made from diamond or diamond-composite, will not conduct heat in the same manner. Through selective use or engineering of materials, heat can be directed away from areas of the module which are more likely to overheat, such as the laser or the ASIC. For example, the coefficient of thermal expansion for silver diamond is <NUM> ppm/K while the thermal conductivity is <NUM> W/(m. The low coefficient of thermal expansion while retaining a high thermal conductivity allows for the module to be more effectively cooled while retaining tight tolerances to maximize the dimensions of the fins and other cooling components. In some examples, the components can be made from any metal matrix composite material. A metal matrix composite material is a material with at least one of the materials being metal to allow for higher thermal conductivity while retaining properties of the other material.

<FIG> illustrates a side view of a module <NUM> with a heatsink <NUM> and fins <NUM>-<NUM>. The spacing of the fins illustrates a varying gap between fins <NUM>-<NUM> designed to optimize airflow and cooling over components or areas of module <NUM>. For example, the gap between fin <NUM> and fin <NUM>, and fin <NUM> and <NUM> is larger, allowing for a greater volume of air to flow closer to the center of module <NUM>. Inlets <NUM>-<NUM> of module <NUM> allow air to enter into the interior volume of module <NUM>. Heatsink <NUM> can make thermal contact with module <NUM> through base <NUM>-C. As can be seen from the side view, two paths for air exist, allowing for additional cooling while keeping compliance with the OSFP specification.

While <FIG> provide several example arrangements of cooling fins, it should be understood that further arrangements are possible. For example, the number, spacing, shape, or combination of fins may be modified. Additionally, although not illustrated in <FIG>, an external housing can house cage <NUM>. An opening with an external housing can be optimized in terms of spacing, size, dimension, or geometry to optimize for a physical parameter of the system such as for example, heat dissipation, pressure drop, or average temperature drop. As there is usually a fixed volume, rate of airflow, or mass-flow rate across the opening of an external housing and through the external housing, the airflow can be divided across the inside of module <NUM> and across heatsink <NUM>. As the total mass-flow rate is typically fixed, the division between the external housing and the internal housing can be determined by the opening of the external housing.

<FIG> illustrate top-down views of a portion of a module. Illustrated in <FIG> are module components <NUM>-<NUM>. Due to the length of a module, such as module <NUM>, there will be a pressure drop from one end to the other of the module and airflow may also be restricted within the module. Components <NUM>-<NUM> are designed to reduce excessive pressure drop along the length of each component and allow for the airflow to be less restricted. The module components can have a top surface, such as surface <NUM>, <NUM>, <NUM>, and <NUM>.

Illustrated in <FIG> is component <NUM> with surface <NUM>. Holes can be formed on surface <NUM>, such as holes <NUM> and <NUM>. Holes <NUM> and <NUM> are circular in shape. Formed on surface <NUM> are a plurality of ridges, including ridge <NUM> and ridge <NUM>, which can minimize the volume occupied by air as it moves over surface <NUM> of component <NUM>. Additionally, the ridges help channel air in one direction or create "tunnels" of air. Ridge <NUM> and ridge <NUM> can extend longitudinally along the length of the module and the space between two adjacent ridges can form "channels" which also extend along the length of the modules. The ridges can be thermally conductive and act as a heatsink or form part of a heat transfer path away from module <NUM>. This can assist in minimizing the pressure difference between the two ends of the surface. Although not illustrated, additional holes can be formed along the length of surface <NUM> to further allow additional inlet air into the interior volume of component <NUM>. The holes can be of any shape or be shaped based on the exact form or dimensions of component <NUM> to maximize the airflow inside the component. In some examples, the holes can be <NUM>-<NUM> in length and spaced at <NUM>-<NUM>. In other examples, holes smaller than <NUM> and larger than <NUM> and at any spacing can be formed. In other examples, the holes can be made in a zig-zag pattern. The holes can be made in a variety of patterns on surface <NUM>.

Illustrated in <FIG> is component <NUM>. Present on surface <NUM> are a plurality of pin-fins extending perpendicular to the length of surface <NUM>, such as pin-fin <NUM>. These pin-fins minimize the air pressure drop from the one end of component <NUM> to the other end of component <NUM>. In addition, pin-fins <NUM> can be shaped to further have an inlet or air foils, which allow air to enter into the interior volume of the component. The height of any one pin-fin is fixed by the OSFP form factor, but the width and the length of the pin-fin can be optimized for the smallest drop of pressure in air flow.

Pin fins may take on a variety of geometric shapes. In one example, as shown in <FIG>, pin-fins have an elongated and diamond shaped body with rounded edges. A width <NUM> at a central portion of pin-fin <NUM> can be greater than a width <NUM> at the outermost and opposed ends of pin-fin <NUM>. In other examples, the pin-fins have a different shape, such as rounded, square, tear-drop, sinusoidal, or any variety or combinations of shapes. The top surface <NUM> of pin-fin <NUM> may be planar, but in other examples, the top surface of pin-fin <NUM> may be non-planar and have a curved surface. In some examples the top-surface of the pin-fin can be planar while in other examples the top surface of the pin-fin can be contoured.

The pin-fins may be positioned on any portion of surface <NUM>. In the example of <FIG>, pin-fins <NUM> are positioned within a front half of surface <NUM> adjacent front edge <NUM>-F of component <NUM>. Pin-fins may instead be positioned within a rear half of surface <NUM> adjacent rear edge of component <NUM>. In still other examples, pin-fins <NUM> may extend along an entire length L or a majority of length L of surface <NUM>. A few of these additional examples will be further discussed below.

Pin-fins may be arranged in any number of patterns. As shown, rows of pins are staggered along length L, such that a second row <NUM> of fin pins is positioned between each of the fin pins in a first row <NUM>. This pattern can continue along the length L of surface <NUM>. In other examples, pin-fins may be arranged in straight lines or columns. Similarly, pin-fins may be arranged at any random points along surface <NUM>.

Illustrated in <FIG> is component <NUM>. Similar to component <NUM>, present on surface <NUM> of component <NUM> are pin-fins <NUM> and <NUM>. This example illustrates pin fins extending along a majority of a length L of surface <NUM>, and covering substantially the entire surface <NUM>. In some examples, the pin-fins can extend away from the surface, such as <NUM> away from the surface. In other examples, the pin-fins can extend less than <NUM> or greater than <NUM> away from the surface.

The pin-fins may be formed in any geometric shape. In some examples, the pin-fins can formed of a fixed or varying height. The pins-fins may take on a variety of shapes and the geometries of the pins may vary from pin to pin or row to row. In yet other examples, a variety of geometries can be used for the pin-fins to create various pathways for airflow over surface <NUM>. In some examples, the geometry of the pin fin may be chosen based on the known throughputs or thermal characteristics of an OFSP module. In other examples the geometry of the pin fin and arrangement of the pin-fins can be chosen based on the thermal characteristic of a module, such as an ASIC or laser contained within it. In some examples, the plurality of pin-fins and foils can be arranged to form a partial array on the surface of a component, as well as arranged to correspond to the location of a heat source within the component to enable the lowest pressure drop. For example, the pin fins may only cover a central one-fourth portion of a surface in a relatively dense pattern while other portions of the surface may not contain pin-fins or may contain pin-fins of relatively lower density. In other examples, more complex geometries, such as a Fibonacci spiral, can be arranged to optimize heat exchange, cooling, airflow, pressure, or other parameters. In some examples, the pin-fins can form an array near an ASIC or laser within the module to allow for additional cooling in that region and improve overall heat dissipation characteristics. The pin-fins can further provide additional thermal connectivity with the cage in which the OSFP module is placed.

Illustrated in <FIG> is component <NUM>. Similar to component <NUM>, present on surface <NUM> of component <NUM> are pin-fins <NUM> and <NUM>. Pin-fins <NUM> and <NUM> have different dimensions.

While <FIG> provide several example arrangements of pin-fins, it should be understood that further arrangements are possible. For example, the number, spacing, shape, or combination of pin-fins may be modified. In some examples, an external heat sink, such as that referenced in <FIG> can be modified to mechanically mate or otherwise make contact with an arrangement of pin-fins to allow for additional thermal dissipation.

<FIG> illustrates a cross sectional view of a housing <NUM> of an OFSP module fitted within a cage <NUM>. Airflow is directed "into" the page or in the direction of arrows <NUM>-<NUM> shown in <FIG>. Housing <NUM> can have a surface <NUM>, and upon it a plurality of pin-fins, such as pin-fin <NUM>. Pin-fin <NUM> can further contain or form an air foil. An air-foil can be created from the volume enclosed by a surface of a pin-fin. The pin-fin can be shaped such that an interior portion of the pin-fin is hollow and forms an interior cavity. The interior cavity can provide a space for air to enter into and fill the volume of the interior cavity. The interior cavity can take on a variety of shapes and in one example may possess a funnel-like shape, which is visible when viewed from the top. In other examples, the outer surface of the pin-fin can include breaks or openings in the surface to allow air to flow into the inner volume of the air-foil. For example, a portion of surface <NUM> enclosed by pin-fin <NUM> can be removed, creating a pathway for air to move across the surface. This can further enhance cooling from the interior of housing <NUM> and maximize airflow into the air foil.

Cage <NUM> can be chamfered to contain depressions within the surface of the cage, such as at chamfer <NUM> and chamfer <NUM>. Chamfers <NUM> and <NUM> can be spring loaded such that they are flush with the internal surface of cage <NUM> unless an external force is applied to them. Upon application of an external force, chamfers <NUM>-<NUM> can be depressed in towards cage <NUM> in the same direction of the application of force. The pin-fins can align within the depression of the chamfers. For example, chamfer <NUM> aligns with pin-fin <NUM>. Thus, when inserting the housing <NUM>, or a module, such as module <NUM>, into a cage, mechanical stresses and damage can be minimized by aligning the chamfers and pin foils. In addition, the pin foil can push against chamfer <NUM>, depressing a spring of chamfer <NUM>, and make a tight connection with the chamfer <NUM>. In this manner, any microcurrent or induced current within the system can be effectively grounded through the mechanical and electrical contact between pin-foil <NUM> and chamfer <NUM>.

Radiated emission or radio frequency energy can be emitted from the housing in the opposite direction of the airflow. Radiation can be generated during operation of the modules, such as by an ASIC or laser within the module. In some examples, pin-fins can be utilized and optimized based on width, length, and to minimize pressure drop through the length of the housing while still attenuating radiated emissions sources. In other examples, the use of pin-fins arranged in rows offset from one another attenuates the radiation as each pin-fin reflects back or attenuates radiation. In some examples, by using multiple rows of pin-fins, the radiation can be attenuated by a larger extent. A person of skill in the art would understand that various combinations and designs are possible for various use cases of module <NUM>.

<FIG> illustrates a partial view of a module, module <NUM>. Module <NUM> can be similar to module <NUM> described above. Illustrated in <FIG> is the connecting side of module <NUM> with a receiver <NUM>. Receiver <NUM> can be any suitable receiver supported by the OSFP specification discussed above. The module can also contain inlets above the receiver, which are designed to optimize airflow into module <NUM>, such as inlet <NUM>. The specific shape and design of the inlets can be based on the geometry of module <NUM> as well as the operating conditions of electrical housing contained within module <NUM>. Illustrated in parallel arrows labeled <NUM> and <NUM> is the direction of airflow into module <NUM>. Additional arrows are not illustrated for clarity in <FIG>, but it is understood that air is flowing into the module <NUM> at many locations of inlet <NUM>.

In some examples, the inlets, such as inlet <NUM>, can be replaced with a vapor chamber. A vapor chamber is a chamber which is filled with a coolant. The coolant, when heated, changes from a liquid phase to a gas phase. Once gaseous, the coolant circulates via convection and moves freely through the chamber. The gaseous molecules condense on cold surfaces, dissipate their heat load, and are channeled back to the coolant reservoir. This process allows for cooling with a fixed or known amount of coolant. The coolant reservoir can extend along part or the entire length of module <NUM>.

<FIG> illustrates a side view of an OSFP module within a cage <NUM>. Illustrated in <FIG> is a module <NUM> with a connector <NUM>, and air duct <NUM>, and a blower <NUM>. Air entering module <NUM> is indicated with a solid line <NUM>. Airflow between the connector <NUM> and air duct <NUM> that is distributed to the blower <NUM> is indicated with a solid line <NUM>. Air leaving the blower <NUM> in indicated with a solid line <NUM>. The temperature of the air increases as it moves through the OSFP module from the left side, adjacent a data connector of the module within cage <NUM>, through the right side of the cage <NUM>. The temperature of the air can reduce or stay similar as it moves out through cage <NUM> and left to right through membrane of air duct <NUM>, and through to the right side, adjacent the blower <NUM>. Module <NUM> can be similar to the modules described above, such as module <NUM>. Air duct <NUM> can have a first end and a second end, and can enclose a fixed volume. Air duct <NUM> can be made of any suitable material, such as plastic, polymer, or metal. Air duct <NUM> be a duct which allows for air to be ducted away from one end of module <NUM>. Blower <NUM> can be attached to one end of air duct <NUM> while module <NUM> is attached to the other end. This attachment can create an airpath <NUM>. As there is an independent pathway for the module, the airflow within a module can be decoupled from the airflow of a tray or housing within which the module is placed, a high pressure pathway can be created for the module and be decoupled from the air-flow requirements of the tray or housing.

Further, the connections between module <NUM>, air duct <NUM>, and blower <NUM> can be formed of a rigid, flexible, or semi-flexible membrane. Membranes and openings between the parts can be chosen on the basis of the geometry of the module, the air pressure, and the specific fluid dynamics generated by the system. For example, it is possible that vortices or other undesirable phenomena are created by choosing the dimensions of the openings or connections between the module, air duct, and blower. Such vortices can disrupt the smooth airflow desired over module <NUM>. In addition, vibrational load, frequency, resonance frequency, temperature and other parameters must be considered when engineering airpath <NUM> to ensure that the airpath can optimally cool the OSFP module. In some examples, air duct <NUM> can be several cm long and form an angle relative to the module. The angle may range, for example, between <NUM>-<NUM> degrees, but in other examples, the angle may be less than <NUM> degrees or greater than <NUM> degrees. The relative geometry of the air duct can be based on physical or operational parameters of the module, such as the module length, the air pressure at any part within the module, the airflow through the module, or the temperature of the air exiting the module.

Blower <NUM> can be any device which can generate an air jet. The blower will create negative pressure, further increasing air flow through module <NUM>. This in turn will allow the module to be more effectively cooled. In some examples, blower <NUM> can operate at a frequency of <NUM>-<NUM> rotations per minute and move <NUM> litres (<NUM> cubic feet) of air per minute. But, in other examples, the frequency may be less than <NUM> rotations per minute or more than <NUM> rotations per minute to move <NUM> litres (<NUM> cubic feet) of air per minute. In still other examples, the rotations per minute can be modified to move less than or more than <NUM> litres (<NUM> cubic feet) per minute. The blower can be chosen to optimize cooling, airflow, pressure, or temperature drop within the module. The blower can be chosen based on its frequency, vibrational characteristics, ability to create pressure gradients, or other similar parameters.

In some examples, the methods and apparatuses described with reference to <FIG> can be used separately or in conjunction with one another.

<FIG> illustrates a schematic cross-sectional view of an OSFP module, module <NUM>. <FIG> illustrates an ASIC <NUM>, a laser <NUM>, a printed circuit board <NUM>, and a housing of the OSFP module, housing <NUM>, a thermal path <NUM>, and a heatsink <NUM>. Also illustrated in <FIG> in a dashed solid line is an expected path or one path for heat dissipation. The ASIC is an application specific integrated circuit. ASIC <NUM> is mounted to the bottom of the module. In some examples, laser <NUM> can be a laser operating at <NUM> watts. Laser <NUM> typically has an upper operational temperature limit of around <NUM>. However, ASIC <NUM> can run at much higher temperatures, and as illustrated in <FIG>, sits below the laser. During normal operation of the ASIC, the excess heat generated may disturb the normal operation of the laser, particularly given that the ASIC is further away from heatsink <NUM>. The indirect thermal path not only causes heat to tend to move towards laser <NUM> but additionally is ineffective in channeling heat away from the ASIC.

<FIG> illustrates a cross-sectional view of an OSFP module <NUM>. Also illustrated in dashed solid lines are paths of heat dissipation from module <NUM>. Similar to module <NUM>, module <NUM> contains an ASIC <NUM>, a laser <NUM>, a printed circuit board <NUM>, a housing of the OSFP module, housing <NUM>, a thermal path <NUM>, and a heatsink <NUM>. By moving ASIC <NUM> above printed circuit board <NUM> and moving laser <NUM> below the printed circuit board, heat is more easily dissipated away from the hotter ASIC. In addition, printed circuit board <NUM> can act as an insulator and prevent some of the heat generated by ASIC <NUM> from reaching laser <NUM>.

<FIG> illustrates a schematic cross-sectional view of an OSFP module <NUM>. <FIG> illustrates an ASIC <NUM>, a laser <NUM>, a printed circuit board <NUM>, and a housing of the OSFP module, housing <NUM>, a thermal path <NUM>, and a heatsink <NUM>. Also illustrates is an additional finned air heatsink, heatsink <NUM>. Heatsink <NUM> sits below the OSFP module <NUM> and makes contact with the module along a portion of the length of the module. This enables the OSFP module to fit within cages without heatsink <NUM> obstructing the insertion of the module <NUM>. Heatsink <NUM> can also contain heatpipes, such as heatpipe <NUM>. Heatpipe <NUM> can be made of any conductive material, such as a metal or metal compound. In some examples, the heatpipe can be made of copper, gold-composites, silver, or other metal composite materials. The material of heatpipe <NUM> can be chosen based on a coefficient of thermal expansion of both the heatsink material and the heatpipe. By adding heatsink <NUM>, it is possible to more efficiently cool ASIC <NUM> and allow more heat to be dissipated via heatsink <NUM> as compared to heat sink <NUM>. In some examples, the surface area of heatsink <NUM> can be increased through the use of fractal geometry. In some examples, the amount of heat dissipated by heatsink <NUM> can be between <NUM>-<NUM> watts. Although heatsink <NUM> is oriented in one direction, it is understood that the heatsink can be oriented at various directions relative to module <NUM>. The airflow can also be oriented in various directions relative to module <NUM> and heatsink <NUM>.

In some examples, heatpipes can be replaced with vapor chambers containing coolant to provide additional cooling. A coolant can be chosen to be a material with a high thermal conductivity, a material with phase changes, or a material with a high specific heat.

<FIG> illustrates a top-down view of a rack which can house several OSFP modules, rack <NUM>. Rack <NUM> has a front side and a back side. Rack <NUM> is designed to house and cool OSFP modules when inserted into the front side. Rack <NUM> can house cages, such as cage <NUM>. Rack <NUM> has a plurality of heat exchangers which correspond to OSFP modules. For example, heat exchanger <NUM> corresponds to four OSFP modules. Heat exchanger <NUM> corresponds to a single OSFP module. The heat exchangers can contain a suitable liquid coolant which can absorb heat generated from an OSFP. The liquid coolant will be directed towards a network of pipes, which will direct heat towards the rear of rack <NUM>. At the rear of rack <NUM> heat carried by the coolant away from the OSFP modules can be removed from the coolant through a liquid to air heat exchanger, such as intercooler <NUM>. Intercooler <NUM> can be made of a material with a high amount of thermal conductivity and be designed with a large surface area to remove the highest amount of heat possible from the intercooler. Additionally, to help maintain airflow through the rack <NUM>, fans can be included at the back side of rack <NUM>.

<FIG> illustrates a top-down view of a rack which can house several OSFP modules. Rack <NUM> can be similar to rack <NUM>. Rack <NUM> has a plurality of heat exchangers which correspond to OSFP modules. For example, heat exchanger <NUM> corresponds to four OSFP modules. Heat exchanger <NUM> corresponds to a single OSFP module. The heat exchangers can contain a suitable liquid coolant which can absorb heat generated from an OSFP. The liquid coolant will be directed towards a network of pipes, which will extend through the front of the rack and be connected with an external coolant distribution unit (CDU), such as CDU <NUM>. CDU <NUM> can be chosen based on size and thermal requirements of the OSFP system or rack. For example, CDU systems which provide upwards of 200kW of cooling in less than <NUM><NUM> of space can be chosen for certain OSFP applications where a greater amount of heat is likely to be generated.

<FIG> illustrate a top-down view and a side view of an OSFP module <NUM> with direct water cooling. Module <NUM>, similar to the modules described above, has a front side which can receive a connector and a back side. The module also has a top surface, surface <NUM>. The module can also contain a cold plate, such as cold plate <NUM>. The cold plate can be a reservoir capable of holding liquid. In other examples, cold plate <NUM> can be a network of pipes of a single pipe running the length of module <NUM> several times or looped within module <NUM>. In some examples, the cold plate can be collected around a hot spot on module <NUM>. The back side of module <NUM> can contain an input for cooler water, input port <NUM> and an output for warm water, output port <NUM> returning from the cold plate <NUM>. Input port <NUM> can be in fluid communication with cold plate <NUM>, which can in turn be in fluid communication with output port <NUM>. Collectively, this forms a closed loop which can be externally cooled before returning to the interior of module <NUM>. The addition of input port <NUM> and output port <NUM> still allows the OSFP form factor to be retained and ensures compatibility with existing OSFP racks. Input port <NUM> and output <NUM> can be made of thermally conductive material with low coefficients of thermal expansion and can be approximately between <NUM> and <NUM>. In addition, the ports can be capable of supporting any suitable flow and pressure depending on cooling requirements.

<FIG> illustrates a schematic cross-sectional view of an OSFP module <NUM>. Module <NUM> can be similar to module <NUM> and its components. <FIG> illustrates an ASIC <NUM>, a laser <NUM>, a printed circuit board <NUM>, and a housing of the OSFP module, housing <NUM>, a thermal path <NUM>, and a heatsink <NUM>. The ASIC is an application specific integrated circuit. ASIC <NUM> is mounted to the bottom of the module. Additionally, OSFP module <NUM> can contain flat heat pipes which are integrated towards the bottom of the module <NUM>, such as heatpipes <NUM> and <NUM>. These flat heat pipes can be made of a highly conductive material. Keeping the heat pipes relatively flat can allow the OSFP module specifications to be maintained.

<FIG> illustrates a schematic cross-sectional view of an OSFP module <NUM>. Module <NUM> can be similar to module <NUM> and its components. <FIG> illustrates an ASIC <NUM>, a laser <NUM>, a printed circuit board <NUM>, and a housing of the OSFP module, housing <NUM>, a thermal path <NUM>, and a heatsink <NUM>. The ASIC is an application specific integrated circuit. ASIC <NUM> is mounted to the bottom of the module. Additionally, OSFP module <NUM> can contain flat heat pipes which are integrated towards the bottom of the module <NUM>, such as heatpipes <NUM>. These flat heat pipes can be made of a highly conductive material. Keeping the heat pipes relatively flat will allow the OSFP module specifications to be maintained while still allowing for improved cooling. In addition, cooling fins can be added to the bottom of the module to provide additional cooling. In some examples, housing <NUM> can be indented or otherwise modified to allow space for additional cooling fins to be incorporated without affecting the dimensions of module <NUM> or preventing it from being integrated within a rack.

<FIG> is another side view of an OSFP module <NUM> with similar features as described with reference to <FIG>.

<FIG> illustrates a schematic cross-sectional view of an OSFP module <NUM>. Module <NUM> can be similar to module <NUM> and its components. <FIG> illustrates an ASIC <NUM>, a laser <NUM>, a printed circuit board <NUM>, and a housing of the OSFP module, housing <NUM>, a thermal path <NUM>, and fins <NUM>. Fins <NUM> can also be a heatsink. The ASIC is an application specific integrated circuit. ASIC <NUM> is mounted to the bottom of the module. Additionally, OSFP module <NUM> can contain flat heat pipes which are integrated towards the bottom of the module <NUM>, such as heatpipes <NUM>. These flat heat pipes can be made of a highly conductive material. Keeping the heat pipes relatively flat will allow the OSFP module specifications to be maintained. In some examples, heatpipe <NUM> can be a vapor chamber.

<FIG> illustrate various views of an OSFP module <NUM>.

<FIG> illustrates an exploded view of an OSFP compatible module <NUM>. Illustrated is an internal cooling cooling component <NUM> with a surface <NUM> and inlets <NUM>. A first middle component <NUM> contains a heat spreader <NUM>. Heat spreader <NUM> can be a heat sink, heat pipe, or heat spreader. Heat spreader <NUM> can be a vapor chamber with an evaporator and condenser. Heat spreader <NUM> can be made of material with high thermal conductivity or can be made of a material with much higher thermal conductivity as compared to other materials of module <NUM>. For example, heat spreader <NUM> can be made of a metal or metal compound. Heat spreader <NUM> can be in thermal contact with cooling component <NUM>. In some examples, heat spreader <NUM> and cooling component <NUM> can be one continuous component. In these examples, additional thermal cooling can be realized as the number of thermal interfaces is reduced. Heat spreader <NUM> can be as thick as a portion of middle component <NUM> and make thermal contact with a heat source. One side of heat spreader <NUM> can make thermal contact with cooling component <NUM> while the opposite side of heat spreader <NUM> can make contact with a heat source. Second middle component <NUM> can contain a front side with a data connector <NUM>. In some examples, data connector <NUM> can contain a layer of a material with low thermal conductivity to prevent a heat source in contact with heat spreader <NUM> from transmitting or conducting heat towards the bottom of module <NUM>. Middle component <NUM> can be configured to house electronics, which are sources of heat, such as a laser or an ASIC. Bottom component <NUM> can contain a heat spreader <NUM>. Heat spreader <NUM> can be a heatsink or a thermally conductive surface in thermal contact with a heat source, such as electronics, an ASIC, or a laser. In some examples, heat spreader <NUM> can extend beyond the bottom surface of module <NUM> and into a larger system. In some examples, heat spreader <NUM> can form an external heatsink. In some examples, heat spreader <NUM> can be a vapor chamber. In some examples, heat spreader <NUM> can contact an external heatsink or cooling component. Heat spreader <NUM>, heat spreader <NUM>, thin vapor chambers, or flat heat pipes can be bonded to the top or bottom of module <NUM> to improve heat dissipation. In some examples, the exterior contact surface of heat spreader <NUM> and heat spreader <NUM>, which can be vapor chambers or heat pipes, can be flush to or slightly sub-flush to the exterior surfaces of the module <NUM>.

<FIG> illustrates a top-down view of assembled OSFP compatible module <NUM> with surface <NUM>, inlets <NUM>, heat spreader <NUM>, heat spreader <NUM>. Also illustrated in <FIG> is a printed circuit board <NUM>. The printed circuit board can interface with electronics inside and external to module <NUM>. In addition, the printed circuit board can be made of materials with low thermal conductivity. In some examples, a laser can be installed in the upper portion of module <NUM> and be in thermal contact with heat spreader <NUM> while an ASIC is installed in the lower portion, under the printed circuit board <NUM>, and in thermal contact with heat spreader <NUM>. The laser would be able to dissipate heat through the heat spreader <NUM> while the ASIC through heat spreader <NUM>. The overall cooling through the module is thus increased in this manner.

<FIG> illustrates a bottom-up view of assembled OSFP compatible module <NUM> with heat spreader <NUM> and data connector <NUM> visible. In some examples, a cut-out can be made in module <NUM> to allow heat spreader <NUM> to contact an external heatsink. In other examples, heat spreader <NUM> can form part of the external surface of module <NUM> or otherwise be flush with the surface. In some examples, heat spreader <NUM> can be in contact with an external cooler. In some examples, the external cooler or heatsink can be a liquid heat exchanger, a peltier heat pump, or an additional heat pipe.

<FIG> illustrates module <NUM> within a cage <NUM>. Cage <NUM> can be mounted to a printed circuit board <NUM>. Cage <NUM> can contain several openings, such as openings <NUM> and <NUM> to house modules, such as module <NUM>. Printed circuit board <NUM> can be installed within a larger enclosure. Printed circuit board <NUM> can interface with electronics within one or more modules. Cage <NUM> and printed circuit board <NUM> can be configured to allow a heatsink, heatsink <NUM>, to make thermal contact with module <NUM> through heat spreader <NUM> as discussed earlier. For example, the printed circuit board and cage can have cutouts matching the external heat sink. In some examples, cage <NUM> can be spring loaded to allow for easier compatibility with mechanical matching of components. In other examples, cage <NUM> can be springless.

<FIG> illustrates a schematic cross-sectional view of module <NUM>, an external heat sink <NUM>, and printed circuit board <NUM>. In addition to the various components discussed with reference to <FIG>, <FIG> illustrates a laser <NUM> and an ASIC <NUM>.

<FIG> illustrates thermal and electrical aspects of an example OSFP compliant transceiver module at various operational temperatures. The horizontal axis of the graph <NUM>, axis <NUM> indicates the throughput of an OSFP module. The vertical axis of graph <NUM>, axis <NUM>, indicates the thermal performance required for a certain throughput. Three data points are plotted, data points <NUM>-<NUM>, corresponding to throughputs of <NUM> Gbps, <NUM> Gbps, and <NUM> Tbps respectively. For example, it is expected that an <NUM> bitrate will require 19W of power while a <NUM>. 6T bitrate will require 25W of power. These latter bitrates cannot be supported with the current OSFP form factor as too much heat is generated for the OSFP module to operate properly. At higher temperatures, the air pressure drop inside the module can be too high to effectively cool the module in ambient and static conditions.

<FIG> illustrates a side view of an OSFP module <NUM> with one or more of the configurations discussed above with reference to <FIG>. <FIG> illustrates an external housing <NUM> which can have an inlet <NUM>. Module <NUM> has a front side with an inlet <NUM>, a back side with a backside or air outlet, outlet <NUM>, and a top surface <NUM> formed between the front side and the back side. Module <NUM> can have an external heat sink <NUM> attached to the top surface <NUM>. Module <NUM> can also have an internal surface <NUM>, which as explained above, can in some examples contain holes to allow air to vent into an interior portion of module <NUM>. Module <NUM> can have a surface <NUM>. In some examples, surface <NUM> can be configured to allow an external bottom heatsink to be in contact with surface <NUM>. Housing <NUM> can have a bottom portion, portion <NUM>. In some examples, portion <NUM> can be cut to create an opening for a bottom heatsink.

Claim 1:
A system comprising:
an Octal Small Formfactor Pluggable (OSFP) module (<NUM>), the module (<NUM>) comprising:
a front side and a back side opposite the front side;
a substantially continuous top surface extending from a portion of the front side to a portion of the back side; rand
a data connector (<NUM>) formed on the front side;
characterised in that the system further comprises:
an air duct (<NUM>) with a first end and a second end, the first end of the air duct (<NUM>) forming a closed connection with the back side of the module (<NUM>);
a blower (<NUM>), with a first end and an exhaust, the first end of the blower (<NUM>) forming a closed connection with the second end of the air duct (<NUM>); and
an airpath (<NUM>) formed from the front side of the module (<NUM>) to the exhaust end of the blower (<NUM>) through at least the air duct (<NUM>).