Patent ID: 12225694

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this disclosure are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly. When an element is referred to as being “connected,” or “coupled,” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. Although the wide numerical ranges and parameters of the present disclosure are approximations, numerical values are set forth in the specific examples as precisely as possible. In addition, although the “first,” “second,” “third,” and the like terms in the claims be used to describe the various elements can be appreciated, these elements should not be limited by these terms, and these elements are described in the respective embodiments are used to express the different reference numerals, these terms are only used to distinguish one element from another element. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. Besides, “and/or” and the like may be used herein for including any or all combinations of one or more of the associated listed items. Alternatively, the word “about” means within an acceptable standard error of ordinary skill in the art-recognized average. In addition to the operation/working examples, or unless otherwise specifically stated otherwise, in all cases, all of the numerical ranges, amounts, values and percentages, such as the number for the herein disclosed materials, time duration, temperature, operating conditions, the ratio of the amount, and the like, should be understood as the word “about” decorator. Accordingly, unless otherwise indicated, the numerical parameters of the present invention and scope of the appended patent proposed is to follow changes in the desired approximations. At least, the number of significant digits for each numerical parameter should at least be reported and explained by conventional rounding technique is applied. Herein, it can be expressed as a range between from one endpoint to the other or both endpoints. Unless otherwise specified, all ranges disclosed herein are inclusive.

FIGS.1to4show a power module according to a first embodiment of the present disclosure.FIG.5is a perspective view illustrating the surface-mounted heat sink of the power module according to the first embodiment of the present disclosure. In the embodiment, the power module1includes a circuit board10, a magnetic element13, at least one power device and at least one surface-mounted heat sink2a.Preferably but not exclusively, the magnetic element13is a transformer or an inductor. The magnetic element13include a magnetic core and winding, the magnetic column of the magnetic core is passed through a hole of the circuit board10, and the winding is wound on the corresponding magnetic column. Preferably but not exclusively, the winding is integrally formed with the circuit board10into one piece, or individually wound. The circuit board10includes a surface100, an upper side102and a lower side101. The upper side102and the lower side101are two opposite sides. The surface100is connected between the upper side102and the lower side101. The magnetic element13is disposed adjacent to the upper side101of the circuit board10and covers a part of the surface100. In the embodiment, a space S is collaboratively defined by the magnetic element13and the lower side101of the circuit board10. Preferably but not exclusively, the at least one power device includes a surface-mounted switching device11and a ceramic capacitor12, which are disposed on the surface100of the circuit board10and located between the magnetic element13and the lower side101of the circuit board10. At least one surface-mounted heat sink2ais disposed on the surface100of the circuit board10. Preferably but not exclusively, the at least one surface-mounted heat sink2ais spatially corresponding to and disposed adjacent to the surface-mounted switching device11. A top surface130disposed on one side of the magnetic element13and the surface100of the circuit board10form a limiting height H0, the surface-mounted heat sink2ahas a first height D1formed between a sucked surface232and a surface-mounted surface211thereof, and the limiting height H0is greater than or equal to the first height D1. The height of the power module1is limited by the limit height H0, and the surface-mounted heat sink2adoes not occupy more internal space of the power module1. Moreover, since the first height D1of the surface-mounted heat sink2ais smaller than the limit height H0of the power module1, it is helpful of guiding the wind flow toward the region where the lower portion of the magnetic element13and the surface-mounted heat sink2aare located. Thus, the heat dissipation of the surface-mounted switching device11is improved.

In the embodiment, the surface-mounted heat sink2aincludes a surface-mounted portion21, a support portion22and a fin portion23. The surface-mounted portion21includes the surface-mounted surface211attached to the surface100of the circuit board10. The support portion22is extended from the surface-mounted portion21and away from surface-mounted surface211. The fin portion23is spatially corresponding to the surface-mounted surface211of the surface-mounted portion21. In the embodiment, the fin portion23includes a bottom surface231and a sucked surface232parallel to each other. Preferably but not exclusively, the support portion22is rectangular and perpendicular to the bottom surface231and the surface-mounted surface211, so that the surface area of the surface-mounted heat sink2ais increased, and it is helpful of enhancing the heat dissipation capacity. In an embodiment, a part of the bottom surface231and the sucked surface232of the fin portion23, and the surface-mounted surface211of the surface-mounted portion21are parallel to each other. In another embodiment, the fin portion23is bent or extended arbitrarily in the space S according to the practical requirements. That is, the pin portion23is not parallel to the surface-mounted surface211of the surface-mounted portion21. The extending direction, the length and the bending magnitude of the pin portion23are adjustable in the space S, and the present disclosure is not limited thereto. Notably, the surface-mounted portion21, the support portion22and the fin portion23of the surface-mounted heat sink2aare integrated molding by an aluminum alloy material, which is easier to shape than the copper in producing process. Preferably but not exclusively, the fin portion23and the surface-mounted portion21are parallel to each other and perpendicular to the support portion22. The producing process is simpler. With the surface tin-plated on the surface-mounted portion21, the surface-mounted heat sink2ais soldered on the soldering pad10aof the circuit board10directly or mounted together with the other surface-mounted switching device11and a ceramic capacitor12by the surface mount technology. It is easy to realize automation, and improve the production efficiency. The accuracy of placement is high. It prevents the power module1from short-circuiting or cracking due to touching peripheral devices when manually installing the heat sink. In addition, the cost of the surface-mounted heat sink2amade of aluminum alloy material is lower than that of the surface-mounted copper block.

Preferably but not exclusively, in the embodiment, the surface-mounted surface211of the surface-mounted heat sink2ais attached to the soldering pad10aon the surface100of the circuit board10through a reflow soldering process. In the embodiment, the fin portion23, the support portion22and the surface-mounted portion21integrally form an H-shaped cross-section. In an embodiment, a projection area of the fin portion23on the surface100of the circuit board10is greater than a projection area of the support portion22on the surface100of the circuit board10.

Preferably but not exclusively, in the embodiment, the projection area of the fin portion23on the surface100of the circuit board10is equal to a projection area of the surface-mounted portion21on the surface100of the circuit board10. In other words, since the above fin portion23and the surface-mounted portion21are connected through the support portion22, when the surface-mounted heat sink2aand the surface-mounted switching device11are arranged on the surface100of the circuit board10, a height difference is formed. In that, the width of the fin portion23is extendable. Preferably but not exclusively, the fin portion23, the support portion22and the surface-mounted portion21collaboratively form a symmetrical H-shaped cross section, so as to provide a larger heat dissipation area, thereby improving the heat dissipation efficiency.

Preferably but not exclusively, in other embodiments, the fin portion23is not parallel to the surface-mounted surface211, and the maximum distance between the bottom surface231and the surface-mounted surface211is defined as a second height D2. Alternatively, the minimum distance between the bottom surface231and the surface-mounted surface211is defined as a second height D2. In this way, the space under the surface-mounted heat sink2ais fully utilized to place electronic components and improve space utilization. Moreover, the space above the surface-mounted switching device11is effectively utilized by the surface-mounted heat sink2awithout affecting the power density of the power module1, and the heat dissipation efficiency is improved.

In the embodiment, the shape of the fin portion23is adjustable according to the practical requirements. For performing the mounting procedure of the surface-mounted heat sink2a,a suction nozzle is used to suck the sucked surface232. In some embodiments, the sucked surface232and the surface-mounted surface211are parallel to each other. Preferably but not exclusively, in other embodiments, the fin portion23is not parallel to the surface-mounted surface211of the surface-mounted portion21, but bent or extended arbitrarily in the space S. In that, an automatic grasping device still can be utilized to realize the installation of the surface-mounted heat sink2a.In the embodiment, a second height D2is formed between the bottom surface231and the surface-mounted surface211of the surface-mounted portion21. Preferably but not exclusively, the second height D2is greater than a device height h1, which is formed by disposing the at least one surface-mounted switching device11on the surface100of the circuit board10. In other embodiments, the power module1includes a plurality of surface-mounted switching devices11, and the plurality of surface-mounted switching devices11are disposed on the surface100of the circuit board10to form different device heights. The second height D2is greater than one of the plurality of device heights. Preferably but not exclusive, the second height D2is greater than the largest one of the plurality of device heights. In other embodiments, the fin portion23is not parallel to the surface-mounted surface211. Preferably but no exclusively, the maximum distance between the bottom surface231and the surface-mounted surface211is defined as the second height D2. Preferably but not exclusively, the minimum distance between the bottom surface231and the surface-mounted surface211is defined as the second height D2. In some embodiments, the second height D2is greater than a capacitor height h2, which is formed by disposing the ceramic capacitor12on the surface100of the circuit board10. In this way, the space under the surface-mounted heat sink2ais fully utilized to place electronic components and improve space utilization. Moreover, the space above the surface-mounted switching device11or the ceramic capacitor12is effectively utilized by the surface-mounted heat sink2awithout affecting the power density of the power module1, and the heat dissipation efficiency is improved.

On the other hand, in the embodiment, the top surface130disposed on one side of the magnetic element13and the surface100of the circuit board10form the limiting height H0, the surface-mounted heat sink2ahas the first height D1formed between the sucked surface232and the surface-mounted surface211thereof, and the limiting height H0is greater than or equal to the first height D1. In other embodiments, the fin portion23is not parallel to the surface-mounted surface211. Preferably but not exclusively, the maximum distance between the bottom surface231and the surface-mounted surface211is defined as the second height D2. Preferably but not exclusively, the minimum distance between the bottom surface231and the surface-mounted surface211is defined as the second height D2. Thus, the space above the surface-mounted switching device11or the ceramic capacitor12is effectively utilized by the surface-mounted heat sink2awithout affecting the power density of the power module1, and the heat dissipation efficiency is improved.

FIG.6is a lateral view illustrating the power module according to a second embodiment of the present disclosure.FIG.7is a lateral view illustrating the power module inserted into a system motherboard according to the second embodiment of the present disclosure. In the embodiment, the power module1ais similar to the power module1shown inFIGS.1to4, and the same labels of the components represent the same components, structures and functions, not redundantly described herein. In the embodiment, the fin portion23of the surface-mounted heat sink2ahas an extension side233coplanar with the lower side101of the circuit board10. The circuit board10further includes a plug-in portion103, which is protruded outwardly from the lower side101and configured to insert the power module1ainto a system motherboard3therethrough. In the embodiment, when the power module1ais inserted into the system motherboard3through the plug-in portion103of the circuit board10, the extension side233of the fin portion23is attached to the surface30of the system motherboard3. In other words, when the power module1ais inserted into the system motherboard3through the plug-in portion103on the lower side101of the circuit board10, the fin portion23of the surface-mounted heat sink2ahas the extension side233to provide a positioning function during soldering the power module1aand the system motherboard3together. It prevents the power module1afrom causing the ceramic capacitor12broken due to manual blind insertion during the process of soldering the power module1aon the system motherboard3.

FIGS.8to11show a power module according to a third embodiment of the present disclosure.FIG.12is a perspective view illustrating the surface-mounted heat sink of the power module according to the third embodiment of the present disclosure. In the embodiment, the power module1band the surface-mounted heat sink2bare similar to the power module1and the surface-mounted heat sink2ashown inFIGS.1to5, and the same labels of the components represent the same components, structures and functions, not redundantly described herein. Preferably but not exclusively, in the embodiment, the surface-mounted heat sink2bis soldered on the soldering pad10bof the circuit board10through a reflow soldering process. The fin portion23of the surface-mounted heat sink2bis extended in two opposite directions from a junction of the support portion22and the fin portion23. Preferably but not exclusively, the two opposite directions are perpendicular to the lower side101of the circuit board10. That is, the fin portion23is extended along the Y-axis direction. Preferably but not exclusively, the fin portion23, the support portion22and the surface-mounted portion21collaboratively form an asymmetrical H-shaped cross section. In the embodiment, a projection area of the fin portion23on the surface100of the circuit board10is greater than a projection area of the support portion22on the surface100of the circuit board10. Moreover, the projection area of the fin portion23on the surface100of the circuit board10is greater than a projection area of the surface-mounted portion21on the surface100of the circuit board10. In other words, since the above fin portion23and the surface-mounted portion21are connected through the support portion22, when the surface-mounted heat sink2band the surface-mounted switching device11or the ceramic capacitor12are installed on the surface100of the circuit board10, a height difference is formed. In that, the width of the fin portion23is extendable and greater than the width of the surface-mounted surface211. Preferably but not exclusively, the fin portion23, the support portion22and the surface-mounted portion21collaboratively form an asymmetrical H-shaped cross section, so as to provide a larger heat dissipation area, thereby improving the heat dissipation efficiency.

In the embodiment, the fin portion23includes a bottom surface231and a sucked surface232parallel to each other. Preferably but not exclusively, the bottom surface231, the sucked surface232and the surface-mounted surface211of the surface-mounted portion21are parallel to each other, and the bottom surface231is connected to the support portion22. In some embodiments, the shape of the fin portion23is adjustable according to the practical requirements. Preferably but not exclusively, in other embodiments, the fin portion23is not parallel to the surface-mounted surface211of the surface-mounted portion21, but bent or extended arbitrarily in the space S. In that, an automatic grasping device still can be utilized to realize the installation of the surface-mounted heat sink2b.In the embodiment, a second height D2is formed between the bottom surface231and the surface-mounted surface211of the surface-mounted portion21. Preferably but not exclusively, the second height D2is greater than a device height h1, which is formed by disposing the at least one surface-mounted switching device11on the surface100of the circuit board10. In some embodiments, a projection area of the fin portion23on the surface100is partially overlapped with a projection area of the surface-mounted switching device11on the surface100. That is, a part of the fin portion23is located above the surface-mount switching device11. In some embodiments, the difference between the second height D2and the device height h1is equal to or greater than 0.5 mm. In some embodiments, the second height D2is greater than a capacitor height h2, which is formed by disposing the ceramic capacitor12on the surface100of the circuit board10.

On the other hand, in the embodiment, the top surface130disposed on one side of the magnetic element13and the surface100of the circuit board10form the limiting height H0, the surface-mounted heat sink2ahas the first height D1formed between the sucked surface232and the surface-mounted surface211thereof, and the limiting height H0is greater than or equal to the first height D1. Thus, the space above the surface-mounted switching device11or the ceramic capacitor12is effectively utilized by the surface-mounted heat sink2bwithout affecting the power density of the power module1b,and the heat dissipation efficiency is improved.

FIGS.13to16show a power module according to a fourth embodiment of the present disclosure.FIG.17is a perspective view illustrating the surface-mounted heat sink of the power module according to the fourth embodiment of the present disclosure. In the embodiment, the power module1cand the surface-mounted heat sink2care similar to the power module1and the surface-mounted heat sink2ashown inFIGS.1to5, and the same labels of the components represent the same components, structures and functions, not redundantly described herein. Preferably but not exclusively, in the embodiment, the surface-mounted heat sink2cis soldered on the soldering pad10cof the circuit board10through a reflow soldering process. The fin portion23of the surface-mounted heat sink2cis extended in two opposite directions from a junction of the support portion22and the fin portion23. Preferably but not exclusively, the two opposite directions are parallel to the lower side101of the circuit board10. That is, the fin portion23is extended along the X-axis direction. In an embodiment, the fin portion23is extended in four directions from the junction of the support portion22and the fin portion23. Preferably but not exclusively, the fin portion23is extended in the same XY plane. In another embodiment, the fin portion23is bent or extended arbitrarily in the space S. That is, the fin portion23is not parallel to the XY plane. Preferably but not exclusively, the surface-mounted heat sink2cincludes two fin portions23designed asymmetrically. The extending direction, the length and the bending magnitude of the pin portion23are adjustable in the space S, and the present disclosure is not limited thereto. In the embodiment, since the above fin portion23and the surface-mounted portion21are connected through the support portion22, when the fin portion23of the surface mount heat sink2cand the surface-mounted switching device11or the ceramic capacitor12are arranged on the circuit board10, a height difference is formed. In that, the width of the fin portion23is extendable and greater than the width of the surface-mounted surface211. Moreover, the fin portion23, the support portion22and the surface-mounted portion21collaboratively form a T-shaped cross section, so as to provide a larger heat dissipation area, thereby improving the heat dissipation efficiency. In the embodiment, the surface-mounted heat sink2cis disposed and corresponding to two surface-mounted switching devices11. The two surface-mounted switching devices11are arranged on the surface100of the circuit board10along the lower side101of the circuit board10. Preferably but not exclusively, the two surface-mounted switching devices11are arranged along the X-axis direction. Preferably but not exclusively, the surface-mounted surface211of the surface-mounted heat sink2cis disposed on the soldering pad10c,which is located between the two surface-mounted switching devices11. Moreover, a projection area of the fin portion23on the surface100is partially overlapped with a projection area of the two surface-mounted switching devices11on the surface100. That is, a part of the fin portion23is located above the two surface-mount switching devices11. Thus, the space above the two surface-mounted switching devices11is effectively utilized by the surface-mounted heat sink2cwithout affecting the power density of the power module1cand the heat dissipation efficiency is improved. In the embodiment, the fin portion23of the surface-mounted heat sink2cand the surface-mount switching device11or the ceramic capacitor12are misaligned in the direction from the upper side102to the lower side101of the circuit board10, and are not located on the same horizontal plane. Preferably but not exclusively, the fin portion23of the surface-mounted heat sink2cis at least partially located above the surface-mounted switching device11or the ceramic capacitor12to provide a larger heat dissipation area, thereby improving the heat dissipation efficiency.

In the embodiment, the fin portion23of the surface-mounted heat sink2chas a lateral side234. Preferably but not exclusively, the lateral side234of the fin portion23, the surface-mounted portion21and the support portion22collaboratively form the lateral side24of the surface-mounted heat sink2c.In the embodiment, the lateral side234of the fin portion23is coplanar with the lower side101of the circuit board10. When the power module1cis inserted into the system motherboard3through the plug-in portion103of the circuit board10, the lateral side234of the fin portion23is attached to the surface30of the system motherboard3. In other words, when the power module1cis inserted into the system motherboard3through the plug-in portion103on the lower side101of the circuit board10, the fin portion23of the surface-mounted heat sink2chas the lateral side234to provide a positioning function during soldering the power module1cand the system motherboard3together. It prevents the power module1cfrom causing the ceramic capacitor12broken due to manual blind insertion during the process of soldering the power module1aon the system motherboard3. In other embodiments, the lateral side234of the fin portion23and the lateral side24of the surface-mounted heat sink2care coplanar with the lower side101of the circuit board10. Certainly, the present disclosure is not limited thereto.

FIGS.18to20show a power module according to a fifth embodiment of the present disclosure. In the embodiment, the power module1dis similar to the power module1shown inFIGS.1to4, and the same labels of the components represent the same components, structures and functions, not redundantly described herein. In the embodiment, the power module1dincludes a surface-mounted heat sink2a,a surface-mounted heat sink2band a surface-mounted heat sink2a.Preferably but not exclusively, the surface-mounted heat sink2a,the surface-mounted heat sink2band the surface-mounted heat sink2care soldered and attached on the soldering pad10a,the soldering pad10band the soldering pad10cof the circuit board10, respectively, through a reflow soldering process. In the embodiment, the fin portions23of the surface-mounted heat sink2a,the surface-mounted heat sink2band the surface-mounted heat sink2care received within the space S collaboratively defined by the magnetic element13and the lower side101of the circuit board10. In an embodiment, the fin portions23are extended along the X-axis direction or the Y-axis direction. In another embodiment, the fin portions23are extended in the same XY plane. In that, the positions above the surface-mounted switching device11or the ceramic capacitor12are effectively utilized to increase the size of the fin portions23and increase the heat dissipation area, thereby increasing the heat dissipation efficiency. Preferably but not exclusively, the sucked surfaces232of the fin portions23of the surface-mounted heat sink2a,the surface-mounted heat sink2band the surface-mounted heat sink2care extended on the same XY plane. The extended sucked surfaces232are beneficial to being sucked through the suction nozzle. Then, the surface-mounted surfaces231are soldered to the periphery of the surface-mounted switching device11or the ceramic capacitor12on the circuit board10through the reflow soldering process. In an embodiment, each of the surface-mounted heat sink2a,the surface-mounted heat sink2band the surface-mounted heat sink2chas the bottom surface231of the fin portion23maintaining a height difference with the surface-mounted switching device11or the ceramic capacitor12. Preferably but not exclusively, the height difference is greater than or equal to 0.5 mm. Since the surface-mounted heat sink2a,the surface-mounted heat sink2band the surface-mounted heat sink2chave small size, and are integrally formed by the aluminum alloy material, they are easy to produce in the modularize production and are suitable for heat dissipation of the switching power supply with high power density. Through the reflow soldering process, the surface-mounted heat sink2a,the surface-mounted heat sink2band the surface-mounted heat sink2care mounted on the circuit board10together with the surface-mounted switching device11or the ceramic capacitor12. It is easy to realize automation and further simplify the assembling process of heat dissipation devices. The cost of the power module1dis reduced, and the product competitiveness is enhanced. Notably, the number, the size, the position and the arrangement direction of the surface-mounted heat sink2a,the surface-mounted heat sink2band the surface-mounted heat sink2care adjustable according to the practical requirements. The present disclosure is not limited thereto and not redundantly described herein.

In summary, the present disclosure provides a surface-mounted heat sink and a power module using the same. The surface-mounted heat sink has a small size and is formed into one piece by aluminum alloy material. It is suitable for heat dissipation of a switching power module with high-power density. With the surface tin-plated, the surface-mounted heat sink is soldered on the circuit board directly or mounted together with the other surface-mounted power devices by the surface mount technology. It is easy to realize automation, and improve the production efficiency. The accuracy of placement is high. It prevents from short-circuiting or cracking due to touching peripheral devices when manually installing the heat sink. In addition, the cost of the surface-mounted heat sink made of aluminum alloy material is lower than that of the surface-mounted copper block. The fin portion above the surface-mounted portion is connected thereto through the support portion. When the surface-mounted heat sink and the power device are installed on the surface of the circuit board, the height difference between the fin portion and the surface-mounted portion is formed, and the width of the fin portion is extendable. Furthermore, the fin portion, the support portion and the surface-mounted portion form a symmetrical or asymmetrical T-shaped or H-shaped cross-section. A larger heat dissipation area is provided so as to improve the heat dissipation efficiency. Since the assembling and manufacturing process of the surface-mounted heat sink is simple, the space above the power device is utilized effectively, the size of the surface-mounted heat sink is small, and the application of the surface-mounted heat sink is flexible, it meets the heat dissipation requirements when the surface-mounted heat sink applied in a smaller space. Moreover, by combining and utilizing the surface-mounted heat sinks with different cross-section types, the heat dissipation problems in confined spaces are solved effectively. On the other hand, the top surface of the fin portion is extended, and it facilitates suction through the suction nozzle. Whereby, when the surface-mounted surface is soldered to the periphery of the power device on the circuit board through the reflow soldering process, it is easy to realize automation and further simplify the assembling process of heat dissipation devices. The cost of the power module is reduced, and the product competitiveness is enhanced. Furthermore, when the surface-mounted heat sink is disposed on the circuit board of the power module through the surface-mounted surface of the surface-mounted portion, the fin portion of the surface-mounted heat sink has a lateral side or an extension side coplanar with the lower side of the circuit board. Thus, when the power module is inserted into the system motherboard through a plug-in portion on the lower side of the circuit board, and soldered together with the system motherboard, the fin portion of the surface-mounted heat sink provides a positioning function. It avoids causing the ceramic capacitor broken due to manual blind insertion during the process of soldering the power module on the system motherboard.

While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.