Patent Description:
Small form-factor pluggable (SFP) transceiver, four-passage small form-factor pluggable (QSFP) transceiver, double-density four-passage small package pluggable (QSFP-DD) transceiver, or octal small form-factor pluggable (OSFP) transceiver are all hot-swappable cable components for high-frequency high-speed transmission cable module.

The known high-frequency high-speed transmission cable module includes a cover body and a control module. A second end of the cover body is used for accommodating one end of a cable therein, and the control module is arranged inside a first end of the cover body. As the control module of the high-frequency high-speed transmission cable module will generate heat during operation, a heat dissipation block is arranged inside the first end of the cover body. Moreover, the first end of the cover body is arranged in a casing, the heat generated by the control module during operation can be directly transferred to the heat dissipation block, the heat of the heat dissipation block will be transferred to the cover body, the heat of the cover body will be transferred to a plurality of heat dissipation fins of the casing, and finally, the heat dissipation fins will discharge the heat to the outside, to achieve the effect of heat dissipation.

However, the conventional heat dissipation method is to use the heat dissipation block to transfer heat to the heat dissipation fins of the casing indirectly through the cover body, so the heat dissipation efficiency is limited. The total data rate of the high-frequency high-speed transmission cable module includes <NUM>, <NUM> and <NUM>. The higher the total data rate, the higher the heat generated when the control module operates. For high-frequency high-speed transmission cable modules with a total data rate of <NUM> or <NUM>, the conventional heat dissipation methods can still sustain the control module and one end of the cable at an appropriate temperature because the heat generated by the control module is relatively low. Appropriate temperature can prevent the IC chip of the control module from reducing the working efficiency, increasing the bit error rate (BER) and decreasing the transmission rate of the cable. However, for the high-frequency high-speed transmission cable module with a total data rate of <NUM>, the conventional heat dissipation means are not enough to maintain the control module and one end of the cable at the appropriate temperature because the heat generated by the control module is relatively high, and the temperature of the control module and one end of the cable is easy to be too high, resulting in a decrease in the working efficiency of the IC chip of the control module, an increase in the bit error rate, and a decrease in the transmission speed of the cable.

<CIT> discloses a high-speed connector module and a manufacturing method thereof. The high speed connector module includes at least one connector assembly which includes an insulating body, a first terminal module fixed to the insulating body, a second terminal module and a third terminal module. The first terminal module and the second terminal module are formed by stacking up and down, the third terminal module is formed by stacking left and right. The first terminal module, the second terminal module and the third terminal module are inserted into the insulation body through assembly.

A primary objective of the present invention is to provide a high-frequency high-speed transmission cable module and the upper cover of the cover body thereof, which can use the heat dissipation block to directly transfer heat to the heat dissipation fins without indirectly passing through the main body, so as to improve the heat dissipation efficiency.

In order to achieve the aforementioned objective, the present invention provides an upper cover of a cover body of a high-frequency high-speed transmission cable module, comprising: a main body, two ends in the length direction of the main body being respectively defined as a first end and a second end, and the first end of the main body being disposed with a through hole); and a heat dissipation block, embedded in the through hole and exposed to a top surface of the first end (of the main body; characterized in that an inner wall of the through hole is disposed with a protruding support portion, and the support portion divides the through hole into a first passage and a second passage, the first passage runs through the top surface of the first end of the main body and the second passage runs through the bottom surface of the first end of the main body, and the support portion is disposed with a connecting passage for communicating between the first passage and the second passage; and in that the heat dissipation block includes a top portion, a middle portion, and a bottom portion, and the top portion of the heat dissipation block is located in the first passage, the top surface of the top portion of the heat dissipation block is exposed to the top surface of the first end of the main body, an outer side of the bottom surface of the top portion of the heat dissipation block abuts against the top surface of the support portion, and the middle portion of the heat dissipation block is disposed at the bottom surface of the top portion of the heat dissipation block and is located in the connecting passage; the bottom portion of the heat dissipation block is disposed on the bottom surface of the middle portion of the heat dissipation block and is located in the second passage, the diameter of the top portion of the heat dissipation block is greater than the diameter of the middle portion of the heat dissipation block, and the diameter of the middle portion of the heat dissipation block is greater than the diameter of the bottom portion of the heat dissipation block.

In a preferred embodiment, the second end of the main body defines a plurality of grooves.

In a preferred embodiment, the top surface of the second end of the main body is higher than the top surface of the first end of the main body.

In a preferred embodiment, the two sides along the length direction of the main body are respectively defined as a first side and a second side, the depth of the groove closest to the first side of the main body and the depth of the groove closest to the second side of the main body are both smaller than the depths of all the remaining grooves.

In a preferred embodiment, the depth of the remaining grooves is <NUM>.

In a preferred embodiment, two adjacent grooves are separated by a partition, the partition has a plurality of protrusions, and the protrusions respectively protrude from both sides of the partition.

In a preferred embodiment, the positions of the plurality of protrusions on two adjacent partitions are staggered.

In a preferred embodiment, the protrusions are arranged in pairs.

In a preferred embodiment, the grooves are parallel to the length direction of the main body.

In order to achieve the aforementioned objective, the present invention provides a high-frequency high-speed transmission cable module, comprising: a cover body, comprising an upper cover and a lower cover, the upper cover further comprising a main body and a heat dissipation block, two ends of the length direction of the main body being respectively defined as a first end and a second end and two ends of the bottom cover of the length direction being defined as a first end and a second end; the first end of the main body and the first end of the lower cover together forming a first end of the cover body, the second end of the main body and the second end of the lower cover together forming a second end of the cover body; the second end of the cover body being used for accommodating one end of a cable therein, the first end of the main body being disposed with a through hole, and the heat dissipation block being embedded in the through hole and exposed to a top surface of the first end of the main body; and a control module, disposed inside the first end of the cover body and located under the heat dissipation block characterized in that an inner wall of the through hole is disposed with a protruding support portion, and the support portion divides the through hole into a first passage and a second passage, the first passage runs through the top surface of the first end of the main body and the second passage runs through the bottom surface of the first end of the main body, and the support portion is disposed with a connecting passage for communicating between the first passage and the second passage; and in that, the heat dissipation block includes a top portion, a middle portion, and a bottom portion, and the top portion of the heat dissipation block is located in the first passage, the top surface of the top portion of the heat dissipation block is exposed to the top surface of the first end of the main body, an outer side of the bottom surface of the top portion of the heat dissipation block abuts against the top surface of the support portion, and the middle portion of the heat dissipation block is disposed at the bottom surface of the top portion of the heat dissipation block and is located in the connecting passage; the bottom portion of the heat dissipation block is disposed on the bottom surface of the middle portion of the heat dissipation block and is located in the second passage , the diameter of the top portion of the heat dissipation block is greater than the diameter of the middle portion of the heat dissipation block, and the diameter of the middle portion of the heat dissipation block is greater than the diameter of the bottom portion of the heat dissipation; and in that the control module is disposed under the bottom portion of the heat dissipation block.

In a preferred embodiment, inner wall of the through hole is disposed with a protruding support portion, and the support portion divides the through hole into a first passage and a second passage, the first passage runs through the top surface of the first end of the main body and the second passage runs through the bottom surface of the first end of the main body, and the support portion is disposed with a connecting passage for communicating between the first passage and the second passage; wherein, the heat dissipation block includes a top portion, a middle portion and a bottom portion, and the top portion of the heat dissipation block is located in the first passage, the top surface of the top portion of the heat dissipation block is exposed to the top surface of the first end of the main body, the outer side of the bottom surface of the top portion of the heat dissipation block abuts against the top surface of the support portion, and the middle portion of the heat dissipation block is disposed at the bottom surface of the top portion of the heat dissipation block and is located in the connecting passage; the bottom portion of the heat dissipation block is disposed on the bottom surface of the middle portion of the heat dissipation block and is located in the second passage, the diameter of the top portion of the heat dissipation block is greater than the diameter of the middle portion of the heat dissipation block, and the diameter of the middle portion of the heat dissipation block is greater than the diameter of the bottom portion of the heat dissipation; and wherein the control module is located under the bottom portion of the heat dissipation block.

The effect of the present invention is that the present invention can utilize the heat dissipation block to directly transfer heat to the heat dissipation fins without indirectly passing through the main body, and therefore the heat dissipation efficiency is greatly improved.

The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiment thereof, with reference to the attached drawings, in which:.

<FIG> are respectively a perspective view, an exploded view and a cross-sectional view of the high-frequency high-speed transmission cable module of the present invention. As shown in <FIG>, the present invention provides a high-frequency high-speed transmission cable module, which includes a cover body <NUM> and a control module <NUM>. The cover body <NUM> includes an upper cover <NUM> and a lower cover <NUM>. The upper cover <NUM> includes a main body <NUM> and a heat dissipation block <NUM>. The two ends of the length direction of the main body <NUM> respectively are defined as a first end <NUM> and a second end <NUM>, the two ends of the length direction of the lower cover <NUM> are respectively defined as a first end <NUM> and a second end <NUM>, the first end <NUM> of the main body <NUM> and the first end <NUM> of the lower cover <NUM> together form a first end <NUM> of the cover body <NUM>, and the second end <NUM> of the main body <NUM> and the second end <NUM> of the lower cover <NUM> together form a second end <NUM> of the cover body <NUM>. The second end <NUM> of the cover body <NUM> is used for accommodating an end of a cable (not shown) therein. The first end <NUM> of the main body <NUM> is disposed with a through hole <NUM>, and the heat dissipation block <NUM> is embedded in the through hole <NUM> and exposed on the top surface of the first end <NUM> of the main body <NUM>. The control module <NUM> is disposed inside the first end <NUM> of the cover body <NUM> and is located below the heat dissipation block <NUM>.

As shown in <FIG>, in actual use, the first end <NUM> of the cover body <NUM> is disposed in a casing <NUM> such that the heat dissipation block <NUM> contacts a plurality of heat dissipation fins <NUM> of the casing <NUM>.

The heat generated during the operation of the control module <NUM> will be transferred to the heat dissipation block <NUM>, then the heat of the heat dissipation block <NUM> will be transferred to the heat dissipation fins <NUM>, and finally the heat dissipation fins <NUM> will discharge the heat to achieve the effect of heat dissipation. Compared with the conventional technology, the present invention can use the heat dissipation block <NUM> to directly transfer heat to the heat dissipation fins <NUM> without transmission through the main body <NUM>, so the heat dissipation efficiency is greatly improved. Whether it is a high-frequency high-speed transmission cable module with a total data rate of <NUM>, <NUM>, or <NUM>, the heat dissipation means of the present invention is sufficient to maintain the control module <NUM> and one end of the cable at an appropriate temperature, preventing the IC chip of the control module <NUM> from reducing work efficiency, increasing the bit error rate and decreasing the transmission rate of the cable.

<FIG> are respectively a perspective view, an exploded view, a top view, and a side view of the upper cover <NUM> of the cover body of the high-frequency high-speed transmission cable module of the present invention. As shown in <FIG> and <FIG>, in a preferred embodiment, a support portion <NUM> protrudes from the inner sidewall of the through hole <NUM>, and the support portion <NUM> divides the through hole <NUM> into a first passage <NUM> and a second passage <NUM>, the first passage <NUM> runs through the top surface of the first end <NUM> of the main body <NUM>, and the second passage <NUM> runs through the bottom surface of the first end <NUM> of the main body <NUM>. The support portion <NUM> is disposed with a connecting passage <NUM>, and the connecting passage <NUM> communicates with the first passage <NUM> and the second passage <NUM>. As shown in <FIG>, <FIG> and <FIG>, the heat dissipation block <NUM> includes a top portion <NUM>, a middle portion <NUM> and a bottom portion <NUM>, the top portion <NUM> of the heat dissipation block <NUM> is located in the first passage <NUM>, the top surface of the top portion <NUM> of the heat dissipation block <NUM> is exposed on the top surface of the first end <NUM> of the main body <NUM>, the outer side of the bottom surface of the top portion <NUM> of the heat dissipation block <NUM> abuts against the top surface of the support portion <NUM>, and the middle portion <NUM> of the heat dissipation block <NUM> is arranged on bottom surface of the top portion <NUM> of the heat dissipation block <NUM> and is also located in the connecting passage <NUM>. The bottom portion <NUM> of the heat dissipation block <NUM> is arranged on the bottom surface of the middle portion <NUM> of the heat dissipation block <NUM> and is located in the second passage <NUM>. The diameter of the top portion <NUM> of the heat dissipation block <NUM> is larger than the diameter of the middle portion <NUM> of the heat dissipation block <NUM>, and the diameter of the middle portion <NUM> of the heat dissipation block <NUM> is greater than the diameter of the bottom portion <NUM> of the heat dissipation block <NUM>. As shown in <FIG>, the control module <NUM> is located under the bottom portion <NUM> of the heat dissipation block <NUM>, and the top surface of the top portion <NUM> of the heat dissipation block <NUM> contacts the heat dissipation fins <NUM>. Thereby, the support portion <NUM> can support the top portion <NUM> of the heat dissipation block <NUM>, so that the heat dissipation block <NUM> can be easily installed in the through hole <NUM>. Furthermore, the bottom portion <NUM> of the heat dissipation block <NUM> is aligned with the control module <NUM> and its diameter is smaller than the diameter of the top portion <NUM> and the diameter of the middle portion <NUM> of the heat dissipation block <NUM>, so that it can quickly absorb the heat generated by the control module <NUM> during operation and improve the heat dissipation efficiency. In addition, the overall structure of the heat dissipation block <NUM> is in an inverted stepped shape, so that the heat can be evenly diffused from the bottom portion <NUM> of the heat dissipation block <NUM> to the top portion <NUM> of the heat dissipation block <NUM> through the middle portion <NUM> of the heat dissipation block <NUM>, thereby improving heat dissipation efficiency. Moreover, the top surface of the top portion <NUM> of the heat dissipation block <NUM> has a larger contact area, so that the heat can be transferred to the heat dissipation fins <NUM> evenly and quickly, thereby improving heat dissipation efficiency.

As shown in <FIG>, in a preferred embodiment, the second end <NUM> of the main body <NUM> is disposed with a plurality of grooves <NUM>. The heat generated during the operation of the control module <NUM> will also be absorbed by the first end <NUM> of the main body <NUM>, and the first end <NUM> of the main body <NUM> will transfer the heat to the second end <NUM> of the main body <NUM>. The grooves <NUM> provide a larger heat dissipation area, so that the airflow passing through the grooves <NUM> can carry more heat away and improve the heat dissipation efficiency.

As shown in <FIG>, in a preferred embodiment, the top surface of the second end <NUM> of the main body <NUM> is higher than the top surface of the first end <NUM> of the main body <NUM>. Therefore, the second end <NUM> of the main body <NUM> has sufficient thickness to form the grooves <NUM>, and the second end <NUM> of the main body <NUM> can provide a sufficient internal space for accommodating one end of the cable.

As shown in <FIG> and <FIG>, in a preferred embodiment, the two sides along the length direction of the main body <NUM> are respectively defined as a first side <NUM> and a second side <NUM>. The groove <NUM> closest to the first side <NUM> of the main body <NUM> has a depth D1 and the groove <NUM> closest to the second side <NUM> of the main body <NUM> also has a depth D1, and D1 is smaller than the depth D2 of the remaining grooves <NUM>. More specifically, the depth D1 of the groove <NUM> closest to the first side <NUM> of the main body <NUM> and the depth D1 of the groove <NUM> closest to the second side <NUM> of the main body <NUM> must not be too deep, otherwise the thickness of the first side <NUM> of the main body <NUM> and the thickness of the second side <NUM> will not be enough to combine with the first side and the second side of the lower cover <NUM> respectively. Therefore, the depth D1 of the groove <NUM> closest to the first side <NUM> of the main body <NUM> and the depth D1 of the groove <NUM> closest to the second side <NUM> of the main body needs to be made shallow so that the first side <NUM> and the second side <NUM> of the main body <NUM> have enough thickness to combine with the first side and the second side of the lower cover <NUM> respectively.

Since the depth D2 of the remaining grooves <NUM> will affect the heat dissipation efficiency and the internal space of the second end <NUM> of the main body <NUM>, the Applicant for present invention conducted a test for heat dissipation efficiency, and the test results are described as follows.

Test condition I: the depth D2 of the remaining grooves <NUM> is less than <NUM>. Pros: the depth D2 allows the internal space of the second end <NUM> of the main body <NUM> to have sufficient height, without causing internal interference, and without excessive pressure on one end of the cable. Cons: The depth D2 will cause insufficient heat dissipation area, reduce heat dissipation efficiency, increase the risk of lower working efficiency of the IC chip of the control module <NUM>, increase bit error rate, and decrease the transmission rate of the cable.

Test condition II: the depth D2 of the remaining grooves <NUM> is greater than <NUM>. Pros: The depth D2 can increase the heat dissipation area and improve the heat dissipation efficiency. Cons: the depth D2 will reduce the height of the internal space of the second end <NUM> of the main body <NUM>, causing internal interference, and even over-pressing one end of the cable.

Test condition III: the depth D2 of the remaining grooves <NUM> is <NUM>. Pros: the depth D2 allows the internal space of the second end <NUM> of the main body <NUM> to have a sufficient height, without causing internal interference, and without excessive pressure on one end of the cable; and the depth D2 can increase the heat dissipation area and improve the heat dissipation efficiency. In other words, the test condition III can have the advantages of the test condition I and the test condition II at the same time without the disadvantages of the test condition I and the test condition II, and the efficacy is good.

As shown in <FIG> and <FIG>, in a preferred embodiment, two adjacent grooves <NUM> are separated by a partition, and the partition <NUM> has a plurality of protrusions <NUM>. These protrusions <NUM> respectively protrude from both sides of the partition <NUM>. Thereby, the protrusions <NUM> can increase the heat dissipation area of the partition <NUM> and improve the heat dissipation efficiency. Preferably, the positions of the plurality of protrusions <NUM> of the two adjacent partitions <NUM> are staggered, so as to prevent the plurality of protrusions <NUM> of the two adjacent partitions <NUM> from being too close to hinder the airflow, thereby affecting the heat dissipation efficiency. Preferably, the protrusions <NUM> are arranged in pairs, for easy manufacturing.

As shown in <FIG>, in a preferred embodiment, the grooves <NUM> are parallel to the length direction of the main body <NUM> and the length direction of the heat dissipation fins <NUM>. Accordingly, the airflow can flow along the grooves <NUM> and a plurality of channels <NUM> of the heat dissipation fins <NUM> to improve heat dissipation efficiency.

In a preferred embodiment, the heat dissipation block <NUM> is made of copper. However, it is not limited thereto, and the material of the heat dissipation block can be any material with high thermal conductivity.

The high-frequency high-speed transmission cable module shown in the aforementioned figures is a quad small form-factor pluggable-double density (QSFP-DD) transceiver. However, it is not limited thereto. In some embodiments, the high-frequency high-speed transmission cable module may also be a small form-factor pluggable (SFP) transceiver, a quad small form-factor pluggable, (QSFP) transceiver, or an octal small form-factor pluggable (OSFP) transceiver. The above-mentioned high-frequency high-speed transmission cable modules are all hot-swappable high-frequency high-speed transmission cable modules.

<FIG> is a comparison chart of the test results between the present invention and the conventional technology under the condition that the ambient temperature is <NUM> and the fan speed is <NUM> RPM. Tj1 is the core temperature of the IC chip of the control module of a conventional high-frequency high-speed transmission cable module, Tj2 is the core temperature of the IC chip of the control module <NUM> of the high-frequency high-speed transmission cable module of the present invention, Tb1 is the temperature of a measurement point P1 of the heat dissipation block of the upper cover of the high-frequency high-speed transmission cable module of the present invention, Tb2 is the temperature of the first end of the main body of the upper cover of the conventional high-frequency high-speed transmission cable module, and Tb3, is the temperature at a measuring point P2 at the first end of the main body of the upper cover of the high-frequency high-speed transmission cable module of the present invention. As shown in <FIG>, Tj1>Tj2, and Tb1>Tb2>Tb3. The above results show that under the conditions of an ambient temperature of <NUM> and a fan speed of <NUM> RPM, the heat dissipation efficiency of the present invention is significantly better than that of the conventional technology.

More specifically, as shown in <FIG>, during the start-up period (i.e., before <NUM> minutes and <NUM> seconds), the core temperature of the IC chip is still rising because the heat generated by the control module is still accumulating. At this time, Tj1-Tj2≥<NUM>, the difference between Tb1 and Tb2 is larger, and the difference between Tb2 and Tb3 is smaller. As shown in <FIG>, during the equilibrium period (i.e., after <NUM> minutes and <NUM> seconds), the core temperature of the IC chip will not rise again because the heat generated during the operation of the control module reaches the equilibrium state. At this time, Tj1-Tj2≥<NUM>, the difference between Tb1 and Tb2 is smaller (Tb1-Tb2≥<NUM>), and the difference between Tb2 and Tb3 is larger.

<FIG> is a comparison chart of the test results between the present invention and the conventional technology under the condition that the ambient temperature is <NUM> and the fan speed is <NUM> RPM. Tj1 is the core temperature of the IC chip of the control module of the conventional high-frequency high-speed transmission cable module, Tj2 is the core temperature of the IC chip of the control module <NUM> of the high-frequency high-speed transmission cable module of the present invention, Tb1 is the temperature of the measurement point P1 of the heat dissipation block of the upper cover of the high-frequency high-speed transmission cable module of the present invention, Tb2 is the temperature of the first end of the main body of the upper cover of the conventional high-frequency high-speed transmission cable module, and Tb3 is the temperature at the measuring point P2 at the first end of the main body of the upper cover of the high-frequency high-speed transmission cable module of the present invention. As shown in <FIG>, Tj1>Tj2, and Tb1>Tb2>Tb3. The above results show that under the conditions of an ambient temperature of <NUM> and a fan speed of <NUM> RPM, the heat dissipation efficiency of the present invention is significantly better than that of the conventional technology.

More specifically, as shown in <FIG>, during the start-up period (i.e., before <NUM> minutes and <NUM> seconds), the core temperature of the IC chip is still rising because the heat generated by the control module is still accumulating. At this time, Tj1-Tj2≥<NUM>, the difference between Tb1 and Tb2 is larger, and the difference between Tb2 and Tb3 is smaller. As shown in <FIG>, during the equilibrium period (i.e., after <NUM> minutes and <NUM> seconds), since the heat generated during the operation of the control module reaches an equilibrium state, the core temperature of the IC chip will not rise again. At this time, Tj1-Tj2≥<NUM>, the difference between Tb1 and Tb2 is smaller (Tb1-Tb2≥<NUM>), and the difference between Tb2 and Tb3 is larger.

In addition, when Tb2 is fixed at <NUM> and the fan speed is 24RPM, Tj1 is <NUM>; when Tb1 is fixed at <NUM> and the fan speed is 30RPM, Tj2 is <NUM>. At this time, Tj1>Tj2. The above results show that the heat dissipation efficiency of the present invention is clearly better than that of the conventional technology under the condition that the temperature of the measurement point is fixed at <NUM>.

Claim 1:
An upper cover (<NUM>) of a cover body (<NUM>) of a high-frequency high-speed transmission cable module, comprising:
a main body (<NUM>), two ends in the length direction of the main body (<NUM>) being respectively defined as a first end (<NUM>) and a second end (<NUM>), and the first end (<NUM>) of the main body (<NUM>) being disposed with a through hole (<NUM>); and
a heat dissipation block (<NUM>), embedded in the through hole (<NUM>) and exposed to a top surface of the first end (<NUM>) of the main body (<NUM>);
characterized in that an inner wall of the through hole (<NUM>) is disposed with a protruding support portion (<NUM>), and the support portion (<NUM>) divides the through hole (<NUM>) into a first passage (<NUM>) and a second passage (<NUM>), the first passage (<NUM>) runs through the top surface of the first end (<NUM>) of the main body (<NUM>) and the second passage (<NUM>) runs through the bottom surface of the first end (<NUM>) of the main body (<NUM>), and the support portion (<NUM>) is disposed with a connecting passage (<NUM>) for communicating between the first passage (<NUM>) and the second passage (<NUM>);
and in that the heat dissipation block (<NUM>) includes a top portion (<NUM>), a middle portion (<NUM>), and a bottom portion (<NUM>), and the top portion (<NUM>) of the heat dissipation block (<NUM>) is located in the first passage (<NUM>), the top surface of the top portion (<NUM>) of the heat dissipation block (<NUM>) is exposed to the top surface of the first end (<NUM>) of the main body (<NUM>), an outer side of the bottom surface of the top portion (<NUM>) of the heat dissipation block (<NUM>) abuts against the top surface of the support portion (<NUM>), and the middle portion (<NUM>) of the heat dissipation block (<NUM>) is disposed at the bottom surface of the top portion (<NUM>) of the heat dissipation block (<NUM>) and is located in the connecting passage (<NUM>); the bottom portion (<NUM>) of the heat dissipation block (<NUM>) is disposed on the bottom surface of the middle portion (<NUM>) of the heat dissipation block (<NUM>) and is located in the second passage (<NUM>), the diameter of the top portion (<NUM>) of the heat dissipation block (<NUM>) is greater than the diameter of the middle portion (<NUM>) of the heat dissipation block (<NUM>), and the diameter of the middle portion (<NUM>) of the heat dissipation block (<NUM>) is greater than the diameter of the bottom portion (<NUM>) of the heat dissipation block (<NUM>).