CN112945408A

CN112945408A - Temperature sensor, printed circuit board and server

Info

Publication number: CN112945408A
Application number: CN202110189479.8A
Authority: CN
Inventors: 冯鹏斌
Original assignee: Shandong Yingxin Computer Technology Co Ltd
Current assignee: Shandong Yingxin Computer Technology Co Ltd
Priority date: 2021-02-19
Filing date: 2021-02-19
Publication date: 2021-06-11

Abstract

The application discloses temperature sensor, printed circuit board and server sets up the integrated circuit board temperature measurement module at inside bottom, and integrated circuit board temperature measurement module includes crystalline grain, substrate and has groove structure and includes the pad of naked pad and pad pin, and the crystalline grain setting is in the substrate top, and the substrate setting is on naked pad. The pad pins are arranged at the edges of the grooves; the bare bonding pad is arranged at the bottom of the groove, has no electrical property and is directly contacted and connected with the bonding pad of the circuit board to be tested. The crystal grain comprises a temperature sensitive element and a temperature calculation unit, and is used for calculating the temperature value of the circuit board to be measured according to the temperature information transmitted by the circuit board to be measured through the bare bonding pad. The problem of current SOP encapsulation because the pin that stretches out the chip body is longer, and pin itself is more thin again, still can receive air temperature's influence when conduction heat efficiency is lower, leads to the temperature that final measurement came out can not be accurate temperature on the reflection integrated circuit board is solved in this application, improves PCB integrated circuit board temperature measurement's precision.

Description

Temperature sensor, printed circuit board and server

Technical Field

The application relates to the technical field of semiconductors, in particular to a temperature sensor, a printed circuit board and a server.

Background

With the development of cloud computing applications, informatization gradually covers all the fields of society, more and more daily work and life are communicated through networks, and the corresponding network data volume is increased continuously. The ever-increasing amount of network data has higher requirements on the performance of the underlying servers and more complex functions, resulting in an increasing load on the servers. The larger the load is, the more serious the heat generation inside the server is, and in order to ensure the stable operation of the server, the effective heat dissipation of the server is urgent.

With the increase of the demand and the progress of the process, the density of devices on each board card forming the server is higher and higher, the overall heat productivity of the server is also higher, in order to ensure better heat dissipation of the server, some chips with complex computation quantity, such as a Central Processing Unit (CPU) and the like, are additionally provided with heat dissipation fins, and heat conduction silicone grease is coated between the chips and the heat dissipation fins, so that the heat is more effectively conducted to the heat dissipation fins and then dissipated to the surrounding air by the heat dissipation fins. In the heat dissipation system inside the server chassis, temperature detection is a very critical loop at the front end of the heat dissipation system process, and based on the consideration of factors such as system integration level and device size, because the integrated temperature sensor is easy and convenient to use, low in price and free from debugging, the current heat dissipation schemes mostly adopt the integrated temperature sensor, which is generally called a sensor for short to perform a temperature detection function. The current integrated temperature sensor is generally manufactured by integrating an emitting junction of a transistor, namely a b-e junction, as a temperature sensitive element, together with a signal amplifying and conditioning circuit, even an a/D conversion circuit, and the like on one chip. The integrated temperature sensor is generally placed on the board card according to simulation results of heat dissipation engineers and suggestions given by experience, and is usually placed beside some high heat-generating devices, or placed at the air inlet and the air outlet according to the chassis structure and the direction of fan airflow. In the first case, the implementation mode is that some high-heat-generating devices generate heat, so as to cause the temperature rise of a Printed Circuit Board (PCB), the current flowing between the emitting junctions of the transistors changes due to the temperature characteristics, the value of the current collected inside the chip is converted and calculated by a certain value, and a specific temperature value is generated by the corresponding emitting junctions, and then the temperature value is read by the main control chip according to the characteristic mode. For the second case, the general purpose is to collect the temperature of the air inlet and the air outlet in the case, or the temperature of the ambient air is collected after the heat is conducted from the heat sink to the large heating chip and the fan cools down. The temperature after the heat dissipation measures are taken can be checked, the temperature difference between the air inlet and the air outlet can be compared, and the heat dissipation strategy is adjusted in time by judging whether the working temperature of the board card and the devices on the board card is met.

The related art uses an SOP (Small Out-Line Package) Package integrated type temperature sensor, and the Package structure is shown in fig. 1. As can be seen, the chip contacts and supports the PCB board with external pins, which are typically attached to the substrate inside the chip, above which is the chip die, and the integrated circuit is on the chip die, in which the temperature sensitive elements for measuring temperature are located. In the current application scene, the temperature on the PCB board card is transmitted to the inside of the chip through a chip pin contacted with the bonding pad to cause the current between the transistor emitter junctions to change, and the chip acquires the changed current and then obtains a temperature value which can be read by the control chip through the conversion of an internal circuit. In the process, because the pins of the chip are thin, the contact area between the chip and the board card is small, and the heat transfer efficiency is low; and the shell after the chip is packaged is generally made of insulating plastic materials, although the heat conducting performance of the shell is poor, the chip pins which are exposed in the air and are long are greatly influenced by the air temperature, so that the temperature which is finally transmitted to the temperature sensitive element to cause the current change is different from the actual temperature of the board card.

In summary, the temperature sensor is affected by the temperature of the ambient air during temperature measurement, the temperature finally expressed by the sensor should be a combination product of the PCB board temperature and the air temperature, although most of the heat is still transferred to the inside of the chip through the chip pins, the influence of the air on the finally obtained temperature cannot be ignored, and especially in some locations requiring precise and fast temperature measurement, these errors may cause device failure, server downtime, even board burning, and serious consequences and loss are brought.

In view of this, how to solve the problem that the finally measured temperature cannot accurately reflect the temperature on the board card due to the fact that the pins extending out of the chip body of the SOP package are long and thin, and the efficiency of heat conduction is low and simultaneously affected by the air temperature, is a technical problem to be solved by technical personnel in the field.

Disclosure of Invention

The application provides a temperature sensor, printed circuit board and server, it is longer owing to stretch out the pin of chip body to have solved current SOP encapsulation, and pin itself is thin again, still can receive air temperature's influence when conduction heat quantity efficiency is lower, leads to the temperature that final measurement came out can not the accurate problem of the temperature on the reflection integrated circuit board, improves PCB integrated circuit board temperature measurement's precision.

In order to solve the above technical problems, embodiments of the present invention provide the following technical solutions:

the embodiment of the invention provides a temperature sensor, which comprises a board card temperature measuring module arranged on the inner bottom layer, wherein the board card temperature measuring module comprises a crystal grain, a substrate and a welding disc with a groove structure;

the bonding pad comprises a bare bonding pad and a bonding pad pin; the pad pins are arranged at the edges of the grooves; the bare bonding pad is arranged at the bottom of the groove, does not have electrical property, and is directly contacted and connected with the bonding pad of the circuit board to be tested;

the die is disposed over the substrate, the substrate disposed on the bare pad;

the crystal grain comprises a temperature sensitive element and a temperature calculation unit, and is used for calculating the temperature value of the circuit board to be measured according to the temperature information of the circuit board to be measured transmitted by the bare bonding pad.

Optionally, the temperature measurement module further comprises an air temperature measurement module arranged on the inner top layer, wherein the air temperature measurement module comprises an upper-layer crystal grain, an upper-layer substrate and an upper-layer bonding pad with a groove structure;

the upper-layer crystal grains are arranged on the upper surface of the upper-layer substrate, and the upper-layer substrate is arranged on the front surface of the bare bonding pad of the upper-layer bonding pad; the bare bonding pad of the upper bonding pad is arranged at the bottom of the groove, does not have electrical property, and is connected with the inner surface of the top layer of the temperature sensor;

the upper-layer crystal grains are used for calculating the temperature value of the air according to the temperature information transmitted by the upper-layer bonding pad through the upper-layer substrate.

Optionally, the back surface of the bare bonding pad of the upper bonding pad is covered with an insulating heat-conducting film.

Optionally, the air temperature measurement module and the board card temperature measurement module are arranged inside the temperature sensor in mirror symmetry.

Optionally, the physical parameters of the upper layer crystal grains are the same as those of the crystal grains.

Optionally, an area of a bare pad of the pad is not smaller than a projected area of the die on the substrate.

Optionally, the pad is a copper pad.

The embodiment of the invention also provides a printed circuit board, which comprises a circuit board welding disc and the temperature sensor; and the bare bonding pad of the temperature sensor is embedded in the bonding pad of the circuit board and is in contact connection with the bonding pad of the circuit board.

Finally, an embodiment of the present invention provides a server, including the printed circuit board as described above.

Optionally, the printed circuit board is disposed at an air inlet or an air outlet of the server.

The technical scheme provided by the application has the advantages that the temperature of the whole circuit board is raised due to the heat generated by the high-heat-generating device in the circuit board to be measured, the temperature is rapidly transferred to the substrate through the bare bonding pad and then transferred to the temperature sensitive element on the crystal grain die through the substrate to cause the change of the transistor emitter junction current, the temperature value is obtained through internal processing and conversion according to the collected current, because the concave bare bonding pad can be directly embedded into the circuit board card and is in direct contact with the bonding pad of the circuit board, no air exists in the middle, the influence of the air temperature on the finally measured temperature value is reduced, the temperature measurement precision is improved, the working temperatures of the board card and the devices on the board are reflected more truly and rapidly, the device faults caused by temperature measurement errors and the breakdown of the server are avoided, even the board burning situation occurs, and the stability and the reliability of the server are improved. The problem of current SOP encapsulation because the pin that stretches out the chip body is longer, and pin itself is thinner again, still can receive air temperature's influence when conduction heat efficiency is lower, lead to the temperature that the final temperature that measures can not accurate reflection integrated circuit board on the temperature is solved.

In addition, the embodiment of the invention also provides the printed circuit board and the server, so that the temperature sensor has higher practicability, and the printed circuit board and the server have corresponding advantages.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the related art, the drawings required to be used in the description of the embodiments or the related art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an SOP package integrated temperature sensor according to an exemplary application scenario in the prior art provided by an embodiment of the present invention;

fig. 2 is a structural diagram of a specific implementation of a temperature sensor according to an embodiment of the present invention;

FIG. 3 is a diagram of a specific embodiment of a bonding pad according to an embodiment of the present invention;

fig. 4 is a structural diagram of another specific implementation of the temperature sensor according to the embodiment of the present invention;

fig. 5 is a structural diagram of a specific implementation of a printed circuit board according to an embodiment of the present invention;

fig. 6 is a block diagram of a specific implementation of a server according to an embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," "third," "fourth," and the like in the description and claims of this application and in the above-described drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may include other steps or elements not expressly listed.

Having described the technical solutions of the embodiments of the present invention, various non-limiting embodiments of the present application are described in detail below.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a temperature sensor according to an embodiment of the present invention, where the embodiment of the present invention includes the following:

the temperature sensor can comprise a board temperature measuring module arranged at the bottom layer in the sensor, and the board temperature measuring module can comprise a crystal grain 11, a substrate 12 and a welding disc with a groove structure.

The bonding pad of the embodiment may include a bare bonding pad 131 and bonding pad pins 132, as shown in fig. 3, the bonding pad pins 132 may be disposed at the edge of the groove, and the number of the bonding pad pins 132 disposed at the periphery of the bonding pad may be adjusted according to different integrated circuits. The bare bonding pad 131 is arranged at the bottom of the groove, the area of the bare bonding pad 131 can be adjusted according to actual conditions, and it can be understood that the larger the area of the bare bonding pad 131 is, the faster the temperature on the circuit board of the object to be measured can be collected. As an alternative embodiment, in order to ensure the accuracy of the board temperature measurement, the area of the bare pad 131 of the pad is not smaller than the projected area of the die11 on the substrate 12. The bare bonding pad 131 does not have electrical property and is directly contacted and connected with a bonding pad of the circuit board to be tested; the recessed bare pad 131 is connected to the circuit board so that the die11 is closer to the circuit board, reducing the influence of the air temperature on the finally measured temperature, so that the temperature of the circuit board can be measured more quickly and accurately. In order to improve the heat-conducting property of the bonding pad, the bonding pad can be a copper bonding pad.

Die11 may be disposed over

substrate

12, and 12 the substrate may be disposed on bare pad 131. That is, a substrate is arranged above the bonding pad, a die11 is arranged above the substrate, and the board card temperature measurement module sequentially comprises the bonding pad, the substrate 12 and the die11 from bottom to top. Substrate 12 may be any type of substrate in a semiconductor chip primarily intended to function as a carrier for die 11.

The die11 of this embodiment is a small block of semiconductor material on which a specific functional circuit is fabricated, and it may include a temperature sensing element and a temperature calculating unit, which can calculate the temperature value of the circuit board to be measured according to the temperature information transmitted by the circuit board to be measured through the bare pad 131. As to how to calculate the temperature value of the circuit board according to the collected temperature information, the calculation method of the temperature in any temperature sensor in the prior art can be used, and the present application is not limited thereto.

In the technical scheme provided by the embodiment of the invention, the temperature of the whole circuit board is raised due to the heat generated by a high-heating device in the circuit board to be measured, the temperature is rapidly transferred to the substrate through the bare bonding pad and then transferred to the temperature sensitive element on the crystal grain die through the substrate to cause the change of the current of the transistor emitter junction, the temperature value is obtained through internal processing and conversion according to the collected current, because the concave bare bonding pad can be directly embedded into the circuit board card and is in direct contact with the bonding pad of the circuit board, no air exists in the middle, the influence of the air temperature on the finally measured temperature value is reduced, the temperature measurement precision is improved, the working temperatures of the board card and the devices on the board are reflected more truly and rapidly, the device faults caused by temperature measurement errors and the breakdown of the server are avoided, even the board burning situation occurs, and the stability and the reliability of the server are improved. The problem of current SOP encapsulation because the pin that stretches out the chip body is longer, and pin itself is thinner again, still can receive air temperature's influence when conduction heat efficiency is lower, lead to the temperature that the final temperature that measures can not accurate reflection integrated circuit board on the temperature is solved.

It should be noted that, the temperature sensor not only can be used as a temperature measuring element, but also can be externally connected with a transistor to realize remote temperature measurement, so that the cost is reduced.

In order to reduce the number of temperature sensors disposed in the circuit board, referring to fig. 4, the temperature sensor may further include an air temperature measurement module disposed on the inner top layer, and the air temperature measurement module may include an upper die 21, an upper substrate 22, and an upper pad 23 having a groove structure.

The upper die 21 may be disposed on an upper surface of an upper substrate, and the upper substrate 22 is disposed on a front surface of a bare pad of the upper pad 23; the bare pad of the upper layer pad 23 is disposed at the bottom of the groove, has no electrical property, and is connected to the top layer inner surface of the temperature sensor. The upper die 21 may also include a temperature sensitive element and a temperature calculation unit that can calculate a temperature value of air based on temperature information transmitted from the upper pad 23 through the upper substrate 22. As to how to calculate the temperature value of the ambient air according to the collected temperature information, the calculation method of the temperature in any temperature sensor in the prior art can be used, and the present application is not limited thereto.

In order to further improve the efficiency of air temperature propagation, the back surface of the bare pad of the upper layer pad 23 is also covered with an insulating and heat-conducting film 24.

In order to improve the accuracy of temperature measurement of the temperature sensor, the air temperature measurement module and the board card temperature measurement module can be arranged inside the temperature sensor in a mirror symmetry mode.

In order to improve the management performance of the temperature sensor and facilitate the preparation of the temperature sensor, the physical parameters and the structures of an upper-layer crystal grain 21, an upper-layer substrate 22 and an upper-layer bonding pad 23 of the air temperature measurement module are respectively the same as those of a crystal grain 11, a substrate 12 and a bonding pad in the board card temperature measurement module. It can be understood that, because the precision of air temperature measurement is lower than the requirement of circuit board temperature measurement, in order to reduce the manufacturing cost of the temperature sensor, the performance of the upper layer crystal grain 21 of the air temperature measurement module can be lower than the performance of the crystal grain 11 in the board card temperature measurement module.

In this embodiment, the inside of temperature sensor comprises upper and lower two parts, and the latter half can be by for example copper material's pad, the substrate of copper top, the die of substrate top is constituteed, and the first half is rather than mirror symmetry arrangement, from the bottom up is die, substrate and pad in proper order, and the difference is that the first half has increased the insulating and good film of thermal conductivity of one deck above the pad, on the copper pad under with the transmission of air temperature maximize to the film under the prerequisite that does not influence electrical property. The bottom layer bonding pads in the board card temperature measurement module are basically consistent with elements packaged by the current DFN, the number of the peripheral bonding pads is only an example, the bonding Pad with the larger middle part is an Exposed Pad, and the board card temperature measurement module mainly has the function of contacting with the bonding Pad on the PCB to quickly transfer the temperature on the PCB to a chip so as to realize subsequent temperature measurement.

This embodiment differs from the previous embodiment in that the upper half has one more die, which is mainly used to measure the temperature of the air surrounding the sensor. The principle is consistent with that of a normal temperature sensor, because plastic materials with poor thermal conductivity are not adopted above the copper bonding pad, a film with good insulation and thermal conductivity is adopted for replacement, the temperature of air is transmitted to the copper bonding pad through the film, then is transmitted to the substrate downwards, and finally is transmitted to the temperature sensor. Then, the temperature value of the air is obtained through the same treatment process as the lower half. Because the chip integrates the upper and lower temperature measuring structures, it is obvious that one temperature sensor can simultaneously realize the measurement of the board card temperature of the circuit board and the measurement of the air temperature around the chip, and the number of the temperature sensors in the server is reduced to a certain extent.

In addition, the embodiment also provides a printed circuit board, please refer to fig. 5, the printed circuit board may include a circuit board pad and any one of the above embodiments of the temperature sensor, and the bare pad of the temperature sensor is embedded and connected with the circuit board pad. The number of the temperature sensors arranged on the printed circuit board can be determined according to the actual number of the heating devices and the actual operation service, which does not influence the realization of the application,

fig. 5 shows a PCB design corresponding to the temperature sensor of the present application, which is different from a component packaged in a normal DFN (Dual Flat No-lead, double-sided Flat non-leaded package) package in that a middle Exposed Pad is extended into a PCB board card to contact with a PCB Pad, and this structure can maximally avoid the influence of air on temperature measurement while rapidly transferring the temperature from the PCB to a chip, thereby improving the accuracy of temperature measurement.

Therefore, in the embodiment, when the temperature sensor is used for measuring the board card temperature of the printed circuit board, the high-heat-generating device generates heat to cause the temperature of the printed circuit board to rise, the temperature is rapidly transmitted to the substrate through the bare Pad Exposed Pad, and then is transmitted to the temperature sensitive element on the die through the substrate to cause the current change of the transistor emitter junction, and the chip acquires the current and then obtains the temperature value through internal conversion. In the process, as can be seen from fig. 2 and 4, the Exposed Pad protruding from the sensor is embedded into the PCB card to contact with the Pad, and no air exists in the middle, so that the influence of the air temperature on the finally measured temperature value is reduced, and the accuracy of temperature measurement is improved. And because the Exposed Pad has large contact area with the PCB and high heat transfer efficiency, the effect of monitoring the temperature change of the PCB board card in real time can be realized, and the heat dissipation strategies such as the rotating speed of the fan and the like can be adjusted in time.

Finally, the present application further provides a server, please refer to fig. 6, in which the server includes one or more embodiments of the printed circuit boards as described above, in fig. 6, the dotted line portion is the printed circuit board, and the solid line portion is the temperature sensor.

Because the top layer of the temperature sensor is provided with the air temperature measuring module, the temperature sensor can be used for measuring the air temperature at the air inlet and the air outlet inside the server, and the printed circuit board can be arranged at the air inlet or the air outlet inside the server. The heat dissipation strategy can be adjusted in sequence, and the effectiveness and efficiency of the current heat dissipation strategy can be reflected.

Therefore, the embodiment of the invention not only removes the influence of the air temperature on the temperature measurement of the PCB, completes the rapid and accurate measurement of the temperature of the PCB, but also realizes the accurate measurement of the air temperature around the chip, and truly and rapidly reflects the temperature change of the PCB and the air, thereby achieving the purpose of timely and correctly adjusting the heat dissipation strategy, avoiding the occurrence of device failure, server downtime, even board burning and the like caused by temperature measurement errors, reducing the risk, and improving the reliability and the safety of the server.

The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

A temperature sensor, a printed circuit board, and a server provided by the present application are described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present application.

Claims

1. A temperature sensor is characterized by comprising a board card temperature measuring module arranged on the inner bottom layer, wherein the board card temperature measuring module comprises a crystal grain, a substrate and a welding disc with a groove structure;

the die is disposed over the substrate, the substrate disposed on the bare pad;

2. The temperature sensor according to claim 1, further comprising an air temperature measurement module disposed at an inner top layer, the air temperature measurement module comprising an upper die, an upper substrate, and an upper pad having a groove structure;

3. The temperature sensor according to claim 2, wherein a back surface of the bare pad of the upper layer pad is covered with an insulating heat conductive film.

4. The temperature sensor of claim 3, wherein the air temperature measurement module and the board temperature measurement module are arranged inside the temperature sensor in mirror symmetry.

5. The temperature sensor of claim 4, wherein the upper layer die has the same physical parameter as the die.

6. The temperature sensor according to any one of claims 1 to 5, wherein an area of a bare pad of the pad is not smaller than a projected area of the die on the substrate.

7. The temperature sensor of claim 6, wherein the pad is a copper pad.

8. A printed circuit board comprising a circuit board pad and a temperature sensor according to any one of claims 1 to 7;

and the bare bonding pad of the temperature sensor is embedded in the bonding pad of the circuit board and is in contact connection with the bonding pad of the circuit board.

9. A server comprising the printed circuit board of claim 8.

10. The server of claim 9, wherein the printed circuit board is disposed at an internal air inlet or outlet of the server.