Abstract:
Disclosed is a device and method for intelligently heating a component of a printed circuit board (PCB) to bring it within a specified operating temperature range quickly. A temperature sensor positioned in proximity to the component and is coupled with a logic circuit that receives a reading from the temperature sensor and compares it to a threshold temperature value. A heating element positioned in proximity to the component is coupled with a power source and a switch. The switch is triggered by the logic circuit to activate the heating element when the temperature sensor reading is cooler than the threshold temperature value thereby causing the component to warm up. The switch is triggered again by the logic circuit to de-activate the heating element when the temperature sensor reaches the threshold temperature value or a predetermined timeout period expires.

Description:
BACKGROUND 
     Mobile to mobile communication devices are being deployed in more extreme environments all the time. Small RF devices that are used for communication and data exchange purposes can be strategically deployed in warehouses, trucks, ships, shipping containers, and a variety of other outdoor environments. These devices must be able to operate over a wide variety of temperature conditions including extreme cold. If the RF device&#39;s components can not warm up in a timely manner, mission critical communications can be lost or delayed. 
     What is needed is a device for providing an intelligent localized heat source for specific circuit components that need to be within a specific temperature operating range to function properly. 
     SUMMARY 
     Disclosed is a device for intelligently heating a component of a printed circuit board (PCB) to bring it within a specified operating temperature range quickly. A temperature sensor positioned in proximity to the component and is coupled with a logic circuit that receives a reading from the temperature sensor and compares it to a threshold temperature value. A heating element positioned in proximity to the component is coupled with a power source and a switch. The switch is triggered by the logic circuit to activate the heating element when the temperature sensor reading is cooler than the threshold temperature value thereby causing the component to warm up. The switch is triggered again by the logic circuit to de-activate the heating element when the temperature sensor reaches a second warmer threshold temperature value or when a predetermined timeout period expires. The logic circuit can be implemented in hardware or software or a combination of hardware and software. 
     Also disclosed is a method of intelligently heating a component of a printed circuit board (PCB) to bring it within a specified operating temperature range quickly. The component is monitored to determine its temperature. The temperature reading is associated with the component and forwarded to a logic circuit for processing. The logic circuit compares the temperature reading to a threshold temperature value and triggers a switch to activate a heating element in proximity to the component when the temperature reading is cooler than the threshold temperature value. This causes the component to warm up. The logic circuit also de-activates the heating element when the temperature reading reaches the threshold temperature value or when a predetermined timeout period expires. The logic circuit can be implemented in hardware or software or a combination of hardware and software. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view illustration of one embodiment of a typical printed circuit board (PCB) that can be found within an RF module showing components utilized in the embodiments of the invention. 
         FIG. 2  is a side view illustration of  FIG. 1 . 
         FIG. 3  is a side view illustration of another embodiment of a typical printed circuit board (PCB) that can be found within an RF module showing components utilized in the embodiments of the invention. 
         FIG. 4  is an illustration of different embodiments of a heating element. 
         FIG. 5  is a block diagram that illustrates the operation of the device according to embodiments of the invention. 
         FIG. 6  is a logic diagram that illustrates the operation of the device according to embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     On a typical printed circuit board (PCB) there may be several components that cannot function at low temperatures (e.g., −30° C. or colder). These components, however, are utilized by devices that may encounter environmental conditions that routinely experience ‘out of range’ temperature conditions. In such cases, the performance of the devices suffers, sometimes to the point of being inoperable. The embodiments of the present invention described herein address such situations by applying an intelligent localized heat source to selected components prior to operating the main device so as to avoid damaging the component or other components of the overall device. 
       FIG. 1  is a top view illustration of one embodiment of a typical printed circuit board (PCB)  10  that can be found within an RF module (not pictured) of an overall main device showing components utilized in the embodiments of the present invention. The PCB  10  has been simplified to illustrate just a single component  12  that is associated with a heat source or heating element  16  that sits atop the component  12 . Pads  14  provide contact points that can relay power to the heating element  16  via a flexible PCB substrate  15 . The flexible PCB substrate  15  can be configured to cover the component  12  needing heat. 
       FIG. 2  is a side view illustration of  FIG. 1 . This illustration shows the base PCB  10  having pads  14  on either side of the component  12  that needs heating. The flexible PCB  15  with an embedded heating element  16  is shown atop the component  12  radiating  17  heat into the component. There are other components to the heating system that have not yet been illustrated including a temperature sensor, some logic or intelligence, and a switch mechanism for engaging and disengaging the heating element  16 . 
       FIG. 3  is a side view illustration of another embodiment of a typical printed circuit board (PCB)  10  that can be found within an RF module showing components utilized in the embodiments of the invention. In this embodiment the base PCB  10  includes a heat layer  18 . Within the heat layer  18 , one or more heating elements  16  are dispersed. In this illustration, a component  12  that may need heating is positioned atop the heating element  16  which can radiate  17  heat upward into the component  12 . 
       FIG. 4  illustrates examples of heating elements  16  that can be used with the embodiments presented above.  FIG. 4(   a ) illustrates a heating element  16  comprised of a resistive element having a plurality of perforations  19  to assist with heat flow.  FIG. 4(   b ) illustrates a heating element  16  comprised of a resistive element  20  arranged in a pattern and embedded with a substrate. The actual pattern can vary and need not be confined to that shown in  FIG. 4(   b ). The resistive element itself can be metallic or made from a material such as, but not limited to, OhmegaPly® embedded resistive material. 
       FIG. 5  is a block diagram that illustrates the operation of the device according to embodiments of the invention. A temperature sensor  50  is positioned on or about a specific PCB component that may need heating. The temperature sensor  50  monitors the ambient temperature for the component to which it is associated. The temperature reading is forwarded to a logic circuit (or software associated with a processor)  52  that determines whether the current temperature exceeds a predetermined threshold indicating the need to heat a component prior to operating the main device. If the temperature reading is below the threshold, a signal is sent that causes a switch  54  to trigger a heating element  16  that is placed in close proximity to the component that needs to be warmed up. If the temperature reading is below the threshold, a signal is sent that causes the switch  54  to close a circuit that causes normal operation  56  of the main device without involving the heating element. The temperature sensor  50  operates to continuously monitor the component temperature and will trigger the switch  54  accordingly when the temperature threshold is crossed in either direction. 
       FIG. 6  is a logic diagram that illustrates the operation of the device according to embodiments of the invention. When the overall main device is started up, it initially takes a temperature sensor reading of the ambient temperature on and about a specific component  60 . If the temperature is determined  62  to be warmer than or above  63  a predetermined threshold via a logic circuit (or software), another check is made to determine whether the heating element is already powered on  64 . If the result is no then the main device is operated normally  66  and control returns to the temperature monitoring process  60 . If the heating element is already powered on then it is powered off  68  via the switch mechanism and control returns to the temperature monitoring process  60 . 
     If the temperature is determined  62  to be cooler than or below  69  the predetermined threshold, it is also determined whether the heating element is already powered on  70 . If the heating element is not already powered on then it is powered on  74  via the switch mechanism and control returns to the temperature monitoring process  60 . If the heating element is already powered on then a determination is made whether a timeout has occurred  72  such that the heating element does not stay on for too long. If the timeout has not occurred yet control returns to the temperature monitoring process  60 . If the timeout has occurred then the heating element is powered off  68  via the switch mechanism and control returns to the temperature monitoring process  60 . 
     The component&#39;s temperature is continuously monitored such that the heating element(s) will power on and off as necessary to keep the component above the predetermined temperature threshold. 
     The present invention has described below with reference to flowchart illustrations and/or block diagrams of methods, and apparatus (systems). It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowcharts and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art appreciate that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown and that the invention has other applications in other environments. This application is intended to cover any adaptations or variations of the present invention. The following claims are in no way intended to limit the scope of the invention to the specific embodiments described herein.