CN105183611A - Method for preventing PCB board card from being burnt out by detecting voltage - Google Patents

Abstract

The invention discloses a method for preventing a PCB card from being burnt down by detecting voltage, which comprises the following concrete implementation processes: the maximum current capacity of the Power copper foil of the PCB is quantified, namely a threshold value is set, then voltages at two ends of the passing copper foil are compared, once the voltages exceed the set threshold value, an alarm is given out, shutdown is completed before the PCB is burnt out, and the PCB is prevented from being burnt out. Compared with the prior art, the method for preventing the PCB board card from being burnt through detecting the voltage has the advantages that the PCB board card is prevented from being burnt through voltage detection, the PCB is shut down before being burnt, the problem that the PCB which cannot be covered by the traditional circuit design is solved, the practicability is high, and the popularization is easy.

Description

A method for preventing PCB board card from burning by detecting voltage

technical field

The invention relates to the technical field of computer servers, in particular to a practical method for preventing PCB boards from being burned by detecting voltage.

Background technique

With the rapid development of the Internet industry in recent years, the industry's demand for servers is increasing. At the same time, higher requirements are put forward for the system performance and system stability of the server.

As far as the power supply is concerned, we will find that large-scale server motherboards are designed with a lot of voltage. Whether it is the early design or the later protection, we usually add corresponding protection circuits during the design process to prevent the board from being damaged during the working process. Uncertain factors will cause damage to the board, and the most serious damage is the burning of the board. However, the current design to prevent board burnout is only focused on the direction of circuit design, and it is not good for PCB board burnout caused by phenomena such as virtual soldering, short-circuiting, CAF and copper ion migration during long-term use in the PCB manufacturing process. way.

The ultimate reason for the burning of the PCB is: passing a current exceeding its carrying capacity on the smaller Power copper foil, causing the PCB to heat up rapidly and in large quantities, and then burning the PCB. The design method of measuring voltage to prevent PCB board from burning.

Contents of the invention

The technical task of the present invention is to provide a practical method for preventing PCB boards from being burned by detecting voltages.

A method for preventing PCB board card from burning by detecting voltage, the specific design process is:

By quantifying the maximum current capability of the PCB's Power copper foil, that is, setting the threshold, and then comparing the voltage across the passing copper foil, once the set threshold is exceeded, an alarm will be issued, and the shutdown will be completed before the PCB is burned. Prevent burning of PCB.

The setting process of the threshold value is: during the PCB design of the server, the maximum current value and the impedance value of the copper foil on the PCB determined according to the design specifications are calculated to calculate the allowable current at both ends of the copper foil. The maximum voltage difference is V1, and then the voltage of 3.3V in the PCB is divided by resistors to generate V1.

The triggering process of the alarm is: untie the sense line at both ends of the copper foil on the PCB, detect the voltage difference V2 between the two ends of the copper foil in real-time operation, V1 and V2 are connected through a comparator, when V2 is greater than V1 , the comparator sends out a low-level signal, and the low-level signal triggers a server alarm signal.

A method of preventing PCB boards from being burned by detecting voltage of the present invention has the following advantages:

The method proposed by the present invention prevents the burning of the PCB board by detecting the voltage, prevents the burning of the PCB by detecting the voltage, completes the shutdown before the burning of the PCB, and solves the problem of the burning of the PCB that cannot be covered by the traditional circuit design. Strong and easy to promote.

Description of drawings

Accompanying drawing 1 is the realization schematic diagram of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The present invention provides a method for preventing PCB board card from burning by detecting voltage, as shown in accompanying drawing 1,

Its specific implementation process is:

By quantifying the maximum current capability of the PCB's Power copper foil, that is, setting the threshold, and then comparing the voltage across the passing copper foil, once the set threshold is exceeded, an alarm will be issued, and the shutdown will be completed before the PCB is burned. Prevent burning of PCB.

The setting process of the threshold value is: during the PCB design of the server, the maximum current value and the impedance value of the copper foil on the PCB determined according to the design specifications are calculated to calculate the allowable current at both ends of the copper foil. The maximum voltage difference is V1, and then the voltage of 3.3V in the PCB is divided by resistors to generate V1.

The triggering process of the alarm is: untie the sense line at both ends of the copper foil on the PCB, detect the voltage difference V2 between the two ends of the copper foil in real-time operation, V1 and V2 are connected through a comparator, when V2 is greater than V1 , the comparator sends out a low-level signal, and the low-level signal triggers the server alarm signal.

Specific examples:

1) According to the design specifications of the PCB, take the PCB copper foil that is designed to require a current of 4A, then the width of the copper foil is 160mil, the length is 1000mil, and the calculated impedance value is 100 milliohms. Therefore, it is calculated that when the 4A current is passed, the voltage difference of the PCB copper foil is 4X100=400 millivolts.

2) The voltage difference detected by sense can be realized by parallel connection of resistors, capacitors and PCB copper foil, and the voltage at the capacitor terminal is the voltage difference. For those whose voltage difference is too small, an operational amplifier can be added to amplify the voltage difference by 10 to 50 times. This article takes no amplification as an example.

3) By reasonably setting the values of R1 and R2 (R1), ensure that V2 is equal to 500 millivolts, of which 100 millivolts is the design margin.

4) Compare V1 and V2 with a comparator. Once V1 is greater than 500 millivolts, the PCB is in a dangerous working state, and board burning is likely to occur. At this time, the comparator needs to send a low-level signal to trigger the server alarm. device.

In this way, a design method proposed in this paper that utilizes over-detection voltage to prevent PCB boards from burning can be realized.

The above-mentioned specific embodiments are only specific cases of the present invention, and the scope of patent protection of the present invention includes but is not limited to the above-mentioned specific embodiments, any claims in accordance with the claims of a method of preventing PCB boards from being burned by detecting voltages of the present invention And any appropriate changes or substitutions made by those of ordinary skill in the technical field shall fall within the patent protection scope of the present invention.

Claims (3)

1. A method for preventing PCB boards from burning by detecting voltage is characterized in that its specific design process is: by quantifying the maximum current capability of the Power copper foil of the PCB, that is, setting the threshold, and then passing through The voltage at both ends of the copper foil is compared, and once it exceeds the set threshold, an alarm will be issued, and the shutdown will be completed before the PCB is burned to prevent the PCB from burning. 2. A method for preventing PCB board card burnout by detecting voltage according to claim 1, characterized in that, the setting process of the threshold value is: during the PCB design of the server, on the PCB determined according to the design specifications The maximum current value that can pass through each copper foil and the impedance value of the copper foil, calculate the maximum allowable voltage difference V1 between the two ends of the copper foil, and then use the voltage of 3.3V in the PCB to divide the voltage through the resistor to generate V1. 3. A method for preventing PCB boards from burning by detecting voltage according to claim 2, characterized in that, the triggering process of the alarm is: respectively untie the sense line at both ends of the copper foil on the PCB, detect Measure the voltage difference V2 between the two ends of the copper foil during real-time operation. V1 and V2 are connected through a comparator. When V2 is greater than V1, the comparator sends a low-level signal, which triggers the server alarm signal.