JP6969931B2 - Circuit board evaluation package and circuit board evaluation method - Google Patents

Description

The present invention relates to a circuit board evaluation package and a circuit board evaluation method.

In a printed circuit board equipped with an LSI (large-scale integrated circuit), when the power supply fluctuation (power supply noise) is large, the power supply noise waveform is measured on the printed circuit board to measure a capacitor, etc. It is common to add parts to deal with this.

As a countermeasure against such power supply noise, it is effective to grasp the frequency characteristics of the characteristic impedance of the power supply line.

In the frequency characteristic of the characteristic impedance of the power supply line, if the impedance peak is present, the power supply noise becomes large at the frequency at which the impedance peak occurs. Therefore, it becomes possible to select a capacitor having a capacity that reduces noise in the frequency band including the frequency of the peak impedance.

In addition, the location of the capacitor for noise suppression is also determined based on the impedance characteristics near the peak frequency.

Patent Document 1 presents a characteristic impedance measuring device for a circuit board line.

Japanese Unexamined Patent Publication No. 2002-148291

However, although it is possible to measure the characteristic impedance by the method according to Patent Document 1, it is difficult to measure the state in which the noise generated by the LSI is mixed from the power supply of the LSI to the power supply line of the circuit board.

In view of the above-mentioned problems, an object of the present invention is a circuit board evaluation package capable of measuring the characteristics of a power supply line simulating a state in which noise generated by an LSI power supply is mixed in the power supply line of the circuit board, and a circuit board. The purpose is to provide an evaluation method.

In order to achieve the above object, the circuit board evaluation package of the present invention is a circuit board evaluation package including a plurality of connection pins arranged in the same manner as the connection pins of the integrated circuit package, and is the integrated circuit. A current source connected between at least one power supply pin in the same arrangement as the power supply pin and at least one ground pin in the same arrangement as the ground pin of the integrated circuit, and a current connected to the current source and the current of the current source. It is provided with a control signal input terminal into which a signal for controlling the current is input, and a power supply measuring terminal connected between the power supply pin and the grounding pin.

In order to achieve the above object, the circuit board evaluation method of the present invention uses a circuit board evaluation package including a plurality of connection pins arranged in the same manner as the connection pins of the integrated circuit package mounted on the circuit board. In the evaluation method, the current of the current generation source connected between at least one power supply pin in the same arrangement as the power supply pin of the integrated circuit and at least one grounding pin in the same arrangement as the grounding pin of the integrated circuit is controlled. Further, the voltage between the power supply pin and the ground pin is measured.

According to the present invention, the circuit board evaluation package and the circuit board evaluation method can measure the characteristics of the power supply line simulating the state in which the noise generated by the power supply of the LSI is mixed in the power supply line of the circuit board.

It is a figure which shows the structural example of the 1st Embodiment. It is a figure which shows the use example of the circuit board evaluation package of 2nd Embodiment. It is a figure which shows the structural example of the 2nd Embodiment. It is a figure which shows the structural example of the 2nd Embodiment. It is a figure which shows the structural example of the 2nd Embodiment. It is a figure which shows the structural example of the 3rd Embodiment.

[First Embodiment]
Next, an embodiment of the present invention will be described in detail with reference to FIG.

The circuit board evaluation package 10 of the present embodiment includes a plurality of connection pins 20 arranged in the same manner as the connection pins of the package of the integrated circuit mounted on the circuit board. The circuit board evaluation package 10 is a current generation source connected between at least one power supply pin 21 having the same arrangement as the power supply pin of the integrated circuit and at least one grounding pin 22 having the same arrangement as the grounding pin of the integrated circuit. 11 is provided. Further, the circuit board evaluation package 10 includes a control signal input terminal 12 connected to the current generation source 11 and to which a signal for controlling the current of the current generation source 11 is input. Further, the circuit board evaluation package 10 includes a power supply measuring terminal 13 connected between the power supply pin 21 and the grounding pin 22.

A signal instructing that the current generation source 11 outputs a signal necessary for measurement to the power supply pin 21 by replacing the package of the integrated circuit mounted on the circuit board with the above-mentioned circuit board evaluation package 10. Is input to the control signal input terminal from an external device. Then, the signal appearing at the power supply measuring terminal 13 is measured by an external measuring device.

By doing so, the circuit board evaluation package 10 of the present embodiment can measure the characteristics of the power supply line simulating the state in which the noise generated by the integrated circuit is mixed in the power supply line of the circuit board.
[Second Embodiment]
Next, the second embodiment will be described with reference to FIGS. 2 to 5.
[Description of configuration]
First, a method of using the circuit board evaluation package of the present embodiment will be described with reference to FIG.

FIG. 2 shows a mother board 130, such as a computer.

The motherboard 130 is equipped with a power connector 131, a peripheral chipset 132 of a CPU (Central Processing Unit), a memory slot 133, an expansion slot 134, and the like.

Further, the motherboard 130 is equipped with a CPU (Central Processing Unit) by LSI. CPUs are often fitted into LSI sockets on the motherboard and electrically connected via connection pins.

The circuit board evaluation package 100 of this embodiment is used by being fitted into an LSI socket instead of a CPU.

FIG. 2 shows a state in which the circuit board evaluation package 100 is mounted instead of the CPU.

Although it is difficult to replace the circuit board, the circuit board evaluation package 100 and the motherboard 130 may be electrically connected by solder melting.

FIG. 3 shows the configuration of the second embodiment.

The circuit board evaluation package 100 of the present embodiment includes a substrate 101, a plurality of connection pins 120, a power supply pin 121, a grounding pin 122, a current generator 110, a control signal input terminal 112, and a power supply measurement terminal 113.

The board 101 is a printed circuit board or the like having the same size as the bottom surface of the originally mounted LSI (hereinafter referred to as LSI) package, and is a base on which each component of the circuit board evaluation package 100 is attached and electrical wiring is performed. Is.

The connection pin 120 is arranged on the bottom surface of the substrate 101 at the same position as the pin arrangement on the bottom surface of the LSI package.

The power supply pin 121 is a pin among the connection pins 120 that is arranged at the position of the power supply pin of the LSI.

The ground pin 122 is a pin of the connection pins 120 that is arranged at the position of the ground pin of the LSI.

Here, the relationship between the substrate 101 and the connection pin 120 will be described.

FIG. 4 is an explanatory view of a cross section of the substrate 101.

The substrate 101 is a multilayer board, and has a power supply layer to which power supply power is applied to the inner layer and a grounding layer having a grounding potential.

Of the connection pins 120, the power supply pin 121 is connected only to the power supply layer in the inner layer and not to the ground layer. Further, the ground pin 122 is connected only to the ground layer in the inner layer and is not connected to the power supply layer.

The other connection pins 120 are not connected to either the power supply layer or the ground layer. However, the other connection pin 120 may be connected to the ground layer depending on the purpose of measurement.

The current generator 110 of FIG. 3 is a power supply circuit having a current generation source, and the current generation source can output by changing the amplitude and frequency of the current by applying a control signal.

The control signal input terminal 112 is a terminal in which a control signal applied to the current generation source of the current generator is input from the outside.

The power supply measurement terminal 113 has two terminals and is a terminal capable of outputting a power supply signal to an external measuring instrument. One terminal is connected to the power supply pin 121 and the other terminal is connected to the ground pin. There is.

FIG. 5 is a diagram illustrating a state of connection of each component of the circuit board evaluation package 100.

The current generator 110 has a current generation source 111 inside. The output of the current generation source 111 is connected to the power supply layer and the ground layer of the substrate 101.

The current generation source 111 changes the frequency and amplitude of the power to be output based on the control signal applied from the outside to the control signal input terminal 112.

The circuit board evaluation package 100 of the present embodiment has a structure in which the power supply pin 121 and the grounding pin 122 are connected to the inner layer of the board 101. This is because the board structure of the LSI has a power supply layer and a ground layer, and the circuit board evaluation package 100 also uses the inner layer in order to simulate the structure of the LSI.

However, as shown in FIG. 1, the current generation source 111, the power supply pin 121, the ground pin 122, and the power supply measurement terminal 113 may be connected by a wiring pattern or an electric wire without going through the inner layer.
[Explanation of operation]
Next, the operation of the circuit board evaluation package 100 will be described with reference to FIG.

The circuit board evaluation package 100 is attached to the LSI socket of the motherboard, and the power of the motherboard is turned on. Here, the power supply of the motherboard is assumed to be direct current.

Next, a control signal is applied to the control signal input terminal 112 from the outside so that the current generator 110 outputs an AC load current whose current fluctuation amount is ΔI and whose frequency is f.

Then, the voltage fluctuation amount ΔV that is output to the power supply measurement terminal 113 and fluctuates with the frequency f is measured by an external measuring instrument connected to the power supply measurement terminal 113.

At this time, the impedance Z of the power supply system of the motherboard at the frequency f can be obtained by Z = ΔV / ΔI.

The frequency characteristics of the impedance can be obtained by measuring the voltage fluctuation amount ΔV by changing the frequency f and displaying the impedance Z of each frequency in a graph, assuming that the AC current fluctuation amount ΔI generated by the current generator 110 is constant. ..

In the graph of the frequency characteristic of this impedance, when the impedance peak exists at a specific frequency, the power supply noise becomes large at this specific frequency (peak frequency). Therefore, by selecting a capacitor having resonance characteristics in the frequency band including the peak frequency, it is possible to take measures against power supply noise.

Further, it is generally possible to determine the location of the capacitor selected in this way on the motherboard from the impedance characteristics near the peak frequency.

As described above, the circuit board evaluation package 100 of the present embodiment can measure the impedance of the power supply system of the motherboard observed from the power supply pin of the LSI.

That is, the circuit board evaluation package 100 of the present embodiment makes it possible to measure the characteristics of the power supply line simulating a state in which noise generated by the LSI is mixed in the power supply line of the circuit board via the power supply pin of the LSI.
[Third Embodiment]
Next, the third embodiment will be described with reference to FIG.
[Description of configuration]
FIG. 6 shows an explanatory view of a cross section of the circuit board evaluation package 200 of the present embodiment.

The circuit board evaluation package 200 of the present embodiment corresponds to a case where the LSI to be replaced with the circuit board evaluation package 200 has two power supply systems.

In the substrate 201 of the present embodiment, the power supply layer, which was one layer in the substrate 101 of the first embodiment, becomes two layers, a power supply layer 1 and a power supply layer 2.

The power supply pin 121 is connected to the power supply layer 1, and the power supply pin 123 is connected to the power supply layer 2. The power supply pins 121 and 123 are arranged at the same positions as the power supply pins on the bottom surface of the LSI.

The current generator 210 has a current generation source 111 and a current generation source 211, the current generation source 111 is connected to the power supply layer 1 and the ground layer, and the current generation source 211 is connected to the power supply layer 2 and the ground layer.

Then, the current generation source 111 is connected to the control signal input terminal 112, and the current generation source 211 is connected to the control signal input terminal 212.

Further, the power supply measuring terminal 113 is connected to the power supply pin 121 and the grounding pin 122, and the power supply measuring terminal 213 is connected to the power supply supply pin 123 and the grounding pin 122.

Since the functions of the above components are the same as the functions of the components of the circuit board evaluation package 100 of the second embodiment, detailed description thereof will be omitted.
[Explanation of operation]
Next, the operation of the circuit board evaluation package 200 of this embodiment will be described with reference to FIG.

Similar to the second embodiment, the circuit board evaluation package 200 is mounted on the LSI socket of the motherboard, and the power of the motherboard is turned on.

Next, a control signal is added to the control signal input terminal 112 so that the current generation source 111 outputs an AC load current whose current fluctuation amount is ΔI and whose frequency is f.

Then, the voltage fluctuation amount ΔV that is output to the power supply measurement terminal 213 and fluctuates with the frequency f is measured by an external measuring instrument connected to the power supply measurement terminal 213.

At this time, the transfer impedance Zt of the power supply system from the power supply pin 121 of the motherboard to the power supply pin 123 at the frequency f can be obtained by Zt = ΔV / ΔI.

The frequency characteristic of the transfer impedance is obtained by measuring the voltage fluctuation amount ΔV by changing the frequency f and displaying the impedance Zt of each frequency in a graph, assuming that the AC current fluctuation amount ΔI generated by the current generation source 111 is constant. Will be.

Similar to the description of the operation of the second embodiment, when the peak frequency of the transmission impedance exists, by arranging the capacitor on the motherboard, it is possible to take measures against noise caused by a plurality of power supply systems.

As described above, the circuit board evaluation package 200 of the present embodiment can measure the transfer impedance between the power supply pins of an LSI having a plurality of power supply systems.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be extended or modified as follows.

Even when the LSI power supply system has three or more systems, it is possible to obtain the transfer impedance characteristics between each power supply by adding a power supply pin and adding a current generation source as in the third embodiment. be.

10 Circuit board evaluation package 11 Current generation source 12 Control signal input terminal 13 Power supply measurement terminal 20 Connection pin 21 Power supply pin 22 Grounding pin 100 Circuit board evaluation package 101 Board 110 Current generator 111 Current generation source 112 Control signal input Terminal 113 Power supply measurement terminal 120 Connection pin 121 Power supply pin 122 Grounding pin 123 Power supply pin 130 Motherboard
130 Motherboard 131 Power connector 132 Peripheral chipset 133 Memory slot 134 Expansion slot 200 Circuit board evaluation package 201 Board 210 Current generator 211 Current source 212 Control signal input terminal 213 Power measurement terminal

Claims (6)

A circuit board evaluation package having a plurality of connection pins arranged in the same manner as the connection pins of the integrated circuit package mounted on the circuit board is available.
A current source connected between at least one power supply pin in the same arrangement as the power supply pin of the integrated circuit and at least one grounding pin in the same arrangement as the grounding pin of the integrated circuit.
Being connected to said current source, and the frequency of the alternating load current the current source is output, a control signal input terminal to which a signal for controlling the current variation amount of the current source is input,
The connected power supply pin and the ground pin, the circuit package board evaluation, characterized in that it comprises a power supply and measuring terminal you output load current of the controlled alternating current by a signal the control. There are a plurality of power supply pins, different current generation sources are connected between the power supply pins and the grounding pin, and one control signal input terminal is provided for each of the different current generation sources. The circuit board evaluation package according to claim 1, wherein the package is connected. The circuit board evaluation package according to claim 1 or 2, wherein the power supply of the circuit board is energized. In a circuit board evaluation method using a circuit board evaluation package having a plurality of connection pins arranged in the same manner as the connection pins of the integrated circuit package mounted on the circuit board.
By the control signal applied to the control signal input terminal of the circuit board evaluation package, between at least one power supply pin having the same arrangement as the power supply pin of the integrated circuit and at least one grounding pin having the same arrangement as the grounding pin of the integrated circuit. By controlling the frequency of the AC load current output by the current generation source in the circuit board evaluation package connected to the circuit board and the amount of current fluctuation of the current generation source,
A circuit board evaluation method , wherein an external measuring instrument further measures a voltage fluctuation amount between the power supply pin and the ground pin. The circuit board according to claim 4, wherein the power supply pin is a plurality of pieces, and the currents of different current generation sources connected between the power supply pin and the grounding pin are individually controlled. Evaluation method. The circuit board evaluation method according to claim 4 or 5, wherein the power supply of the circuit board is energized.

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