JP2003014824A - Magnetic field measuring method and magnetic field measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it was hitherto difficult to with high accuracy and efficiently a magnetic field caused by an electronic circuit in a semiconductor package. SOLUTION: In a method for measuring a magnetic field, a magnetic field value of an integrated circuit having a plurality of energization lines inside an integrated circuit package is measured. The method comprises the steps of: measuring a first induced voltage which is caused in an electromagnetic field of the energization line and contains a first electric field induced voltage; measuring a second induced voltage which is caused in the electromagnetic field of the energization line and contains a second electric field voltage which is substantially equal to the first electric field induced voltage; and determining (measuring) components of the magnetic field based on a difference between the first induced voltage and the second induced voltage.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates generally to the field of electromagnetic wave measurement, and more particularly to techniques for measuring the magnetic field of ICs inside IC packages, including integrated circuits (ICs) without IC packages. More specifically,
It relates to that of an IC with a density approximately equal to or greater than the current large scale integrated circuit (LSI).

[0002]

2. Description of the Related Art FIG. 1 shows an integrated circuit (IC) such as L.
An example of a magnetic field distribution 114 of a package 110 having an SI or an ultra large scale integrated circuit (ULSI) is shown. In FIG. 1, the package 110 is an IC inside the package.
Cutaway cross section 1 with the surface layer cut off
It is shown in the form with twelve. Conventional package 11
A magnetic probe or sensor 116 is used to measure the magnetic field distribution 114 outside 0, through which the induced voltage is measured. In other words, usually IC
Is performed outside the IC package. The induced voltage is generated by the current in the integrated circuit and is used to measure the magnetic field at a location of the magnetic probe or sensor 116.

Measuring the magnetic field distribution of the package 110 1
One reason is the solution of electromagnetic interference (EMI) problems that can be caused by current in the IC. In order to reduce EMI, it is necessary to pinpoint the interference source with high accuracy. An example thereof is disclosed in Japanese Patent Application Laid-Open No. 2000-304790, "Electromagnetic wave generation source exploration apparatus, method thereof, and analysis method thereof". However, as the circuit size becomes smaller, for example, today's LSI has 0.1
Although manufactured by the μm process, it has become necessary to perform magnetic field measurements in the circuit wiring, for example, in close proximity to the cross-section 112 inside the package 110, to accurately identify potential sources of interference.

In addition to the above, measuring the magnetic field distribution inside the IC package 110 leads to the manufacture of low noise integrated circuits. The position on the IC showing a relatively strong magnetic field strength is
It means a relatively high noise generation point. Examples of some conventional techniques for suppressing the magnetic field at this location include modifying the wiring pattern for noise reduction.

Japanese Unexamined Patent Application Publication No. 2000-206163, "Method and apparatus for measuring electromagnetic field strength and method and apparatus for measuring current-voltage distribution" describes, for example, a loop antenna as a probe for measuring a magnetic field above a circuit board. Discloses the use. Other examples shown include several centimeters of lead wires, microstrip lines (or planar transmission lines), units of components on board, and circuit boards of electrical devices. The loop probe is used for measurements close to a distance of 2 mm from the device under test. The usage thus disclosed is intended to improve the measurement of the magnetic field above the device, eg above the unit on the board, and not to the inside of the IC package.

In the above-mentioned Japanese Patent Laid-Open No. 2000-206163, an electric field coupling current and a magnetic field coupling current are generated in the loop antenna above the circuit board by the electromagnetic field of the circuit board. Focusing on the output of the electric field coupling current and the magnetic field coupling current in the probe, they are directed in the same direction at a specific part of the loop probe, but opposite to each other at another part of the loop probe. . The first combined current, the field coupled current and magnetic field, measured at one end of the loop probe by the current measuring device is the sum of the field coupled current and the field coupled current. A second combined current measured with the same current measuring device at the same end of the loop probe, after rotating the loop probe 180 degrees, results in the difference between the electric field coupling current and the magnetic field coupling current. Therefore, these two composite currents can be used to calculate the electric and magnetic field coupling currents. Also, the electric field component and magnetic field component of the electromagnetic field in the loop probe can be derived from these composite currents.

[0007]

However, in the measurement of the magnetic field distribution of the IC package, Japanese Patent Laid-Open No. 2000-20 has been proposed.
The use of 6163 only brings about a secondary improvement in the measurement of the distribution of the near field. Thus, while the prior art provides accurate magnetic field measurements, the packaged I
The use of the technique disclosed in Japanese Unexamined Patent Publication No. 2000-206163 for measuring the magnetic field of C does not bring a great advantage over the conventional technique. In addition, Japanese Patent Laid-Open No. 2000-206163 measures the composite current by rotating the probe when using one current measuring device. This rotation requires time, and there is a need for a more efficient method of measurement.

In order to accurately identify the potential noise source in the IC, it is necessary to measure the magnetic field above several tens of micrometers (μm) above the IC wiring inside the IC package, for example, above 30 μm. The cross section 112 shows the inside of the IC package 110. However, IC
In the measurement of the magnetic field inside the package, there is a large coupling capacitance due to the electric field, and the accuracy of the magnetic field probe that measures only the magnetic field deteriorates. Therefore, there is a need for a technique for minimizing the influence of the electric field on the magnetic field probe inside the IC package and improving the measurement accuracy of the magnetic field distribution.

[0009]

The present invention provides a magnetic field measuring method and device for accurately measuring the magnetic field distribution of an integrated circuit inside an IC package including an IC without an IC package. In one embodiment, by using a magnetic probe with a loop of wire parallel to the current for measuring the induced voltage of the horizontal component of the magnetic field, inside the IC package (or, for example, the IC before packaging). At the measurement height of 30 μm, the induced voltage due to only the magnetic field is measured. The induced voltage due to the electric field is removed by using a calculation that includes the difference between the two measurements. The first measurement is made by coupling a voltmeter to the first terminal of the wire loop and coupling the second terminal to ground. Also, the second measurement is performed by reversing the coupling with a crossbar switch, that is, coupling the voltmeter to the second terminal of the wire loop and coupling the first terminal to ground. In this way, only the induced voltage due to the magnetic field remains after the calculation. The magnetic field distribution for an integrated circuit can be measured by scanning in a grid pattern over the IC using the procedure described above.

In another embodiment, a method is provided for measuring a component of a magnetic field of an IC whose height from the IC is equal to the line distance of the IC. The method includes measuring a first induced voltage having a first electric field induced voltage due to an electromagnetic field in a current carrying line. The second induced voltage caused by the electromagnetic field of the energization line is the second induced voltage which is substantially equal to the first electric field induced voltage.
Of the electric field voltage; the magnetic field component is measured based on the difference between the first induced voltage and the second induced voltage.

Another embodiment of the present invention provides a method for measuring a magnetic field for one of a plurality of current lines inside an IC package, such as an LSI or VLSI circuit package. The method includes measuring a first induced voltage due to the electromagnetic field of the current carrying line, wherein the first induced voltage has a first measured voltage proportional to the magnetic field generated by the current carrying line. . Next, the second induced voltage caused by the electromagnetic field of the energization line has a second voltage in which the second induced voltage is substantially equal to the magnitude of the first measured voltage and the sign is reversed. At; the component or part of the magnetic field is measured based on the difference between the first induced voltage and the second induced voltage.

Another embodiment provides a magnetic field probe for measuring the magnetic field distribution of an LSI circuit, wherein the size is equal to the distance between the current-carrying lines of the circuit of the LSI, above the integrated circuit. A measuring probe for measuring an induced voltage generated by an electromagnetic field of an LSI circuit at a height, the measuring probe comprising a first terminal point coupled to a second terminal point by an electronic circuit; said induced voltage And a first end coupled to the measurement probe via the first and second terminal points and a second end coupled to the voltage measurement device and ground. A switch, the first terminal point being coupled to the voltage measuring device when the switch is in the first position. And the second terminal point is coupled to ground and the switch is in the second position, the first terminal point is coupled to ground and the second terminal point is coupled to the voltage measuring device. Equipped with a switch. A magnetic field measuring method for measuring a magnetic field value of an integrated circuit having a plurality of current-carrying lines inside an integrated circuit package, the method being a first induced voltage caused by an electromagnetic field of the current-carrying lines, Measuring the first induced voltage including the induced voltage, and a second electric field caused by an electromagnetic field of the energizing line, the second electric field being substantially equal to the first electric field induced voltage. A step of measuring the second induced voltage including a voltage, and a step of determining (measuring) the component of the magnetic field based on the difference between the first induced voltage and the second induced voltage. is there. Further, a magnetic field measurement method of the described, the first induced voltage and V _P, when the second induction voltage V _N, by performing the calculation of (V P _-V N) / ₂ To measure the magnetic field value. Also,
The magnetic field measuring method described above, wherein the first and second induced voltages generated from the plurality of current-carrying lines are measured at a height that is substantially the same as the distance between the plurality of current-carrying lines. Is. Further, in the magnetic field measuring method described above, the plurality of energization lines include a power supply line. Further, in the magnetic field measuring method described above, the plurality of energization lines include signal lines. Further, in the magnetic field measuring method described above, the first
Is the first root mean square (rms) voltage, and the second foot voltage is the second root mean square voltage. Further, in the magnetic field measuring method described above, the integrated circuit has a transistor density equal to or higher than that of a large scale integrated circuit (LSI) circuit. Also, in a magnetic field distribution measuring method for measuring a magnetic field distribution of an electronic circuit of an LSI inside a large scale integrated circuit (LSI) circuit package, a first end is connected to a ground and a second end is connected to a voltage measuring device. Measuring the first voltage induced in the measuring circuit by the electromagnetic field of the electronic circuit using the measuring circuit described above, the first end being the voltage measuring device and the second end being the second end. Measuring a second voltage induced in the measurement circuit by the electromagnetic field of the electronic circuit using a measurement circuit having a part coupled to ground; the first induced voltage and the second induction. There is the step of calculating the magnetic field induced voltage using the difference between the voltages. Further, in the magnetic field distribution measuring method described above, the measuring circuit is not rotated between the step of measuring the first voltage and the step of measuring the second voltage. In the magnetic field distribution measuring method described above, the electronic circuit has a signal line.
In the magnetic field distribution measuring method described above, the electronic circuit has a power supply line. Further, in the magnetic field distribution measuring method described above, the measurement of the induced voltage from the measuring circuit is performed about 30 micrometers above the electronic circuit. A magnetic field probe system for measuring a magnetic field distribution of an integrated circuit inside the integrated circuit package, which is above the integrated circuit and at a height substantially equal to a distance between current lines of the integrated circuit, Measuring an induced voltage generated by an electromagnetic field of the integrated circuit, and measuring a second voltage by an electronic circuit.
A measurement probe comprising a first terminal point coupled to a second terminal point, a voltage measuring device for measuring said induced voltage, and a first end said measuring via said first and second terminal points. Second bound to the probe
Is coupled to the voltage measuring device and ground and the switch is in the first position, the first terminal point is coupled to the voltage measuring device and the second terminal point is coupled to ground. And a switch in which the first terminal point is coupled to ground and the second terminal point is coupled to the voltage measuring device when the switch is in the second position. Also,
In the magnetic field probe system described above, the switch is a crossbar switch. Further, in the magnetic field probe system described above, the measurement probe has substantially the same dimension as the distance between the current-carrying lines of the integrated circuit. Further, in the magnetic field probe system described above, the measurement probe is about 30 μm.
It is a square probe of 30 μm. In the magnetic field probe system described above, the measurement probe has a loop shape. Further, in the magnetic field probe system described above, the measurement probe is a coil oriented parallel to a current-carrying line of the integrated circuit. Also, in the magnetic field probe system described above, further comprising a positioning grid that determines at least one path for the measurement probe to follow, the measurement probe at each point in the positioning grid. , At least two measurements are performed without rotation. A computer program for measuring a magnetic field value of an integrated circuit inside an integrated circuit package, the measuring circuit having a first end coupled to ground and a second end coupled to a voltage measuring device. And a code for measuring (determining) the first voltage induced in the measuring circuit by the electromagnetic field of the wiring of the integrated circuit, and the first voltage by the switch.
A second voltage induced in the measuring circuit by an electromagnetic field of the wiring of the integrated circuit using a measuring circuit having an end coupled to a voltage measuring device and the second end coupled to ground. And a code for measuring (determining)
And a code for calculating the magnetic field induced voltage by using the difference between the induced voltage of 1 and the second induced voltage.

The above and other embodiments of the present invention will be described in detail with reference to the text and the accompanying drawings.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The following is a description of embodiments of the invention.

FIG. 2 shows a magnetic probe in one embodiment of the invention for obtaining measurements from a circuit. A magnetic field probe is conventionally used above the IC package 110 and is shown as a magnetic field probe 216 in the figure, but its size is 1000 μm.
It is a stand. When the measurement height is on the order of 30 μm and is inside the IC 210, the magnetic field probe 212 having a size on the order of 30 μm is used. In that case, the coupling capacitance or parasitic capacitance shown as the coupling capacitance C213 occurs between the circuit 210 and the probe 212. For illustrative purposes, a “U” shaped active current line 230 is connected to the horizontal plane (circuit 210).
Parallel plane 231), in which circuit lines 230 include integrated circuit 210 within package 110.
2 shows an example of the signal or power supply line. Line 2
30 has an AC or noise voltage source V _S 232, which drives a current “i” 236 through line 230 towards ground 234. The two parallel lines 230 are separated by a distance “d” μm. Magnetic field probe 2 having substantially an induction loop
20 is arranged in parallel with the line 230, and has a horizontal plane 231.
Has a height 242 of “h” μm above. The magnetic field probe 220 has an x direction 22 perpendicular to the line 234.
2 (ie, “x” 224) or in the y-direction 226 parallel to line 230. Current line 23
4 has a magnetic field indicated by H250 and H252. The horizontal component of magnetic field H252 induces a voltage in magnetic field probe 220. The current 236 also produces an electric field represented by the coupling capacitance C214, which also induces a voltage in the magnetic field probe 220. Accurate, or "true," at the position of the magnetic field probe 220
To determine the magnetic field measurement, the voltage due to the coupling capacitance 214 must be removed from the magnetic field calculation.

FIG. 3 shows a curve 310 relating to the required measuring height h314 for a given resolution distance d312. Given resolution distance d31
2 represents the distance between the power lines of the IC, for example. The measurement height h314 is the height from the power supply line to the bottom of the probe 220. Circuit package 1
For conventional measurements with the probe 216 located above the 10 power pins, d = 250 μm (32 in the figure).
2) and h = 375 μm (324 in the figure). In the power line corresponding to line 230 used to test one embodiment of the magnetic field probe 220, d = 20
μm (332 in the figure) and h = 30 μm (334 in the figure)
Met.

FIG. 4 illustrates an inner side 422 of an LSI circuit package and an outer side 41 of an LSI circuit package measured by a magnetic field probe 220 according to one embodiment of the present invention.
6 induced magnetic field 41 due to magnetic field and capacitive coupling
4 in relation to the measured height h412 in mV. The straight line 410 represents the induced voltage 41 generated by the magnetic field on the outer side 416 of the LSI circuit package.
4 and the straight line 420 indicates the induced voltage 414 generated in the inside 422 of the LSI circuit package. The straight line 424 represents the induced voltage 414 generated in the magnetic field probe by capacitive coupling with respect to both the outer side 416 of the LSI circuit package and the inner side 422 of the LSI circuit package.
Is shown. Referring to FIG. 4, for the outer side 416 of the LSI circuit package, the induced voltage (straight line 424) due to the coupling capacitance is the induced voltage (straight line 4) due to the magnetic field.
It can be seen that it is about 1/20 of that of 10). However, in the inner side 422 of the LSI circuit package, the induced voltage (straight line 424) caused by the coupling capacitance is larger than the induced voltage (straight line 420) generated by the magnetic field. Thus, capacitive coupling only causes significant problems in measuring the magnetic field inside the 422 of the LSI circuit package.

FIG. 4 shows the outside 41 of the LSI circuit package.
6 shows that the effect of capacitive coupling is secondary, which is neglected in conventional magnetic field measurement systems. That is, regarding the measurement of the magnetic field distribution of one or a plurality of LSI devices on the circuit board, since a system as disclosed in Japanese Patent Application No. 2000-206163 is used, a significant advantage over the conventional system is obtained. I can't get it at all.

In one embodiment of the present invention, the magnetic field measurement is performed inside the IC, and the height from the IC to the magnetic probe is equal to the distance between the current-carrying lines of the IC inside the IC package. In addition, as an option, the magnetic probe has dimensions (eg length and width) approximately equal to the measured height from the IC. In a simplified example in which d = 20 μm, h = approximately 30 μ
m, and a square probe of about 30 μm × 30 μm is used.

FIG. 5 shows the measured induced voltage versus distance relationship for the example of FIG. 2 enlarged. The cross section of the line 230 in FIG. 2 is the cross section 520 of the line in FIG.
And 522. The x-axis of FIG. 5 is a measurement of distance along the “x” 224 of FIG. The induced voltage 514 measured by the magnetic field probe is represented on the vertical axis in millivolts. 5 shows the probe 220 and the line 2 on the horizontal plane 231 in FIG.
It is a 10 times enlarged model of 30. That is, d = (10 × 2
0) = 200 μm and h = (10 × 30) = 300
μm. Graph 510 shows the theoretical curve for the induced voltage due to the magnetic field only. Two cross sections 520
There is a null between 522 and 522 because a current flows toward the back side of the paper at 522 and a current flows toward the front side of the paper at 520. That is, the cross section 520
At the center plane between and 522, the horizontal components of the magnetic field due to each cross section cancel each other out. However, the measurement of the induced voltage by the magnetic field probe is shown by graph 530. Graph 530 shows the induced voltage due to the electric field as well as the magnetic field.

6-9 illustrate the magnetic field probe 220 of the present invention.
Shows why it works effectively. Although one embodiment of a magnetic field probe is shown here, any magnetic field measurement device that uses the same concept to eliminate the effects of electric fields from induced voltage measurements is also within the scope of the present invention.

FIG. 6 illustrates a magnetic field probe 622 for measuring the induced voltage V _H 632 due to the magnetic field only, in accordance with one embodiment of the present invention. AC (or noise) voltage source _{V S}
The current i616 comes from 612, and this current i616
Is a magnetic field H6 that induces a current 630 in the probe 622.
Have twenty. It should be noted here that the voltage source V _S 612 is a fluctuating voltage, and the bias voltage, if any, is not shown. The induced current 630 passes from the positive side terminal 624 to the negative side terminal 6 in the magnetic field probe 622.
It flows toward 26. Induced voltage due to the magnetic field H620 _is given as V H 632. This voltage V _H is
It can be an average or root mean square (rms) voltage.

FIG. 7 shows the current i6 according to one embodiment of the present invention.
The induced voltage V _C in the magnetic field probe 622 due to only 16 electric fields is shown. The electric field is the coupling capacitance C63.
Modeled by 0, the figure shows two induced currents 63
2 and 636 are shown. The induced current 632 flows from the voltage source V _S 612 through the coupling capacitance _C 630 toward the terminal 624 of the magnetic field probe 622, and the induced voltage V _C
Yields 644. On the other hand, the second induced current 636 flows from the voltage source V _S 612 to the terminal 626 of the magnetic field probe 622 via the coupling capacitance _C 630, and the induced voltage V _C
Yields 640. Induction voltage V _C 644 (or 64)
0) is from terminal 624 (or 626) to ground 6
It can be measured by connecting a voltmeter to 42 (or 638). This voltage V _C 640 becomes equal to the voltage V _C 644 with the opposite sign. The voltage V _C can be a mean or root mean square (rms) voltage.

FIG. 8 shows the induced voltage V _P 810 measured with the magnetic field probe 622 of one embodiment of the present invention. The terminal 624 and the positive terminal, _V P 810 of the terminal 626 is connected to ground, the induced voltage _V H 632 due to the magnetic field H620, the induced voltage _V C 640 due to the coupling capacitance C630 and the induced current 636 plus Equal to the voltage Since there is no induced current 632, there is also no induced voltage V _C 644. That is, V _P = V _H + V _C (Formula 1)

FIG. 9 shows the induced voltage V _N 910 measured with the magnetic field probe 622 of one embodiment of the present invention. V _N 910 with terminal 626 as the positive terminal and terminal 624 connected to ground is equal to the induced voltage V _H 641 due to magnetic field _H 620. Ground 64
With reference to 2, V _H 640 is subtracted from the induced voltage V _C 644 due to coupling capacitance _C 630 and induced current 632. Since there is no induced current 636, there is also no induced voltage V _C 640. That is, V _N = (− V _H ) + V _C (Equation 2) When Equation 2 is subtracted from Equation 1, In other words, to obtain _{V H = (V P -V N} ) / 2 Equation (4).

FIG. 10 shows an example of a magnetic field probe system according to an embodiment of the present invention. The magnetic field probe system includes a coil or loop 1010, a switch 1030, a connection to ground 1032, and a connection to a voltmeter 1034. The switch 1030 is provided, for example, with a voltmeter 1034 connected to a terminal 1040.
Respectively, ground 1032 to terminal 1042 (switch position A), or alternatively, voltmeter 1034 to terminal 1042 and ground 1032
Are respectively connected to terminals 1040 (switch position B) to form a crossbar switch. First, the coil 1010 is used with the crossbar switch 1030 set to position A, for example, and the induced voltage, e.g.
_P , which is measured via voltmeter 1034 and stored in the memory of a computer (not shown). Then, without moving the position of the coil 1010, the crossbar switch 1030 is set to position B (the control is also done by the computer) and the induced voltage, say V _N, is measured again and stored again in the memory of the computer. To do. Therefore, if a simple program is executed by the processor of the computer, V _P
And V _N can be read and V _H can be calculated using Equation 4 above.

FIG. 11 shows another embodiment of the magnetic probe system configuration. The probe 2101 is, for example, an induction coil or loop, with switches 2104A and 21 at each end point.
It is connected to 04B. Switches 2104A and 2
One output of 104B is terminating resistors 2105A and 2105A.
105B and ground, the other outputs are connected together and then to a cable or network 2103. Switch 210
4A and 2104B are controlled by computer 2108 (control lines not shown), which connects switch 2104A to its terminating resistor 2105A and switch 2104B to a cable or network 2103, respectively, or vice versa. I do. Switches 2104A and 2104B are connected via cable or network 2103 to a measuring device 2106, such as a voltmeter or digital scope. Measuring device 210
6 measures the voltage induced in the probe 2101. The measuring device 2106 passes its measurement value to a computer 2108, eg a PC or workstation, where the magnetic field calculation takes place. The system shown in FIG. 11 functions similarly to the system shown in FIG.

FIG. 12 shows the I in one embodiment of the present invention.
C210 (eg, inside 4 of the LSI circuit shown in FIG.
22) for plotting the magnetic field distribution of 1)
Shows an xy grid to guide 050 movement
It Its purpose is similar to the magnetic field distribution 114 in FIG.
It is to obtain the magnetic field distribution,
As shown in FIG. 1, the height h is 1 above the package 110.
Instead of 000 μm, it is on the order of 30 μm. FIG. 12 shows x
The grids for 1052 and y1054 are shown.
In this, the x and y components of the magnetic field H are measured
A magnetic field probe 105 similar to that shown in FIG.
0 (or probe 1050 rotated 90 degrees 105
The movement of 3) is performed. These two components are
Of the magnetic field H in a horizontal plane such as 231 shown in
Represents the mathematical basis of the tor component. Another embodiment
In, any other two independent vectors
And use the grid as the basis and adjust the grid accordingly
It can be modified. First, parallel to line 1066
The probe 1053 shown in the posture
Started from 1068, 1070, 1072, 1074,
It moves along the y component path that continues, etc., but it smells
The probe 1053 has grid lines 1066, 10
It becomes parallel to 70 and 1074. Grid line
On 1068 and 1072, the probe 105
3 does not measure. The measurement is x line 1052 and y line
At the intersection of in 1054, that is, at each grid point
And two measurements of the induced voltage, namely V_POh
And V_NTake in. Also, at each grid point
And the x component vector H of the magnetic field_xWith respect to V_HCalculate
Where the x-component vector of H is V_HProportional to
To do. Then y component H_yProbe 10 for measuring
Rotate 53 by 90 degrees and, for example, probe 1050
In posture, 1056, 1060 (via 1058),
And 1064 (via 1062), and so on.
Move in parallel and along. Also in this case,
Two measurements of induced voltage at each grid point
Value, ie V _PAnd V_NIs taken in and the magnetic field H is generated y
V of the minute vector_HIs calculated, in which y
The minute vector is V_HProportional to. Finally, each
X component vector and y component vector for each lid point
Tor and synthesize the magnetic field at that grid point
Ask. In this way, IC circuits close to the circuit itself
The magnetic field distribution with respect to is measured. These calculations are
Computer is used to image the magnetic field on the display.
It can be plotted in Cull. In another embodiment
First move the probe 1050 along the x-axis and
After that, rotate it 90 degrees (probe 1053) to the y-axis
Move along. In another embodiment, the probe
Move the hub 1050 first along the x-axis 1052 and then
Rotate it by 90 degrees and put it again on the same path on the x-axis 1052.
Move along. In yet another embodiment, a plurality
Of the probe, for example, probe 1050 with x-axis 1
052 and at the same time probe 1053
Is moved along the y-axis 1054.

Referring to FIG. 13, in one embodiment of the present invention, I
Figure 3 shows a simplified flow chart for measuring the magnetic field at grid points above C. These steps or functions can be performed by using software on a computer that has a processor and memory. In step 1080, the magnetic field probe 1050 is moved to position (x, y) according to the pattern given by FIG. 12 above. There, using a voltmeter 1034, V
_P is measured and the result is stored in the memory of the computer (step 1082). Followed by toggling the crossbar switch 1030 under the control of the computer, that is, switching (step 1084), measures the _{V N} by then voltmeter 1034 use, store the result in the memory of the computer (Step 1086 ).
The computer then uses Equation 4 to calculate V _H and places this value on the magnetic field at probe position (x, y), ie, on whichever probe 1050 is shown in FIG. Depending on what is present, it is stored as a voltage induced by the magnetic field in either the x-direction or the y-direction (step 1088). The next step 1090 is optional and returns the crossbar switch 1030 to the switch bag or toggle, i.e., original position. The computer then moves the probe to the next grid position according to the procedure described with reference to Figure 12 and repeats the above process (step 1080). In another embodiment, step 1090 is omitted and step 1080
When the steps from 1 to 1088 are repeated, steps 1082 and 1086 are alternated each time. this is,
For example, in the next iteration, first measure V _N, it is subsequently carried out in order to measure the V _P. Thus, in its also next iteration, the V _P measured first, it continues in the form of measuring the V _N subsequently. Once all of the x and y components of V _H have been calculated, the magnetic field distribution for this grid can be measured as described above.

FIG. 14 is a graph showing the induced voltage 1116 measured by a magnetic field probe (similar to FIG. 10) of one embodiment of the present invention with respect to horizontal distance x1114. The graph shown is for the 10 × (10 ×) magnification model of FIG. 2;
(Not d = 20 μm, h = 30 μm) d = 200 μ
m and h = 300 μm. The magnified model is used only for test simplification, and the results are substantially the same as for a real size magnetic probe. Graph 111
0 indicates the measured value regarding the induced voltage V _P , and the graph 1112 indicates the measured value regarding the induced voltage V _N. These differences, by obtaining i.e. (V P _{-V N),} the result of the graph 1140 is obtained which twice the value obtained by equation 4 above, i.e. the calculation value corresponding to 2 × V _H is there. The two graphs shown here are related to the magnetic field theoretically obtained, and are a graph 1130 in which the theoretical value is plus 10% and a graph 11 in which the theoretical value is minus 10%, respectively.
32. The calculated value (2 × V _H ) 1140 is calculated from these 2
Since it is sandwiched between two theoretical graphs 1130 and 1132, it can be said that the theoretical values of the magnetic field alone are in agreement with a margin of 10%.

In another embodiment of the present invention, a computer program for determining (measuring) the magnetic field distribution of a semiconductor having an electronic circuit, recorded on a computer recording medium, is provided. The computer program includes code for determining (measuring) a first voltage induced in a measuring circuit by an electromagnetic field of the electronic circuit, the measuring circuit determining the first voltage. When used for (measuring), the first end shall be coupled to ground and the second end shall be coupled to the voltage measuring device; and induced in the measuring circuit by the electromagnetic field of the electronic circuit. A code for determining (measuring) a measured second voltage, wherein the measuring circuit, when used to determine (measuring) the second voltage, causes the first end to Coupled to a voltage measuring device and having a second end coupled to ground; and calculating the magnetic field induced voltage using the difference between the first induced voltage and the second induced voltage It includes code for, the magnetic field in the measurement circuit in which shall be proportional to the magnetic field induced voltage.

Yet another embodiment is a computer program for determining (measuring) a magnetic field recorded in a computer recording medium at a position near an integrated circuit. The computer program includes code for making at the location a first measurement of a first induced voltage due to a magnetic field and an electric field; and at the location a second result due to the magnetic field and the electric field. Including code for making a second measurement of the induced voltage of
Therein, the second measurement is such that the first portion of the second induced voltage due to the magnetic field is the same in magnitude as the second portion of the first induced voltage due to the magnetic field. Are opposite in sign, and the second
The third part of the induced voltage is equal to the fourth part of the first induced voltage due to the electric field; and from the first measured value to the second measured value. Code is included for subtracting the value to obtain a result proportional to the magnetic field at the location.

While the above description of functions has been generally described with respect to specific hardware and software, it will be appreciated that the invention has a much broader range of applicability. For example, it is possible to further combine software functions or even divide them vice versa. Similarly, the hardware functions are the same and can be further combined or divided in the opposite way. It is also possible to implement by replacing the software function with hardware, or by implementing a combination of hardware and software. Similarly, hardware functions can be implemented in software or in a combination of hardware and software. Thus, any number of different combinations can be developed depending on the application.

Various modifications and changes of the present invention are possible. Therefore, the portions not specifically described should be construed as being able to be implemented within the scope of the claims attached with the present invention.

[0035]

According to the present invention, it is possible to provide a magnetic field measuring method and a magnetic field measuring apparatus for accurately measuring the magnetic field distribution of an integrated circuit inside an IC package including an IC without an IC package.

[Brief description of drawings]

FIG. 1 shows an example of a magnetic field distribution of a package having an integrated circuit (IC), for example, a large scale integrated circuit (LSI).

FIG. 2 shows a magnetic probe according to one embodiment of the invention for taking measurements from a circuit.

FIG. 3 shows the curve for the measurement height h required for a given resolution distance d.

FIG. 4 shows the induced voltage, which is measured by a magnetic field probe according to an embodiment of the present invention, caused by a magnetic field and capacitive coupling with respect to the inside of the LSI and the outside of the LSI in relation to the measurement height h in mV. ing.

FIG. 5 shows the measured induced voltage versus distance relationship for the example of FIG. 2 enlarged.

FIG. 6 illustrates a magnetic field probe for measuring the induced voltage V _H due to the magnetic field only, according to one embodiment of the present invention.

FIG. 7 shows the induced voltage V _C in a magnetic field probe due only to the electric field of the current, according to one embodiment of the present invention.

FIG. 8 shows an induced voltage V _P measured using a magnetic field probe according to an embodiment of the present invention.

FIG. 9 shows the induced voltage V _N measured using the magnetic field probe of one embodiment of the present invention.

FIG. 10 shows an example of a magnetic field probe according to an embodiment of the present invention.

FIG. 11 illustrates another embodiment of a magnetic probe system configuration.

FIG. 12 illustrates an xy grid that guides the movement of a magnetic field probe to plot the magnetic field distribution of an IC in one embodiment of the invention.

FIG. 13 shows a simplified flow chart for determining the magnetic field of a grid point above an IC in one embodiment of the invention.

FIG. 14 is a graph showing an induced voltage measured by a magnetic field probe according to an embodiment of the present invention with respect to a horizontal distance x.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Nakamura             292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Inside the Hitachi, Ltd. production technology laboratory (72) Inventor Yoshihiko Hayashi             292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Inside the Hitachi, Ltd. production technology laboratory F-term (reference) 2G011 AA01 AC00 AE03                 2G017 AA02 AD01 CB02                 2G132 AA00 AB00 AF16 AL11

Claims (20)

[Claims] 1. A magnetic field measuring method for measuring a magnetic field value of an integrated circuit having a plurality of conducting lines inside an integrated circuit package, comprising: a first induced voltage caused by an electromagnetic field of the conducting line, Measuring the first induced voltage including a first electric field induced voltage, and a second induced voltage caused by an electromagnetic field of the energization line, the first induced voltage being substantially equal to the first electric field induced voltage. Measuring the second induced voltage including two electric field voltages, and determining a component of the magnetic field based on a difference between the first induced voltage and the second induced voltage. Characteristic magnetic field measurement method. 2. A magnetic field measuring method according to claim 1, said first inductive voltage is V _P, the second induced voltage when the _{V N, (V P -V N} ) / A magnetic field measuring method, characterized in that a magnetic field value is measured by performing the calculation of 2. 3. The magnetic field measuring method according to claim 1, wherein the heights of the first and the second conducting lines are substantially the same as the distance between the plurality of conducting lines. 2. A magnetic field measuring method characterized by measuring the induced voltage of 2. 4. The magnetic field measuring method according to claim 3, wherein the plurality of energization lines include a power supply line. 5. The magnetic field measuring method according to claim 3, wherein the plurality of energization lines include signal lines. 6. The magnetic field measuring method according to claim 1, wherein the first induced voltage is a first root mean square (rm).
s) voltage, and the second induced voltage is a second root mean square voltage. 7. The magnetic field measuring method according to claim 1, wherein the integrated circuit has a transistor density equal to or higher than that of a large scale integrated circuit (LSI) circuit. 8. A magnetic field distribution measuring method for measuring a magnetic field distribution of an electronic circuit of an LSI inside a large scale integrated circuit (LSI) circuit package, wherein a first end is grounded and a second end is voltage measured. Measuring a first voltage induced in the measuring circuit by an electromagnetic field of the electronic circuit using a measuring circuit coupled to the device; the first end being connected to the voltage measuring device; A second circuit induced in said measuring circuit by said electromagnetic field of said electronic circuit using a measuring circuit having its two ends coupled to ground
And a step of calculating a magnetic field induced voltage using a difference between the first induced voltage and the second induced voltage. 9. The magnetic field distribution measuring method according to claim 8, wherein the measuring circuit is not rotated between the step of measuring the first voltage and the step of measuring the second voltage. Characteristic magnetic field distribution measurement method. 10. The magnetic field distribution measuring method according to claim 8, wherein the electronic circuit has a signal line. 11. The magnetic field distribution measuring method according to claim 8, wherein the electronic circuit has a power supply line. 12. The magnetic field distribution measuring method according to claim 8, wherein the measurement of the induced voltage from the measuring circuit is performed about 30 μm above the electronic circuit. Measuring method. 13. A magnetic field probe system for measuring a magnetic field distribution of an integrated circuit inside an integrated circuit package, the magnetic field probe system being above the integrated circuit and having a height substantially equal to a distance between current lines of the integrated circuit. Measuring an induced voltage generated by an electromagnetic field of the integrated circuit and measuring the induced voltage, the measuring probe including a first terminal point coupled to a second terminal point by an electronic circuit. A voltage measuring device for coupling a first end to the measuring probe via the first and second terminal points, a second end to the voltage measuring device and ground, and a switch to When in the 1 position, the first terminal point is coupled to the voltage measuring device and the second terminal point is ground. To the first position when the switch is in the second position.
A terminal point of the
A switch coupled to the voltage measuring device at a terminal point thereof. 14. The magnetic field probe system according to claim 13, wherein the switch is a crossbar switch. 15. The magnetic field probe system according to claim 13, wherein the measurement probe has substantially the same dimension as a distance between current lines of the integrated circuit. 16. The magnetic field probe system of claim 13, wherein the measurement probe is about 30 μm × 30.
A magnetic field probe system characterized by being a μm square probe. 17. The magnetic field probe system according to claim 13, wherein the measurement probe has a loop shape. 18. The magnetic field probe system according to claim 13, wherein the measurement probe is a coil oriented parallel to a current-carrying line of the integrated circuit. 19. The magnetic field probe system of claim 13, further comprising: positioning for determining at least one path for the measurement probe to follow.
A magnetic field probe system having a grid, wherein the measurement probe makes at least two measurements at each point in the positioning grid without rotation. 20. A computer program for measuring a magnetic field value of an integrated circuit inside an integrated circuit package, the first end coupled to ground and the second end coupled to a voltage measuring device. A measuring circuit for determining a first voltage induced in the measuring circuit by an electromagnetic field of the wiring of the integrated circuit, and a switch for causing the first end to become a voltage measuring device. A code for determining a second voltage induced in the measurement circuit by an electromagnetic field of wiring of the integrated circuit using the measurement circuit coupled to the second end to ground; A computer program having code for calculating a magnetic field induced voltage using a difference between the first induced voltage and the second induced voltage.