JP3832306B2 - Probe, and multi-probe and electric circuit inspection apparatus using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric circuit inspection apparatus for measuring and inspecting electric characteristics of an electric circuit, and in particular, a probe that is required to measure a plurality of measurement points simultaneously, for example, for inspection of a semiconductor package, and the like. The present invention relates to a multi-probe and an electric circuit inspection apparatus.
[0002]
[Prior art]
Conventionally, for example, in a characteristic test of a semiconductor package, a socket type contact device is most frequently used. FIG. 7 shows an example of a socket type probe.
[0003]
That is, the conventional probe includes, for example, a guide member 94 for guiding the package portion 92 of the semiconductor package 91 and a plurality of leaf springs 95 arranged around the guide member 94 at the same pitch as the lead terminals 93 of the semiconductor package 91. Are fixed by a resin 96.
[0004]
Then, the semiconductor package 91 held by the upper guide 97 by suction is lowered along the guide material 94, so that the semiconductor package 91 is positioned, for example, as shown in FIG. 95 is in contact with each other.
[0005]
At that time, the leaf spring 95 sinks due to the bending, and scrapes off the oxide film adhering to the surface of the lead terminal 93, for example, as shown in FIG.
As described above, each lead terminal 93 of the semiconductor package 91 is reliably brought into contact with each of the plate springs 95 of the probe, whereby the characteristic test of the semiconductor package 91 is performed.
[0006]
[Problems to be solved by the invention]
However, the above-described type of probe has the following problems.
For example, as shown in FIG. 9, for example, as shown in FIG. 9, the contact due to the bending of the leaf spring did not cause a reliable contact by simply scraping off the oxide film adhering to the surface of the lead terminal 93.
In addition, the lead terminals 93 have a large number of pins and a narrow pitch, and accordingly, there are disadvantages such as a complicated probe structure.
[0007]
That is, the increase in the number of pins and the narrow pitch of the lead terminals 93 lead to an increase in the number of leaf springs 95 and a decrease in the pitch between them, and there is a disadvantage that the assembly of the probe is complicated accordingly.
Therefore, there has been a demand for a probe that can achieve reliable contact and can cope with a narrow pitch, a multi-probe using the probe, and an electric circuit inspection apparatus.
[0008]
Furthermore, in the conventional method, it is a linear inspection, and for the surface inspection, the inspection must be performed while moving the inspection device little by little.
Therefore, a probe capable of collectively inspecting measurement points scattered in a planar shape, a multi-probe using the probe, and an electric circuit inspection apparatus have been desired.
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, in the invention described in claim 1, a probe, a signal wiring for extracting an electric signal from the probe, a capacitive element, an inductive element, and a photoelectric conversion element are provided at the end. The probe comprises a substrate and a counter electrode facing the capacitive element and the photoelectric conversion element, and the capacitive element and the inductive element form an antenna.
[0010]
As a result, the oxide film can be easily removed even when the oxide film removal of the electrode to be inspected by conventional bending is insufficient.
[0011]
According to a second aspect of the present invention, there is provided a multi-probe characterized in that the probe according to the first aspect is formed in a matrix.
[0012]
Thereby, since it is a simple structure, it came to be able to respond to the inspection of a narrow pitch.
[0013]
According to a third aspect of the present invention, the probe according to the first aspect is formed in a matrix, the multi-probe according to the second aspect, means for supplying electromagnetic waves to the antennas of all the probes, and photoelectric conversion elements of the probes are selected. In particular, the present invention provides an electric circuit inspection apparatus characterized by comprising means for irradiating light and inspection means for inspecting an electric circuit with a signal obtained by a probe.
[0014]
As a result, it has become possible to reliably remove the oxide film from the electrode to be inspected.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The probe of the present invention includes a substrate, a signal wiring, a capacitive element, an inductive element, a photoelectric conversion element, and a counter electrode, and the substrate is supported by a rotatable support member.
Various members such as a plate-like member and a rod-like member are conceivable. The signal wiring is preferably formed into a circuit in the inspection apparatus through this support member.
In order to easily tilt the substrate, a cylindrical shape is preferable, and it is preferable to form the substrate separately from the substrate.
However, in some cases, it is preferable to manufacture in common with the substrate, and a plate shape is preferable because it is easy to manufacture and it is easy to limit the bending direction only to the vertical direction.
[0016]
Since the substrate is a probe and a capacitive element, an inductive element, or a photoelectric conversion element attached to or formed on the substrate, it is easier to form a capacitive element, an inductive element, or a photoelectric conversion element with a semiconductor material. , It may not be preferable.
In the case of a semiconductor material, electrical conduction occurs between the elements. Therefore, in order to electrically separate the probe side and the counter electrode side in order to prevent electrical influence between them, an insulating layer is provided between them. It is practical to provide.
[0017]
For example, a flexible silicon wafer that can be finely processed.
The substrate is supported on a straight line at the center by the support member. Therefore, the substrate is divided on both sides by the support member, and a probe is provided at one end of the substrate.
An inductive element is provided in a region other than the probe on the surface of the probe on the side where the probe is present.
[0018]
For example, two silicon wafers sandwiched between insulating films represented by Mylar and Kapton are formed by patterning, and inductive elements, capacitive elements, and photoelectric conversion elements are formed on the surface by, for example, photolithography. Form with.
[0019]
The probe may have a structure just used for measurement, but it needs to have a function to scrape off the surface that can interfere with measurement, such as an oxide film. However, it is preferable because the lifetime that can be used is extended.
The shape with a blunt tip is preferable for the service life only, but it is preferable that the tip is sharp when considering scraping performance, and this may be appropriately selected depending on the application.
[0020]
The capacitive element and the photoelectric conversion element are preferably opposed to the counter electrode. However, the capacitive element and the photoelectric conversion element cannot be opposed to each other at the same time. In some cases, it may be formed on a surface that does not face the electrode.
[0021]
The counter electrode is provided on some fixed support member, and these elements and the counter electrode are opposed to each other with a constant interval when no electrical force is applied.
These elements may have almost the same area, but there are cases where reception or light reception may be hindered only at the opposite location, so that not only facing the counter electrode but also taking into account the reception or light reception area In many cases, the area is preferable.
[0022]
By forming in this way, the capacitive element and the photoelectric conversion element can draw the counter electrode and the Coulomb force to attract each other, or change the angle of the substrate by making contact, so that either side can be closer to or away from the electric circuit. .
Thereby, the probe can be brought into contact with or away from the electric circuit.
This is made possible by the bending of the support portion of the substrate.
[0023]
The probe material must be conductive and have some rigidity. Accordingly, copper, copper alloy, silver alloy, aluminum alloy and the like can be appropriately selected depending on the application.
The joining of the probe needs to be highly accurate in alignment, but can be made by methods such as electroforming and annealing.
[0024]
The counter electrode is provided on a support member different from the substrate, but is formed at a position and size at which the Coulomb force with respect to the capacitor element and the photoelectric conversion element is increased.
[0025]
The multi-probe of the present invention is such that such probes are arranged in a matrix. In this case, it is not necessary to provide the same number of counter electrodes as the probe, and a common electrode can be used as long as it defines the ground potential.
[0026]
In this case, since many multiprobes are produced at a narrow pitch, it is easier to produce a plate-like shape by means such as pressing, etching, or electrodeposition.
Including the multi case, any method such as conductive printing or pattern etching may be used as the method of providing electrodes and wirings on the probe.
[0027]
The control means includes at least a vibration mode, a measurement mode, and a stop mode. Of course, other modes such as a test mode may be realized.
[0028]
In the vibration mode, the substrate is moved away from the support member, that is, the vibration is applied in a state where the electric circuit and the probe are in contact with each other, and is performed prior to the measurement mode.
[0029]
Therefore, it irradiates an electromagnetic wave having a frequency of 1 kHz which is the same as the resonance frequency of the LC circuit of the probe provided on the entire surface. Vibrate.
Note that the stop mode may or may not be included between the vibration mode and the vibration mode. However, even if the electromagnetic wave transmission is stopped in the vibration mode, the vibration does not completely disappear, but the resonance is attenuated and the vibration is settled, so that the mode is automatically shifted to another mode.
[0030]
In the measurement mode, the substrate is moved away from the support member, that is, fixed in a state where the electric circuit and the probe are in contact with each other.
Accordingly, only the photoelectric conversion element of the probe that needs to be measured is selectively or simultaneously irradiated, and the irradiated probe is maintained for a half-life of 0.5 seconds or more, and the probe comes into contact.
In the stop mode, the support portion is fixed without being bent.
[0031]
The inspection means is performed based on a signal from the signal wiring drawn from the probe. The signal processing is inspected by measuring the resistance value between two target points or between the target point and the ground.
[0032]
The means for supplying electromagnetic waves is provided on the back surface of the probe, particularly farther than the counter electrode, and may be any means as long as it can irradiate the entire surface with electromagnetic waves of 100 Hz to 100 kHz for 5 W or more.
[0033]
The means for irradiating light is provided on the back surface of the probe, particularly farther than the counter electrode, and may be any means as long as it can irradiate the entire surface.
[0034]
【Example】
Example 1
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of an embodiment of the present invention, FIG. 2 is a plan view of a substrate of the same embodiment, and FIG. 4 is a conceptual block diagram of the same embodiment.
[0035]
The substrate 11 is supported by two support members 16 joined at the center of the opposite sides, and the support member 16 divides the substrate region into two sides of approximately the same size.
A probe 12 is provided at the end of one side of the substrate 11. A signal wiring 17 for extracting an electric signal from the probe 12 is drawn out as a wiring to the outside via the support member 16.
[0036]
An inductive element 13 is provided in a region on the same surface as the probe except for the probe on the same side as the probe.
The inductive element 13 is formed with a minimum interval so that electrical contact with the probe 12 and its signal wiring 17 does not occur.
[0037]
In addition, a capacitive element 14 is provided in a region on the same surface as the probe except for the probe on the side opposite to the probe.
The capacitive element 14 and the inductive element 13 are wired to form an LC resonance circuit, thereby simultaneously serving as an antenna.
[0038]
A photoelectric conversion element 15 is provided on the entire surface opposite to the probe.
A counter electrode 18 supported by the base material 19 is provided so as to face a portion of the surface opposite to the probe on the side opposite to the probe.
This is actually arranged in a 32 × 32 matrix.
[0039]
The substrate is composed of an insulating film, an element silicon wafer sandwiching the insulating film, and a strength maintaining silicon wafer.
Oxide films were formed on the front and back surfaces of a silicon wafer for devices (manufactured by Mitsubishi Materials Corporation).
[0040]
Next, a resist was formed on the surface, and pattern exposure was performed using a photomask.
This photomask pattern is a pattern of the connecting pin base portion of the support member, the pads, and their connection wiring forming portions.
[0041]
Next, development was performed to remove the unexposed portion, and then the entire surface was subjected to vapor deposition treatment with copper, and the resist was removed to remove the copper formed on the resist and patterning was performed.
[0042]
As a result, the copper layer remained only in the pattern of the connecting pin base portion of the support member, the pad, and the connection wiring forming portion thereof.
Further, a resist was formed on the wafer surface, and pattern exposure was performed using a photomask.
This photomask pattern is a pattern that forms an antenna which is an LC resonance circuit by wiring the connecting pin portion of the support member, the capacitive element pattern, the inductive element pattern, and these.
[0043]
Next, develop and remove the unexposed parts, then perform electroforming with copper on the entire surface using copper and remove the resist to remove the chromium formed on the resist, and patterning Went.
Further, a backing agent was formed on the back surface of the wafer to form a photoelectric conversion element (light receiving element).
[0044]
Thereafter, a resist was formed on the back surface of the wafer, and pattern exposure was performed using a photomask.
This photomask pattern is a pattern for forming photoelectric conversion element electrodes, pads, and wirings thereof.
[0045]
Next, development was performed to remove the unexposed portion, and then the entire back surface was subjected to vapor deposition treatment with copper, and the resist was removed to remove the copper formed on the upper portion of the resist, followed by patterning.
[0046]
Finally, a resist was formed on the wafer surface, and pattern exposure was performed using a photomask.
This photomask pattern is a substrate external pattern.
[0047]
Next, development was performed, unexposed portions were removed, then dry etching was performed, and the resist was removed to prepare a device silicon wafer.
[0048]
Next, an oxide film was formed on both the front and back surfaces of a strength maintaining silicon wafer (film thickness: 1.5 mm).
[0049]
Next, a resist was formed on the surface, and pattern exposure was performed using a photomask.
This photomask pattern is a pattern of a probe region, a pad, and a connection wiring formation portion thereof.
[0050]
Next, development was performed to remove the unexposed portion, and then the entire surface was subjected to vapor deposition treatment with copper, and the resist was removed to remove the copper formed on the resist and patterning was performed.
As a result, the copper layer remained only in the pattern of the probe region, the pad, and the connection wiring formation portion thereof.
[0051]
Finally, the element silicon wafer and the back surface of the strength maintaining silicon wafer were thermocompression bonded with an insulating film (material mylar, film thickness 150 μm) sandwiched therebetween to form a substrate.
[0052]
After the probe is provided on the substrate thus formed, wiring between both silicon wafers is performed.
Further, the support member is fixed to the support member connecting pin base of the substrate, and the pin is fixed to the substrate.
Next, the counter electrode 18 is uniformly formed on the base material 19.
[0053]
The base material 19 is provided at a position corresponding to the portion of the substrate 11 where the probe 12 is not provided, and is provided only at the outside, and of course, a position corresponding to the portion of the substrate 11 where the probe 12 is provided. Is a void.
[0054]
Furthermore, a broadband high-frequency antenna 71 is provided on the back surface of the substrate 19 as means for supplying electromagnetic waves to the antennas of all probes.
[0055]
Separately, an optical system for selecting individual probes and irradiating light is provided on the back surface of the base material 19, which includes a light source 73 and a mirror device 72. The light source 73 is irradiated with light rays horizontally from outside the multi-probe range, and can be irradiated after the individual probes are aligned by the mirror device 72.
[0056]
A broadband high-frequency antenna 71 is provided as means for supplying electromagnetic waves to the antenna.
As a result, when 100 V was applied to both the counter electrodes 13 and 14 and the counter electrode 18 to obtain a steady state, the electrodes repelled as a result, and the substrate 11 repelled at the probe 12 portion.
[0057]
When the broadband high-frequency antenna 71 outputs the maximum output, the substrate tilts and swings. As a result, the oxide film on the surface of the electric circuit can be removed.
Further, when a light beam is emitted from the light source 73 at the maximum output, the direction of the light beam is changed by the mirror device 72, the focal point is aligned, and the probe on the multi-probe 31 is irradiated, the probe continues to contact from the irradiation. It was.
[0058]
The control means includes a measurement front-end controller 21, a personal computer 22, a controller 23, and a measurement jig 24.
The measurement jig 24 is fixed at a position where the probe 12 comes into contact when the inspection object 43 is placed and fixed, and also performs an operation of providing a predetermined potential to the inspection object 43.
[0059]
FIG. 4 is a block diagram of the present invention for explaining the details of the front-end controller 21. Reference numeral 31 denotes a multi-probe, and reference numeral 42 denotes a mirror device actuator 75 that controls the position of the mirror device 73 so as to sequentially scan the probe. Reference numeral 82 denotes a switching circuit that emits a light beam from the light source 72 when it comes to the probe. An irradiation control circuit 50 controls the irradiation by controlling the switching circuit 82 and the scanning circuit 42.
[0060]
On the other hand, 83 is a switching circuit that controls switching of the broadband high-frequency antenna 71. A mode circuit 81 for controlling the mode by controlling the switching circuit 82 and the switching circuit 83 is provided.
Further, 43 is an object to be inspected, 44 is an actuator for correcting the inclination of the object to be inspected so that each probe of the multi-probe is in contact with the object to be inspected 34, and 45 is an inclination correction control circuit. Reference numeral 46 denotes a structure that supports these members.
[0061]
The position control circuit 49 controls the overall position control by supervising the irradiation control circuit 50, the mode circuit 81, and the inclination correction circuit 45. This position control is performed based on the position information and operation information of the probe control circuit 47.
The measurement front-end controller 21 includes a probe control circuit 47, a decoder encoder 48, a position control circuit 49, an irradiation drive circuit 50, a mode circuit 81, and an inclination correction circuit 45.
[0062]
First, a signal emitted from the personal computer 22 in the vibration mode is encoded by the decoder encoder 48, transferred to the probe control circuit 47, and a control signal is output to the mode circuit 81. The mode circuit 81 includes the switching circuit 82. A control signal is output to the switching circuit 83 and a control signal is output to the switching circuit 83.
[0063]
The switching circuit 82 outputs a control signal to the light source 72, and the switching circuit 83 outputs a control signal to the broadband high frequency antenna 71.
[0064]
As a result, an electromagnetic wave is emitted from the broadband high-frequency antenna 71 and received by the antenna composed of the LC circuit, and the substrate 11 swings as the charge of the capacitor circuit 14 fluctuates.
On the other hand, the position control circuit 49 outputs a signal to the inclination correction circuit 45 and causes a current to flow to the measurement jig 44.
The multi-probe 31 is driven by vibrating and vibrates while contacting the object to be inspected.
[0065]
Next, the signal emitted from the personal computer 22 in the measurement mode is encoded by the decoder encoder 48, transferred to the probe control circuit 47, and a control signal is output to the position control circuit 49. The position control circuit 49 The irradiation drive circuit 50 outputs a control signal to the scanning circuit 42 and simultaneously outputs a control signal to the switching circuit 82.
[0066]
The scanning circuit 42 performs the multi-probe controller 75 with reference to a scanning clock 51 described later.
[0067]
On the other hand, the position control circuit 49 performs the multi-probe controller 75 with reference to a scanning clock 51 described later. In that case, a signal is output to the inclination correction circuit 45 and a current is passed through the measurement jig 44.
In such a state, the multi-probe 31 is driven to contact the object to be inspected.
[0068]
Even if the probe-medium distance control is not successful, for example, when the probe is tilted, a signal is generated from the personal computer 22 based on the inspection result, and is encoded by the decoder encoder 48, and the probe control circuit. 47 and multi-probe tilt control is performed in the same manner as described above.
[0069]
In FIG. 6, the detailed block block diagram of the measurement part 25 is shown.
[0070]
The timing for accessing each probe is based on a scanning clock 51 that is shared with the scanning circuit 42.
This scanning clock is used as a multi-probe clock signal CLK_Y, and further input to the Y address counter 52.
The Y address counter 52 has the same number of counts as the number of stages of the multi-probe Y shift register.
The carry output of the Y address counter 52 is a multi-probe clock signal CLK_X and is further input to the X address counter 53.
The X address counter 53 has the same number of counts as the number of stages of the multi-probe X shift register.
The count output of these X and Y address counters is set as a probe address 54.
[0071]
A read output Vout from the multi-probe is input to the comparator 55. The comparator 55 binarizes using Vref 56 as a reference voltage.
This binarized output is written in the recording unit of the probe control table 57 specified by the probe address 54.
[0072]
The measurement tables 57 to 59 have 1 to several pages, where one page is a temporary storage memory composed of the same number of recording units as the number of probes of the multi-probe.
Each recording unit records at least six logical values such as a driving state value indicating each operation of reading, ON writing, OFF writing, or erasing, in addition to the recording data logical value read from the multi-probe.
[0073]
When accessing the multi-probe, φr (read signal), φd (erase signal), and φw (write signal) are generated so as to control the corresponding probe according to the driving state of each unit of the measurement table.
[0074]
When transferring data from a multi-probe, the probe is first scanned to a predetermined position on the recording medium.
Next, the data of the measurement tables 57 to 59 is read by the personal computer 22 via the data bus and the address bus 60 to the recording unit corresponding to the address of the probe to be read, and processed by the personal computer 22, thereby Inspect for pass / fail.
[0075]
Finally, the signal emitted from the personal computer 22 in the stop mode is encoded by the decoder encoder 48, transferred to the probe control circuit 47, and a control signal is output to the position control circuit 49. The position control circuit 49 A control signal is output to the mode circuit 81, a control signal is output to the switching circuit 82, and a control signal is output to the switching circuit 83.
In this case, the switching circuit 82 stops the light source, and the switching circuit 83 stops the transmission of the broadband high-frequency antenna 71.
[0076]
As a result, the terminal having an oxide film on the surface could be subjected to an accurate inspection of electrical characteristics because only the inspection portion of the oxide film was removed immediately before the inspection.
【The invention's effect】
As described above, it is possible to provide a probe that can reliably contact an oxide film or the like on the surface, can cope with a narrow pitch, and can inspect a flat surface at once, and a multi-probe and an electric circuit inspection apparatus using the probe. It was.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a multi-probe according to an embodiment of the present invention.
FIG. 2 is a conceptual bottom view of a substrate in the embodiment of FIG.
3 is a conceptual perspective view of the multi-probe at the time of light beam irradiation in the embodiment of FIG. 1;
4 is a conceptual block diagram of the embodiment of FIG.
5 is a block configuration diagram for explaining details of a front-end controller in the embodiment of FIG. 4; FIG.
6 is a block diagram for explaining details of a measurement unit in the embodiment of FIG. 5; FIG.
FIG. 7 is a side sectional view of a contact device shown for explaining the prior art and its problems.
8 is a conceptual diagram for explaining the electrical connection between the lead terminal of the semiconductor package and the leaf spring of the contact device in the contact device of FIG. 7;
FIG. 9 is a conceptual diagram for explaining the electrical connection between the lead terminal of the semiconductor package and the leaf spring of the contact device, similar to FIG. 8;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Board | substrate 12 ... Probe 13, 14 ... Counter electrode 15, 16 ... Support part 17 ... Wiring area | region 18 ... Counter electrode 19 ... Base material 20 ... Gap part 21 ... Front end controller 22 ... Personal computer 23 ... Controller 24 ... For measurement Jig 25 ... Measuring unit 26 ... Piezoelectric element 31 ... Probe 42 ... Scanning circuit 45 ... Inclination correction circuit 47 ... Probe control circuit 48 ... Decoder encoder 49 ... Position control circuit 50 ... Irradiation drive circuits 57-59 ... Measurement table 71 ... broadband high frequency antenna 72 ... mirror device 73 ... light source 74 ... light beam 75 ... mirror device controller 81 ... mode circuit 82, 83 ... switching circuit 91 ... semiconductor package 92 ... package part 93 ... lead terminal 94 ... guide material 95 ... leaf spring

Claims (3)

Consists of a probe at the end, a signal wiring for extracting an electrical signal from the probe, a substrate provided with a capacitive element, an inductive element, and a photoelectric conversion element, and a counter electrode facing the capacitive element and the photoelectric conversion element A probe characterized in that a capacitive element and an inductive element form an antenna. A multi-probe characterized in that the probe according to claim 1 is formed in a matrix. The multi-probe according to claim 2, wherein the probe according to claim 1 is formed in a matrix, means for supplying electromagnetic waves to the antennas of all probes, means for selectively irradiating light to the photoelectric conversion elements of the probes, An electric circuit inspection apparatus comprising an inspection means for inspecting an electric circuit with a signal obtained by a probe.

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