JP2010181251A - Semiconductor test device - Google Patents

Abstract

In a semiconductor test apparatus configured to be able to contact and separate between a test head and a probe card, or between a relay member that relays them, a complete non-contact type signal transmission using light is performed. An object of the present invention is to test a semiconductor device at high speed and stably.
A semiconductor test apparatus comprising a probe card (5) having a probe needle (8) that contacts a semiconductor wafer (W) and a test head (2) provided so as to be able to contact and separate from the probe card (5). In order to perform signal transmission by optical space transmission between the head 2 and the performance board 3, optical transmission units 11, 14, 15, 18 and light receiving units 12, 13, 16, 17 are provided. .
[Selection] Figure 1

Description

  The present invention relates to a semiconductor test apparatus for testing a device under test, and more particularly to a semiconductor test apparatus including a test head and a probe card.

  2. Description of the Related Art Conventionally, a semiconductor testing apparatus has been used in which a probe test is performed by bringing a probe needle into contact with a semiconductor wafer on which many semiconductor devices such as an IC chip, an LSI chip, a memory, and a CMOS image sensor are formed. This semiconductor test apparatus will be described with reference to FIG. The semiconductor test apparatus shown in FIG. 5 includes a prober 101, a test head 102, a performance board 103, a contact ring 104, and a probe card 105.

  The prober 101 is provided with the semiconductor wafer W inside a casing, and the semiconductor wafer W is fixed and supported by an inspection stage 106 by an arbitrary suction means or the like. Below the inspection stage 106 is an elevating mechanism 106Z that can be moved up and down in the Z-axis direction, a rotating mechanism 106θ that can be adjusted in the rotating direction, a Y-axis moving mechanism 106Y that can move in the Y-axis direction, and an X-axis that can move in the X-axis direction. A moving mechanism 106X is provided, and the position of the inspection stage 106 can be adjusted in the X, Y, θ, and Z directions by these mechanisms. Although not shown, a camera or the like is provided on the prober 101 or outside thereof, and alignment is performed so that the probe card 105 and the inspection stage 106 are strictly aligned.

  The test head 102 is a test unit that tests the electrical characteristics of the semiconductor wafer W, and is equipped with a plurality of measurement modules 107. The measurement module 107 is a so-called pin electronics card, and generates a test signal to be applied to the semiconductor wafer W, determines whether the test signal output from the semiconductor wafer W is good or bad, and the like. FIG. 5 shows one measurement module 107, but actually, a plurality of measurement modules 107 are connected to the test head 102.

  The performance board 103 and the contact ring 104 serve as relay members for relaying between the prober 101 and the test head 102. The performance board 103 is provided on the test head 102 side, and the contact ring 104 is provided on the prober 101 side. It has been. The performance board 103 is a board provided with various circuits necessary for the test, and can be connected to both the test head 102 and the contact ring 104. The contact ring 104 is a ring-shaped member that relays between the performance board 103 and the probe card 105. The probe card 105 is a card having a plurality of probe needles 108 that come into contact with the semiconductor wafer W.

  Between the test head 102 and the performance board 103, between the performance board 103 and the contact ring 104, and between the contact ring 104 and the probe card 105 are configured to be detachable (detachable). Electrical connection is made by pogo pins. The test head 102 is provided with a large number of pogo pins 110, and the pogo pins 110 come into contact with one surface of the performance board 103 and are connected to each other. Also, a large number of elastically extendable pogo pins 111 and 112 are provided on both the front and back surfaces of the contact ring 104. One side is connected to the performance board 103 and the other side is connected to the probe card 105.

  In addition, the technique which comprised each part so that contact / separation was possible with a pogo pin like FIG. 5 is disclosed by patent document 1. FIG.

JP 2005-276916 A

  In the method of FIG. 5 and the method of Patent Document 1, each part is electrically connected using pogo pins, and is configured so as to be able to contact and separate. In addition to pogo pins, some parts are electrically connected using the ZIF (Zero Insertion Force Socket) method, but these pogo pins and ZIF must be in physical contact with pins and sockets. Thus, signal transmission is performed.

  In recent years, semiconductor devices have been trending toward higher performance. For example, a CMOS image sensor as a semiconductor device has a large number of pixel signals, and pixel signals are output as high-speed serial data when testing a CMOS image sensor. Is done. At this time, since the pogo pin cannot perform high-speed signal transmission, the pixel signal output from the CMOS image sensor is converted into low-speed parallel data, and then signal transmission is performed via the pogo pin. For this reason, since both the pin electronics card to be tested and the CMOS image sensor to be tested can operate at high speed, signal transmission is performed via pogo pins, so the performance of pogo pins The test speed is slowed by being dragged by.

  In this respect, it is conceivable to increase the number of pogo pins and simultaneously transmit a large number of signals, so that it can be operated at high speed, but the hardware becomes extremely complicated and large. In particular, with the recent improvement in performance of semiconductor devices, a drastic improvement in test speed is required, and a large number of tests must be performed at one time, so that the number of pogo pins to be increased becomes enormous. In this respect, since there is a demand for space saving in the semiconductor test apparatus, it is not very realistic to significantly increase the number of pogo pins to make the hardware extremely complicated and large.

  In the first place, in the case of a method using pogo pins or ZIF, there is a problem that the waveform quality deteriorates. When signal transmission is performed by physically contacting pins or sockets, impedance mismatch occurs at the contact point, and the waveform quality deteriorates due to this impedance mismatch. Further, when the pins and sockets are repeatedly brought into and out of contact with each other, the contact resistance changes due to wear or the like, which also deteriorates the waveform quality. For this reason, it becomes a big problem in terms of stability and reliability of the test. Furthermore, since the waveform quality further deteriorates according to the length of the pins and sockets, the length of the pins and sockets must be made as short as possible, thereby losing the freedom of mechanical design.

  In Patent Document 1, the contact ring is provided with a test unit, which is very effective in avoiding deterioration of waveform quality. However, since signal transmission is performed using pogo pins, the test as described above is also performed. There are a number of problems such as speed problems and waveform quality degradation.

  Therefore, the present invention provides a complete non-contact type signal transmission using light in a semiconductor test apparatus configured to be able to contact and separate between a test head and a probe card or between relay members that relay them. The purpose of this is to perform a semiconductor device test at high speed and stably.

  In order to solve the above problems, a semiconductor test apparatus according to claim 1 of the present invention includes a probe card having a probe needle that contacts a device under test and a test head provided so as to be able to contact and separate from the probe card. In the semiconductor test apparatus, the probe card and the test head include optical transmission means for performing signal transmission by optical spatial transmission between the probe card and the test head.

  According to this semiconductor test apparatus, the probe card and the test head are configured to be able to contact and separate, and signal transmission between the probe card and the test head is performed by optical space transmission. Here, optical space transmission refers to signal transmission in which light is transmitted and received using air space, and is different from signal transmission using fiber fibers such as an optical fiber. Since signal transmission is performed by optical space transmission, members such as pins and sockets are not physically brought into contact with each other, so there is no deterioration in waveform quality, and the light transmission speed is extremely high. Can be tested.

  The semiconductor test apparatus according to claim 2 of the present invention is the semiconductor test apparatus according to claim 1, wherein the optical transmission means includes a transmission-side transmission optical transmission means and a reception-side reception side of the optical transmission means. Serial transfer is performed with the optical transmission means.

  According to this semiconductor test apparatus, since signal transmission is performed by serial transfer, it is only necessary to provide one transmission side optical transmission unit and one reception side optical transmission unit for signal transmission in one direction. Compared to the case where pins and sockets are provided, the hardware can be significantly simplified and miniaturized. When bidirectional signal transmission is performed, two sets of transmission side optical transmission means and reception side optical transmission means are provided.

  A semiconductor test apparatus according to a third aspect of the present invention is the semiconductor test apparatus according to the first aspect, wherein one or a plurality of semiconductor test apparatuses are provided between the probe card and the test head. The above-mentioned optical transmission means is provided in a relay member provided so as to be able to contact or separate from one or both.

  According to this semiconductor test apparatus, even in an apparatus configuration in which a relay member is interposed, an optical space is provided between the probe card and the relay member, between the relay member and the measurement module, or between the relay members. Transmission can be performed.

  The semiconductor test apparatus according to claim 4 of the present invention is the semiconductor test apparatus according to claim 3, wherein the measurement module is a pin electronics card, and the relay member is one or both of a performance board and a contact ring. It is characterized by being.

  According to this semiconductor test apparatus, signal transmission can be performed by optical space transmission between the probe card, the performance board, the contact ring, and the probe card.

  The semiconductor test apparatus according to claim 5 of the present invention is the semiconductor test apparatus according to claim 2, wherein the transmission side optical transmission means adds control data indicating start and end of serial data for serial transfer. And the reception side optical transmission means includes a decoding unit that decodes the serial data based on the control data.

  According to this semiconductor test apparatus, the serial data of the low-speed signal is encoded by adding the control data to the encoding unit so that the serial data of the high-speed signal and the serial data of the low-speed signal are combined into one. Serial transfer paths can be mixed, and the number of paths can be reduced to one.

  The semiconductor test apparatus according to claim 6 of the present invention is the semiconductor test apparatus according to claim 2, wherein the transmission side optical transmission means includes a data conversion unit for converting parallel data into the serial data. Features.

  According to this semiconductor test apparatus, even when parallel data is output, the data conversion unit converts the data into serial data, so that serial transfer can be performed.

  The semiconductor test apparatus according to claim 7 of the present invention is the semiconductor test apparatus according to claim 1, wherein the test head includes a plurality of measurement modules, and some or all of the plurality of measurement modules are connected to each other. The optical transmission means is provided in one of the mutually connected measurement modules.

  According to this semiconductor test apparatus, as one group in which a plurality of measurement modules are connected to each other, optical transmission means is provided in one measurement module of the group, so that optical transmission is performed to other measurement modules in the group. There is no need to provide means. As a result, effects such as a reduction in the mounting area of the measurement module and simplification of the circuit configuration can be obtained.

  The semiconductor test apparatus according to an eighth aspect of the present invention is the semiconductor test apparatus according to the third aspect, wherein the relay member includes an optical path conversion member that converts an optical path of an optical signal.

  According to this semiconductor test apparatus, even if a member that obstructs the optical path of the optical signal is disposed in the space between the probe card and the measurement module, the optical path is changed by the relay member. Transmission can be performed.

  The semiconductor test apparatus according to claim 9 of the present invention is the semiconductor test apparatus according to claim 3, wherein the relay member includes optical path dividing means for dividing the optical path of the optical signal into two, and the optical path dividing means One of the divided optical signals is received by a light receiving means provided on the relay member, and the other is transmitted by the optical spatial transmission.

  According to this semiconductor test apparatus, one of the divided optical signals can be received by the light receiving means provided on the relay member, so that the optical signal can be supplied to various circuits of the relay member, and the other is optically transmitted. By performing spatial transmission, an optical signal can be transmitted to the probe card, the measurement module, and other relay members.

  In the present invention, since signal transmission is performed between the probe card and the measurement module of the test head or between the relay member by optical space transmission, it is possible to perform signal transmission in a completely non-contact state. become. Therefore, since signal transmission can be performed while maintaining high waveform quality, it is possible to perform a stable test, and since signal transmission is performed using an optical signal, a test can be performed at high speed. .

It is a figure explaining schematic structure of the semiconductor test equipment of the present invention. It is a figure explaining schematic structure of an optical transmission unit and a light reception unit. It is a figure explaining schematic structure of the semiconductor test equipment of the 1st modification. It is a figure explaining schematic structure of the semiconductor testing apparatus of the 2nd modification. It is a figure explaining schematic structure of the conventional semiconductor test equipment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The semiconductor test apparatus according to the present invention includes a prober 1, a test head 2, a performance board 3, a contact ring 4, a probe card 5, an inspection stage 6, and a measurement module 7. A semiconductor wafer W as a test object is mounted on the inspection stage 6 of the prober 1, and an elevating mechanism 6Z, a rotating mechanism 6θ, a Y-axis moving mechanism 6Y, and an X-axis moving mechanism 6X are provided below the inspection stage 6. Thus, the position can be adjusted in the X-axis direction, the Y-axis direction, the θ-direction, and the Z-axis direction. Further, the probe card 5 is provided with a probe needle 8, and a test is performed in contact with the semiconductor wafer W. These configurations and operations are the same as those of the background art described above. As the semiconductor wafer W, any semiconductor device such as an IC, LSI, memory, or CMOS image sensor can be applied.

  The measurement module 7 is a so-called pin electronics card, and a plurality of measurement modules 7 are mounted on the test head 2. FIG. 1 shows one measurement module 7, and an optical transmission unit 11 and a light reception unit 12 are provided in the measurement module 7 at positions facing the performance board 3. The optical transmission unit 11 as the transmission side optical transmission means is a unit for transmitting light, and the light receiving unit 12 as the reception side optical transmission means is a unit for receiving light. The transmission side optical transmission means and the reception side optical transmission means constitute a set to constitute an optical transmission means.

  Similarly, the light receiving unit 13 and the light transmitting unit 14 are provided on the surface of the performance board 3 facing the measurement module 7, and the light transmitting unit 15 and the light receiving unit 16 are disposed on the surface facing the contact ring 4 of the performance board 3. Is provided. A light receiving unit 17 and an optical transmission unit 18 are provided on the surface of the probe card 5 facing the contact ring 4. Hereinafter, the mechanisms (measurement module 7, performance board 3, contact ring 4, and probe card 5) on which the optical transmission unit and the light receiving unit are mounted are collectively referred to as a unit mounting mechanism. Among the unit mounting mechanisms, the performance board 3 serves as a relay member.

  The optical transmission units 11, 14, 15 and 18 are the same, and the light receiving units 12, 13, 16 and 17 are the same. As shown in FIG. 2, the optical transmission unit includes an interface unit (shown as an I / F unit in the drawing) 21, a data conversion unit 22, an encoding unit 23, a light emitting element 24, and a collimator lens 25. It is composed. The interface unit 21 is connected to various circuits provided in the unit mounting mechanism, and serves as an interface unit for inputting signals from the various circuits provided in the unit mounting mechanism. For example, in the case of the measurement module 7 as a unit mounting mechanism, the interface unit 21 is connected to a driver circuit for applying a test signal.

  The data conversion unit 22 is a serializer that converts serial data when the data input by the interface unit 21 is parallel data. Depending on the circuit of the unit mounting mechanism, there are serial data and parallel data as data to be handled. In the case of parallel data, the data conversion unit 22 converts the data into serial data. If the data input to the interface unit 21 is serial data, the data conversion unit 22 outputs the data as it is. From this point, it is not necessary to provide the data conversion unit 22 when all the data to be handled is serial data.

  The encoding unit 23 performs encoding when the serial data output from the data conversion unit 22 is a low-speed signal. The serial data is encoded by adding special data called a K code (also called a K code or K character). The K code is special data indicating the start and end of serial data. By adding this special data, serial data consisting of a low-speed signal and serial data consisting of a high-speed signal are transmitted through one transmission path. It becomes possible to do. If encoding is not performed, the encoding unit 23 need not be provided.

  The light emitting element 24 is connected to the encoding unit 23, receives data encoded by the encoding unit 23, converts an electrical signal into light, and oscillates as signal light. For example, signal light can be generated by oscillating light when the signal indicates “1” and not oscillating light when the signal indicates “0”. Only one light emitting element 24 is provided in the optical transmission unit. In this sense, the optical transmission unit serially transmits a signal to be transmitted. The laser light oscillated from the light emitting element 24 is input to the collimator lens 25 while diverging. The collimator lens 25 is a lens that outputs divergent light as parallel light, and signal light having a very small light diameter is guided to the light receiving unit 13. The signal light oscillated from the light emitting element 24 is most preferably laser light, but may be an LED or the like.

  2B, the light receiving unit 13 includes a light receiving element 26, a decoding unit 27, and an interface unit (shown as “I / F unit” in the figure) 28, and is schematically configured. ing. The light receiving element 26 is a photodiode, and photoelectrically converts the input signal light to generate an electric signal. Based on the K code included in the electrical signal, the decoding unit 27 recognizes the start and end of the data and decodes the encoded data. The interface unit 28 outputs the decrypted data to the circuit of the unit mounting mechanism. When the light receiving area of the light receiving element 26 is narrow, the light receiving element 26 may receive the collected signal light by providing a condensing lens.

  2A is provided in the optical transmission units 11, 14, 15, and 18, and the configuration in FIG. 2B is provided in the light receiving units 12, 13, 16, and 17. The signal can be serially transferred by oscillating and receiving the signal light between the light transmitting unit and the light receiving unit. The space between the light transmitting unit and the light receiving unit is a signal path for an optical signal, and the optical signal is transmitted through this air space. In this respect, unlike an optical fiber or the like, light does not travel through some medium such as fiber fiber, but signal light is transmitted through the air. For this reason, the light transmitting unit and the light receiving unit are completely in a non-contact state, and each unit mounting mechanism can be freely contacted and separated (detached) independently. As described above, the transmission and reception of signals by transmitting light in the air is referred to as optical space transmission. In FIG. 1, a line connecting the optical transmission unit and the light receiving unit is a signal path of signal light for optical space transmission.

  On the other hand, as shown in FIG. 1, pogo pins 31, 32, between the test head 2 and the performance board 3, between the performance board 3 and the contact ring 4, and between the contact ring 4 and the probe card 5, respectively. 33 is provided. These pogo pins do not perform signal transmission but are provided to supply power from the test head 2. The power supply necessary for the performance board 3, the contact ring 4, and the probe card 5 is supplied by a power supply unit (not shown) provided in the test head 2.

  In other words, the semiconductor test apparatus of the present invention separates signal transmission and power supply into two independent paths, and signal transmission that requires high speed uses optical space transmission, and the operation speed is high. For power supply that is hardly required, a method of contacting members like a pogo pin (or ZIF) as in the prior art is used. Since the signal transmission path is optical space transmission, pogo pins need only be provided for power supply, and the number of pogo pins can be greatly reduced.

  The operation in the above will be described. In the following description, it is assumed that the semiconductor device of the semiconductor wafer W to be tested is a CMOS image sensor. First, the measurement module 7 generates test data for testing the semiconductor wafer W, and outputs this test data to the interface unit 21 as serial data. The serial data is high-speed serial data. Data conversion processing in the data conversion unit 22 (processing for converting parallel data into serial data) and encoding processing in the encoding unit 23 (processing for adding a K code and encoding) ) Is not performed. The light emitting element 24 generates signal light from the test data and oscillates. The signal light is collimated by the collimator lens 25 and received by the light receiving element 26 of the light receiving unit 12 in the performance board 3.

  The light receiving element 26 converts the received signal light into an electrical signal by photoelectric conversion, and generates transmitted test data. Since this test data is unencoded serial data, the decoding process (the process of decoding based on the K code) is not performed. The performance board 3 is provided with various circuits (for example, a measurement circuit, an A / D converter, a sample hold circuit, etc.), and test data is supplied to these circuits, and the interface unit 21 of the optical transmission unit 15 is provided. Test data is output to. The optical transmission unit 15 oscillates signal light from the light emitting element 24 based on the test data, and the oscillated signal light is received by the light receiving element 26 in the light receiving unit 17 of the probe card 5. Then, test data is supplied from the interface unit 28 to various circuits of the probe card 5.

  As described above, the test data generated by the measurement module 7 is transmitted to the probe card 5. The probe needle 8 provided on the probe card 5 tests the semiconductor wafer W based on the received test data.

  The semiconductor device on the semiconductor wafer W is a CMOS image sensor that operates at high speed, and most of the device is occupied by pixel signals. Most CMOS image sensors output pixel signals as high-speed serial data, and high-speed serial data is output from the semiconductor wafer W. On the other hand, CMOS image sensor data includes not only pixel signals, but also signals (VD pulses) indicating the head of all images and signals (HD pulses) indicating the head of lines, which are different from pixel signals. Slow signal. Therefore, data (output data) output from the semiconductor wafer W is data in which high-speed pixel signals and low-speed VD pulses, HD pulses, and other signals are mixed. Further, some types of CMOS image sensors output in the form of parallel data.

  Therefore, the data conversion unit 22 of the probe card 5 performs data conversion processing for converting the output data into serial data if the output data is parallel data. If low-speed serial data such as a VD pulse or an HD pulse is included, an encoding process for adding a K code indicating start and end to a low-speed signal such as a VD pulse or an HD pulse is performed. By performing this encoding process, it is possible to serially transfer a high-speed pixel signal and a low-speed VD pulse or HD pulse signal through one signal path. In this regard, when the output data is only one of a high-speed signal and a low-speed signal, there is no need for encoding processing.

  The light emitting element 24 oscillates the output data encoded by the encoding unit 23 as signal light and causes the light receiving element 26 of the light receiving unit 16 in the performance board 3 to receive the light. The signal photoelectrically converted by the light receiving element 26 is decoded by the decoding unit 27 to generate output data. This output data is supplied to various circuits of the performance board 3 and the output data is sent to the optical transmission unit 14. Supplied. Since the optical transmission unit 14 includes both high-speed signals and low-speed signals in output data to be transmitted, the encoding unit 23 performs encoding again. Then, signal light is oscillated from the light emitting element 24 and received by the light receiving unit 12. Output data is generated based on the signal light received by the light receiving unit 12. When output data is not required in various circuits of the performance board 3, it is not necessary to perform decoding and encoding in the light receiving unit 16 and the optical transmission unit 14 of the performance board 3, respectively. May be transmitted as it is.

  As described above, output data is transmitted from the probe card 5 to the measurement module 7. Regardless of the path from the measurement module 7 to the probe card 5 (outward path) or the path from the probe card 5 to the measurement module 7 (return path), completely non-contact optical space transmission is performed. For this reason, the problem of impedance mismatching does not occur, and since signal light is transmitted in the air instead of a metal medium such as a pin or a socket, stable signal transmission is possible. And since signal transmission is performed using light, it becomes possible to perform signal transmission at a remarkably high speed.

  Further, since the pogo pins can be used only for power supply, the number of pogo pins can be greatly reduced, and the hardware can be greatly simplified. Further, since the signal light uses air as a transmission medium and can be transmitted with almost no loss, the signal light can be reliably transmitted even if the optical transmission unit and the light receiving unit are separated from each other. For this reason, the intervals between the unit mounting mechanisms can be freely separated. Furthermore, even when a low-speed signal and a high-speed signal are mixed, as in a CMOS image sensor, etc., since the encoding unit performs encoding, the signal is serially transmitted through one signal path. It can be transmitted.

  In the above, the optical transmission unit and the light receiving unit are each provided at the end of the unit mounting mechanism. For example, as shown in FIG. 1, the light transmission unit 11 and the light reception unit 12 are provided at both ends of the measurement module 7, and the light reception unit 17 and the light transmission unit 18 are provided at the ends of the probe card 5, respectively. Yes. The test head 2, the performance board 3, the contact ring 4 and the probe card 5 are provided with various members that obstruct the optical path at the center, and the space facing the end is an open space. . Therefore, by arranging the pair of the light transmitting unit and the light receiving unit at the end, signal light can be transmitted without being disturbed by other members.

  Further, by providing the light transmitting unit and the light receiving unit at both end positions of one unit mounting mechanism, they are separated to some extent. Thus, stable signal transmission can be performed without crosstalk between the signal light transmitted from the optical transmission unit and the signal light received by the light receiving unit. In order to eliminate crosstalk more reliably, for example, a shielding member may be arranged between the signal light transmitted from the optical transmission unit and the signal light received by the light receiving unit. However, since the signal light transmitted from the optical transmission unit is parallel light having a very small diameter, there is almost no crosstalk between the signal lights. For this reason, the optical transmission unit and the light receiving unit may be provided in close proximity.

  In the example of FIG. 1, the optical transmission unit and the light receiving unit are not provided in the contact ring 4, but the optical transmission unit and the light receiving unit may be provided in the contact ring 4. When a circuit provided in the contact ring 4 requires test data transmitted from the measurement module 7 or output data received by the measurement module 7, the contact ring 4 can be relayed to use the data. It becomes like this. In this case, not only the performance board 3 but also the contact ring 4 constitutes a relay member.

  In addition, only one set of the optical transmission unit and the light reception unit is provided in the unit mounting mechanism in one direction for serial transfer, but two or more paths may be provided. For example, by providing two sets in one direction, a high-speed signal path and a low-speed signal path may be assigned. However, since high-speed signals and low-speed signals can be mixed by the encoding unit 23, it is desirable to provide only one set from the viewpoint of hardware simplification.

  Further, as described above, a plurality of measurement modules 7 are mounted on the test head 2, and each measurement module 7 can be provided with an optical transmission unit and a light reception unit. One group may be connected to each other, and an optical transmission unit and a light reception unit (optical transmission means) may be provided in one measurement module 7 of each group. If an optical transmission unit and a light receiving unit are provided in each of the plurality of measurement modules 7, the hardware becomes complicated. For this reason, hardware can be greatly simplified by providing an optical transmission means in one measurement module 7 among a plurality of sheets.

  Further, a dedicated module for the optical transmission means may be provided for each of the groups. A large number of circuits are formed in the measurement module 7, and there is not so much room for providing the optical transmission means. For this reason, when the optical transmission means cannot be mounted on the measurement module 7, a dedicated module (transmission module) for the optical transmission means is provided, and a plurality of measurement modules 7 are connected to the transmission module. The transmission module may be responsible for signal transmission of the plurality of measurement modules 7. Therefore, the optical transmission means may be provided not only in the measurement module 7 but also in a transmission module provided in the test head 2, and may be provided in any one of the test heads 2.

  By the way, as described above, since the number of signal transmission pogo pins is greatly reduced, the space where the pogo pins are originally arranged becomes an open section. The pogo pin is configured by mounting a pin member on a cylindrical or prismatic hole. By not mounting the signal transmission pogo pin, the hole in which the pogo pin is originally mounted becomes an open space. Therefore, this open space can be used for optical space transmission. That is, by directing the light oscillated from the light transmitting unit toward the light receiving unit to the through hole after removal of the pogo pin, the transmission path of the signal light can be reliably secured. When the size of the unit mounting mechanism is reduced by the space of the reduced pogo pin, a new through hole is provided in the unit mounting mechanism in order to secure a signal light transmission path. Further, in the case of an open space originally between the measurement module and the performance board, it is not necessary to form a through hole. However, when a wiring or the like for connecting the unit mounting mechanisms is provided, a transmission path for signal light is secured by collecting the wiring.

  Next, a first modification will be described with reference to FIG. In this modification, the performance board 3 is not provided with an optical transmission unit and a light receiving unit, but is provided with reflection mirrors 41 to 44 as optical path conversion members instead. Then, the various circuits of the performance board 3 do not use the test data and transmit the test data directly from the measurement module 7 to the probe card 5.

  First, the signal light oscillated from the optical transmission unit 11 of the measurement module 7 is reflected by a reflection mirror provided on the performance board 3. The reflection mirror 41 is provided such that its incident surface forms an angle of 45 degrees with respect to the optical path of the signal light oscillated from the optical transmission unit 11, whereby the optical path of the signal light is bent by 90 degrees. Similarly, the reflection mirror 42 is provided such that its incident surface forms an angle of 45 degrees with respect to the optical path of the signal light, and thereby the optical path of the signal light is bent by 90 degrees. Then, the signal light is guided to the light receiving unit 17 of the probe card 5.

  As shown in FIG. 3, the width of the probe card 5 is smaller than the width of the measurement module 7 and is installed at both ends of the light transmission unit 11, the light reception unit 12 and the measurement module 7, and the light reception unit 17 and the light transmission unit 18. Are installed at both ends of the probe card 5, the optical path of the signal light cannot be made linear. For this reason, reflection mirrors 41 to 44 for converting the optical path of the signal light are provided.

  In the first modified example, the performance board 3 is simply provided on a path through which signal light passes, and the performance board 3 is not provided with an optical transmission unit and a light receiving unit. As described above, when the serial data for testing is not required in the relay member, it is not necessary to provide the optical transmission unit and the light receiving unit, so that the hardware can be simplified. In FIG. 3, in order to allow the signal light to pass, a through hole for securing an optical path is formed in the performance board 3.

  Similarly, as shown in FIG. 3, the reflection mirrors 43 and 44 are arranged on the performance board 3 so that the optical path of the signal light is bent by 90 degrees, respectively, thereby directing the signal light directly from the probe card 5 to the measurement module 7. Will be able to. Even in this case, the output data is not used in the probe card 3. The angles of the reflection mirrors 41 to 44 are securely fixed by a holder (not shown). Further, when another member is present on the signal light path, the reflection mirror is arranged using a plurality of reflection mirrors so that the optical path avoids the member.

  As described above, by providing a reflecting mirror for converting the optical path on the relay member such as a performance board, the transmission path of the signal light can be reliably ensured regardless of the size or arrangement of the unit mounting mechanism. Become. Further, when test data and output data are not used in the performance board 3, it is not necessary to arrange the light transmitting unit and the light receiving unit, so that the hardware can be simplified.

  Next, a second embodiment will be described with reference to FIG. In the first modification, since the signal light passes through the performance board 3, output data from the probe card 5 is not supplied to the performance board 3. In the second modification, a half mirror 46 as a light splitting unit is provided at the position of the reflection mirror 44 of the performance board 3, and a light receiving unit 47 is provided. The half mirror 46 divides the signal light into light that is reflected toward the light receiving unit 12 and light that is transmitted toward the light receiving unit 47. The light receiving unit 47 is the same as the light receiving units 12, 13, 16 and 17 described above, and photoelectrically converts the received signal light and outputs signals to various circuits of the performance board 3.

  As described above, in the second embodiment, it is possible to freely convert the optical path of the signal light and supply the signal to the performance board 3 as well. For example, by providing a mechanism for observing the waveform from the semiconductor wafer W in the performance board 3, the waveform of the test result can be observed. In addition, by providing a half mirror at the position of the reflection mirror 42 and arranging the light receiving unit at a position where the signal light transmitted through the half mirror can be received, test data from the measurement module 7 is also supplied to the performance board 3. It becomes possible.

DESCRIPTION OF SYMBOLS 1 Prober 2 Test head 3 Performance board 4 Contact ring 5 Probe card 7 Measurement module 8 Probe needle 21 Interface part 22 Data conversion part 23 Encoding part 24 Light emitting element 25 Collimator lens 26 Light receiving element 27 Decoding part 11, 14, 15, 18 Light transmitting units 12, 13, 16, 17 Light receiving units 41 to 44 Reflecting mirror

Claims (9)

A semiconductor test apparatus comprising a probe card having a probe needle that comes into contact with a device under test and a test head provided so as to be able to contact and separate from the probe card
The semiconductor testing apparatus, wherein the probe card and the test head include an optical transmission means for performing signal transmission by optical spatial transmission between the probe card and the test head. 2. The semiconductor test apparatus according to claim 1, wherein the optical transmission means performs serial transfer between a transmission-side transmission optical transmission means and a reception-side reception optical transmission means of the optical transmission means. . One or more are provided between the probe card and the test head, and the optical transmission means is provided on a relay member provided so as to be able to contact with or separate from one or both of the probe card and the test head. The semiconductor test apparatus according to claim 1, wherein: The semiconductor test apparatus according to claim 3, wherein the measurement module is a pin electronics card, and the relay member is one or both of a performance board and a contact ring. The transmission side optical transmission means includes an encoding unit that performs encoding by adding control data indicating start and end of serial data for serial transfer,
The semiconductor test apparatus according to claim 2, wherein the receiving-side optical transmission unit includes a decoding unit that decodes the serial data based on the control data. The semiconductor test apparatus according to claim 2, wherein the transmission side optical transmission unit includes a data conversion unit that converts parallel data into the serial data. The test head includes a plurality of measurement modules,
2. The semiconductor according to claim 1, wherein a part or all of the plurality of measurement modules are connected to each other, and the optical transmission means is provided in one measurement module among the measurement modules connected to each other. Test equipment. The semiconductor test apparatus according to claim 3, wherein the relay member includes an optical path conversion member that converts an optical path of an optical signal. The relay member includes an optical path dividing means for dividing the optical path of the optical signal into two,
4. The semiconductor test according to claim 3, wherein one of the optical signals divided by the optical path dividing means is received by a light receiving means provided on the relay member and the other is transmitted by the optical space transmission. apparatus.

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