JP4072250B2 - IC test equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an IC test apparatus for testing various electronic components (hereinafter, typically referred to as IC) such as a semiconductor integrated circuit element, and more particularly to an IC test apparatus provided with a low-temperature application device.
[0002]
[Prior art]
In an IC test apparatus called a handler, a large number of ICs stored in a tray are transported into the test apparatus, and each IC is brought into electrical contact with the test head. To do the test. When the test is completed, each IC is unloaded from the test head and placed on a tray according to the test result, whereby sorting into categories such as non-defective products and defective products is performed.
[0003]
When the conventional handlers are roughly classified by the temperature application method, the IC under test is placed on a dedicated tray called a test tray, and this IC is loaded into the temperature application chamber to bring the IC under test to a predetermined temperature. The chamber type handler that presses the IC under test against the test head while mounted on the test head, and the IC under test are placed on a heat plate (also referred to as a hot plate) to apply high temperature stress, and this is applied once by the suction head. There is a heat plate type that sucks and conveys several of each to the test head.
[0004]
In particular, when a test is performed by applying a low temperature thermal stress, a chamber type handler is mainly used. By introducing liquid nitrogen into the chamber, a low temperature thermal stress of about −30 ° C. is applied to the IC, for example. The
[0005]
[Problems to be solved by the invention]
By the way, when applying low-temperature thermal stress in the handler, a supply source of liquid nitrogen is required as described above, or it is conventionally drawn from the separately installed liquid nitrogen reservoir to the handler using factory piping, Alternatively, a liquid nitrogen cylinder was installed near the handler and was supplied to the handler from here by piping.
[0006]
However, when liquid nitrogen is pumped from a separately installed liquid nitrogen reservoir by factory piping, there are problems such as restrictions on the space for operating the factory piping and high costs for heat insulation and other facilities. . Further, if a liquid nitrogen cylinder is installed near the handler, this problem is solved, but a new problem arises that the replacement work of the liquid nitrogen cylinder is troublesome.
[0007]
Furthermore, since liquid nitrogen is a substance that requires attention in handling, it cannot be used carelessly, and it is necessary to pay sufficient attention to countermeasures therefor, and in that sense, the cost is high.
[0008]
The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide an IC test apparatus provided with a low-temperature application device in place of liquid nitrogen.
[0009]
[Means for Solving the Problems]
(1) In order to achieve the above object, an IC test apparatus according to the present invention is an IC test apparatus that performs a test by applying at least low-temperature thermal stress to the IC under test, and transports the IC under test to a test process. Then, after performing a low-temperature test, a handler that classifies the IC under test according to the test result, a refrigeration cycle in which at least a compressor, a condenser, an expansion valve, and an evaporator are connected in this order by a refrigerant pipe, and the evaporation a refrigeration system having a cold air supply system having a blower fan for supplying heat exchanged gas to the IC before the test by the heater and the evaporator for heating the heat exchanged gas by vessel, said cold air supply Control means for controlling the temperature of the cold air supplied from the system, and the handler tests a soak chamber for raising and lowering the IC under test, and the IC under test. A test chamber, and a temperature sensor provided in the soak chamber for measuring a temperature inside the soak chamber, wherein the soak chamber of the handler includes a vertical transfer means inside, and the soak The chamber and the test chamber are in communication, the soak chamber and the test chamber of the handler are connected to the cold air supply system of the cooling device by an external duct, and the cold air supplied from the cold air supply system is The control means is supplied to the soak chamber and exhausted from the test chamber. The control means includes an input means for inputting a set temperature, a temperature sensor provided in the soak chamber, and the temperature sensor. Supplyed from the cold air supply system based on the detected actual temperature and the set temperature input to the input means. It is to control the temperature of the cold air that.
[0010]
In the IC test apparatus of the present invention, low temperature thermal stress is applied to the IC under test by generating cold air by the refrigeration cycle, so that the problem of the space for installing the factory piping and the problem of equipment cost compared to using liquid nitrogen And all the safety issues are resolved.
[0013]
By supplying the cool air from the cold air supply system to the soak chamber and exhausting it from the test chamber, the temperature raising / lowering efficiency of the IC under test in the soak chamber is improved. In addition, it is possible to contribute to maintaining the temperature in the test chamber by guiding the cold air supplied to the soak chamber to the test chamber.
[0016]
In order to control the cold air temperature only by the refrigeration cycle, the amount of refrigerant circulating in the evaporator, the rotational speed of the blower fan, etc. may be controlled. However, the IC test apparatus of the present invention has a heater, It is sufficient to heat the cold air that has passed through the vessel so as to increase it by a desired temperature. Therefore, it is easy to accurately control the cold air temperature.
[0018]
In the IC test apparatus of the present invention, the actual temperature of the chamber to which the cold air is supplied is detected and compared with the set temperature, thereby controlling the cold air temperature supplied from the cold air supply system, so that accurate temperature management is performed. And the reliability of the IC test is improved.
[0019]
( 2 ) Although not particularly limited in the above invention, the IC test apparatus according to claim 2 is characterized in that the control means controls the cool air supplied from the cool air supply system by controlling the blower fan and / or the heater. It is characterized by controlling the temperature.
[0020]
As described above, the temperature of the cold air supplied from the cold air supply system can be appropriately adjusted by the amount of cold air supplied by the blower fan, the cold air heating by the heater, or a combination thereof.
[0021]
( 3 ) Although not particularly limited in the above invention, the IC test apparatus according to claim 3 includes an operation state detection means for detecting an operation state of at least one of the refrigeration cycle or the cold air supply system, and the operation state detection. The operation or stop of the refrigeration cycle or the cold air supply system is controlled based on the operating state detected by the means.
[0022]
In the IC test apparatus of the present invention, at least one of the operation states of the refrigeration cycle or the cold air supply system is detected by the operation state detection means, and when an abnormality is detected, the refrigeration cycle or the cold air supply system is stopped. At this time, it is desirable to alert the operator. As a result, the IC under test can be prevented from being tested under an inappropriate temperature condition, the reliability of the test is improved, and the yield of the IC test apparatus is also improved.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a perspective view showing an embodiment of an IC test apparatus according to the present invention, FIG. 2 is a circuit diagram showing a refrigeration cycle and a cold air supply system of FIG. 1, and FIG. 3 is a circuit of an IC under test in the IC test apparatus of FIG. It is a flowchart of the tray which shows a method.
[0024]
Handler 10
First, the handling of the IC under test in the handler 10 will be described with reference to the flowchart of FIG. Note that FIG. 3 is a diagram for understanding the method of handling the IC under test, and in the actual handler 10, there is also a portion showing the members arranged side by side in the vertical direction (Z-axis direction) in plan view. .
[0025]
The handler 10 according to the present embodiment is an apparatus that tests (inspects) whether an IC operates properly in a state where a high-temperature or low-temperature stress is applied to the IC under test, and classifies the IC according to the test result. In such an operation test in a state where temperature stress is applied, the IC test apparatus 1 is transported from a tray (hereinafter also referred to as a customer tray KT) on which many ICs to be tested are mounted. This is performed by replacing the IC under test on the test tray TT.
[0026]
For this reason, the handler of this embodiment stores an IC under test to be tested from now on, as well as an IC storage unit 100 for classifying and storing tested ICs, and an IC storage unit 100 as shown in FIG. It includes a loader unit 200 that sends an IC to be tested to the chamber unit 300, a chamber unit 300 including a test head, and an unloader unit 400 that classifies and extracts the tested ICs that have been tested in the chamber unit 300. ing.
[0027]
The IC storage unit 100 includes a pre-test IC stocker that stores ICs to be tested before testing, a tested IC stocker that stores ICs to be tested classified according to the test results (collectively these are simply the stocker 101). Is provided). FIG. 3 shows a state in which these stockers 101 are pulled out by dotted lines.
[0028]
The pre-test IC stocker and the tested IC stocker 101 are composed of a frame-like tray support frame 102 and an elevator 103 that can enter from the bottom of the tray support frame 102 and move up and down. A plurality of customer trays KT (indicated by a one-dot chain line in the figure) are stacked and supported on the support frame 102, and only the stacked customer trays KT are moved up and down by the elevator 103.
[0029]
Since the pre-test IC stocker and the tested IC stocker are the same stocker 101, the number of each of the pre-test IC stocker and the tested IC stocker should be appropriately set as necessary. Can do. For example, in the example shown in FIG. 3, one stocker STK-B is allocated as a pre-test stocker, and one empty stocker STK-E sent to the unloader unit 400 is allocated next to it, and 5 as tested IC stockers. The stockers STK-1, STK-2,..., STK-5 are allocated and can be sorted and stored in a maximum of five categories according to the test results. That is, in addition to good products and defective products, the non-defective products are classified into high-speed, medium-speed, low-speed, or defective products that require retesting.
[0030]
The above-described customer tray KT is carried from the lower side of the device substrate 105 to the window 201 of the loader unit 200 by the tray transfer arm 104 provided between the IC storage unit 100 and the device substrate 105. Then, in the loader unit 200, the IC under test loaded on the customer tray KT is once transferred to the precursor 204 by the XY transport device 202, and the mutual position of the IC under test is corrected here. Further, the IC under test transferred to the precursor 204 is reloaded onto the test tray TT stopped at the loader unit 200 by using the XY transport device 202 again.
[0031]
An XY transport device 202 that reloads ICs to be tested from the customer tray KT to the test tray TT is provided with a movable head 203 that can move in the XY direction shown in the figure. (Not shown). By moving the suction head while sucking air, the IC under test is sucked from the customer tray KT, and the IC under test is transferred to the test tray TT. For example, about eight such suction heads are mounted on the movable head 203, so that eight ICs to be tested can be transferred to the test tray TT in one operation.
[0032]
Incidentally, the precursor 204 provided between the window portion 201 of the loader unit 200 and the test tray TT is a position correcting means for the IC under test. The IC under test mounted on the customer tray KT is temporarily recessed in the precursor 204. , The mutual positions of the ICs under test are accurately determined, and the ICs under test whose positions have been corrected are again adsorbed by the adsorption head and transferred to the test tray TT. The IC under test can be transshipped with high precision in the storage recess.
[0033]
The above-described test tray TT is loaded into the chamber section 300 after the ICs to be tested are loaded by the loader unit 200, and each IC under test is tested while being mounted on the test tray TT.
[0034]
The chamber section 300 is in a state in which a thermal stress is applied in the soak chamber 301 that gives a target high or low temperature thermal stress to the IC under test loaded on the test tray TT. The test chamber 302 is configured to bring the IC under test into contact with the test head 304, and an exit chamber (heat removal tank) 303 for removing the applied thermal stress from the IC under test tested in the test chamber 302.
[0035]
The soak chamber 301 is provided with a vertical transfer device (not shown), and a plurality of test trays TT stand by while being supported by the vertical transfer device until the test chamber 302 becomes empty. Mainly during this standby, high or low temperature thermal stress is applied to the IC under test.
[0036]
A test head 304 is disposed at the center of the test chamber 302, and a test tray TT is carried on the test head 304 to electrically contact input / output terminals of the IC under test with contact pins of the test head 304. The test is performed.
[0037]
In the exit chamber 303, when a high temperature is applied in the soak chamber 301, the IC under test is cooled to the room temperature by blowing air, and when a low temperature of, for example, about −30 ° C. is applied in the soak chamber 301, the IC under test is removed. After returning to a temperature at which dew condensation does not occur by heating with warm air or a heater, it is discharged to the unloader section 400.
[0038]
The unloader unit 400 is also provided with an XY transport device 402 having substantially the same structure as the XY transport device 202 provided in the loader unit 200, and a movable head 403 provided in the XY transport device 402 Tested ICs are transferred from the test tray TT carried out to the unloader unit 400 to the customer tray KT.
[0039]
The device substrate 105 of the unloader unit 400 is provided with four windows 401 so that the customer tray KT transported to the unloader unit 400 faces the upper surface of the device substrate 105. Although not shown, an elevating table for elevating and lowering the customer tray KT is provided below each window 401. Here, tested ICs to be tested are reloaded and become full. The customer tray KT is loaded and lowered, and the full tray is transferred to the tray transfer arm 104.
[0040]
Incidentally, in the handler 10 of this embodiment, although the maximum number of categories that can be sorted is five, only a maximum of four customer trays KT can be arranged in the window 401 of the unloader unit 400. Therefore, the categories that can be sorted in real time are limited to four categories. For this reason, in the handler 10 of the present embodiment, a buffer unit 404 is provided between the test tray TT of the unloader unit 400 and the window unit 401, and ICs under test that are rarely generated in the buffer unit 404 are temporarily stored. I am going to leave it with you.
[0041]
Refrigeration equipment 20
The IC test apparatus 1 of this embodiment includes a refrigeration apparatus 20 for supplying cold air to the soak chamber 301 and the test chamber 302 of the handler 10 described above. The refrigeration apparatus 20 is used when a low-temperature thermal stress is applied to the IC under test, and a refrigeration cycle 210 and a cold air supply system 220 are provided inside.
[0042]
The refrigeration cycle 210 is mainly driven by an electric motor to condense and liquefy the compressor 211 that sucks and compresses the refrigerant into the high-temperature and high-pressure gas, and heat-exchanges the high-temperature and high-pressure gas with the outside air. A condenser (condenser) 212, a receiver tank 213 for separating the gas-liquid mixed gas and taking out only the liquid refrigerant, and expansion of the high-pressure liquid refrigerant rapidly into a low-temperature and low-pressure mist refrigerant. A valve 214 and an evaporator (evaporator) 215 for cooling air using this low-temperature and low-pressure mist refrigerant are connected by a refrigerant pipe 216 so as to form a closed loop circuit.
[0043]
The capacitor 212 includes a fan 217 that sucks air from the outside (ceiling) of the casing 201 and cools the high-temperature refrigerant as shown in the external view of FIG. The expansion valve 214 includes a temperature sensing cylinder 218 that detects the refrigerant temperature on the outlet side of the evaporator 215, and when the temperature detected by the temperature sensing cylinder 218 is high (that is, when the heat load on the evaporator 215 is large). Increases the opening of the expansion valve 214 and increases the amount of refrigerant supplied to the evaporator 215. On the contrary, when the refrigerant temperature on the outlet side of the evaporator 215 is low, the heat load on the evaporator 215 is not so large, so the amount of refrigerant supplied to the evaporator 215 is suppressed by reducing the opening of the expansion valve 214.
[0044]
On the other hand, the cold air supply system 220 supplies air to the evaporator 215 of the refrigeration cycle 210 to cool it, supplies the air thus cooled to the soak chamber 301 of the handler 10, and supplies this cold air from the test chamber 302. A closed loop circuit for returning to the refrigeration apparatus 20 is configured again.
[0045]
For this reason, the cool air supply system 220 is provided with ducts 222 and 224 having a blower fan 223. When the blower fan 223 is operated, the intake air is sent to the evaporator 215 via the internal duct 222 and is cooled by heat exchange. The The outlet side of the blower fan 223 and the soak chamber 301 of the handler 10 are connected by an external duct 224, and the test chamber 302 and the inlet side of the evaporator 215 are connected by an external duct 224. The cool air cooled by the evaporator 215 is supplied to the soak chamber 301 via the internal duct 222 and the external duct 224, and then supplied again to the evaporator from the test chamber 302 via the external duct 224 and the internal duct 222. .
[0046]
When applying the low temperature heat stress, the cold air is circulated by setting the cold air supply system 220 to the above-described closed loop. However, when the test of the IC under test is finished and the inside of the chamber 300 is returned to the normal temperature. Takes in air at room temperature from an inlet 221 for taking in indoor air provided on the side surface of the casing 201 or an inlet 225 to which a compressed air pipe in the factory is connected. The cold air of the cold air supply system 220 is exhausted from the outlet 226 into the room. In order to perform such air path switching, the cool air circulation system 220 is provided with switching valves 227a to 227d.
[0047]
Furthermore, in the refrigeration apparatus 20 of the present embodiment, an electric heater (corresponding to a heater referred to in the present invention) 228 for finely adjusting the temperature of the air cooled by the evaporator 215 is provided on the downstream side of the evaporator 215. 222 is provided. This is used when it is difficult to control the cold air temperature only by the evaporator 215, and it is not always necessary to use it. For example, even if it is referred to as low temperature heat stress, there are tests performed under extremely low temperature conditions such as −30 ° C. and other tests performed under low temperature conditions of about −10 ° C. to 0 ° C.
[0048]
Therefore, although the cooling capacity by the refrigeration cycle 210 is required to be able to realize an extremely low temperature condition of −30 ° C., the cooling capacity is too large when the refrigeration cycle is used at a low temperature condition of about −10 ° C. become. At this time, the electric heater 228 is used to heat the air that has been supercooled by the evaporator 215 to a target temperature and is supplied to the soak chamber 301.
[0049]
In this embodiment, a temperature sensor 229 for detecting the temperature in the soak chamber 301 is provided, and the electric heater 228 is mainly controlled based on the actual temperature measured by the temperature sensor 229.
[0050]
In addition, since the blower fan 223 of this embodiment can perform inverter control, a certain amount of temperature control is possible by adjusting the amount of cold air supplied to the soak chamber 301.
[0051]
Further, in the IC test apparatus 1 of the present embodiment, control signals are communicated between the handler 10 and the refrigeration apparatus 20, and the setting and monitoring of the refrigeration apparatus 20 are mainly performed on the handler 10 side. That is, an input means for the applied temperature by the refrigeration apparatus 20 is provided in the handler 10, and this set temperature and the actual temperature data by the temperature sensor 229 described above are sent to the control section of the refrigeration apparatus. An operation command signal and a stop command signal are also sent from the handler 10 to the refrigeration apparatus 20, and the operation start and stop of the refrigeration apparatus 20 are operated on the handler 10 side. On the other hand, a signal indicating the operating state of the refrigeration apparatus 20 is sent from the refrigeration apparatus 20 side to the handler 10 side. When an abnormality occurs in the refrigeration apparatus 20, a stop command signal is sent from the handler 10.
[0052]
Next, the operation will be described.
When performing an operation test by applying a low-temperature thermal stress to the IC under test, first set the use of the refrigeration apparatus 20 on the handler 10 side, then set the applied temperature and press the start button of the refrigeration apparatus 20 input. As a result, the set temperature is sent from the handler 10 to the refrigeration apparatus 20 side together with the operation start signal.
[0053]
In the refrigeration apparatus 20, when an operation start command is received, the compressor 211 and the condenser fan 217 are activated and the refrigeration cycle 210 is activated, and the blower fan 223 is activated and air is circulated.
[0054]
When the compressor 211 is activated, the refrigerant sucked into the compressor 211 is compressed into a high-temperature and high-pressure gas, and is cooled by the condenser 212 to be a low-temperature and high-pressure gas-liquid mixed gas. Only the liquid refrigerant is extracted from the gas-liquid mixed gas in the receiver tank 213 and sent to the expansion valve 214. The expansion valve 214 rapidly expands the high-pressure liquid refrigerant to form a low-temperature and low-pressure mist refrigerant, which is sent to the evaporator 215.
[0055]
On the other hand, the supply of cold air to the soak chamber 301 is performed with the switching valve 227c opened and the switching valves 227a, 227b, 227d closed (the switching valve 227b may be opened), and the low-temperature low-pressure mist is supplied. Heat is exchanged by allowing air to pass through the evaporator 215 through which the gaseous refrigerant flows. For example, -30 ° C. cold air is supplied to the soak chamber 301. Since the soak chamber 301 and the test chamber 302 communicate with each other, the cold air supplied to the soak chamber 301 cools the IC under test (mounted on the test tray TT) that has been transported into the soak chamber 301. Then, it flows into the test chamber 302 and is returned to the evaporator 215 via the external duct 224 and cooled again.
[0056]
At this time, the actual temperature in the soak chamber 301 is measured by the temperature sensor 229 provided in the soak chamber 301, which is sent from the handler 10 to the refrigeration apparatus 20 and fed back to the operation of the electric heater 228. For example, when the actual temperature of the soak chamber 301 is too lower than the set temperature (reference temperature), the electric heater 228 is operated to heat the supercooled cold air and supply it to the soak chamber 301. Such actual temperature data is sent from the handler 10 to the refrigeration apparatus 20 at regular intervals, and the above-described control of the electric heater 228 is executed each time.
[0057]
When the actual temperatures of the soak chamber 301 and the test chamber 302 reach the conditions, the test of the IC under test is started. During the test, the refrigeration apparatus 20 starts operating conditions of the refrigeration apparatus itself, for example, the compressor 211, the condenser fan 217, Whether the blower fan 223, the electric heater 228, and other components are operating normally is sent to the handler 10 side. If an abnormality occurs, an operation stop command signal is sent from the handler 10 to the refrigeration apparatus 20 to stop the refrigeration apparatus 20, and an alarm is issued to alert the operator. When this alarm is released, an operation start command signal is sent again from the handler 10 to the refrigeration apparatus 20, and the test is resumed.
[0058]
The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.
[0059]
For example, the handler 10 in the present invention is not limited to the type described above, and other handlers are within the scope of the present invention. The specific configurations of the refrigeration cycle 210 and the cold air supply system 220 shown in FIG. 2 are not particularly limited and can be changed as appropriate.
[0060]
【The invention's effect】
As described above, according to the present invention, cold air is generated by a refrigeration cycle to apply low-temperature thermal stress to the IC under test. All cost and safety issues are eliminated.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of an IC test apparatus of the present invention.
2 is a circuit diagram showing the refrigeration cycle and the cold air supply system of FIG. 1. FIG.
3 is a flow chart of a tray showing a method for routing an IC under test in the IC test apparatus of FIG. 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... IC test apparatus 10 ... Handler 100 ... IC storage part 200 ... Loader part 300 ... Chamber part 400 ... Unloader part KT ... Customer tray TT ... Test tray 20 ... Refrigeration apparatus 201 ... Casing 210 ... Refrigeration cycle 211 ... Compressor 212 ... Condenser (Condenser)
213 ... Receiver tank 214 ... Expansion valve 215 ... Evaporator
216 ... Refrigerant piping 217 ... Condenser fan 218 ... Temperature sensitive cylinder 220 ... Cold air supply system 221 ... Inlet port 222 ... Internal duct 223 ... Blower fan 224 ... External duct 225 ... Inlet port 226 ... Discharge ports 227a to 227d ... Switching valve 228 ... Electric heater (heater)
229 ... Temperature sensor

Claims (3)

An IC test apparatus for performing a test by applying at least a low temperature thermal stress to an IC under test,
A handler for transporting the IC under test to a test process, performing a low temperature test, and classifying the IC under test according to a test result;
A refrigeration cycle in which at least a compressor, a condenser, an expansion valve, and an evaporator are connected in this order by refrigerant piping, and a heater that heats the gas heat-exchanged by the evaporator and a gas that is heat-exchanged by the evaporator a refrigeration system having a cold air supply system having a blower fan for supplying to the IC before the test,
Control means for controlling the temperature of the cold air supplied from the cold air supply system ,
The handler is provided with a soak chamber for raising and lowering the IC under test, a test chamber for testing the IC under test, and a temperature inside the soak chamber provided in the soak chamber. Have a temperature sensor,
The soak chamber of the handler is provided with a vertical transfer means inside, and the soak chamber and the test chamber communicate with each other,
The soak chamber and the test chamber of the handler are connected to the cold air supply system of the cooling device by an external duct, and the cold air supplied from the cold air supply system is supplied to the soak chamber and exhausted from the test chamber. Is supposed to be
The control means is based on input means for inputting a set temperature, a temperature sensor provided in the soak chamber, an actual temperature detected by the temperature sensor, and a set temperature input to the input means. An IC test device for controlling the temperature of cold air supplied from a cold air supply system . The control means, the blowing fan and / or IC testing device according to claim 1, wherein the controlling the temperature of the cold air supplied from the cold air supply system by controlling the heater. An operation state detection unit that detects an operation state of at least one of the refrigeration cycle or the cold air supply system, and an operation or stop of the refrigeration cycle or the cold air supply system based on the operation state detected by the operation state detection unit The IC test apparatus according to claim 1 , wherein the IC test apparatus is controlled.

Images