Wafer test cassette

Abstract

To provide a test cassette with thermal isolation such that the thermal effects provided during preburning do not affect the operation of a probe and test host.SOLUTION: A wafer test cassette includes a fluid inlet and a fluid outlet. The wafer test cassette includes a first housing, a second housing, a heat source, and a barrier device. The first housing includes a probe card, and the probe card includes a probe. The second housing is coupled to the first housing to form a test space, and carries a wafer within the second housing, the wafer is positioned within the test space, and the probe is in electrical contact with the top surface of the wafer to perform a test process. The heat source heats the bottom surface of the wafer and defines a high temperature region between the bottom surface and the second housing. The barrier device surrounds the high temperature region and is used for thermal isolation between the high temperature region and the test space. The fluid inlet receives a gas, which flows through the test space to fill the space between the probe card and the top surface of the wafer, and flows out of the fluid outlet.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wafer test cassette, and more particularly to a wafer test cassette having heat conduction and heat isolation functions. [Background technology]

[0002] Once the design of an integrated circuit is completed on a wafer, the wafer must undergo a pre-burn test and an electrical test. Conventionally, the pre-burn and reliability tests have been carried out by testing each wafer individually using a test device and a probe card. Each wafer is placed on a carrier stage and the test is completed by making electrical contact with the probes of the probe card. Therefore, the more wafers there are, the more test devices and probe cards are required. This increases the time and equipment costs required for the test process.

[0003] In recent years, a wafer test cassette has been developed, and a method has been introduced in which a probe card and a wafer are pre-positioned and placed in the wafer test cassette, and the wafer test cassette is directly electrically connected to a test machine and placed in a test unit to perform a pre-burn test and an electrical test. During the pre-burn test, the wafer test cassette is placed in a high-temperature environment, and the heat may affect the operation of the probe and the test machine, reducing the efficiency of the test process.

[0004] Therefore, how to improve the usage effect of the wafer test cassette through improving the structural design and overcome the above-mentioned shortcomings has become one of the important problems to be solved in the technical field. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a wafer test cassette that compensates for the deficiencies of existing technology, and relates to a wafer test cassette that has a thermal isolation effect so that the heat provided during pre-burning does not affect the operation of the probe and test host. [Means for solving the problem]

[0006] A wafer test cassette having a fluid inlet and a fluid outlet is provided. The wafer test cassette includes a first housing, a second housing, a heat source, and a barrier device. The first housing has a probe card, and the probe card has a probe. The second housing is coupled to the first housing to form a test space, and carries a wafer within the second housing, the wafer is positioned within the test space, and the probe is in electrical contact with an upper surface of the wafer to perform a test process. The heat source heats an underside of the wafer and defines a high temperature region between the underside and the second housing. The barrier device surrounds the high temperature region and is used for thermal isolation between the high temperature region and the test space. The fluid inlet receives a gas, and the gas flows through the test space to fill a gap between the probe card and the upper surface of the wafer, and flows out of the fluid outlet. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a schematic diagram showing a state in which a wafer test cassette according to an embodiment of the present invention is used; [Diagram 2] FIG. 2 is a schematic diagram showing a state in which a wafer test cassette according to an embodiment of the present invention is used; [Diagram 3] FIG. 2 is a schematic diagram showing a state in which a wafer test cassette according to an embodiment of the present invention is used; [Figure 4] FIG. 2 is a schematic diagram showing a state in which a wafer test cassette according to an embodiment of the present invention is used; [Diagram 5] FIG. 2 is a schematic diagram showing a state in which a wafer test cassette according to an embodiment of the present invention is used; [Figure 6] FIG. 2 is a schematic diagram showing a state in which a wafer test cassette according to an embodiment of the present invention is used; [Figure 7]FIG. 2 is a schematic diagram showing a state in which a wafer test cassette according to an embodiment of the present invention is used; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Please refer to FIG. 1. FIG. 1 is a schematic diagram showing a state in which a wafer test cassette 1A according to an embodiment of the present invention is used. The wafer test cassette 1A has a fluid inlet 113 and a fluid outlet 114, and includes a first housing 11, a second housing 12, a heat source 14, and a barrier device 15. The first housing 11 has a probe card 111, and the probe card 111 has a plurality of probes 1111. The second housing 12 is coupled to the first housing 11 to form a test space S1. The wafer 13 is carried in the second housing 12 and is located in the test space S1. The probes 1111 are in electrical contact with the upper surface of the wafer 13 (for example, in electrical contact with the solder pads 131 on the wafer 13) to perform a test process. The heat source 14 is located, for example, inside the second housing 12 in which the wafer 13 is located, and heats the lower surface of the wafer 13 to form a high-temperature region S2 between the lower surface and the second housing 12. The high temperature area S2 can be a space or a heated "surface". The barrier device 15 surrounds the high temperature area S2 and functions as a thermal insulator between the high temperature area S2 and the test space S1. In this embodiment, the barrier device 15 is used to block the thermal energy transferred from the heat source 14 from entering the test space S1 and suppress the decrease in the heat dissipation efficiency of the gas CA due to the transfer of thermal energy. The gas CA flows into the test space S1 through the fluid inlet 113, fills the space between the probe card 111 and the upper surface of the wafer 13, and flows out from the fluid outlet 114. The temperature of the gas CA can be room temperature or a cold gas below room temperature.

[0009] In some embodiments, the gas CA is formed from air or an inert gas. In addition, in some embodiments, the thermal conductivity of the gas CA is less than 0.026 W / mK. In some embodiments, the specific heat of the gas CA is less than 1.015 kJ / (kga·K).

[0010] According to some embodiments, the heat source 14 is, but is not limited to, a heater, while according to other embodiments, the heat source 14 may be hot air or hot gas (see the embodiment description below for details).

[0011] In this embodiment, the fluid inlet 113 and the fluid outlet 114 are provided in the first housing 11, but according to some embodiments, one of the fluid inlet 113 and the fluid outlet 114 may be provided in the first housing 11 and the other in the second housing 12, and the present invention is not limited thereto. When the probe 1111 performs the test process, the gas CA flows into the test space S1 and is then discharged, thereby preventing the temperature of the wafer 13 during pre-burning from affecting the operation of the probe 1111 and its electrically connected test host.

[0012] Please refer to FIG. 2. FIG. 2 is a schematic diagram showing a state in which a wafer test cassette 1B according to an embodiment of the present invention is used. According to this embodiment, the heat source 14 is provided outside the second housing 12 in which the wafer 13 is located. In addition, the second housing 12 is provided with a barrier device 15. The barrier device 15 surrounds the wafer 13, and when projected along the projection direction D, its projected area includes the heat source 14. In this way, the heat source 14 can heat the wafer 13 through the second housing 12, and the barrier device 15 prevents the thermal energy from entering the test space S1, or prevents the thermal energy from being transferred to the first housing 11 through the second housing 12 and affecting the temperature in the test space S1.

[0013] Please refer to Fig. 3. Fig. 3 is a schematic diagram showing a state in which a wafer test cassette 1C in an embodiment according to the present invention is used. According to this embodiment, the heat source 14 is hot air. The second housing 12 has a heat flow inlet and a heat flow outlet in the high temperature region S2. The hot air enters from the heat flow inlet and exits from the heat flow outlet. In other words, the barrier device 15 supports the wafer 13, and the hot air flows in the high temperature region S2 to heat the wafer 13.

[0014] According to some embodiments, when the probe 1111 performs the test process, the first housing 11 and the second housing 12 are in a tightly coupled state, and the pressure in the test space S1 is greater than the pressure outside the test space S1. In this way, discharge from the tip of the probe 1111 to the wafer 13 can be suppressed, and damage to the wafer 13 due to tip discharge can be avoided.

[0015] Please refer to FIG. 4. FIG. 4 is a schematic diagram showing a state in which a wafer test cassette 1D according to an embodiment of the present invention is used. The wafer test cassette 1D further includes a valve 16, a sensor 17, and a control circuit 18. The sensor 17 and the valve 16 are respectively connected to the control circuit 18, and the valve 16 can open and close the fluid outlet 114. The sensor 17 senses at least one of the pressure or temperature in the test space S1 and transmits the sensing information to the control circuit 18. The control circuit 18 controls the opening and closing of the valve 16 based on the sensing information. That is, the control circuit 18 receives the sensing information and determines whether to discharge the gas CA from the fluid outlet 114 according to the pressure and / or temperature in the test space S1. This achieves the purpose of controlling the pressure and / or temperature in the test space S1.

[0016] Please refer to FIG. 5. FIG. 5 is a schematic diagram showing a state in which a wafer test cassette 1E according to an embodiment of the present invention is used. According to this embodiment, the wafer test cassette 1E also includes an exhaust device 19. The exhaust device 19 is connected to the fluid outlet 114 and can reduce the flow rate of the gas CA in the test space S1. According to some embodiments, the exhaust device 19 can gradually exhaust the gas CA in the test space S1 or exhaust different flow rates of the gas CA according to the degree of required thermal conduction of the test space S1. According to some embodiments, the exhaust device 19 is connected to a control circuit 18 (see FIG. 4), and the control circuit 18 determines the exhaust flow rate of the exhaust device 19.

[0017] Please refer to FIG. 6. FIG. 6 is a schematic diagram showing a state in which a wafer test cassette 1F is used in an embodiment according to the present invention. According to this embodiment, the wafer test cassette 1F also includes an air intake device 20. The air intake device 20 is connected to the fluid inlet 113 and can determine the flow rate of the gas CA entering the test space S1. According to some embodiments, the air intake device 20 can input the gas CA in the test space S1 stepwise or input different flow rates of the gas CA according to the required flow rate of the test space S1. According to some embodiments, the air intake device 20 is connected to a control circuit 18 (see FIG. 4). Then, the control circuit 18 determines the input (increased) flow rate of the gas CA by the air intake device 20.

[0018] Please refer to Fig. 7. Fig. 7 is a schematic diagram showing a state in which a wafer test cassette 1G according to an embodiment of the present invention is used. According to this embodiment, the wafer test cassette 1G includes an exhaust device 19 and an air intake device 20. In this manner, the wafer test cassette 1G can adjust the flow rate of the gas CA in the test space S1 by reducing the flow rate of the gas CA in the test space S1 through the exhaust device 19, increasing the flow rate of the gas CA in the test space S1 through the air intake device 20, or by a combination thereof.

[0019] One beneficial effect of the present invention is that the wafer test cassette provided by the present invention uses the technical solution of "a barrier device enclosing the high temperature area and thermally isolating the high temperature area from the test space" and "a fluid inlet receives gas, the gas flows through the test space, and flows out from the fluid outlet", so that gas can be filled between the probe card and the upper surface of the wafer and isolated from the high temperature area. This protects the test results by preventing the probe card from being affected by the high temperature of the wafer when performing the test process, and also protects the test device (e.g., probe card) and test end (e.g., test host) of the wafer test cassette, thereby improving the efficiency of the inspection process of the wafer test cassette. [Explanation of symbols]

[0020] 1A, 1B, 1C, 1D, 1E, 1F, 1G Wafer test cassette 11 First Case 111 Probe Card 1111 Probe 113 Fluid inlet 114 Fluid outlet 12 Second housing 13 Wafer 14 Heat source 15 Barrier Device 16 valves 17 Sensors 18 Control circuit 19 Exhaust system 20 Air intake device S1 Test Space S2 high temperature area CA Gas

Claims

1. at least one fluid inlet; at least one fluid outlet; a first housing including a probe card having at least one probe; a second housing coupled to the first housing to form a test space and configured to position the wafer within the test space so that the at least one probe is in electrical contact with an upper surface of the wafer to perform a test process; a heat source that heats a bottom surface of the wafer and forms a high temperature region between the bottom surface and the second enclosure; a barrier device surrounding the high temperature region and providing thermal isolation between the high temperature region and the test volume; Equipped with a gas flows through the test space via the fluid inlet, filling a space between the probe card and the top surface of the wafer, and exits through the at least one fluid outlet; Wafer test cassette.

2. The pressure within the test space is greater than the pressure outside the test space.

2. The wafer test cassette of claim 1.

3. Further comprising a valve, a sensor and a control circuit; Each of the valves and the sensors is connected to the control circuit; the valve is operable to open and close the at least one fluid outlet; The sensor senses at least one of a pressure or a temperature in the test space and transmits the sensed information to the control circuit; The control circuit controls the opening and closing of the valve based on the sensing information.

2. The wafer test cassette of claim 1.

4. Further comprising at least one exhaust device; the at least one exhaust device is connected to the at least one fluid outlet for reducing a flow rate of the gas in the test volume.

2. The wafer test cassette of claim 1.

5. Further comprising an air intake device, the air inlet is connected to the at least one fluid inlet for increasing the flow rate of the gas in the test volume.

2. The wafer test cassette of claim 1.

6. The gas is formed from air or an inert gas.

2. The wafer test cassette of claim 1.

7. The thermal conductivity of the gas is less than 0.026 W / m K.

2. The wafer test cassette of claim 1.

8. The specific heat of the gas is less than 1.015 kJ / (kga·K); 2. The wafer test cassette of claim 1.

9. the second housing has a heat flow inlet and a heat flow outlet in the high temperature area, The heat source is hot air, which enters through the heat flow inlet and exits through the heat flow outlet.

2. The wafer test cassette of claim 1.

10. the heat source is located inside or outside the second enclosure relative to the wafer and provides thermal energy to heat the hot zone or the wafer; 2. The wafer test cassette of claim 1.

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