Probe card structure for high-frequency test and test method thereof

Abstract

The invention discloses a probe card structure for high-frequency testing and a testing method thereof, and the probe card structure comprises a circuit board, a silicon substrate and a probe head assembly. The silicon substrate is arranged on one side of the circuit board and is electrically connected with the circuit board. And a signal processing circuit is arranged on the silicon substrate. The probe head assembly includes a plurality of probes electrically connected to the silicon substrate.

Description

Technical Field

[0001] The present invention relates to a probe card structure and a testing method thereof, and in particular to a probe card structure and a testing method thereof for high frequency testing. Background Art

[0002] In the existing wafer testing, an automated test equipment (ATE) is coupled to a wafer probe tester to provide a test signal to the device under test through a probe head and a probe card, and to determine whether the operation and / or performance of the device under test is normal by measuring the response of the device under test to the test signal. However, the line connecting the probe card to the automatic tester is long, and a larger space is required to place the line, which is not conducive to high-speed transmission.

[0003] In addition, in order to adapt to the increasingly smaller chip sizes, in the prior art, an adapter plate or space converter (such as a multi-layer organic board, MLO) is used to shorten the pitch of the probes. However, as the chip is miniaturized, the adapter plate or space converter is limited by its process capabilities and cannot provide a smaller pitch, and therefore cannot meet the test point spacing requirements of the miniaturized chip. Since the spacing provided by the adapter plate or space converter is limited, the contact between the probe and the contact point will be limited, thereby lengthening the time required for the test and reducing the test efficiency. In addition, the signal path cannot be further shortened, so that the transmission of the signal cannot effectively reduce interference.

[0004] Therefore, how to provide an innovative probe card structure design so that the adapter plate or space converter can provide a smaller spacing, and how to speed up the test speed of the probe card used for high-frequency testing, reduce the signal transmission path and reduce the impact of signal interference to overcome the above-mentioned defects has become one of the important issues that this business wants to solve. Summary of the invention

[0005] In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a probe card structure for high-frequency testing, including: a circuit board; a silicon substrate, a probe head assembly and a signal processing circuit. The silicon substrate is arranged on one side of the circuit board and is electrically connected to the circuit board. The probe head assembly includes a plurality of groups of vertical probes, and the probe head assembly receives the high-frequency signal of the object to be tested through the probes and transmits the high-frequency signal to the silicon substrate. The signal processing circuit is arranged on the silicon substrate, and is used to process the high-frequency signal into an output signal, and transmit the output signal to the tester.

[0006] In one embodiment of the present invention, the signal processing circuit is an active component or a passive component.

[0007] In one embodiment of the present invention, the signal processing circuit includes a power supply, an amplifier, an oscillator, a digital signal processor, and an analog signal converter.

[0008] In an embodiment of the present invention, the signal processing circuit includes a first circuit element, a second circuit element and a third circuit element.

[0009] In one embodiment of the present invention, each of the probes has a first contact end and a second contact end opposite to each other, the first contact end is electrically connected to the silicon substrate, the second contact end contacts the object to be tested, and the silicon substrate and the object to be tested have the same material properties.

[0010] In one embodiment of the present invention, the electrical signal of the object to be tested is processed by the signal processing circuit on the silicon substrate instead of passing through the circuit board.

[0011] In one embodiment of the present invention, the distance between any two adjacent probes is less than 40 micrometers.

[0012] In one embodiment of the present invention, a plurality of solder balls are provided on the surface of the silicon substrate facing the circuit board, and the material of the plurality of solder balls is metal or alloy.

[0013] In one embodiment of the present invention, the probe is made of at least one of copper, palladium, silver, gold, platinum, tungsten, rhenium tungsten, beryllium copper, palladium gold, palladium silver, tungsten carbide or alloys thereof.

[0014] In order to solve the above-mentioned technical problems, another technical solution adopted by the present invention is to provide a high-frequency signal testing method, including: using multiple groups of vertical probes in a probe head assembly to receive the high-frequency signal of the object to be tested, and transmitting the high-frequency signal to a silicon substrate; using a signal processing circuit on the silicon substrate to process the high-frequency signal to process the high-frequency signal into an output signal, and transmitting the output signal to a testing machine.

[0015] One of the beneficial effects of the present invention is that the probe card structure for high-frequency testing provided by the present invention can accelerate the processing speed of the probe card and avoid interference under long paths through the technical solutions of "the probe head assembly is used to receive the high-frequency signal of the object to be tested and transmit the high-frequency signal to the silicon substrate" and "the signal processing circuit is arranged on the silicon substrate, and is used to process the high-frequency signal into an output signal, and transmit the output signal to the tester", so as to make the probe card suitable for high-frequency transmission.

[0016] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A side view schematic diagram of an embodiment of the present invention;

[0018] Figure 2 It is a side view schematic diagram of another embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following is a specific embodiment to illustrate the implementation of the "probe card structure for high-frequency testing and its testing method" disclosed in the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations, not depictions based on actual sizes, and it is stated in advance. The following embodiments will further explain the relevant technical content of the present invention in detail, but the disclosed content is not used to limit the scope of protection of the present invention. In addition, it should be understood that although the terms "first", "second", "third" and the like may be used in this article to describe various elements, these elements should not be limited by these terms. These terms are mainly used to distinguish one element from another element. In addition, the term "or" used in this article may include any one or more combinations of the associated listed items depending on the actual situation. In addition, the term "or" used in this article may include any one or more combinations of the associated listed items depending on the actual situation.

[0020] [Example]

[0021] See also Figure 1 As shown, the probe card structure M1 of the present invention includes a circuit board 1, a silicon substrate 2 and a probe head assembly 3. The circuit board 1 can be a printed circuit board (PCB) or a flexible printed circuit board (FPCB). However, the above example is only one feasible embodiment and is not intended to limit the present invention. In the probe card structure M1 of the present invention, a silicon substrate 2 is provided on one side of the circuit board 1, and the silicon substrate 2 can be electrically connected to the circuit board 1.

[0022] The silicon substrate 2 of the present invention can be used as an adapter plate or a space converter. Compared with the adapter plate or space converter made of a PCB board, the use of the silicon substrate 2 can provide a smaller spacing between the probes. It is worth mentioning that, based on cost and size considerations, the signal processing circuit 21 cannot be set on the PCB board. Therefore, the silicon substrate 2 of the present invention is preferably a silicon wafer. Since the silicon substrate 2 of the present invention is made of silicon-based materials, the signal processing circuit 21 can be set on the silicon substrate 2. The signal processing circuit 21 can be an active component or a passive component. For example, the material of the silicon substrate 2 may include silicon nitride or silicon carbide. In other words, the silicon substrate 2 can be made of the same material as the object under test DUT, so that the silicon substrate 2 and the object under test DUT have the same material properties. In this way, since the multiple probes 33 on the probe head assembly 3 are electrically connected to the silicon substrate 2, and the silicon substrate 2 and the object under test DUT have the same material properties, when the conductive contact P on the surface of the object under test DUT is displaced due to thermal expansion and contraction, the offset of the conductive contact P will be the same as the offset of the multiple probes 33, thereby improving the accuracy of the insertion of the multiple probes 33.

[0023] For example, the signal processing circuit 21 can be a power supply, an amplifier, an oscillator, a digital signal processor (DSP), and an analog signal converter, so that the silicon substrate 2 can directly correspond to the DUT for signal processing without the need to pull a wire through the circuit board 1 to transmit the electrical signal to the tester (tester) outside the probe card structure M1. In other words, the electrical signal measured from the DUT will not pass through the circuit board 1. It should be noted that as long as the electrical signal of the DUT can be tested directly on the silicon substrate 2, the present invention does not particularly limit the type of signal processing circuit 21. Furthermore, the high-frequency signal detected by multiple probes 33 from the DUT is transmitted to the signal processing circuit 21 of the silicon substrate 2, and different groups of probes correspond to different signal processing circuits 21, so that the signal processing circuit 21 processes the signals of different groups of probes. The detected high-frequency signal is processed by the signal processing circuit 21 on the silicon substrate 2, and the processing result is then transmitted to the tester through the circuit board and the conductive wire to complete the test. During the signal processing, the high-frequency signal starts from the DUT and only passes through multiple probes 33 and the signal processing circuit 21 of the silicon substrate 2 to complete the signal processing, thereby greatly shortening the transmission path of the high-frequency signal and effectively reducing the interference of the high-frequency signal.

[0024] Further, the plurality of probes 33 may be vertical probes. For example, the plurality of probes 33 may be elastic probes, such as vertical spring-type test pins (Pogo Pin). However, as long as they can be mounted on a probe card to test the object under test DUT, the present invention does not particularly limit the type of probe 33. For example, the probe 33 may be an elastic structure that can bend and deform after being subjected to an axial external force and exceeding a critical load, so that the probe 33 is not easily broken due to external compression. For example, the plurality of probes 33 are made of at least one of copper, palladium, silver, gold, platinum, tungsten, rhenium tungsten, beryllium copper, palladium gold, palladium silver, tungsten carbide or alloys of the above materials. In one embodiment of the present invention, the spacing between each two adjacent probes 33 is less than 40 microns to manufacture a probe card suitable for testing small chips.

[0025] In another embodiment of the present invention, Figure 2 As shown, in the probe card structure M2 of the present invention, the signal processing circuit 21 may include a first circuit element 21a, a second circuit element 21b and a third circuit element 21c. For example, the first circuit element 21a is a resistor, the second circuit element 21b is a capacitor, and the third circuit element 21c is an inductor. In other words, the present invention can establish an RLC circuit on the silicon substrate 2 and electrically connect it to the probe 33 to speed up the test. Accordingly, the present invention can also compensate for the electrical path (for example: impedance matching).

[0026] In detail, the signal processing circuit 21 is arranged on the silicon substrate 2, so that a loop back structure is formed between the signal processing circuit 21 and the conductive contact P of the object under test DUT. When testing, the electrical signal of the object under test DUT can be processed by the signal processing circuit 21 on the silicon substrate 2, without passing through the circuit board 1, and there is no need to set up additional lines to transmit the electrical signal to the automatic tester outside the probe card structure M2. Therefore, the processing of the electrical signal can be completed quickly, and the interference caused by long lines can be avoided, and the components and costs required for the test device can be reduced, which is particularly suitable for the field of high-frequency testing. In other words, setting the signal processing circuit 21 on the silicon substrate 2 can speed up the processing speed of the probe card test.

[0027] Furthermore, the circuit board 1 and the silicon substrate 2 are electrically connected to each other via a plurality of solder balls 4. Specifically, a plurality of solder balls 4 are provided on the surface of the silicon substrate 2 facing the circuit board 1. The silicon substrate 2 is electrically connected to the circuit board 1 via the plurality of solder balls 4 so as to firmly solder the silicon substrate 2 to the circuit board 1. Furthermore, the material of the plurality of solder balls 4 is metal or alloy. Preferably, the material of the plurality of solder balls 4 is tin, tin alloy, gold or gold alloy. However, the above example is only one feasible embodiment and is not intended to limit the present invention.

[0028] Further, the probe head assembly 3 may include an upper guide plate 31, a lower guide plate 32 and a plurality of probes 33. The upper guide plate 31 and the lower guide plate 32 are arranged parallel to each other and respectively have a plurality of upper guide plate holes and a plurality of lower guide plate holes (not shown), and the two ends of the plurality of probes 33 are respectively penetrated through the upper guide plate 31 and the lower guide plate 32 through the plurality of upper guide plate holes and the plurality of lower guide plate holes. In addition, each of the plurality of probes 33 is a structure integrally formed by a conductor, and includes a first contact end 331 and a second contact end 332 opposite to each other. The first contact end 331 is electrically connected to the silicon substrate 2, and the second contact end 332 contacts a conductive contact P on the object under test DUT. For example, the probes 33 may be formed by micro-electromechanical process, electroforming or laser cutting.

[0029] That is, the first contact end 331 of the probe 33 passes through the upper guide plate hole of the upper guide plate 31 and is electrically connected to the silicon substrate 2, and the second contact end 332 of the probe 33 passes through the lower guide plate hole and is electrically connected to the conductive contact P on the surface of the object under test DUT. For example, the conductive contact P can be a solder pad, a bump or a solder ball. It should be noted that the upper guide plate 31 and the lower guide plate 32 of the present invention are not limited to one. In one embodiment of the present invention, the probe head assembly 3 may include multiple upper guide plates 31 and multiple lower guide plates 32.

[0030] The high-frequency signal testing method provided by the present invention includes step S100 and step S200. In step S100, a probe head assembly 3 is used to receive a high-frequency signal of the object under test DUT, and the probe head assembly 3 includes a plurality of sets of vertical probes for transmitting the high-frequency signal to the silicon substrate 2. In step S200, the high-frequency signal is processed by a signal processing circuit 21 on the silicon substrate 2 to process the high-frequency signal to process the high-frequency signal into an output signal, and the output signal is transmitted to a tester. Compared with the existing high-frequency testing method that requires the high-frequency signal to be transmitted back to the tester for processing, the testing method of the present invention can directly process the high-frequency signal through the signal processing circuit 21 on the silicon substrate 2, and can provide the shortest path for the high-frequency signal, thereby avoiding interference of the high-frequency signal through a long path.

[0031] [Beneficial Effects of Embodiments]

[0032] One of the beneficial effects of the present invention is that the probe card structure for high-frequency testing provided by the present invention can accelerate the processing speed of the probe card and avoid interference under long paths through the technical solutions of "the probe head assembly is used to receive a high-frequency signal of an object to be tested and transmit the high-frequency signal to the silicon substrate" and "the signal processing circuit is arranged on the silicon substrate to process the high-frequency signal into an output signal and transmit the output signal to the tester", so as to make the probe card more suitable for high-frequency transmission.

[0033] Furthermore, the probe card structure of the present invention sets active / passive elements on the silicon substrate, so that a loopback structure is formed between the active / passive elements and the conductive contacts of the object to be tested. Therefore, the electrical signal measured from the object to be tested does not need to be sent back to the automatic tester outside the probe card structure via a line coupled to the wafer probe test machine, but can be processed through the loopback structure between the active / passive elements and the conductive contacts of the object to be tested, which can speed up the processing speed, avoid interference under long paths, and reduce the components and costs of the settings, and is particularly suitable for use in the field of high-frequency probe testing.

[0034] In addition, in the probe card structure of the present invention, since multiple probes are electrically connected to the silicon substrate, and the silicon substrate and the object to be tested have the same material properties, when the conductive contacts on the surface of the object to be tested are displaced due to thermal expansion and contraction, the offset of the position to be tested will be the same as the offset of the multiple probes, thereby improving the accuracy of the insertion of the multiple probes.

[0035] The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the protection scope of the claims of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention description and drawings are included in the protection scope of the claims of the present invention.

Claims

1. A probe card structure for high frequency testing, characterized in that: The probe card structure comprises: Circuit boards; A silicon substrate, disposed on one side of the circuit board and electrically connected to the circuit board; A probe head assembly, comprising a plurality of groups of vertical probes, the probe head assembly being used to receive high-frequency signals of an object to be tested through the probes and transmit the high-frequency signals to the silicon substrate; and The signal processing circuit is arranged on the silicon substrate and is used for processing the high-frequency signal into an output signal and transmitting the output signal to the test machine.

2. The probe card structure according to claim 1, characterized in that: The signal processing circuit is an active component or a passive component.

3. The probe card structure according to claim 1, characterized in that: The signal processing circuit includes a power supply, an amplifier, an oscillator, a digital signal processor, and an analog signal converter.

4. The probe card structure according to claim 1, characterized in that: The signal processing circuit includes a first circuit element, a second circuit element and a third circuit element.

5. The probe card structure according to claim 1, characterized in that: Each of the probes has a first contact end and a second contact end opposite to each other, the first contact end is electrically connected to the silicon substrate, the second contact end contacts the object to be tested, and the silicon substrate and the object to be tested have the same material properties.

6. The probe card structure according to claim 5, characterized in that: The electrical signal of the object to be tested is processed by the signal processing circuit on the silicon substrate without passing through the circuit board.

7. The probe card structure according to claim 1, characterized in that: The distance between each two adjacent probes is less than 40 microns.

8. The probe card structure according to claim 1, characterized in that: A plurality of solder balls are disposed on the surface of the silicon substrate facing the circuit board, and the material of the plurality of solder balls is metal or alloy.

9. The probe card structure according to claim 1, characterized in that: The probe is made of at least one of copper, palladium, silver, gold, platinum, tungsten, rhenium tungsten, beryllium copper, palladium gold, palladium silver, tungsten carbide or alloys of the above materials.

10. A method for testing high-frequency signals, characterized in that: The high-frequency signal testing method includes: Using a plurality of groups of vertical probes in the probe head assembly to receive high-frequency signals of the object to be tested, and transmitting the high-frequency signals to the silicon substrate; and The high frequency signal is processed by a signal processing circuit on the silicon substrate to process the high frequency signal into an output signal, and the output signal is transmitted to a tester.

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