TDR test method, TDR test structure and preparation method thereof

Abstract

The invention provides a TDR test method, a TDR test structure and a preparation method thereof, the TDR test structure comprises a to-be-tested sample and a connection structure, the to-be-tested sample comprises at least one test pin area, and the test pin area comprises a first test pin and a second test pin which are arranged at an interval; the connecting structure is located on the upper surface of the test pin area, a preset distance is arranged between the first end part of the connecting structure and the first test pin, the second end part of the connecting structure is electrically connected with the second test pin, and the first end part is electrically connected with the second end part. According to the invention, the connection structure is arranged in the test pin area, so that the TDR test can be carried out on any two different pins in the test pin area without replacing a probe in the TDR test process, the TDR test cost is reduced, the test efficiency is improved, and the test range of TDR test equipment is expanded.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor failure analysis, and relates to a TDR test method, a TDR test structure and a preparation method thereof. Background Art

[0002] With the rapid development of integrated circuits, a variety of advanced packaging methods have emerged. Due to the characteristics of complex internal structures and high-density distribution of leads in 2.5D and 3D packaging methods, products are prone to failure during the manufacturing process, and it is also very difficult to locate the failure. The terahertz pulsed time domain reflectometer (Time domain Reflectomtry, abbreviated as TDR), with advantages such as a rising edge time less than 12 ps and a 5-μm fault location resolution, is applied to the failure analysis of 2.5D and 3D packaging, and can quickly display the chip failure position. The device contacts the pins through probes, enabling high-frequency terahertz signals to propagate in the chip. The distance between the probes is fixed, as Figure 1 shown, while the distance between the pins of the chip to be analyzed is not fixed. In this case, only probes with corresponding distances can be replaced, and various sizes of probes need to be prepared, which is costly, cumbersome to operate, and inefficient. Some of the currently packaged products can reach more than 10 cm. Facing such large products, there may be no probes that can cover the pins with such a large distance, resulting in the inability to perform tests.

[0003] Therefore, there is an urgent need to find a TDR test structure that does not require probe replacement, reduces test costs, is simple to operate, and has a large measurement range. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a TDR test method, a TDR test structure and a preparation method thereof, which are used to solve the problems in the prior art that due to the fixed distance of the probes in TDR testing, different probes need to be replaced to measure pins with different distances, resulting in low measurement efficiency, high cost and small measurement range.

[0005] To achieve the above purpose and other related purposes, the present invention provides a preparation method of a TDR test structure, including the following steps:

[0006] Provide a sample to be tested, the sample to be tested includes at least one test pin area, and the test pin area includes a first test pin and a second test pin arranged at intervals;

[0007] Form a connection structure on the upper surface of the test pin area, a first end of the connection structure is spaced from the first test pin by a preset distance, a second end of the connection structure is electrically connected to the second test pin, and the first end and the second end are electrically connected.

[0008] Optionally, the sample to be tested includes a chip and a packaging structure.

[0009] Optionally, an electrical connection part for electrically connecting the first end part and the second end part is further provided in the connection structure.

[0010] Optionally, the material of the electrical connection part includes copper, aluminum, nickel, gold, silver, and titanium.

[0011] Optionally, the length of the electrical connection part is not less than the distance between the first end part and the second end part.

[0012] Optionally, the first end part further includes a first fixing part, the second end part further includes a second fixing part, the first fixing part is fixed on the upper surface of the test pin area, and the second fixing part is fixedly and electrically connected to the second test pin.

[0013] Optionally, the method for fixing the first fixing part on the upper surface of the test pin area includes welding; the method for fixedly and electrically connecting the second fixing part to the second test pin includes welding.

[0014] Optionally, the material of the first fixing part includes tin; the material of the second fixing part includes tin.

[0015] The present invention also provides a TDR test structure, including:

[0016] A sample to be tested, including at least one test pin area, where the test pin area includes a first test pin and a second test pin arranged at intervals;

[0017] A connection structure, located on the upper surface of the test pin area, where a first end part of the connection structure is spaced from the first test pin by a preset distance, a second end part of the connection structure is electrically connected to the second test pin, and the first end part and the second end part are electrically connected.

[0018] The present invention also provides a TDR test method, including the following steps:

[0019] Providing a TDR test structure manufactured by the manufacturing method of the above-mentioned TDR test structure;

[0020] Providing a test probe electrically connected to a TDR test device, where the test probe includes a first detection part and a second detection part arranged at intervals, and the distance between the first detection part and the second detection part is equal to the distance between the first end part and the first test pin in the TDR test structure;

[0021] Bringing the first detection part and the second detection part into electrical contact with the first test pin and the first end part in the TDR test structure respectively.

[0022] As described above, in the TDR testing method, TDR testing structure and preparation method thereof of the present invention, the connection structure is fabricated on the upper surface of the testing pin area, the second end is fixedly and electrically connected to the second testing pin, and then the second testing pin is led to the first end spaced from the first testing pin by a preset distance by combining the electrical connection portion with the second end, so that the electrical signal between the first end and the first testing pin is equivalent to the electrical signal between the first testing pin and the second testing pin. Subsequently, the TDR testing of any two different pins in the testing pin area can be realized without replacing the probe. In addition, the connection structure is simple to fabricate, convenient to remove and low in cost. Meanwhile, after the connection structure is removed, it has no influence on the subsequent normal operation of the sample to be tested, reduces the cost of TDR testing, improves the testing efficiency, expands the testing range of TDR testing equipment, and has high industrial utilization value. Description of the Drawings

[0023] Figure 1 Shows a schematic structural diagram of a probe.

[0024] Figure 2 Shows a process flow diagram of the preparation method of the TDR testing structure of the present invention.

[0025] Figure 3 Shows a schematic structural diagram of a sample to be tested in the preparation method of the TDR testing structure of the present invention.

[0026] Figure 4 Shows a schematic structural diagram after forming the first fixing portion in the preparation method of the TDR testing structure of the present invention.

[0027] Figure 5 Shows a schematic cross-sectional structural diagram after forming the connection structure in the preparation method of the TDR testing structure of the present invention.

[0028] Figure 6 Shows a schematic diagram of probe testing in the TDR testing method of the present invention.

[0029] Description of the Reference Numerals in the Drawings

[0030] 01 Probe

[0031] 011 First Detection Portion

[0032] 012 Second Detection Portion

[0033] 1 Sample to be Tested

[0034] 11 Testing Pin Area

[0035] 12 First Testing Pin

[0036] 13 The second test pin

[0037] 2 Connection structure

[0038] 21 The first fixing part

[0039] 22 Electrical connection part

[0040] 3 Probe

[0041] 31 The first detection part

[0042] 32 The second detection part

[0043] 33 Probe main body part Detailed implementation manners

[0044] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0045] Please refer to Figures 2 to 6 . It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0046] Embodiment 1

[0047] This embodiment provides a preparation method for a TDR test structure. As Figure 2 shown, it is a process flow diagram of the preparation method for the TDR test structure, including the following steps:

[0048] S1-1: Provide a sample to be tested, and the sample to be tested includes at least one test pin area, and the test pin area includes a first test pin and a second test pin arranged at intervals;

[0049] S1-2: Form a connection structure on the upper surface of the test pin area. The first end of the connection structure is spaced from the first test pin by a preset distance, the second end of the connection structure is electrically connected to the second test pin, and the first end and the second end are electrically connected.

[0050] Please refer to Figures 3 to 5, perform the steps S1-1 and S1-2: Provide a sample 1 to be tested, where the sample 1 to be tested includes at least one test pin area 11, and the test pin area 11 includes a first test pin 12 and a second test pin 13 arranged at intervals; form a connection structure 2 on the upper surface of the test pin area 11, a first end (not shown) of the connection structure 2 is spaced from the first test pin 12 by a preset distance, a second end (not shown) of the connection structure 2 is electrically connected to the second test pin 13, and the first end and the second end are electrically connected.

[0051] As an example, as Figure 3 shown, it is a schematic structural diagram of the sample 1 to be tested, and the sample 1 to be tested includes a chip, a packaging structure or other integrated circuit structures that need to perform TDR testing.

[0052] Specifically, the size of the test pin area 11 and its position in the sample 1 to be tested are determined by the layout design of each part of the sample 1 to be tested, which will not be elaborated here.

[0053] Specifically, the first test pin 12 and the second test pin 13 are any two different pins in the test pin area 11, and the number and size of the pins in the test pin area 11 are determined by the actual situation of the product, which will not be elaborated here.

[0054] Specifically, the first test pin 12 includes solder balls or other pins that are convenient for lead-out, and the second test pin 13 includes solder balls or other pins that are convenient for lead-out. In this embodiment, both the first test pin 12 and the second test pin 13 are solder balls.

[0055] Specifically, on the premise of ensuring the accuracy of the subsequent TDR test results, the size of the connection structure 2 can be selected according to the actual situation, and no further limitation is imposed here.

[0056] Specifically, on the premise of ensuring the accuracy of the subsequent TDR test results, the size of the first end can be selected according to the actual situation, and no further limitation is imposed here; the size of the second end can be selected according to the actual situation, and no further limitation is imposed here.

[0057] As an example, as Figure 5 shown, it is a schematic structural diagram after the connection structure 2 is formed, and an electrical connection part 22 for electrically connecting the first end and the second end is further provided in the connection structure 2.

[0058] Specifically, the electrical connection portion 22 is used to electrically connect the first end portion and the second end portion. To ensure the accuracy of subsequent TDR test results, the electrical connection portion 22 can be in the shape of a conductive wire or a conductive sheet. In this embodiment, a metal foil (conductive sheet) is used as the electrical connection portion 22 to electrically connect the first end portion and the second end portion.

[0059] As an example, the material of the electrical connection portion 22 includes copper, aluminum, nickel, gold, silver, titanium, or other suitable conductive materials.

[0060] As an example, the length of the electrical connection portion 22 is not less than the distance between the first end portion and the second end portion.

[0061] Specifically, when there are no pins on the straight line from the first end portion to the second end portion, the length of the electrical connection portion 22 can be equal to the distance between the first end portion and the second end portion. When there are pins on the straight line from the first end portion to the second end portion, to avoid the electrical connection portion 22 making electrical contact with the pins located between the first end portion and the second end portion and affecting the test results, the length of the electrical connection portion 22 is greater than the distance between the first end portion and the second end portion.

[0062] Specifically, when the electrical connection portion 22 is a conductive sheet, the width of the conductive sheet-shaped electrical connection portion 22 can be selected according to actual circumstances as long as it ensures that the electrical connection portion 22 only forms electrical connections with the first end portion and the second end portion. There is no further limitation here. The width here refers to the dimension in the direction parallel to the upper surface of the test pin area 11 and perpendicular to the straight line between the first end portion and the second end portion.

[0063] As an example, as Figure 4 , which is a schematic structural diagram after forming the first fixing portion 21. The first end portion further includes a first fixing portion 21, and the second end portion further includes a second fixing portion (not shown). The first fixing portion 21 is fixed to the test pin area 11, and the second fixing portion is fixedly and electrically connected to the second test pin 13.

[0064] Specifically, the first fixing portion 21 is used to fix the first end portion to the upper surface of the test pin area 11 at a preset distance from the first test pin 12, and the second fixing portion is used to fix the second end portion to the second test pin 13 and achieve the electrical connection between the second test pin 13 and the second end portion.

[0065] Specifically, the first fixing part 21 and the second fixing part are used to fix the first end part and the second end part respectively. At the same time, the second fixing part is used to electrically connect the second end part to the second test pin 13, and the electrical connection part electrically connects the first end part and the second end part, so that the electrical signal between the first test pin 12 and the first end part is equivalent to the electrical signal between the first test pin 12 and the second test pin 13. Then, the second test pin 13 is led to a position at a preset distance from the first end part of the first test pin 12, which is convenient for subsequent TDR testing.

[0066] Specifically, when ensuring the accuracy of the subsequent TDR test results, the size of the first fixing part 21 can be selected according to the actual situation and will not be limited here; the size of the second fixing part can be selected according to the actual situation and will not be limited here.

[0067] As an example, the method of fixing the first fixing part 21 to the test pin area 11 includes soldering or other suitable fixing methods; the method of fixedly electrically connecting the second fixing part to the second test pin 13 includes soldering or other suitable methods.

[0068] As an example, the material of the first fixing part 21 includes tin or other suitable fixing and soldering materials; the material of the second fixing part includes tin or other suitable fixing and soldering materials. In this embodiment, solder balls with sizes similar to those of the first test pin 12 and the second test pin 13 are selected. The solder balls are placed at a position at a preset distance from the first test pin 12 with tweezers, and then heated with a hot air gun to melt the solder balls, and then the solder balls are cooled to fix the solder balls at the preset distance from the first test pin 12, obtaining the first fixing part 21. Then, a metal foil with a suitable size is selected as the electrical connection part 22. The two ends of the metal foil are respectively abutted against the solder ball and the second test pin 13, and the solder ball and the second test pin 13 are melted with an electric soldering iron. After cooling, the two ends of the metal foil are fixedly electrically connected to the solder ball and the second test pin 13 respectively. Then, the second test pin 13 is led to one end where the metal foil and the solder ball are fixed. At the same time, the second test pin 13 is equivalent to the second fixing part. In addition, the solder ball can also be replaced by solder wire.

[0069] Specifically, by forming the connection structure 2 on the upper surface of the test pin area 11, the first end and the second end are electrically connected by the electrical connection portion 22. The second end in the connection structure 2 and the second test pin 13 are fixedly and electrically connected through the second fixing portion. The first end in the connection structure 2 is fixed at a preset distance from the first test pin 12 through the first fixing portion 21, so as to lead the second test pin 13 to the first end spaced from the first test pin 12 by a preset distance, which is convenient for TDR test measurement and has a relatively low manufacturing cost.

[0070] The preparation method of the TDR test structure in this embodiment forms the connection structure 2 on the upper surface of the test pin area 11. The second end and the second test pin 13 are fixedly and electrically connected through the second fixing portion. The first end is fixed at a preset distance from the first test pin 12 through the first fixing portion 21, and the first end and the second end are electrically connected by the electrical connection portion 22, so as to lead the second test pin 13 to the first end spaced from the first test pin 12 by a preset distance, making the electrical signal between the first test pin 12 and the first end equivalent to the electrical signal between the first test pin 12 and the second test pin 13, which is convenient for TDR test measurement and has a low cost.

[0071] Embodiment 2

[0072] This embodiment provides a TDR test structure, as Figure 5 shown, which is a schematic structural diagram of the TDR test structure, including: a sample under test 1 and a connection structure 2. The sample under test 1 includes at least one test pin area 11. The test pin area 11 includes a first test pin 12 and a second test pin 13 arranged at intervals; the connection structure 2 is located on the upper surface of the test pin area 11. The first end of the connection structure 2 is spaced from the first test pin 12 by a preset distance. The second end of the connection structure 2 is electrically connected to the second test pin 13, and the first end and the second end are electrically connected.

[0073] Specifically, the size of the sample under test 1 is determined by the actual situation of the product to be subjected to failure analysis, which will not be elaborated here.

[0074] Specifically, the test pin area 11 includes multiple test pins, and the first test pin 12 and the second test pin 13 are any two different test pins among the multiple test pins in the test pin area 11.

[0075] Specifically, on the premise of ensuring the accuracy of subsequent TDR test results, the shape of the connection structure 2 can be selected according to the actual situation and will not be limited here.

[0076] Specifically, the connection structure 2 further includes an electrical connection portion 22 that electrically connects the first end portion and the second end portion.

[0077] Specifically, the first end portion further includes a first fixing portion 21, the second end portion further includes a second fixing portion. The first fixing portion 21 is fixed to the test pin area 11, and the second fixing portion is fixedly and electrically connected to the second test pin 13.

[0078] Specifically, through the setting of the connection structure 2, the second test pin 13 is led to the first end portion at a preset distance from the first test pin. The first end portion is used to replace the second test pin 13, making the subsequent TDR test on the sample to be tested convenient and fast. The connection structure 2 is easy to remove and does not affect the subsequent normal operation of the sample to be tested.

[0079] In this embodiment, the TDR test structure sets the connection structure 2 on the upper surface of the test pin area 11, realizing leading the second test pin 13 to the first end portion at a preset distance from the first test pin, making the first end portion equivalent to the second test pin 13, facilitating the subsequent TDR test on the sample to be tested. The connection structure 2 is easy to remove and does not affect the subsequent normal operation of the sample to be tested.

[0080] Embodiment Three

[0081] This embodiment provides a TDR test method, and the TDR test method includes the following steps:

[0082] S2-1: Provide a TDR test structure fabricated by the preparation method of the TDR test structure as described in Embodiment One.

[0083] S2-2: Provide a test probe electrically connected to the TDR device. The test probe includes a first detection portion and a second detection portion arranged at intervals, and the distance between the first detection portion and the second detection portion is equal to the distance between the first end portion and the first test pin in the TDR test structure.

[0084] S2-3: Electrically contact the first detection portion and the second detection portion with the first test pin and the first end portion in the TDR test structure respectively.

[0085] Please refer to Figure 6, perform the steps S2-1, S2-2, and S2-3: Provide a TDR test structure fabricated by the preparation method of the TDR test structure described in an embodiment; Provide a test probe 3 electrically connected to the TDR test device, the test probe 3 includes a first detection portion 31 and a second detection portion 32 arranged at intervals, and the distance between the first detection portion 31 and the second detection portion 32 is equal to the distance between the first end portion and the first test pin 12 in the TDR test structure; Electrically contact the first detection portion 31 and the second detection portion 32 with the first test pin 12 and the first end portion in the TDR test structure respectively.

[0086] Specifically, the test probe 3 further includes a probe main body portion 33, the first detection portion 31 and the second detection portion 32 are fixedly arranged at intervals on the probe main body portion 33, and the probe main body portion 33 is electrically connected to the TDR test device.

[0087] Specifically, under the condition of ensuring the accuracy of the TDR test result, the size and shape of the probe main body portion 33 can be selected according to the actual situation and will not be limited here.

[0088] Specifically, a first pointed end for electrically connecting to the test pin is further provided on the first detection portion 31, and a second pointed end for electrically connecting to the test pin is further provided on the second detection portion 32.

[0089] Specifically, under the condition of ensuring the accuracy of the TDR test result, the shape and size of the first detection portion 31 can be selected according to the actual situation and will not be limited here; the shape and size of the second detection portion 32 can be selected according to the actual situation and will not be limited here; the shape and size of the first pointed end can be selected according to the actual situation and will not be limited here; the shape and size of the second pointed end can be selected according to the actual situation and will not be limited here. In this embodiment, both the first pointed end and the second pointed end are conical.

[0090] Specifically, since the connection structure 2 leads the second test pin 13 to the first end through the second end and the electrical connection portion 22, the electrical signal between the first test pin 12 and the first end is equivalent to the electrical signal between the first test pin 12 and the second test pin 13. The distance between the first end and the first test pin 12 is the same as the distance between the first detection portion 31 and the second detection portion 32. Only by bringing the first tip of the first detection portion 31 and the second tip of the second detection portion 32 into contact with the first end and the first test pin 12 respectively, the electrical connection between the first detection portion 31 and the first end and between the second detection portion 32 and the first test pin 12 can be achieved, thereby realizing the TDR test between the first test pin 12 and the second test pin 13.

[0091] Specifically, by combining the TDR test structure with each pin in the test pin area 11, the TDR test can be performed on any two pins in the test pin area 11 without replacing the probe 3, reducing the cost of the TDR test, improving the test efficiency, and being applicable to the test scenarios of various products to be tested.

[0092] The TDR test method of this embodiment is obtained by using the TDR test structure preparation method described in Embodiment 1 to produce the TDR test structure. By combining the TDR test structure with the pins in the test pin area 11, the TDR test can be performed on any two pins in the test pin area 11, and the probe 3 does not need to be replaced during the test process, reducing the cost of the TDR test, improving the test efficiency, and expanding the test range of the TDR test equipment.

[0093] In summary, the TDR test method, TDR test structure and its preparation method of the present invention are achieved by manufacturing a connection structure on the upper surface of the test pin area. By combining the electrical connection portion in the connection structure with the second end electrically connected to the second test pin, the second test pin is led to the first end spaced from the first test pin by a preset distance, so that the electrical signal between the first end and the first test pin is equivalent to the electrical signal between the first test pin and the second test pin. Then, the TDR test can be performed on any two different pins in the test pin area without replacing the probe. In addition, the manufactured connection structure has a low cost and is simple to manufacture. At the same time, the connection structure is easy to remove and has no impact on the subsequent normal operation of the sample to be tested after removal, reducing the cost of the TDR test, improving the test efficiency and expanding the test range of the TDR test equipment. Therefore, the present invention effectively overcomes various disadvantages in the prior art and has high industrial utilization value.

[0094] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A preparation method of a TDR test structure, characterized in that It includes the following steps: Provide a sample to be tested, the sample to be tested includes at least one test pin area, and the test pin area includes a first test pin and a second test pin which are arranged at intervals; Form a connection structure on the upper surface of the test pin area, a first end of the connection structure is spaced from the first test pin by a preset distance, a second end of the connection structure is electrically connected to the second test pin, and the first end and the second end are electrically connected.

2. The preparation method of the TDR test structure according to claim 1, characterized in that: The sample to be tested includes a chip and a packaging structure.

3. The preparation method of the TDR test structure according to claim 1, characterized in that: The connection structure further includes an electrical connection portion that electrically connects the first end and the second end.

4. The preparation method of the TDR test structure according to claim 3, characterized in that: The material of the electrical connection portion includes copper, aluminum, nickel, gold, silver, and titanium.

5. The preparation method of the TDR test structure according to claim 3, characterized in that: The length of the electrical connection portion is not less than the distance between the first end and the second end.

6. The preparation method of the TDR test structure according to claim 1, characterized in that: The first end further includes a first fixing portion, the second end further includes a second fixing portion, the first fixing portion is fixed on the upper surface of the test pin area, and the second fixing portion is fixedly and electrically connected to the second test pin.

7. The preparation method of the TDR test structure according to claim 6, characterized in that: The method of fixing the first fixing portion on the upper surface of the test pin area includes welding; the method of fixedly and electrically connecting the second fixing portion to the second test pin includes welding.

8. The preparation method of the TDR test structure according to claim 6, characterized in that: The material of the first fixing portion includes tin; the material of the second fixing portion includes tin.

9. A TDR test structure, characterized in that, It includes: A sample to be tested, including at least one test pin area, and the test pin area includes a first test pin and a second test pin which are arranged at intervals; A connection structure, located on the upper surface of the test pin area, a first end of the connection structure is spaced from the first test pin by a preset distance, a second end of the connection structure is electrically connected to the second test pin, and the first end and the second end are electrically connected.

10. A TDR testing method, characterized in that, It includes the following steps: Provide a TDR test structure manufactured by the preparation method of the TDR test structure according to any one of claims 1 to 8; Provide a test probe electrically connected to a TDR test device, the test probe includes a first detection portion and a second detection portion which are arranged at intervals, and the distance between the first detection portion and the second detection portion is equal to the distance between the first end and the first test pin in the TDR test structure; Electrically contact the first detection portion and the second detection portion with the first test pin and the first end in the TDR test structure respectively.

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