Test pad structure and test system for reliability package test

Abstract

The invention provides a test pad structure and a test system for a reliability package test, and the test pad structure for the reliability package test comprises a first test pad unit which comprises a plurality of first test pads which are arranged at intervals, and the first test pads are used for being connected with different ends of a to-be-tested device in a one-to-one correspondence manner; the second test pad unit comprises a plurality of second test pads arranged at intervals, and the second test pads are used for being connected with different ends of the to-be-tested device in a one-to-one correspondence manner; wherein the first test pads and the second test pads are alternately arranged; and the testing device is respectively connected with the first testing pad unit and the second testing pad unit during testing before and after packaging. Through the configuration, different test pad units can be used in tests before packaging and after packaging, electrical data required by a test structure can be collected before packaging, packaging abnormity caused by test probe marks can be avoided, and comprehensive analysis of packaging test data is facilitated.

Description

Technical Field

[0001] The invention relates to the field of semiconductor manufacturing, and in particular to a test pad structure and a test system for reliability packaging testing. Background Art

[0002] The reliability packaging tests of integrated circuit devices mainly include HCI (Hot Carrier Injection), BTI (Bias Temperature Instability) and VTS (Via Thermal Stress), which are important items in reliability test evaluation.

[0003] Currently, most test structures are four-terminal test structures, which are connected to the gate, source, drain and base of the device respectively. These four terminals are connected through four test pads and tested.

[0004] Conventional packaging tests will select several locations before packaging to test the initial electrical parameters of the structure to ensure the accuracy of the entire wafer process and test structure. If a structure whose initial electrical parameters have not been tested is packaged, and if abnormal electrical parameters are found during sample testing after packaging, it is impossible to determine whether the abnormality is caused by packaging, which makes data analysis difficult. At the same time, the existing test pad structure will leave probe needle marks after wafer-level data collection before packaging, and there is a certain possibility of packaging abnormalities during subsequent packaging and wiring, which will affect the test and cause loss of test samples.

[0005] Based on this, how to avoid using the same set of test pad structures before and after packaging, which affects the test results and also causes the loss of test samples, has become a technical problem that technicians in this field need to solve. Summary of the invention

[0006] The purpose of the present invention is to provide a test pad structure and a test system for reliability packaging testing, so as to solve the problem in the prior art that the same set of test pad structures needs to be used before and after packaging, which affects the test results and causes the loss of test samples.

[0007] In order to achieve the above object, the present invention provides a test pad structure for reliability packaging testing, comprising:

[0008] A first test pad unit, comprising a plurality of first test pads arranged at intervals, wherein the first test pads are used to be connected to different ends of the device to be tested in a one-to-one correspondence;

[0009] A second test pad unit, comprising a plurality of second test pads arranged at intervals, wherein the second test pads are used to be connected to different ends of the device to be tested in a one-to-one correspondence;

[0010] Wherein, the first test pads and the second test pads are arranged alternately;

[0011] The testing device is connected to the first testing pad unit and the second testing pad unit respectively when performing pre-packaging and post-packaging tests.

[0012] Optionally, the first test pad and an adjacent second test pad are connected in sequence; wherein, the first test pad in the first test pad unit is connected to the first second test pad in the second test pad unit; and the last first test pad in the first test pad unit is connected to the last second test pad in the second test pad unit.

[0013] Optionally, when the second test pad is located between the last first test pad in the previous first test pad unit and the first first test pad in the next first test pad unit, the second test pad is connected to two first test pads respectively.

[0014] Optionally, the first test pad and the second test pad are connected via a metal interconnection layer.

[0015] Optionally, a size of the first test pad is larger than a size of the second test pad.

[0016] Optionally, the first test pad unit is used to connect with the test device to perform a test before packaging; and the second test pad unit is used to connect with the test device to perform a test after packaging.

[0017] Optionally, the first test pad unit includes four first test pads, which are respectively connected to the source, drain, gate and base of the device to be tested in a one-to-one correspondence;

[0018] The second test pad unit includes four second test pads, which are respectively connected to the source, drain, gate and base of the device under test in a one-to-one correspondence.

[0019] Optionally, the spacings between the first test pads in the same first test pad unit are equal; the spacings between the second test pads in the same second test pad unit are equal.

[0020] Optionally, all first test pads in the same first test pad unit have the same size, and all second test pads in the same second test pad unit have the same size.

[0021] In order to achieve the above object, the present invention also provides a test system, comprising: a test device, a device to be tested, and a test pad structure for reliability packaging testing as described above;

[0022] Different ends of the device under test are respectively led out through different first test pads in the first test pad unit and different second test pads in the second test pad unit;

[0023] The testing device is connected to the first testing pad unit and the second testing pad unit respectively during the testing process of the device under test before and after packaging.

[0024] Compared with the existing test pad structure, the test pad structure and test system for reliability packaging test provided by the present application have the following advantages:

[0025] The test pad structure for reliability packaging testing provided by the present application is provided with a first test pad unit and a second test pad unit, wherein a plurality of test pads are provided in the two test pad units, and different ends on the device to be tested are respectively led out through the test pads one by one. During the test, one of the test pad units can be used as a wafer-level test of the test structure before packaging, and the other test pad unit can be used for wiring during packaging testing. The use of the two test pad units can not only collect the electrical data required for the test structure before packaging, but also avoid packaging anomalies caused by needle marks of the test probes, which is conducive to the comprehensive analysis of the packaging test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of a test pad in the prior art;

[0027] Figure 2 A schematic diagram of the structure of a test pad for reliability packaging testing provided by an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of the connection relationship between the first test pad and the second test pad provided in an embodiment of the present invention;

[0029] Figure 4 A cross-sectional view of the connection relationship between a first test pad and a second test pad provided by an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of the dimensions of a first test pad and a second test pad provided in an embodiment of the present invention.

[0031] The description of each reference numeral is as follows:

[0032] 1-first test pad unit; 10-first test pad;

[0033] 2-second test pad unit; 20-second test pad;

[0034] 3-Metal interconnect layer;

[0035] 4- Test pad. DETAILED DESCRIPTION

[0036] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0037] As used in this specification, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used to include the meaning of "and / or", the term "several" is generally used to include the meaning of "at least one", and the term "at least two" is generally used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features, "one end" and "the other end" and "the proximal end" and "the distal end" generally refer to two corresponding parts, which include not only the endpoints, and the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. In addition, as used in this specification, an element disposed on another element generally only indicates that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements may be direct or indirect through an intermediate element, and it cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element may be in any orientation such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. The terms "upper", "lower", "top" and "bottom" are generally relative position relationships arranged in the direction of gravity; the terms "vertical, vertical direction" generally refer to the direction of gravity, which is generally perpendicular to the ground, and "horizontal, horizontal plane direction" generally refers to the direction parallel to the ground; for ordinary technicians in this field, the specific meanings of the above terms in this specification can be understood according to specific circumstances.

[0038] The purpose of the present invention is to provide a test pad structure and a test system for reliability packaging testing, so as to solve the problem in the prior art that the same set of test pad structures needs to be used before and after packaging, which affects the test results and causes the loss of test samples.

[0039] Those skilled in the art can understand that the reliability packaging test of integrated circuit devices is a key link to ensure the stability of products in long-term use. It mainly includes environmental reliability test, mechanical and physical stress test, life accelerated aging test, pretreatment and process verification test and other special tests. Please refer to Figure 1 , the existing test pad structure has only one group of test pads 4. After the wafer-level data collection before packaging, test probe needle marks will be left on the test pads 4. There is a certain possibility of packaging abnormalities during subsequent packaging wiring, which affects the integrity of data collection after packaging and may also cause the loss of test samples. Based on this, this embodiment sets a first test pad unit and a second test pad unit, and uses one group of test pad units as a test structure for wafer-level testing before packaging, and uses the other group of test pad units as a test structure for reliability testing after packaging, thereby ensuring that complete data collection can be performed before and after packaging, and providing more comprehensive data support for packaging test results.

[0040] Please refer to Figure 2 and Figure 3 The present invention provides a test pad structure for reliability packaging testing, comprising: a first test pad unit 1, comprising a plurality of first test pads 10 arranged at intervals, the first test pads 10 being used to connect to different ends of the device to be tested in a one-to-one correspondence; a second test pad unit 2, comprising a plurality of second test pads 20 arranged at intervals, the second test pads 20 being used to connect to different ends of the device to be tested in a one-to-one correspondence; wherein the first test pads 10 and the second test pads 20 are arranged alternately; and the testing device is connected to the first test pad unit 1 and the second test pad unit 2, respectively, when performing pre-packaging and post-packaging tests. It should be noted that, in the present embodiment, the test structure is a four-terminal test structure, that is, the first test pad unit 1 is provided with four first test pads 10, which are respectively connected to the source, gate, drain and base of the device to be tested; the second test pad unit 2 is provided with four second test pads 20, which are also respectively connected to the source, gate, drain and base of the device to be tested. Please refer to Figure 2 , the device to be tested is located in the lower layer of the second test pad b and the second test pad f. In other embodiments, the test structure may not be a four-terminal test structure. In this case, the first test pad unit 1 and the second test pad unit 2 may also be provided with other different numbers of test pads, as long as it can be ensured that the same device to be tested can be tested using different test pads before and after packaging.

[0041] With such configuration, by setting up a first test pad unit 1 and a second test pad unit 2, a plurality of test pads are provided in the two test pad units, and different ends on the device to be tested are respectively led out through the test pads one by one. During the test, one of the test pad units can be used for wafer-level testing of the test structure before packaging, and the other test pad unit can be used for wiring during packaging testing. The use of two test pad units can not only collect the electrical data required for the test structure before packaging, but also avoid packaging anomalies caused by needle marks of the test probes, which is conducive to the comprehensive analysis of packaging test data.

[0042] Please refer to Figure 3 to Figure 4 , the first test pad 10 and the adjacent second test pad 20 are connected in sequence; wherein, the first test pad 10 in the first test pad unit 1 is connected to the first second test pad 20 in the second test pad unit 2; the last first test pad 10 in the first test pad unit 1 is connected to the last second test pad 20 in the second test pad unit 2. In this embodiment, the test pad on the far left in the same test pad unit is the first test pad, and the test pad on the far right is the last test pad. Please refer to Figure 3 , the first test pad unit 1 is provided with a first test pad A, a first test pad B, a first test pad C and a first test pad D from left to right, and the second test pad unit 2 is provided with a second test pad a, a second test pad b, a second test pad c and a second test pad d from left to right. Among them, the first test pad A is connected to the second test pad a, the first test pad B is connected to the second test pad b, the first test pad C is connected to the second test pad c, and the first test pad D is connected to the second test pad d.

[0043] Preferably, when the second test pad 20 is located between the last first test pad 10 in the previous first test pad unit 1 and the first first test pad 10 in the next first test pad unit 1, it is connected to the two first test pads 10 respectively. Figure 3 , two first test pad units 1 and two second test pad units 2 are respectively provided in the figure, the first first test pad unit 1 includes the first test pad A, the first test pad B, the first test pad C and the first test pad D, and the second first test pad unit 1 includes the first test pad E, the first test pad F, the first test pad G and the first test pad H; the first second test pad unit 2 includes the second test pad a, the second test pad b, the second test pad c and the second test pad d, and the second second test pad unit 2 includes the second test pad d, the second test pad e, the second test pad f and the second test pad g. Among them, the second test pad d is located between the first test pad D and the first test pad E, and is connected to both the first test pad D and the first test pad E, which can save the occupied area of ​​the test pad.

[0044] As an alternative embodiment, please refer to Figure 4, the first test pad 10 and the second test pad 20 are connected through the metal interconnection layer 3. It should be noted that in this embodiment, the first test pad 10 is stacked in sequence through various layers of metal and through holes, and is finally connected to the device under test, and the second test pad 20 is connected to the first test pad 10 through the metal interconnection layer 3, which further saves the cost of process manufacturing.

[0045] Please refer to Figure 3 and Figure 5 , the size of the first test pad 10 is larger than the size of the second test pad 20. Furthermore, the first test pad unit 1 is used to connect with the test device to perform a test before packaging; the second test pad unit 2 is used to connect with the test device to perform a test after packaging. It can be understood by those skilled in the art that since the spacing between the test pads needs to be compatible with the spacing between the probe cards of the standard test machine, the spacing between each test pad is fixed and limited. When setting two groups of test pad units, it is necessary to appropriately reduce the size of the test pads in one group of test pad units. At the same time, since the package bonding also has requirements on the size of the test pad, it should not be too small. In this embodiment, it is preferred to use the first test pad unit 1 to perform device packaging reliability testing after package bonding, and use the second test pad unit 2 to collect electrical data before packaging, so that the pre-packaging and post-packaging tests do not affect each other, and complete data can be obtained.

[0046] Please refer to Figures 3 to 5 , the spacings between the first test pads 10 in the same first test pad unit 1 are equal; the spacings between the second test pads 20 in the same second test pad unit 2 are equal. It should be noted that since the spacings of the probe cards of the standard test machine are fixed, Figure 3 In the embodiment, the spacing between the first test pad A, the first test pad B, the first test pad C and the first test pad D in the first test pad unit 1 is equal, and the spacing between the second test pad a, the second test pad b, the second test pad c and the second test pad d in the second test pad unit 2 is also equal; at the same time, the spacing between each first test pad 10 and the spacing between each second test pad 20 need to be adapted to the spacing of the probe card for testing. In this embodiment, the spacing between each first test pad 10 is 55μm, and the spacing between each second test pad 20 is 65μm.

[0047] In an optional embodiment, all first test pads 10 in the same first test pad unit 1 have the same size, and all second test pads 20 in the same second test pad unit 2 have the same size. It should be noted that in this embodiment, Figure 5 The test pad dimensions in Figure 4The size of the lower surface of the trapezoidal through hole in the first test pad 10 is a square with a length and height of 45μm, and the second test pad 20 is a rectangle with a length of 25μm and a height of 45μm. The sizes of the four first test pads 10 in the same first test pad unit 1 are equal, and the sizes of the four second test pads 20 in the same second test pad unit 2 are equal. On the one hand, it is convenient for process manufacturing, and on the other hand, it is also convenient for probe card insertion, and there is no need to adjust the probe card insertion position due to different sizes of test pads. Of course, in some other embodiments, the sizes of the first test pads 10 in different first test pad units 1 may also be different, and those skilled in the art can configure this according to actual conditions, and this embodiment does not limit this.

[0048] In another embodiment, the present invention also provides a test system, including: a test device, a device to be tested, and a test pad structure for reliability packaging testing as described above; different ends of the device to be tested are respectively led out through different first test pads 10 in the first test pad unit 1 and different second test pads 20 in the second test pad unit 2; the test device is connected to the first test pad unit 1 and the second test pad unit 2 respectively during the test process of the device to be tested before and after packaging. It should be noted that in this embodiment, the test device can be a standard wafer-level test machine, which is connected to the first test pad unit 1 and the second test pad unit 2 respectively during the test through a probe card to obtain corresponding data.

[0049] With such configuration, by using the above-mentioned test pad structure for reliability packaging testing, the test device can be connected to the first test pad unit 1 and the second test pad unit 2 respectively during the test process before and after packaging; the use of two test pad units can not only collect the electrical data required for the test structure before packaging, but also avoid packaging anomalies caused by test probe marks, which is conducive to the comprehensive analysis of packaging test data.

[0050] In summary, in the test pad structure and test system for reliability packaging testing provided by the embodiments of the present invention, the test pad structure for reliability packaging testing includes: a first test pad unit, including a plurality of first test pads arranged at intervals, and the first test pads are used to connect one-to-one with different ends of the device to be tested; a second test pad unit, including a plurality of second test pads arranged at intervals, and the second test pads are used to connect one-to-one with different ends of the device to be tested; wherein the first test pads and the second test pads are arranged alternately; and the test device is connected to the first test pad unit and the second test pad unit respectively when performing pre-packaging and post-packaging tests.

[0051] With such configuration, by setting up a first test pad unit and a second test pad unit, multiple test pads are set in the two test pad units, and different ends on the device to be tested are respectively led out through the test pads one by one. During the test, one of the test pad units can be used for wafer-level testing of the test structure before packaging, and the other test pad unit can be used for wiring during packaging testing. The use of two test pad units can not only collect the electrical data required for the test structure before packaging, but also avoid packaging anomalies caused by test probe marks, which is conducive to the comprehensive analysis of packaging test data.

[0052] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A test pad structure for reliability packaging testing, characterized in that: include: A first test pad unit, comprising a plurality of first test pads arranged at intervals, wherein the first test pads are used to be connected to different ends of the device to be tested in a one-to-one correspondence; A second test pad unit, comprising a plurality of second test pads arranged at intervals, wherein the second test pads are used to be connected to different ends of the device to be tested in a one-to-one correspondence; Wherein, the first test pads and the second test pads are arranged alternately; The testing device is connected to the first testing pad unit and the second testing pad unit respectively when performing pre-packaging and post-packaging tests.

2. The test pad structure for reliability packaging testing according to claim 1, characterized in that: The first test pad and an adjacent second test pad are connected in sequence; wherein, the first test pad in the first test pad unit is connected to the first second test pad in the second test pad unit; and the last first test pad in the first test pad unit is connected to the last second test pad in the second test pad unit.

3. The test pad structure for reliability packaging testing according to claim 2, characterized in that: When the second test pad is located between the last first test pad in the previous first test pad unit and the first first test pad in the next first test pad unit, it is connected to two first test pads respectively.

4. The test pad structure for reliability packaging testing according to claim 3, characterized in that: The first test pad and the second test pad are connected through a metal interconnection layer.

5. The test pad structure for reliability packaging testing according to claim 1, characterized in that: The size of the first test pad is larger than that of the second test pad.

6. The test pad structure for reliability packaging testing according to claim 5, characterized in that: The first test pad unit is used to connect with the test device to perform a test before packaging; the second test pad unit is used to connect with the test device to perform a test after packaging.

7. The test pad structure for reliability packaging testing according to claim 1, characterized in that: The first test pad unit includes four first test pads, which are respectively connected to the source, drain, gate and base of the device under test in a one-to-one correspondence; The second test pad unit includes four second test pads, which are respectively connected to the source, drain, gate and base of the device under test in a one-to-one correspondence.

8. The test pad structure for reliability packaging testing according to claim 1, characterized in that: The spacings between the first test pads in the same first test pad unit are equal; the spacings between the second test pads in the same second test pad unit are equal.

9. The test pad structure for reliability packaging testing according to claim 1, characterized in that: All the first test pads in the same first test pad unit have the same size, and all the second test pads in the same second test pad unit have the same size.

10. A testing system, characterized in that: include: A test device, a device to be tested, and a test pad structure for reliability packaging testing according to any one of claims 1 to 9; Different ends of the device under test are respectively led out through different first test pads in the first test pad unit and different second test pads in the second test pad unit; The testing device is connected to the first testing pad unit and the second testing pad unit respectively during the testing process of the device under test before and after packaging.

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