A method for manufacturing a probe in a semiconductor probe card

Abstract

The application provides a preparation method of a probe in a semiconductor probe card, a second photoresist layer is formed on the top surface of an intermediate product, a first metal arm is formed by exposure and development and coating; a third photoresist layer is formed on the top surface of the first metal arm and the second photoresist layer, a first metal pillar is formed by exposure and development and coating; all photoresist layers are removed; a fourth photoresist layer is formed on the top surface of the silicon substrate, the first metal layer and the first metal arm which is not covered, a second metal pillar is formed by exposure and development and coating; a fifth photoresist layer is formed on the top surface of the first metal pillar, the second metal pillar and the fourth photoresist layer and between the first metal pillar and the second metal pillar, a second metal arm is formed by exposure and development and coating; and all photoresist layers are removed. The preparation method of the probe in the semiconductor probe card can effectively prevent the probe from breaking and improve the service life of the probe.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor, and particularly relates to a preparation method of a probe in a semiconductor probe card. BACKGROUND

[0002] The probe card is a key device for wafer testing in the front-end of a semiconductor, and realizes electrical connection between a wafer chip and a tester. The probe card is composed of a plurality of probes, and the electrical performance of the wafer chip is tested by contacting the wafer chip.

[0003] The MEMS probe card is a new type of probe card manufactured by using micro-electro-mechanical system (MEMS) technology. The MEMS probe is manufactured by using micro-processing technology, and more than 100k probes can be integrated in one probe card to meet the testing requirements of electronic devices. The shape of the tip of the MEMS probe is fine, and the diameter of the tip can be as small as several microns. In a small contact area, the MEMS probe can provide stable and reliable contact force and electrical contact, and greatly improve the testing accuracy.

[0004] The specific process of the current MEMS probe manufacturing method is as follows: first, a first metal layer is formed on a silicon substrate by multiple film plating, then glue coating, photoetching and development are performed to obtain a pattern, then the first metal layer and the silicon substrate are etched to obtain a groove shape, and then the groove is plated to fill the groove with a second metal, thereby forming a probe. The second metal layer in the silicon substrate is the probe tip, the second metal layer beside the first metal layer is the probe body, and the probe body is bonded to the ceramic substrate during packaging. However, the probe will bend during use, and after being subjected to bending stress for many times, the bonding part of the probe will be subjected to greater stress, thereby more easily causing metal fatigue and causing the probe to break. SUMMARY

[0005] The present application provides a preparation method of a probe in a semiconductor probe card, which can effectively prevent the probe from breaking and improve the service life of the probe.

[0006] To solve the above technical problems, the present application provides a preparation method of a probe in a semiconductor probe card, comprising the following steps:

[0007] Step 10: applying photoresist on the top surface of the intermediate product to form a second photoresist layer; the intermediate product comprises a silicon substrate, a first metal layer covering part of the top surface of the silicon substrate, a probe tip in the silicon substrate, and a probe body on the top end of the probe tip, and the first photoresist layer covers the space between the probe body and the first metal layer and other areas on the top surface of the silicon substrate;

[0008] Step 20: exposing and developing at a predetermined position of the second photoresist layer to form a first arm growth site; the first arm growth site is located above the first metal layer and the probe tip;

[0009] Step 30, forming a first metal arm at the first arm growth position by using electroplating method;

[0010] Step 40, applying photoresist on the top surface of the first metal arm and the second photoresist layer to form a third photoresist layer;

[0011] Step 50, exposing and developing the third photoresist layer at the preset position to form a plurality of first pillar growth positions arranged at intervals;

[0012] Step 60, forming a plurality of first metal pillars at the first pillar growth positions by using electroplating method;

[0013] Step 70, removing the first photoresist layer, the second photoresist layer and the third photoresist layer;

[0014] Step 80, applying photoresist on the top surface of the silicon substrate, the first metal layer and the first metal arm which is not covered to form a fourth photoresist layer;

[0015] Step 90, exposing and developing the fourth photoresist layer at the preset position to form a second pillar growth position between two adjacent first metal arms;

[0016] Step 100, forming a second metal pillar at the second pillar growth position by using electroplating method;

[0017] Step 110, applying photoresist on the top surface of the first metal pillar, the second metal pillar and the fourth photoresist layer to form a fifth photoresist layer;

[0018] Step 120, exposing and developing the fifth photoresist layer at the preset position to form a second arm growth position;

[0019] Step 130, forming a second metal arm at the second arm growth position by using electroplating method;

[0020] Step 140, removing the fourth photoresist layer and the fifth photoresist layer.

[0021] As a further improvement of the present application, the thickness of the second photoresist layer is 40-80 μm.

[0022] As a further improvement of the present application, the material of the first metal arm is different from that of the first metal layer, and the material of the first metal arm is the same as that of the second metal arm.

[0023] As a further improvement of the present application, the material of the first metal pillar is different from that of the first metal layer, and the material of the second metal pillar is the same as that of the first metal layer.

[0024] As a further improvement of the present application, the number of the first metal pillars is two, and the two first metal pillars are symmetrically arranged at the two ends above the first metal arm.

[0025] As a further improvement of the present application, the second metal arm and the first metal arm are coincident in the projection on the horizontal plane.

[0026] As a further improvement of the present application, in step 30, the surface of the first arm growth site is pretreated before electroplating; in step 60, the surface of the first pillar growth site is pretreated before electroplating; in step 100, the surface of the second pillar growth site is pretreated before electroplating; in step 130, the surface of the second arm growth site is pretreated before electroplating.

[0027] As a further improvement of the present application, in step 100, the second metal pillar formed has a spacing with the first metal pillar.

[0028] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0029] The preparation method of the probe in the semiconductor probe card provided by the present application forms the first metal arm, the first metal pillar and the second metal arm on the probe in sequence after forming the probe, the first metal arm, the first metal pillar and the second metal arm form a structure, which plays a role of a stress barrier, one end of the structure connected with the probe is a support end, and the other end is a bonding end, the stress received by the probe in the use process of the probe card is dispersed, the probe is prevented from being broken, the probe can bear greater stress, more complex test environment can be coped with, the service life of the probe card is improved, and the test frequency is increased. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The figure is a flow chart of the preparation method of the probe in the semiconductor probe card according to the embodiment of the present application.

[0031] In the figure, there are: a silicon substrate 1, a first metal layer 2, a probe needle tip 31, a probe needle body 32, a first photoresist layer 4, a second photoresist layer 5, a first arm growth site 51, a first metal arm 6, a third photoresist layer 7, a first pillar growth site 71, a first metal pillar 8, a fourth photoresist layer 9, a second metal pillar 10, a fifth photoresist layer 11, a second arm growth site 111, and a second metal arm 12. DETAILED DESCRIPTION

[0032] The technical scheme of the present application will be described in detail below with reference to the drawings.

[0033] The embodiment of the present application provides a preparation method of a probe in a semiconductor probe card, as shown in the figure, including the following steps: Figure 1 As shown in the figure, including the following steps:

[0034] Step 10: Apply photoresist on the top surface of the intermediate product to form a second photoresist layer 5.

[0035] The intermediate product comprises the silicon substrate 1, the first metal layer 2 covering a part of the top surface of the silicon substrate 1, the probe tip 31 located in the silicon substrate 1, and the probe body 32 located at the top end of the probe tip 31. The first photoresist layer 4 covers the space between the probe body 32 and the first metal layer 2 and the other part of the top surface of the silicon substrate.

[0036] The first photoresist layer 4 between the probe body 32 and the first metal layer 2 is formed in the previous process. The space between the probe body 32 and the first metal layer 2 is provided to facilitate the removal of the first metal layer 2 after the bonding process, so as to ensure that there is enough space around the probe for testing.

[0037] Specifically, the photoresist is coated by using the spin coating method, and baking is performed after coating. The thickness of the second photoresist layer 5 is 40-80 μm.

[0038] Step 20: Expose and develop at the preset position of the second photoresist layer 5 to form the first arm growth site 51. The first arm growth site 51 is located above the first metal layer 2 and the probe tip 31.

[0039] Step 30: First, flush the surface of the first arm growth site 51 with deionized water to remove the photoresist on the surface, and then perform spin-drying. The first metal arm 6 is formed on the first arm growth site 51 by using the electroplating method. Preferably, the projection of the first metal arm 6 on the horizontal plane completely covers the projection of the probe on the horizontal plane, and can not completely cover the projection of the first metal layer 2 on the horizontal plane.

[0040] Since the first metal layer 2 needs to be removed after the subsequent bonding process, the first metal arm 6 is made of a material different from that of the first metal layer 2, so that the first metal arm 6 will not be damaged when the first metal layer 2 is removed.

[0041] Step 40: Apply photoresist to the top surface of the first metal arm 6 and the second photoresist layer 5 to form the third photoresist layer 7.

[0042] Step 50: Expose and develop at the preset position of the third photoresist layer 7 to form a plurality of first pillar growth sites 71 arranged at intervals.

[0043] Preferably, the number of first pillar growth sites 71 is 2, and the two first pillar growth sites 71 are symmetrically arranged above the two ends of the first metal arm 6.

[0044] Step 60: First, flush the surface of the first pillar growth site 71 with deionized water to remove the photoresist on the surface, and then perform spin-drying. A plurality of first metal pillars 8 are formed on the first pillar growth site 71 by using the electroplating method.

[0045] Preferably, the number of the first metal pillars 8 formed is 2, and the two first metal pillars 8 are symmetrically arranged at the two ends above the first metal arm 6.

[0046] Preferably, since the first metal layer 2 needs to be removed after the subsequent bonding process, the first metal pillar 8 is made of a material different from that of the first metal layer 2, so that the first metal pillar 8 will not be damaged when the first metal layer 2 is removed.

[0047] Step 70, remove the first photoresist layer 4, the second photoresist layer 5 and the third photoresist layer 7.

[0048] Subsequently, it is necessary to form a second pillar growth site 91 between adjacent first metal pillars 8, and the third photoresist layer 7 is filled between the adjacent first metal pillars 8, and the third photoresist layer 7 has participated in the exposure and development reaction, so the third photoresist layer 7 needs to be removed, and the first photoresist layer 4 and the second photoresist layer 5 are also removed at the same time.

[0049] Step 80, coat photoresist on the top surface of the silicon substrate 1, the first metal layer 2 and the first metal arm 6 which are not covered, to form a fourth photoresist layer 9.

[0050] Step 90, exposure and development is performed at the preset position of the fourth photoresist layer 9 to form a second pillar growth site 91 between the adjacent two first metal pillars 8.

[0051] Step 100, first rinse the surface of the second pillar growth site 91 with deionized water to remove the photoresist on the surface, and then perform spin-drying. Use electroplating method to form a second metal pillar 10 on the second pillar growth site 91.

[0052] In order to facilitate the formation of a structure above the first metal pillar 8, a second metal pillar 10 is arranged between the adjacent first metal pillars 8, and the second metal pillar 10 needs to be removed after the subsequent bonding process, and the second metal pillar 10 is made of the same material as the first metal layer 2, so that the second metal pillar 10 can be removed at the same time as the first metal layer 2 in the subsequent process.

[0053] Preferably, the second pillar growth site 91 has a spacing with the first metal pillar 8, that is, the photoresist is reserved between the second pillar growth site 91 and the first metal pillar 8. After electroplating, the second metal pillar 10 does not contact the first metal pillar 8 on both sides, which facilitates the subsequent removal of the second metal pillar 10.

[0054] Step 110, coat photoresist on the top surface of the first metal pillar 8, the second metal pillar 10 and the fourth photoresist layer 9 to form a fifth photoresist layer 11.

[0055] Step 120, exposure and development are performed at the preset position of the fifth photoresist layer 11 to form a second arm growth site 111.

[0056] Step 130, the surface of the second arm growth site 111 is first rinsed with deionized water to remove the photoresist on the surface, and then spin-dried. The second metal arm 12 is formed on the second arm growth site 111 by electroplating.

[0057] Preferably, the second metal arm 12 is made of the same material as the first metal arm 6 and is made of a different material from the first metal layer 2, so that the second metal arm 12 will not be damaged when the first metal layer 2 is removed.

[0058] Preferably, the projection of the second metal arm 12 on the horizontal plane coincides with the projection of the first metal arm 6 on the horizontal plane.

[0059] Step 140, the fourth photoresist layer 9 and the fifth photoresist layer 11 are removed.

[0060] The preparation method of the embodiment of the application forms a probe, then forms a first metal arm, a plurality of first metal pillars and a second metal arm on the probe in sequence, the first metal arm, the plurality of first metal pillars and the second metal arm form a structure, the structure has a support end connected to the probe and a bonding end, disperses the stress received by the probe during use of the probe card, prevents the probe from breaking, allows the probe to withstand greater stress, copes with more complex test environments, improves the service life of the probe card and increases the number of tests.

[0061] The structure formed by the first metal arm, the plurality of first metal pillars and the second metal arm increases the cross-sectional moment of inertia of the probe card, and the greater the cross-sectional moment of inertia, the smaller the bending deflection and stress received. The gaps between the plurality of first metal pillars can better disperse the stress during testing without excessively increasing the weight of the probe card.

[0062] The above description is only a specific implementation of the application, but the protection scope of the application is not limited thereto, and any changes or replacements within the technical scope disclosed by the application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the application.

Claims

1. A method for preparing a probe in a semiconductor probe card, characterized in that: The following steps are involved: Step 10, applying photoresist on the top surface of the intermediate product to form a second photoresist layer (5); the intermediate product comprises a silicon substrate (1), a first metal layer (2) covering a portion of the top surface of the silicon substrate (1), a probe tip (31) embedded in the silicon substrate (1), and a probe body (32) located at the top of the probe tip (31), and the area between the probe body (32) and the first metal layer (2) and other areas on the top surface of the silicon substrate are covered with the first photoresist layer (4); Step 20, performing exposure and development at a preset position of the second photoresist layer (5) to form a first arm growth position (51); the first arm growth position (51) is located above the first metal layer (2) and the probe needle tip (31); Step 30, forming a first metal support arm (6) at the first support arm growth position (51) by using an electroplating method; Step 40, applying photoresist on the top surface of the first metal arm (6) and the second photoresist layer (5) to form a third photoresist layer (7); Step 50, performing exposure and development at preset positions of the third photoresist layer (7) to form a plurality of first pillar growth positions (71) arranged at intervals; Step 60, forming a plurality of first metal pillars (8) at the first pillar growth position (71) by electroplating; Step 70, removing the first photoresist layer (4), the second photoresist layer (5) and the third photoresist layer (7); Step 80, applying photoresist on the uncovered top surfaces of the silicon substrate (1), the first metal layer (2) and the first metal arm (6) to form a fourth photoresist layer (9); Step 90, performing exposure and development at a preset position of the fourth photoresist layer (9) to form a second pillar growth position (91) located between two adjacent first metal pillars (8); Step 100, forming a second metal pillar (10) at a second pillar growth position (91) by electroplating; Step 110, applying photoresist on the top surfaces of the first metal pillar (8), the second metal pillar (10) and the fourth photoresist layer (9) to form a fifth photoresist layer (11); Step 120, performing exposure and development at a preset position of the fifth photoresist layer (11) to form a second arm growth position (111); Step 130, forming a second metal arm (12) at the second arm growth position (111) by electroplating; Step 140: removing the fourth photoresist layer (9) and the fifth photoresist layer (11).

2. The method for preparing a probe in a semiconductor probe card according to claim 1, wherein: The thickness of the second photoresist layer (5) is 40-80 μm.

3. The method for preparing a probe in a semiconductor probe card according to claim 1, wherein: The first metal support arm (6) and the first metal layer (2) are made of different materials, and the first metal support arm (6) and the second metal support arm (12) are made of the same material.

4. The method for preparing a probe in a semiconductor probe card according to claim 1, wherein: The first metal support (8) is made of a different material from the first metal layer (2), and the second metal support (10) is made of the same material as the first metal layer (2).

5. The method for preparing a probe in a semiconductor probe card according to claim 1, wherein: The number of the first metal pillars (8) is 2, and the two first metal pillars (8) are symmetrically arranged at both ends above the first metal support arm (6).

6. The method for preparing a probe in a semiconductor probe card according to claim 1, wherein: The projections of the second metal support arm (12) and the first metal support arm (6) on the horizontal plane coincide with each other.

7. The method for preparing a probe in a semiconductor probe card according to claim 1, wherein: In step 30, the surface of the first arm growth position (51) is pretreated before electroplating; in step 60, the surface of the first pillar growth position (71) is pretreated before electroplating; in step 100, the surface of the second pillar growth position (91) is pretreated before electroplating; in step 130, the surface of the second arm growth position (111) is pretreated before electroplating.

8. The method for preparing a probe in a semiconductor probe card according to claim 1, wherein: In step 100, a gap is formed between the formed second metal pillar (10) and the first metal pillar (8).

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