A thin film probe card

Abstract

The application discloses a kind of film probe card in the technical field of round crystal test, to solve the problem of different contact force provided by each probe in the multiple parallel distribution film probe in prior art, affect the working effect of device.It includes mutually connected PCB board and film probe head, film probe head includes support body, thin film arranged on the active surface of support body and multiple rows of probes on the first surface of thin film, each row of probes includes row head probe and row tail probe, each row of probes includes first probe and second probe, and thin film is provided with first rigid element and second rigid element below first probe and second probe respectively;The application is suitable for wafer testing, and the first rigid element and the second rigid element respectively play a reinforcing role on the area below the first probe and the second probe, hinder the rotation of the first probe and the second probe, so that the structure deformation below each probe is basically consistent, and the contact force provided by each probe is basically consistent.

Description

Technical Field

[0001] This invention relates to a thin-film probe card, belonging to the field of wafer testing technology. Background Technology

[0002] With the continuous advancement of semiconductor technology, chips are gradually developing towards higher integration, higher frequency, and miniaturization. Wafer testing, as a crucial step before chip packaging, can significantly improve the yield rate of packaged chips. Probe cards, acting as a bridge between the wafer and the testing machine, can transmit test signals from the testing machine to the wafer and also transmit the response signals generated by the wafer back to the testing machine, thereby determining the quality of the wafer.

[0003] Compared to other types of probe cards, thin-film probe cards offer smaller size and higher precision, while also ensuring better signal integrity and lower dielectric loss, making them widely used in high-frequency wafer testing. A thin-film probe card mainly consists of a PCB board, connectors, and thin-film probe heads. The PCB board and connectors act as external signal inputs, while the thin-film probe heads transmit signals to the object under test and return response signals, thus achieving the measurement purpose. In practical applications, after the probe tip contacts the pad under test, it needs to compress the elastic support downwards and provide a certain elastic force to push away the oxide on the surface of the solder pad or bump to achieve a stable electrical contact. The contact force between a single probe and the wafer is typically 3-5 gf. A larger contact force can easily damage the wafer, while a smaller force will not be enough to pierce the oxide on the wafer surface to form a stable electrical contact. Therefore, ensuring that the contact force provided by each probe is basically consistent is crucial.

[0004] For existing multi-row parallel thin-film probes, the contact force generated by the two probes at the end of each row is approximately 1.5-2 times that of the two adjacent inner probes. This is mainly because when the outermost probe moves downwards, it needs to compress the thin film outside its probe area, causing deformation. The thin film below the inner probes is compressed by all the inner probes together, resulting in a smaller average compressed area per probe and thus a relatively smaller contact force. Furthermore, the uneven deformation of the thin film causes the outer probes to rotate inwards and the adjacent inner probes to rotate outwards, creating a height difference between the probe tips. This further exacerbates the uneven distribution of contact force between the probes, leading to different contact forces provided by each probe and affecting the device's performance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a thin film probe card that solves the problem that the contact force provided by each probe in the existing multi-row parallel distribution of thin film probes is different, which affects the working effect of the device.

[0006] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution:

[0007] This invention provides a thin-film probe card, comprising an interconnected PCB board and a thin-film probe head. The thin-film probe head includes a support, a thin film disposed on the working surface of the support, and multiple rows of probes located on a first surface of the thin film. Each row of probes includes a head probe and a tail probe. Each row of probes includes a first probe closest to the head probe and a second probe closest to the tail probe. The thin film has a first rigid element and a second rigid element respectively below the first probe and the second probe. The first rigid element overlaps with the first probe along the projection perpendicular to the first surface, but does not overlap with the head probe along the projection perpendicular to the first surface. The second rigid element overlaps with the second probe along the projection perpendicular to the first surface, but does not overlap with the tail probe along the projection perpendicular to the first surface.

[0008] Furthermore, one end of the first rigid element coincides with the edge of the first probe along the projection perpendicular to the first surface, and the other end extends along the first adjacent probe in the direction of the tail probe, and does not overlap with the first adjacent probe along the projection perpendicular to the first surface.

[0009] Furthermore, one end of the second rigid element coincides with the edge of the second probe along the projection perpendicular to the first surface, and the other end extends along the second adjacent probe in the direction of the head probe, and does not overlap with the second adjacent probe along the projection perpendicular to the first surface.

[0010] Furthermore, the thin film includes a signal layer and an insulating layer. The signal layer connects the probe and the PCB board via signal lines. The first rigid element and the second rigid element are located in the insulating layer. The insulating layer is connected to the support via an adhesive layer.

[0011] Furthermore, an insulating material is filled between the first rigid element and the second rigid element.

[0012] Furthermore, each probe in each row, excluding the first probe, the second probe, the head probe, and the tail probe, has a third rigid element underneath. The third rigid element overlaps with the projection of the arbitrary probe along the first surface, but does not overlap with the projection of its adjacent probe along the first surface.

[0013] Furthermore, adjacent probes are spaced apart by the insulating material.

[0014] Furthermore, it also includes the reinforcing plate, which is used to connect the PCB board and the thin film probe head.

[0015] Furthermore, the first rigid element and the second rigid element are metal blocks.

[0016] Furthermore, the projections of the first rigid element and the second rigid element along the arrangement direction of each row of probes completely overlap.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0018] This thin-film probe card, by adding a first rigid element and a second rigid element below the first probe and the second probe respectively, strengthens the area around the first probe and the second probe, hindering the rotation of the first probe and the second probe. Therefore, it reduces the influence of the head probe on the first probe and the tail probe on the second probe, making the structural deformation under each probe basically consistent, thereby ensuring that the contact force provided by each probe is basically consistent. At the same time, because the structural deformation under each probe is basically consistent, it avoids the height difference between the tips of each probe, effectively achieving the uniform distribution of contact force on each probe and ensuring the working effect of the device. Attached Figure Description

[0019] Figure 1 This is a front cross-sectional view of a thin-film probe card provided according to an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0021] Figure 3 This is a schematic diagram of the deformation of the thin film during testing according to an embodiment of the present invention;

[0022] Figure 4 yes Figure 3 Enlarged diagram of point B in the middle.

[0023] In the figure: 1. PCB board; 2. Thin film probe head; 21. Support body; 22. Thin film; 221. Signal layer; 222. Insulating layer; 223. Adhesive layer; 23. Probe; 231. Head probe; 232. Tail probe; 233. First probe; 234. Second probe; 235. Arbitrary probe; 24. First surface; 3. Reinforcing plate; 4. First rigid element; 5. Second rigid element. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] In existing thin-film probe cards, when testing wafers, the probes 23 move downwards during compression. The head probe 231 and tail probe 232 cause the surrounding thin film 22 and adhesive to deform together. The head probe 231 rotates towards the first probe 233, and the tail probe 232 rotates towards the second probe 234, which in turn causes the first probe 233 and the second probe 234 to rotate together. This results in a height difference between the tips of the probes 23, exacerbating the uneven distribution of contact force between the probes 23 and affecting the working effect of the device.

[0028] like Figure 1-4As shown, the present invention provides a thin-film probe card, including a PCB board 1 and a thin-film probe head 2 interconnected with each other. The thin-film probe head 2 includes a support body 21, a thin film 22 disposed on the working surface of the support body 21, and multiple rows of probes 23 located on the first surface 24 of the thin film 22. Each row of probes 23 includes a head probe 231 and a tail probe 232. Each row of probes 23 includes a first probe 233 closest to the head probe 231 and a second probe 234 closest to the tail probe 232. The thin film 22 is located below the first probe 233 and the second probe 234 respectively. The device includes a first rigid element 4 and a second rigid element 5. The first rigid element 4 overlaps with the projection of the first probe 233 along the first surface 24, but does not overlap with the projection of the head probe 231 along the first surface 24. The second rigid element 5 overlaps with the projection of the second probe 234 along the first surface 24, but does not overlap with the projection of the tail probe 232 along the first surface 24. The projections of the first rigid element 4 and the second rigid element 5 along the arrangement direction of each row of probes 23 are completely coincident.

[0029] Specifically, when testing the wafer, after the tip of probe 23 contacts the wafer, the support 21 is compressed downwards and a certain elastic force is provided, causing probe 23 to move downwards as a whole. When the head probe 231 and tail probe 232 drive the first probe 233 and the second probe 234 to rotate together, the present invention adds a first rigid element 4 and a second rigid element 5 below the first probe 233 and the second probe 234. The first rigid element 4 and the second rigid element 5 respectively strengthen the area around the first probe 233 and the second probe 234, hindering the rotation of the first probe 233 and the second probe 234. Therefore, the influence of the head probe 231 on the first probe 233 and the influence of the tail probe 232 on the second probe 234 are reduced, so that the structural deformation below each probe 23 is basically the same, thereby ensuring that the contact force provided by each probe 23 is basically the same. At the same time, since the structural deformation below each probe 23 is basically the same, the height difference between the tips of each probe 23 is avoided, effectively realizing the uniform distribution of contact force on each probe 23 and ensuring the working effect of the device.

[0030] In one embodiment, one end of the first rigid element 4 coincides with the edge of the first probe 233 along the projection perpendicular to the first surface 24, and the other end extends along the first adjacent probe in the direction of the tail probe 232, and does not overlap with the first adjacent probe along the projection perpendicular to the first surface 24. One end of the second rigid element 5 coincides with the edge of the second probe 234 along the projection perpendicular to the first surface 24, and the other end extends along the second adjacent probe in the direction of the head probe 231, and does not overlap with the second adjacent probe along the projection perpendicular to the first surface 24.

[0031] Specifically, when testing the wafer, the first rigid element 4 is located below the first probe 233. One end of the first rigid element 4 extends towards the first adjacent probe but is not located below the first adjacent probe, thus ensuring that the structural deformation below the first probe 233 and the first adjacent probe is basically consistent, thereby avoiding a height difference between the tips. Similarly, the second rigid element 5 is used to ensure that the structural deformation below the second probe 234 is basically consistent with the second adjacent probe, thereby further ensuring that the structural deformation below each probe 23 is basically consistent, realizing the uniform distribution of contact force on each probe 23, and ensuring the working effect of the device.

[0032] In one embodiment, the thin film 22 includes a signal layer 221 and an insulating layer 222. The signal layer 221 is connected to the probe 23 and the PCB board 1 through a signal line. The first rigid element 4 and the second rigid element 5 are located in the insulating layer 222. The insulating layer 222 is connected to the support 21 through an adhesive layer 223, which ensures the stability of the overall structure of the device.

[0033] In one embodiment, an insulating material is filled between the first rigid element 4 and the second rigid element 5, and adjacent probes 23 are separated by the insulating material to prevent the first rigid element 4 and the second rigid element 5 from affecting the normal operation of the device and to ensure the stability of the device during operation; it also includes the reinforcing plate 3, which is used to connect the PCB board 1 and the thin film probe head 2 to ensure the stability of the device structure.

[0034] In one embodiment, the first rigid element 4 and the second rigid element 5 are metal blocks; optionally, the first rigid element 4 and the second rigid element 5 are made of copper.

[0035] In one embodiment, each row of probes 23, excluding the first probe 233, the second probe 234, the head probe 231, and the tail probe 232, has a third rigid element below any probe 235. This third rigid element overlaps with the projection of any probe 235 along the first surface 24, but does not overlap with the projection of its adjacent probes along the first surface 24. When the number of probes 23 within each row is large, the third rigid element provides support for the probes 235 in each row, excluding the first probe 233, the second probe 234, the head probe 231, and the tail probe 232. The arbitrary probe 235 provides support, further ensuring that the structural deformation under each probe 23 is basically consistent. Optionally, the material of the third rigid element is copper. Optionally, when the total number of probes 23 in each row of probes 23 is six, the number of arbitrary probes 235 is two, that is, there are two third rigid elements, and the two are located under the two arbitrary probes 235 respectively and support them. Similarly, when the number of probes in each row of probes 23 is seven, the number of arbitrary probes 235 and the number of third rigid elements are both three, and the three third rigid elements are located under the three arbitrary probes 235 respectively and provide support for them.

[0036] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A thin film probe card, characterized by, The probe head (2) comprises a support body (21), a film (22) arranged on the surface of the support body (21), and a plurality of probe rows (23) arranged on the first surface (24) of the film (22), each probe row (23) comprising a head probe (231) and a tail probe (232), each probe row (23) comprising a first probe (233) closest to the head probe (231) and a second probe (234) closest to the tail probe (232), the film (22) being provided with a first rigid element (4) and a second rigid element (5) below the first probe (233) and the second probe (234) respectively, the first rigid element (4) overlapping the first probe (233) along the projection perpendicular to the first surface (24) and not overlapping the head probe (231) along the projection perpendicular to the first surface (24), and the second rigid element (5) overlapping the second probe (234) along the projection perpendicular to the first surface (24) and not overlapping the tail probe (232) along the projection perpendicular to the first surface (24).

2. A thin film probe card according to claim 1, wherein One end of the first rigid element (4) coincides with the edge of the first probe (233) along the projection perpendicular to the first surface (24), and the other end extends along the first adjacent probe in the direction of the tail probe (232) and does not overlap the first adjacent probe along the projection perpendicular to the first surface (24).

3. A thin film probe card according to claim 2, wherein One end of the second rigid element (5) coincides with the edge of the second probe (234) along the projection perpendicular to the first surface (24), and the other end extends along the second adjacent probe in the direction of the head probe (231) and does not overlap the second adjacent probe along the projection perpendicular to the first surface (24).

4. The thin film probe card of claim 1, wherein The film (22) comprises a signal layer (221) and an insulating layer (222), the signal layer (221) connecting the probes (23) and the PCB board (1) through signal lines, the first rigid element (4) and the second rigid element (5) being located in the insulating layer (222), and the insulating layer (222) being connected to the support body (21) through a glue layer (223).

5. The thin film probe card of claim 1, wherein The first rigid element (4) and the second rigid element (5) are filled with insulating material.

6. The thin film probe card of claim 1, wherein Each probe row (23) has a third rigid element below any probe (235) other than the first probe (233), the second probe (234), the head probe (231) and the tail probe (232), the third rigid element overlapping the any probe (235) along the projection perpendicular to the first surface (24) and not overlapping its adjacent probe along the projection of the first surface (24).

7. A thin film probe card according to claim 5, wherein Adjacent probe rows (23) are separated by the insulating material.

8. The thin film probe card of claim 1, wherein Also included is a reinforcing plate (3) for connecting the PCB board (1) and the thin film probe head (2).

9. The thin film probe card of claim 1, wherein The first rigid element (4) and the second rigid element (5) are metal blocks.

10. The thin film probe card of claim 1, wherein The first rigid element (4) and the second rigid element (5) are completely coincident in projection along the arrangement direction of each row of the probes (23).

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