CN114200279B

CN114200279B - Film probe card and probe head thereof

Info

Publication number: CN114200279B
Application number: CN202111431283.1A
Authority: CN
Inventors: 赵梁玉; 于海超; 王艾琳
Original assignee: Maxone Semiconductor Suzhou Co Ltd
Current assignee: Strong Half Conductor Suzhou Co ltd
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2023-03-14
Anticipated expiration: 2041-11-29
Also published as: CN114200279A; WO2023092898A1

Abstract

The invention relates to a film probe card and a probe head thereof, wherein the film probe card comprises a film probe head (3), and the film probe head (3) comprises a supporting body (31), a film (32), probes (33) and interconnecting wires (34); a supporting elastic layer (35) is arranged between the action surface (311) of the supporting body (31) and the film (32), the supporting elastic layer (35) comprises a first elastic body (351) and a second elastic body (352), the elastic forces of the first elastic body (351) and the second elastic body (352) are unequal, the first elastic body (351) and the second elastic body (352) are spliced on one plane, and the connecting parts of the first elastic body (351) and the second elastic body (352) are butted to form a splicing seam (354); the probe (33) corresponds to the splicing seam (354), and the projection of the probe (33) spans the splicing seam (354).

Description

Film probe card and probe head thereof

Technical Field

The invention belongs to the technical field of probe cards and wafer testing, and particularly relates to a film probe card and a probe head thereof.

Background

In recent years, with the development and popularization of 5G technology and consumer electronics technology, semiconductor devices are increasingly miniaturized, integrated and pad pitch-dense, the operating frequency is increasing, and wafer level testing for high frequency is becoming an important ring unavailable in RF chip production. Compared with other types of probe cards, the thin film probe card realizes small-scale probe structure processing and high-precision signal line structure parameter control, reduces the generation of parasitic capacitance and inductance, greatly shortens a signal path, improves the impedance matching degree, and is widely applied to high-frequency-oriented wafer-level test analysis.

During the wafer testing process, the appropriate measurement slip amount and controllable contact force magnitude need to be provided.

And measuring slippage, namely, when the probe is contacted with the Pad to be measured and vertical lifting motion is started, the probe makes a slight horizontal motion. Proper amount is necessary to push away the surface oxide of the tested bonding pad or bump to obtain stable electric contact: too little slippage may result in too much vertical contact force required by the probe to obtain stable contact, causing damage to Pad; excessive slippage may cause the probe to contact the outer passivation layer region of Pad, damaging the object to be tested.

The controllable contact force has a positive effect on ensuring that the chip pad is not damaged. Currently common pad and bump materials include aluminum, gold, copper or solder: the surface of aluminum is easy to be oxidized in the air, and a force of 3-5gf is generally needed in the test process to penetrate or push away the surface oxide to realize stable contact; the gold has a soft material, so the required contact force is small and is generally between 0.1 and 1 gf; the copper material then requires a greater force to establish good contact, about 5-6gf. With the miniaturization and integration of semiconductor technology, the metal layer of the bonding pad and the dielectric layer between low-K layers become thinner, and the requirement on the contact force control of the probe is also improved.

Patent US5395253 proposes: the initial film is in a stretching state, when the probe is in contact with the detected Pad and starts to move vertically, the film is gradually in a relaxing state, and the probe can make a small horizontal movement towards the central area of the film to generate measurement slip. A significant disadvantage of this approach is that the measured slippage of the probe is not uniform with respect to the center position of the probe relative to the film.

In the prior art, the most representative structure can be referred to US7893704, which proposes a novel film probe structure, in which the probe is designed to be a cantilever-like structure, and the measurement slippage is realized by using the rotation of the cantilever-like probe structure around the end of the cantilever during the test process, but in this way, the probe needs to rotate around the end of the cantilever repeatedly, so that the stress is concentrated at the position, and the film is easy to damage.

Therefore, there is a need in the art for a thin film probe card that can achieve proper measurement slip and provide controllable contact force, and in particular, reduce stress of the thin film probe and improve the life of the thin film probe.

Disclosure of Invention

The invention aims to provide a film probe card and a probe head thereof, which can realize the proper measurement slippage of a probe in the test process, provide controllable contact force, particularly reduce the stress of the film probe in the use process and prolong the service life.

In order to achieve the purpose, the technical scheme of the thin film probe card adopted by the invention is as follows: a film probe card comprises a PCB, a connecting piece and a film probe head; the thin film probe head comprises a support body for providing an action surface, a thin film covering the action surface of the support body, and a probe and an interconnecting wire which are arranged on the thin film; a supporting elastic layer is arranged between the action surface of the supporting body and the film in a cushioning mode, the supporting elastic layer comprises a first elastic body and a second elastic body, the elastic forces of the first elastic body and the second elastic body are unequal, the first elastic body and the second elastic body are spliced on the same plane, and the joints of the first elastic body and the second elastic body are butted to form a splicing seam; the probes correspond to the splicing seams, and the projections of the probes cross the splicing seams.

In the above solution, the action surface of the support body is covered with a rigid support body, and the elastic support layer is integrally formed on the surface of the rigid support body facing the probe.

In the above solution, the middle part of the support body has a protrusion protruding downward, and the lower surface of the protrusion is used as the acting surface; the periphery of the convex part on the support body is provided with a connecting surface which is abutted against the PCB, the connecting surface is also covered by the film, the film part corresponding to the connecting surface is also provided with a probe, and the supporting elastic layer is also arranged between the connecting surface of the support body and the film in a cushioning manner.

In the above scheme, the supporting elastic layer includes a plurality of first elastic bodies and a plurality of second elastic bodies, and the first elastic bodies and the second elastic bodies are arranged at intervals on a plane and are spliced together.

In order to achieve the purpose, the technical scheme of the thin film probe head adopted by the invention is as follows: a film probe head comprises a support body for providing an action surface, a film covering the action surface of the support body, and a probe and an interconnecting wire which are arranged on the film; a supporting elastic layer is arranged between the action surface of the supporting body and the film in a cushioning mode, the supporting elastic layer comprises a first elastic body and a second elastic body, the elastic forces of the first elastic body and the second elastic body are unequal, the first elastic body and the second elastic body are spliced on the same plane, and the joints of the first elastic body and the second elastic body are butted to form a splicing seam; the probes correspond to the splicing seams, and the projections of the probes cross the splicing seams.

The invention skillfully adds the supporting elastic layer, and the supporting elastic layer is spliced by the first elastic body and the second elastic body, so that the elastic force of the elastic layer lined at the two sides of each probe is unequal, and the probes can generate proper measurement slippage in the contact process to penetrate or push away the oxide on the surface layer of the chip to be tested, thereby realizing more stable contact. And because the supporting elastic layer is arranged between the action surface of the supporting body and the film for transformation, the probe is not changed and can be in a common symmetrical structure. During the test: the probe in the initial state is not contacted with the detected chip Pad, the elastic component lined above the supporting body is in the initial compression state, and the supporting elastic layer is also in the uncompressed state; with the application of a test OD, the probe is contacted with a tested chip Pad, displacement occurs in the vertical direction, most displacement is absorbed by the elastic component, and the rest displacement is absorbed by the probe and the supporting elastic layer together; at this time, because the elastic forces of the supporting elastic layers lined at the two sides of the probe are not equal, the probe slightly inclines when moving vertically, the probe slides in the horizontal direction, dirt and oxide on the surface of the tested chip can be pushed away, and more stable electric connection is realized.

The invention has the beneficial effects that:

1. according to the invention, the supporting elastic layer is added and is spliced by the first elastic body and the second elastic body, so that the elastic force of the supporting elastic layer lined on the two sides of each probe is unequal, the probes move in the vertical direction and simultaneously realize lateral sliding in the horizontal direction, and stable and reliable electric contact is realized;

2. according to the invention, the control on the measurement slippage and the contact force can be finally realized by controlling the material selection ratio of the first elastomer and the second elastomer and adjusting the elasticity difference of the first elastomer and the second elastomer;

3. according to the invention, by adding the supporting elastic layer, the absorption and compatibility of flatness problems such as local height difference and integral inclination of the probe are realized, and the problems of excessive contact force, detected Pad damage or probe virtual connection, open circuit and the like caused by too long or too short local probe are prevented.

Drawings

Fig. 1 is a schematic structural diagram of a thin film probe card according to a first embodiment and a second embodiment of the invention;

FIG. 2 is a schematic structural diagram of a membrane probe head according to a first embodiment and a second embodiment of the present invention;

FIG. 3 is a schematic diagram of a bevel support structure of a membrane probe head according to a first embodiment and a second embodiment of the invention;

FIG. 4 is a schematic diagram of the corresponding positions of the stitching seams and the probes according to the first and second embodiments of the present invention;

FIG. 5 is a schematic diagram of probe positions before testing in accordance with one and two embodiments of the present invention;

FIG. 6 is a schematic diagram illustrating a comparison of probe positions during testing according to the first embodiment and the second embodiment of the present invention.

In the above drawings: 1. a PCB board; 11. a coaxial connector; 12. a signal connection point; 13. routing a PCB; 14. a spring structure; 15. a PCB end threaded hole;

2. a connecting member;

3. a membrane probe head;

31. a support body; 311. acting surface; 312. a connecting surface;

32. a film;

33. a probe; 331. a needle seat structure; 332. a needle tip structure;

34. interconnecting lines;

35. a supporting elastic layer; 351. a first elastic body; 352. A second elastomer; 353. A supporting rigid body; 354. splicing seams;

36. an adhesion layer;

37. an elastic component;

38. a reinforcing plate; 381. screw holes for assembly; 382. screw holes for leveling;

39. leveling screws.

Detailed Description

The invention is further described with reference to the following figures and examples:

the first embodiment is as follows: referring to figures 1-6:

a film probe card comprises a PCB (printed Circuit Board) 1, a connecting piece 2 and a film probe head 3; the thin film probe head 3 includes a supporting body 31 providing an active surface 311, a thin film 32 covering the active surface 311 of the supporting body 31, and probes 33 and interconnection lines 34 provided on the thin film 32.

The PCB board 1 is a multilayer epoxy resin circuit board, coaxial connectors 11 and signal connection points 12 are distributed on the PCB board, PCB wiring 13 is distributed in the PCB board, and the PCB board is respectively connected with the coaxial connectors 11 to the corresponding signal connection points 12 to realize electric signal conduction and transmission; the surface of the PCB 1 is also distributed with a spring structure 14 and a PCB end threaded hole 15; the central position of the PCB board 1 is hollowed out and is used for accommodating the film probe head 3; the spring structure 14 is located at the periphery of the central hollow of the PCB board 1 for realizing the tight connection with the membrane probe head 3.

The support 31 is a rigid body, and has a protrusion protruding downward at the middle, and the lower surface of the protrusion serves as the acting surface 311. The support 31 is provided with a connection surface 312 on the periphery of the projection for abutting against the PCB board 1, the connection surface 312 is also covered with the film 32, and a probe 33 is also provided on a portion of the film 32 corresponding to the connection surface 312, the probe 33 is used for abutting against the PCT board 1.

A supporting elastic layer 35 is arranged between the action surface 311 of the supporting body 31 and the film 32, the supporting elastic layer 35 is formed by arranging and splicing a plurality of first elastic bodies 351 and a plurality of second elastic bodies 352 on a plane, and the joints of the supporting elastic layers are butted to form splicing seams 354; the probe 33 corresponds to the splice seam 354, and the projection of the probe 33 spans the splice seam 354. As shown in fig. 4, the splice 354 is linear, and the probes 33 are arranged in a plurality of rows along the splice 354. For example, the number of the first elastic body 351 and the second elastic body 352 may be only one, and the splicing seam 354 may also be in various forms such as arc, curve, etc., that is, the first elastic body 351 and the second elastic body 352 may be spliced together in various arrangement shapes.

Specifically, the device further comprises a supporting rigid body 353, and the supporting rigid body 353 is fixedly arranged on the acting surface 311 of the supporting body 31 through an adhesive layer 36. The material of the supporting rigid body 353 can be high temperature resistant hard material such as silicon, glass, PMMA and the like.

The supporting elastic layer 35 is made of flexible materials such as PDMS and silica gel, and can be elastically adjusted by adjusting conditions such as material proportion and curing temperature, so that the absorption and compatibility of the small height difference between the structures of the tested chip Pad or probe can be realized. Specifically, the supporting elastic layer 35 is integrally formed and adhered to the supporting rigid body 353.

Specifically, the film 32 may be secured to the supporting elastic layer 35 by an adhesive layer 36.

In order that the probe that is connected to the PCB 1 also has a measuring slip, a supporting spring layer 35 is also provided between the connection surface 312 of the support 31 and the membrane 32, which supporting spring layer 35 lines behind the membrane 32. The specific structure of the supporting elastic layer 35 is the same as that of the supporting elastic layer 35 between the active surface 311 of the support 31 and the film 32, and will not be described herein.

The probe 33 specifically includes a needle mount structure 331 and a needle tip structure 332. The needle tip structure 332 is positioned above the needle hub structure 331. The needle base structure 331 is in the shape of cuboid, cylinder, prism, etc., and may be made of rhodium, ni, pd-Ni, ni-B alloy, etc. high hardness material. The needle point structure is in a truncated pyramid shape, a frustum, a truncated cone and the like, and the material is wear-resistant material such as rhodium, ni or Pd-Ni, ni-B alloy and the like.

A reinforcing plate 38 is further disposed above the supporting body 31, the reinforcing plate 38 is a metal plate with a central recessed area, on which screw holes 381 for assembly and screw holes 382 for adjusting the elasticity are distributed, the edge of the metal plate is connected to the supporting body 31, the central recessed area is used for accommodating the elastic component 37, the elastic component 37 can be an elastic body structure such as an air bag, a multi-claw spring, etc., and as shown in the figure, the elastic component 37 is an air bag. The leveling screws 39 are disposed in the leveling screw holes 382, and the bottoms thereof are in contact with the upper surface of the elastic member 37, and the inclination between the reinforcing plate 38 and the supporting body 31 can be corrected by adjusting the relative positions of the plurality of leveling screws 39.

The elastic component 37 is located between the reinforcing plate 38 and the supporting body 31, and the elastic component 37 is in a compressed state during the test, and when OD is applied, the elastic component 37 can be elastically deformed to absorb the movement displacement in the vertical direction.

In the testing process: as shown in fig. 5, in the initial state, the probe 33 is not in contact with the chip Pad to be tested, the elastic element 37 is in the initial compression state, and the supporting elastic layer 35 is in the uncompressed state; with the application of the test OD, as shown in fig. 6, the probe contacts the chip Pad to be tested, and the vertical displacement occurs, most of the displacement is absorbed by the elastic component 37, and the rest of the displacement is absorbed by the probe 33 and the supporting elastic layer 35 together; because the elastic forces of the supporting elastic layers 35 on the two sides of the probe 33 are not consistent, the probe 33 can incline while moving vertically, and the probe 33 can slide laterally by a distance L to push away dirt and oxide on the surface of a chip to be tested, so that more stable electrical connection can be realized.

Example two: referring to figures 1-6:

a thin film probe head comprises a supporting body 31 for providing an action surface 311, a thin film 32 covering the action surface 311 of the supporting body 31, and a probe 33 and an interconnecting wire 34 arranged on the thin film 32, wherein the specific structure of the thin film probe head is the same as that of the thin film probe head in the first embodiment, and the detailed description is omitted.

The above embodiments are examples, and in practice the following practical variations may be made:

1. the number of the first elastic bodies 351 and the number of the second elastic bodies 352 in the supporting elastic layer 35 may be multiple as in the first embodiment, or may be only one, the shape of the splicing seam 354 between the first elastic body 351 and the second elastic body 352 is not limited, and may be a straight line, a curved line, or the like, and the actual splicing shape is adjusted according to the distribution of the probes 33;

2. the splicing seams 354 need to correspond to the probes 33, where the correspondence may be that one splicing seam 354 corresponds to one probe 33, or one splicing seam 354 corresponds to multiple probes 33;

3. the supporting elastic layer 35 may include, in addition to the first elastic body 351 and the second elastic body 352, other elastic bodies with different elastic forces, such as a third elastic body 351, that is, two, three or more elastic bodies are combined;

4. the supporting rigid body 353 can be eliminated, and the supporting elastic layer 35 is directly arranged on the acting surface 311 of the supporting body 31;

5. the adhesive layer 36 between the film 32 and the supporting elastic layer 35 can be removed and the film 32 can be fixed in other ways relative to the surface of the supporting elastic layer 35 or not fixed but merely tightened against the supporting elastic layer 35.

The above embodiments are only for illustrating the technical idea and features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the content of the present invention and implement the present invention, and not to limit the protection scope of the present invention by this means. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A film probe card comprises a PCB (1), a connecting piece (2) and a film probe head (3); the thin film probe head (3) comprises a supporting body (31) providing an action surface (311), a thin film (32) covering the action surface (311) of the supporting body (31), probes (33) arranged on the thin film (32) and interconnecting wires (34) arranged on the thin film (32); the method is characterized in that:

a supporting elastic layer (35) is arranged between the action surface (311) of the supporting body (31) and the film (32), the supporting elastic layer (35) comprises a first elastic body (351) and a second elastic body (352), the elastic forces of the first elastic body (351) and the second elastic body (352) are unequal, the first elastic body (351) and the second elastic body (352) are spliced on one plane, and the joints of the first elastic body and the second elastic body are butted to form a splicing seam (354); the probe (33) corresponds to the splicing seam (354), and the projection of the probe (33) spans the splicing seam (354).

2. The thin film probe card of claim 1, wherein: the action surface (311) of the supporting body (31) is covered with a supporting rigid body (353), and the supporting elastic layer (35) is integrally formed on the surface of the supporting rigid body (353) facing the probe (33).

3. The thin film probe card of claim 1, wherein: the middle part of the supporting body (31) is provided with a convex part protruding downwards, and the lower surface of the convex part is used as the acting surface (311); the periphery of the convex part on the supporting body (31) is provided with a connecting surface (312) which is abutted against the PCB (1), the connecting surface (312) is also covered by the film (32), the part of the film (32) corresponding to the connecting surface (312) is also provided with a probe (33), and the supporting elastic layer (35) is also arranged between the connecting surface (312) of the supporting body (31) and the film (32).

4. The thin film probe card of claim 1, wherein: the supporting elastic layer (35) comprises a plurality of first elastic bodies (351) and a plurality of second elastic bodies (352), and the first elastic bodies (351) and the second elastic bodies (352) are arranged and spliced at intervals on a plane.

5. A membrane probe head, characterized by: comprises a supporting body (31) for providing an action surface, a thin film (32) covered on the action surface (311) of the supporting body (31), a probe (33) arranged on the thin film (32) and an interconnecting wire (34) arranged on the thin film (32); the method is characterized in that:

6. The membrane probe head of claim 5, wherein: the action surface (311) of the supporting body (31) is covered with a supporting rigid body (353), and the supporting elastic layer (35) is integrally formed on the surface of the supporting rigid body (353) facing the probe (33).

7. The membrane probe head of claim 5, wherein: the middle part of the supporting body (31) is provided with a convex part protruding downwards, and the lower surface of the convex part is used as the acting surface (311); the periphery of the convex part on the supporting body (31) is provided with a connecting surface (312) which is abutted against the PCB (1), the connecting surface (312) is also covered by the film (32), the part of the film (32) corresponding to the connecting surface (312) is also provided with a probe (33), and the supporting elastic layer (35) is also arranged between the connecting surface (312) of the supporting body (31) and the film (32).

8. The membrane probe head of claim 5, wherein: the supporting elastic layer (35) comprises a plurality of first elastic bodies (351) and a plurality of second elastic bodies (352), and the first elastic bodies (351) and the second elastic bodies (352) are arranged and spliced at intervals on a plane.