CN113059483A

CN113059483A - Substrate leveling jig, leveling method and probe card

Info

Publication number: CN113059483A
Application number: CN202110294568.9A
Authority: CN
Inventors: 张振明; 罗雄科; 陶克文
Original assignee: Shanghai Zenfocus Semi Tech Co ltd
Current assignee: Shanghai Zenfocus Semi Tech Co ltd
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2021-07-02

Abstract

The invention discloses a substrate leveling jig, a leveling method and a probe card. The bearing platform is used for bearing the substrate. The locking device is used for locking the substrate to the bearing platform. The grinding mechanism of the leveling device is positioned above the substrate and is parallel to the bearing platform. Under the drive of the driving mechanism, the grinding mechanism is used for grinding the welding points on the upper surface of the tin ball, so that the welding points are all positioned on the same plane. In this patent, load-bearing platform makes the base plate can fully contact with grinding mechanism, ensures that grinding mechanism can fully grind the solder joint department of tin ball upper surface, makes a plurality of solder joints all be located the coplanar, and then can ensure that all solder joints homoenergetic enough with the PCB survey test panel the tin face fully contact. The flatness of the substrate after being welded on the PCB test board can be improved to a great extent, so that the flatness error of the whole substrate is reduced to within 50um, and the test performance of the manufactured probe card can be greatly improved.

Description

Substrate leveling jig, leveling method and probe card

Technical Field

The present invention relates to the field of probe card technology, and more particularly, to a substrate leveling tool, a substrate leveling method and a probe card.

Background

In the semiconductor field, probe cards are used to test and analyze interfaces during wafer manufacturing, and to test parameters of chips by connecting to a tester to transmit signals to the chips. The probe card directly contacts the probe with the welding pad on the chip to lead out chip signals, and the purpose of automatic measurement is achieved by matching with peripheral test instruments and software control. The probe card is widely applied to wafer testing of scientific and technological products such as memories, logics, consumption, driving, communication ICs and the like, and belongs to a very fine ring in the semiconductor industry. After the IC design is completed, a single IC is sent to the foundry for fabrication. After the wafer is fabricated and before the package is cut, in order to ensure the wafer yield and avoid the waste of the package, the wafer electrical test and analysis process are performed. The probe card and the tester form a test loop, and the probe is used for testing the crystal grain before IC packaging, so that the chip with poor electrical function is screened out, and waste of rear-section manufacturing cost caused by poor products is avoided.

With the continuous improvement of wafer technology, the types of Probe cards are continuously updated, and the Probe cards widely used in wafer testing in wafer test factories are cantilever Probe cards (epoxy) and Vertical Probe cards (Vertical Probe cards). In particular, cantilever probe cards are popular, and are mainly characterized in that a single probe can be replaced for high current testing, while vertical probe cards are characterized by higher capability and efficiency. Vertical probe cards have significant cost and performance advantages for testing at pitches less than 150um as semiconductor wafer processing advances below 28 nm. The vertical probe card mainly comprises three main components, namely a PCB test board (Loadboard), a space transformer (MLO/MLC substrate) and a probe (MEMS probe, cobra probe and the like). The precision in the vertical and horizontal directions determines the basic performance of the probe card, including the flatness of the test area of the PCB test board, the flatness of the solder connections of the space transformer to the PCB test board, the uniformity of the length dimension of the vertical probes, and the flatness of the C4 Pad of the chip to be tested. At present, the conventional flatness error of the space transformer in the industry is controlled to be about 100um, and the excellent flatness error is controlled to be about 50 um. And the welding flatness error requirement of the space transformer welded to the PCB test board is less than 50 um. This means that not only the magnitude of the warp deformation cannot be increased during the welding process, but also the amount of warp deformation already existing in the space transformer is reduced to within 50 um.

Referring to fig. 1 and 2, the main factors affecting the flatness of the solder joints between the space transformer and the PCB test board are: the space transformer is deformed, and the thickness of the substrate after the solder paste is printed has an error of about 100 um. The height and diameter of the solder balls for ball planting are uniform, and after the ball planting process is completed, the whole welding surface of the space transformer is uneven and cannot present a plane state.

In the prior art, referring to fig. 3, in order to meet the requirement that the solder flatness error of the space transformer soldered to the PCB test board is less than 50um, currently, in the SMT (Surface mount Technology), when the space transformer is soldered to the PCB carrier board, a pressing block is usually placed on the Surface of the space transformer, and by the weight of the pressing block, the solder balls on the substrate and the solder paste on the PCB carrier board are forcibly melted into one body when the reflow solder paste is melted. However, because the required pressing block deforms when the reflow soldering is heated, the force of the pressing block distributed on the substrate cannot reach the uniformity of each welding point, and the welding points with large stress points overflow tin and are connected with tin after the reflow soldering. And the flatness of the surface of the substrate after welding is between 50 and 100um, and the requirement of flatness cannot be met.

Therefore, it is a problem to be solved by those skilled in the art that how to effectively improve the flatness of the bonding surface of the space transformer, so that after the space transformer is soldered on the PCB test board, the flatness error of the whole space transformer is reduced to within 50um, and the test performance of the manufactured probe card is improved.

Disclosure of Invention

The invention aims to provide a substrate leveling jig, a leveling method and a probe card, wherein the substrate leveling jig is used for grinding welding points on the upper surfaces of solder balls, so that the welding points of the solder balls are all positioned on the same plane, the flatness of the substrate after being welded on a PCB test board is effectively improved, the flatness error of the whole substrate is reduced to be within 50 micrometers, and the test performance of the manufactured probe card can be improved to a great extent.

The technical scheme provided by the invention is as follows:

the present invention in a first aspect provides a substrate leveling jig comprising:

the bearing platform is used for bearing the substrate attached with the plurality of solder balls;

a locking device for locking the substrate attached with the plurality of solder balls to the bearing platform;

the leveling device comprises a driving mechanism and a grinding mechanism;

the grinding mechanism is positioned above the substrate and is parallel to the bearing platform;

under the drive of the driving mechanism, the grinding mechanism is used for grinding welding points on the upper surface of the solder ball, so that the welding points are all positioned on the same plane.

In this patent, load-bearing platform is used for the level to place the base plate for the base plate can with grind the mechanism and fully contact, ensure that grinding mechanism can fully grind the solder joint department of tin ball upper surface, make a plurality of solder joints all be located same plane of welding, and this plane and load-bearing platform are parallel, so, can ensure that all solder joints homoenergetic can with the PCB survey test panel the tin face fully contact. That is to say, the plane that grinds out through the grinding machanism of this patent is parallel with the base plate of ideal state, so can improve the roughness of base plate after welding in PCB test panel to a great extent for the roughness error of whole base plate reduces to within 50um, and then can improve the test performance of the probe card of making greatly.

Further preferably, the driving mechanism comprises a lifting member and a driving motor assembled on the lifting member;

the grinding mechanism comprises a grinding wheel assembled at the driving end of the driving motor;

one surface of the grinding wheel, back to the driving end, is a flat grinding surface;

when the grinding surface contacts with the welding points on the upper surface of the tin ball, the driving motor drives the grinding wheel to rotate so as to grind the welding points of the tin ball, and in the grinding process, the lifting piece drives the driving motor and the grinding wheel to move downwards so as to grind the welding points to be in the same plane.

Further preferably, the locking device comprises a bracket and a limiting net plate arranged on the bracket;

the bracket is assembled at the edge of the bearing platform;

the limiting screen plate is parallel to the bearing platform and used for locking the substrate;

the limiting screen plate is configured to at least enable welding spots at the upper end of the solder balls at the lowest position of the substrate to extend to the outer side of the solder balls through meshes of the limiting screen plate; and the solder balls extend to the welding spots on the outer side of the limiting screen plate for the grinding wheel to grind.

Further preferably, the limiting screen plate is parallel to the grinding surface of the grinding wheel;

when the welding spots are ground to be in the same plane, the plane is higher than the upper end face of the limiting screen plate or is superposed with the upper end face of the limiting screen plate;

and/or

The limiting screen plate can be assembled on the bracket in an up-and-down adjusting mode and can be fixed at any position in the moving process of the bracket.

The invention also provides a substrate leveling method in a second aspect, which comprises the following steps:

assembling a substrate attached with a plurality of solder balls on a bearing platform;

locking the substrate attached with the plurality of solder balls on the bearing platform through a locking device;

the driving mechanism drives the grinding mechanism to operate so as to grind the welding points on the upper surface of the tin balls and enable the welding points of the tin balls to be positioned on the same plane.

Further preferably, the method further comprises the following steps:

and cleaning the welding spots of the plurality of the ground solder balls on the substrate.

The invention also provides a probe card in a third aspect, which comprises a substrate, a PCB test board and a plurality of probes, wherein the substrate is manufactured by the substrate leveling method; the substrate is fixedly welded with the PCB test board through welding points so as to be electrically interconnected with the PCB test board; and the probes are sequentially inserted into the guide holes of the substrate and are used for being electrically interconnected with the chip so as to lead out chip signals.

Further preferably, after the substrate and the PCB test board are soldered and fixed, the flatness error of the substrate is less than or equal to 50 micrometers, and the distance between the solder points of the solder balls and the substrate is less than or equal to 120 micrometers.

The invention has the technical effects that:

1. in this patent, load-bearing platform is used for the level to place the base plate for the base plate can with grind the mechanism and fully contact, ensure that grinding mechanism can fully grind the solder joint department of tin ball upper surface, make a plurality of solder joints all be located same plane of welding, and this plane of welding and load-bearing platform are parallel, so, can ensure that all solder joints homoenergetic and PCB survey the tin face of surveying the board and fully contact. That is to say, the plane that grinds out through the grinding machanism of this patent is parallel with the base plate of ideal state, so can improve the roughness of base plate after welding in PCB test panel to a great extent for the roughness error of whole base plate reduces to within 50um, and then can improve the test performance of the probe card of making greatly.

2. In this patent, locking device includes a support and locates the spacing otter board of support. The tin balls extend to the outer side of the limiting screen plate through the meshes. Therefore, on one hand, under the limiting action of the meshes, the plurality of solder balls cannot easily drive the substrate to generate transverse movement in the grinding process, so that the stability in the grinding process is better; on the other hand, the part of the solder ball extending to the outer side of the limiting screen plate is used for being ground by the grinding mechanism, so that the reduction of the welding capacity caused by the over-grinding that the volume of the solder ball is too small can be effectively avoided.

3. In this patent, spacing otter board can be assembled in the support with adjusting from top to bottom, and can be fixed in along any position of support motion in-process, so, can directly adjust spacing otter board and tin ball and carry out the butt, convenient operation and error are little, have improved the quantity that the base plate ground in unit interval to a great extent.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a schematic view of a substrate and solder balls in a state of the art;

FIG. 2 is a schematic view of a substrate and solder balls in another state of the art;

FIG. 3 is a schematic diagram of a prior art arrangement in which a compact acts on a substrate;

FIG. 4 is a schematic view of the substrate leveling tool acting on the substrate and the solder balls in the present patent;

FIG. 5 is a schematic view of the structure of the present invention after the solder ball is ground;

FIG. 6 is a schematic view showing a structure in which the substrate and the PCB test board are soldered in one state after the solder balls are ground in the present invention;

FIG. 7 is a schematic view showing a structure in which the substrate and the PCB test board are soldered in another state after the solder ball is polished in the present invention.

The reference numbers illustrate:

100. a substrate; 110. tin balls; 111. welding spots; 112. welding a surface; 120. tin paste; 200. a PCB test board; 300. a load-bearing platform; 400. a leveling device; 410. a drive mechanism; 420. a grinding mechanism; 421. grinding the surface; 500. a locking device; 510. a support; 520. a limiting screen plate; 521. and (4) meshes.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

The space transformer may be a multi-layer organic board or a multi-layer ceramic board for fixing metal probes for signal transmission with the chip to test the parameters of the chip, which will be referred to as the substrate 100 hereinafter. The precision of the vertical probe card in the horizontal and vertical directions determines the basic performance of the probe card in the test process to a great extent. The precision may include the flatness of the test area of the PCB test board 200, the flatness of the solder of the substrate 100 to the PCB test board 200, the uniformity of the length dimension of the probe, and the flatness of the chip to be tested.

Currently, the flatness error of the substrate 100 is controlled to be about 100 micrometers conventionally in the industry, and the excellent flatness error is controlled to be about 50 micrometers. And the solder flatness error of the substrate 100 soldered to the PCB test board 200 is required to be less than 50 μm. This means that not only the magnitude of warpage cannot be increased during soldering, but also the amount of warpage of the substrate already existing is reduced to within 50 μm.

Referring to fig. 1 and 2, the main factors affecting the flatness of the solder joint of the substrate 100 to the PCB test board 200 are: the substrate 100 is not a flat plate-like structure, and there is a deformation, i.e. there is a tilting of the edge, so that the whole appears like an arc. The thickness of the substrate 100 after the solder paste 120 is printed has an error of about 100 μm. The height and diameter of the solder balls 110 for ball attachment are uniform, and after the ball attachment process is completed, the entire bonding surface 112 of the substrate 100, i.e., the surface formed by the free end surfaces of the solder balls 110, is uneven and cannot present a planar state.

In the prior art, referring to fig. 3, in order to meet the requirement that the welding flatness error of the substrate 100 welded to the PCB test board 200 is less than 50 μm, in the current SMT (Surface mount Technology) welding process of the substrate 100 and the PCB test board 200, a pressing block 600 is usually disposed on the Surface of the substrate 100, and it is worth mentioning that the specific structure of the pressing block 600 is not limited, and it is only required to ensure that the end Surface of the pressing block 600 attached to the substrate 100 is a flat Surface, and the pressure of the pressing block 600 exerted on each position of the substrate 100 is uniform. By the weight of the press block 600, the solder balls 110 on the substrate 100 are forcibly melted together with the solder paste 120 on the PCB test board 200 while the solder paste 120 is melted. However, because the required press block 600 deforms when the reflow soldering is heated, the force of the press block 600 distributed on the substrate 100 cannot reach the uniformity of each solder joint 111, and the solder joints 111 with large stress points overflow tin and are connected with tin after the reflow soldering. Moreover, the flatness of the surface of the welded substrate 100 is between 50 and 100 micrometers, and the flatness requirement cannot be met.

Based on the problems in the prior art, the inventors (or people) have continuously thought and explored for many years to design a substrate leveling jig for grinding the solder joints 111 on the upper surfaces of the solder balls 110, so that the solder joints 111 of the solder balls 110 are all located on the same plane, which effectively improves the flatness of the substrate 100 after being welded on the PCB test board 200, so that the flatness error of the whole substrate 100 is reduced to within 50um, and the test performance of the manufactured probe card can be improved to a great extent.

Specifically, according to an embodiment of the present invention, as shown in fig. 4 and 5, the present invention provides a substrate leveling apparatus in a first aspect, which includes a carrier platform 300, a locking device 500, and a leveling device 400. The carrier platform 300 is used for carrying the substrate 100 attached with a plurality of solder balls 110. The locking device 500 is used to lock the substrate 100 with the solder balls 110 on the platform 300. The flattening apparatus 400 includes a drive mechanism 410 and a grinding mechanism 420. The polishing mechanism 420 is disposed above the substrate 100 and parallel to the supporting platform 300. Under the driving of the driving mechanism 410, the polishing mechanism 420 is used for polishing the pads 111 on the upper surface of the solder ball 110, so that the pads 111 are all located on the same plane.

In this technical solution, the supporting platform 300 can horizontally place the substrate 100, so as to ensure that the substrate 100 can fully contact with the grinding mechanism 420, and the grinding mechanism 420 can fully grind the solder joints 111 on the upper surface of the solder balls 110, so that the solder joints 111 are all located on the same plane, i.e. on the soldering surface 112, and the soldering surface 112 is parallel to the supporting platform 300. Thus, all the pads 111 can be ensured to be in full contact with the tin surface of the PCB test board 200. That is, the plane polished by the polishing mechanism 420 of the present patent is parallel to the flat substrate 100 in an ideal state. Before the solder balls 110 are not polished, since the substrate 100 is deformed and the height and diameter of the solder balls 110 are uniform, after the ball mounting process is completed, the entire bonding surface 112 of the substrate 100, i.e., the surface formed by the free end surfaces of the solder balls 110, is uneven and cannot present a planar state. Therefore, through the above grinding process, the flatness of the substrate 100 after being welded to the PCB test board 200 can be improved to a great extent, so that the flatness error of the whole substrate 100 is reduced to within 50um, and the test performance of the manufactured probe card can be greatly improved.

It is worth mentioning that the deformation degree of the substrate 100 is in the micrometer level, which is not perceived by the naked eye of the ordinary person, and therefore, the jig for leveling the substrate 100, that is, in the very precise level, is greatly different from the ordinary polishing device in the prior art.

Specifically, in the present embodiment, referring to fig. 4, the carrying platform 300 is used for carrying the substrate 100 attached with a plurality of solder balls 110. Since the substrate 100 is substantially flat when viewed from a macroscopic perspective, the bending amplitude of the substrate cannot be directly detected by the naked eye, and therefore, the end surface of the supporting platform 300 for engaging the substrate 100 should also be set to a very flat state. In order to effectively ensure that the substrate 100 is not displaced by a lateral force when the polishing mechanism 420 of the leveling device 400 polishes the solder bumps 111 on the upper surface of the solder balls 110, the supporting platform 300 may be configured as a solid block structure, which can provide sufficient lateral supporting force for the substrate 100, i.e., the polishing force of the polishing mechanism 420 is smaller than the weight of the supporting platform 300, so that the polishing mechanism 420 cannot push the supporting platform 300 to displace, but the specific structure of the supporting platform 300 may be specifically set according to the actual application scenario, and is not limited thereto.

Further, referring to fig. 4, in order to effectively ensure that the substrate 100 is not easily separated from the supporting platform 300 when the substrate 100 is subjected to the polishing force after the substrate 100 is assembled on the supporting platform 300, a locking device 500 may be additionally provided for locking the substrate 100 to the supporting platform 300, so that the substrate 100 and the supporting platform 300 always have a unique assembly posture and cannot move laterally.

As a preferred example of this embodiment, the locking device 500 may include a bracket 510 and a position-limiting mesh 520 provided on the bracket 510. Specifically, the support 510 may be a hollow frame structure and is adapted to the contour of the edge of the platform 300. The position limiting screen 520 is assembled in the bracket 510, and the position limiting screen 520 is matched with the outline of the substrate 100. The bracket 510 is assembled at an edge of the carrier platform 300, and is used to assemble the position-limiting screen 520 on the carrier platform 300 carrying the substrate 100, so that the position-limiting screen 520 and the substrate 100 are in cooperation. Preferably, the position-limiting mesh plate 520 is arranged in parallel with the loading platform 300. It can be ensured that each solder ball 110 can correspond to the mesh 521 on the position-limiting mesh plate 520, so that each solder ball 110 has an adaptive mesh 521, which facilitates the solder ball 110 to extend to the outer side of the position-limiting mesh plate 520 through the mesh 521, and the portion of the solder ball 110 extending to the outer side is used for being ground by the grinding mechanism 420. With such an arrangement, on one hand, the plurality of solder balls 110 cannot easily drive the substrate 100 to move transversely in the grinding process under the limiting action of the mesh 521, so that the stability in the grinding process is better; on the other hand, the portion of the solder ball 110 extending to the outer side of the position-limiting mesh plate 520 is used for being ground by the grinding mechanism 420, and the position-limiting mesh plate 520 can be used as a reference target, thereby effectively avoiding the reduction of the welding stability caused by the over-grinding resulting in the too small volume of the solder ball 110.

As a further optimization, referring to fig. 4, the diameter of the solder ball 110 should be greater than or equal to the aperture of the mesh of the limiting screen 520, so as to effectively ensure that the mesh can limit the solder ball 110, and the solder ball 110 will not leak out of the mesh. At least, the upper end of the solder ball 110 at the lowest position of the substrate 100 can be ensured to extend out of the outer side of the position-limiting screen 520 through the meshes of the position-limiting screen 520, the upper part of the solder ball 110 at the highest position of the substrate 100 can be ensured to extend out of the outer side of the position-limiting screen 520, and the lower part of the solder ball 110 can only be positioned at the inner side of the position-limiting screen 520. Thus, the flatness of the bonding surface 112 can be effectively ensured and over-polishing can be prevented.

As a further optimization, referring to FIG. 4, the position-limiting net plate 520 can be assembled on the bracket 510 in an up-and-down adjustable manner, and can be fixed at any position along the bracket 510 in the process of moving. The specific adjustment mode of the limiting screen 520 is not limited, and can be specifically set according to the actual application scene, which is not described herein in detail. By the arrangement, the substrate 100 can be directly abutted against the solder balls 110 by adjusting the limiting screen plate 520, the operation is convenient, the error is small, and the grinding quantity of the substrate 100 in unit time is improved to a great extent.

Of course, it should be mentioned that the bracket 510 and the position-limiting net plate 520 disposed on the bracket 510 are only one preferred solution of the locking device 500, and the locking device 500 may also be of other structures, that is, the substrate 100 may be locked on the supporting platform 300 at will, so that the substrate 100 and the supporting platform 300 always have the unique assembly posture, and no part or assembly of the position moving laterally occurs, which are within the protection scope of this patent and are not described herein in too much detail.

In the present embodiment, referring to fig. 4, the polishing mechanism 420 is disposed above the substrate 100 and parallel to the supporting platform 300. Thus, the grinding mechanism 420 is ensured to be aligned with the substrate 100, and the grinding mechanism 420 is ensured to grind the solder points 111 on the upper surfaces of the solder balls 110 to a soldering surface 112 parallel to the carrier platform 300. In this way, the bonding surface 112 is parallel to the substrate 100 in an ideal state.

As a preferred example of this embodiment, the driving mechanism 410 may include a lifting member (not shown) and a driving motor mounted to the lifting member, and the grinding mechanism 420 may include a grinding wheel mounted to a driving end of the driving motor. The specific structure of the lifting member is not limited, and any member that can be used for lifting is within the protection scope of the patent. Of course, the driving mechanism 410 may be any other mechanism for driving the grinding mechanism 420 to operate, and is not limited to a driving motor; and grinding mechanism 420 may be any other mechanism for grinding and still be within the scope of this patent. Specifically, the driving motor drives the grinding wheel to rotate so as to grind the pads 111 on the upper surface of the solder ball 110, so that the pads 111 are all located on the same plane. Specifically, the driving end of the driving motor faces downward and is directed toward the substrate 100. And because of the fine grinding, referring to fig. 4 to 7, the surface of the grinding wheel opposite to the driving end is a flat grinding surface 421 parallel to the limiting screen 520, the surface layer of the grinding surface 421 is smooth, when the grinding surface 421 contacts with the welding spot 111 on the upper surface of the solder ball 110, the driving motor drives the grinding wheel to rotate so as to grind the welding spot 111 of the solder ball 110, and in the grinding process, the lifting member drives the driving motor and the grinding wheel to move downwards so as to grind the welding spots 111 in the same plane. As a further optimization, the welding surface 112 should be higher than the upper end surface of the position-limiting net plate 520 or coincide with the upper end surface of the position-limiting net plate 520. Thus, even when the grinding is about to be finished, the limiting net plate 520 still can play a role in limiting and fixing.

It should be noted that, in order to effectively ensure the stability and wear resistance of the position-limiting net plate 520, the position-limiting net plate 520 may be made of a metal material, but is not limited thereto.

After grinding, each welding spot 111 is transformed from spherical to planar, and a plurality of welding spots 111 in planar form together form a welding surface 112. If the solder balls 110 are not ground, the surface formed by the free end surfaces of the solder balls 110 is uneven and cannot present a planar state, and if the solder balls are directly soldered on the tin surface of the PCB test board 200, the substrate 100 will have an error of about 50 to 100 μm. Therefore, the solder bumps 111 on the upper surface of the solder ball 110 are polished to have a flat surface, thereby ensuring that all the solder bumps 111 can be fully contacted with the solder surface of the PCB test board 200. The flatness of the substrate 100 after being soldered to the PCB test board 200 can be greatly improved.

The present invention also provides a method for leveling a substrate, which can perform the following steps on the substrate leveling jig: assembling the substrate 100 with the solder balls 110 on the platform 300; locking the substrate 100 attached with the plurality of solder balls 110 to the loading platform 300 by the locking device 500; the driving mechanism 410 drives the grinding mechanism 420 to operate, so as to grind the positions of the solder joints 111 on the upper surface of the solder balls 110, and the solder joints 111 of the solder balls 110 are all located on the same plane; cleaning the soldering points 111 of the plurality of solder balls 110 polished on the substrate 100, that is, cleaning the soldering surface 112 in all aspects, so as to ensure that impurities and the like do not exist to influence the soldering stability; finally, the substrate 100 is soldered to the PCB test board 200 by the solder joint 111.

The present invention also provides a probe card in a third aspect, which includes a substrate 100, a PCB test board 200, and a plurality of probes. The substrate 100 is fabricated by the above-described substrate leveling method. The substrate 100 is soldered to the PCB test board 200 by the solder joints 111 to electrically interconnect with the PCB test board 200. The plurality of probes are sequentially inserted into the guiding holes of the substrate 100 for electrically interconnecting with the chip to extract the chip signals. Specifically, referring to fig. 6 and 7, after the substrate 100 and the PCB test board 200 are soldered and fixed, the flatness error of the entire substrate 100 is reduced to within 50 micrometers, and the distance between the solder points 111 of the solder balls 110 and the substrate 100 is less than or equal to 120 micrometers, so that the test performance of the manufactured probe card can be greatly improved. Wherein, the solder paste 120 is additionally arranged on the tin surface of the PCB test board 200 to be soldered and fixed with the soldering points 111.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides a base plate flattening tool which characterized in that includes:

the leveling device comprises a driving mechanism and a grinding mechanism;

2. The substrate leveling tool of claim 1,

the driving mechanism comprises a lifting piece and a driving motor assembled on the lifting piece;

3. The substrate leveling tool of claim 2,

the locking device comprises a bracket and a limiting screen plate arranged on the bracket;

the bracket is assembled at the edge of the bearing platform;

4. The substrate leveling tool of claim 3,

the limiting screen plate is parallel to the grinding surface of the grinding wheel;

and/or

5. A method for flattening a substrate, characterized in that the following steps are performed on the substrate flattening jig according to any one of claims 1 to 4:

6. The method of planarizing a substrate of claim 5, further comprising the steps of:

7. A probe card comprising a substrate, a PCB test board and a plurality of probes, wherein the substrate is manufactured by the substrate leveling method according to claim 5 or 6;

the substrate is fixedly welded with the PCB test board through welding points so as to be electrically interconnected with the PCB test board; and

the probes are sequentially inserted into the guide holes of the substrate and are used for being electrically interconnected with the chip so as to lead out chip signals.

8. The probe card of claim 7,

after the substrate and the PCB test board are welded and fixed, the flatness error of the substrate is less than or equal to 50 micrometers, and the distance between the welding points of the solder balls and the substrate is less than or equal to 120 micrometers.