CN112285395A

CN112285395A - Probe card and manufacturing method thereof

Info

Publication number: CN112285395A
Application number: CN202011190580.7A
Authority: CN
Inventors: 李正运; 严日东
Original assignee: Mingzhen Micro Electromechanical Shanghai Co ltd
Current assignee: Mingzhen Micro Electromechanical Shanghai Co ltd
Priority date: 2020-10-30
Filing date: 2020-10-30
Publication date: 2021-01-29

Abstract

The invention discloses a probe card and a manufacturing method thereof, and particularly relates to the technical field of probe substrates and probe card production. The probe tip of the present invention is not directly mounted on the space transducer and is convenient for mounting the probe, and secondly, when the space transducer and the probe tip are connected, they can be arranged and bonded together, and at the same time, the thickness of the probe card can be minimized even if the probe is mounted using a separate probe substrate.

Description

Probe card and manufacturing method thereof

Technical Field

The present invention relates to the field of probe substrate and probe card manufacturing technology, and more particularly, to a probe card with a probe substrate, which facilitates mounting of probes and connection of the probes to a space transformer, and a method for manufacturing the same.

Background

Generally, in order to test semiconductor devices (e.g., semiconductor memory, flat panel display) for defects during or after manufacturing, a probe card is generally used to electrically connect a wafer and a semiconductor device testing apparatus, and an electrical signal from the testing apparatus is transmitted to a semiconductor bare chip formed on the wafer and a signal from the semiconductor bare chip is transmitted to the semiconductor device testing apparatus.

Fig. 1 is a cross-sectional view of a conventional probe card, which includes a Printed Circuit Board (PCB) (10), a space transformer (20), an interface device (30) electrically connecting the PCB (10) and the space transformer (20), and a probe (40) mounted on the space transformer (20). Although not shown in fig. 1, the probe card is generally equipped with a deformation compensation means for compensating for geometric deformation of the space transformer (20). The printed circuit board (10) receives the electrical signals from the semiconductor test equipment and transmits the signals thereof to the probes (40) mounted on the space transformer (20) through the interface device (30); instead, signals from the probes (40) are transmitted to the semiconductor test equipment. The space transformer (20) is typically in the form of an mlc (multi Layer ceramic) composed of a plurality of ceramic substrates, and the manufacturing process of the space transformer is complicated and the manufacturing cost is high. The upper surface and the lower surface of the space transformer (20) are provided with bonding pads, the bonding pad interval on the upper surface is different from the bonding pad interval on the lower surface, so that the function of changing the interval is achieved, and the bonding pads on the upper surface are electrically connected with the bonding pads on the lower surface through an internal circuit of the space transformer (20). A plurality of microprobes (40) fabricated in an MEMS (micro Electric Mechanical System) manner are mounted on a plurality of pads (50) on the upper surface of the space transformer (20) collectively or individually.

Generally, to ensure the reliability of the test result, all the probes (40) installed on the space transformer (20) must be precisely installed corresponding to the pads (50) of the space transformer (20), but one or more probes (40) among the plurality of probes (40) are not properly installed on the space transformer (20), which not only wastes the expensive entire space transformer (20), but also reinstalls the probes (40) on a new space transformer (20). And requires that the probe tips must contact the pads of the space transformer within a tolerance of several micrometers, and the probe substrate and stiffener plate assembly is mounted to the space transformer in a mechanically fastened (e.g., screw-strong) manner, so that precise alignment of the probe tips and pads has certain limitations.

In addition, the assembly of the probe substrate and the reinforcing plate is sandwiched between the space transformer and the probes, with the accompanying problem that it is difficult to reduce the thickness of the probe card.

The above information disclosed in this background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art.

Disclosure of Invention

In order to overcome the above-mentioned defects in the prior art, embodiments of the present invention provide a probe card and a method for manufacturing the same, and the technical problem to be solved by the present invention is: the method reduces the limitation of accurate butt joint of the probe tip and the bonding pad and reduces the thickness of the probe card.

In order to achieve the purpose, the invention provides the following technical scheme: a probe card comprises a printed circuit board, wherein a space converter is arranged at the top of the printed circuit board, a probe and a probe substrate are arranged at the top of the space converter, the probe substrate is clamped between the space converter and the probe, the probe substrate comprises a silicon substrate and a conductive socket, a plurality of grooves are formed in the top of the silicon substrate, a photoresist layer is coated on the top surface of the silicon substrate, plating layers are electroplated on the top surface of the silicon substrate and the grooves, the conductive socket penetrates through the silicon substrate and comprises an opening part for installing the probe and a base part which is jointed with the space converter, an interface device is arranged between the printed circuit board and the space converter and is electrically connected with the printed circuit board and the space converter through the interface device, a bonding pad is arranged at the position, corresponding to the conductive socket, of the top of the space converter, the probe is matched and spliced with the conductive socket.

In a preferred embodiment, the number of the probes and the conductive sockets is multiple, the bumps are conductive material members, and the plating layer is a conductive plating layer.

In a preferred embodiment, on a probe substrate of a plurality of the conductive sockets formed through the silicon substrate, a plurality of the conductive sockets may be further formed by removing a portion of the silicon substrate by etching.

In a preferred embodiment, the surface of the silicon substrate is provided for polishing.

In a preferred embodiment, the electrically conductive socket is arranged open through one of the surfaces of the silicon substrate, while the other surface is arranged closed.

The invention also provides a manufacturing method of the probe card, which comprises the working procedure of manufacturing the probe substrate of which a plurality of conductive sockets penetrate through the silicon substrate by the MEMS process; a step of manufacturing a space transformer, which includes forming a plurality of pads at positions corresponding to the plurality of conductive sockets; a step of disposing a plurality of bumps having a conductive function between the plurality of conductive sockets and the plurality of pads, respectively; and a step of collectively bonding the plurality of conductive sockets and the plurality of terminals of the space transformer.

In one preferred embodiment, the step of fabricating the probe substrate includes a step of forming a plurality of grooves in a silicon substrate, a step of forming a conductive material on one surface of the silicon substrate on which the plurality of grooves are formed, a step of polishing one surface of the silicon substrate, and a step of polishing the other surface of the silicon substrate.

The invention has the technical effects and advantages that:

the probe tip of the present invention is not directly mounted on the space transducer and is convenient for mounting the probe, and secondly, when the space transducer and the probe tip are connected, they can be arranged and bonded together, and at the same time, the thickness of the probe card can be minimized even if the probe is mounted using a separate probe substrate.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 is a schematic diagram of a conventional probe card;

FIGS. 2a to 2e are flow charts illustrating a probe substrate according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of bumps formed on space transformer pads for a probe card according to one embodiment of the invention;

FIG. 4a is a schematic diagram illustrating a bonding state of a probe substrate and a space transformer according to an embodiment of the present invention;

FIG. 4b is a schematic view of the probe substrate of FIG. 4a with the silicon substrate removed;

FIG. 5 is a partial oblique view of the probe substrate of FIG. 4 b;

FIG. 6 is a schematic diagram of a probe card according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a probe card according to another embodiment of the invention.

The reference signs are: 100: a silicon substrate; 110: a photoresist layer; 120: a trench; 130: plating; 140: a conductive socket; 200: a space transformer; 210: a pad; 300: a bump; 400: a probe; 500: a printed circuit board; 600: an interface device.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted.

In the description, when a certain portion is described as being "connected" to another portion, the portion may be "directly connected" or "electrically connected" to the other portion through an intermediate member. When a portion is described as "comprising" a component herein, it is not intended to exclude other components, but rather may include other components unless stated to the contrary. The described features, structures, or characteristics may be combined in any suitable manner in one or more exemplary embodiments. In the following description, numerous specific details are provided to give a thorough understanding of example embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the subject matter of the present disclosure can be practiced without one or more of the specific details, or with other methods, components, steps, and so forth. In other instances, well-known structures, methods, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the disclosure.

The invention provides a probe card, comprising a printed circuit board 500, wherein a space transformer 200 is arranged on the top of the printed circuit board 500, a probe 400 and a probe substrate clamped between the space transformer 200 and the probe 400 are arranged on the top of the space transformer 200, the probe substrate comprises a silicon substrate 100 and an electric conduction socket 140, a plurality of grooves 120 are arranged on the top of the silicon substrate 100, a photoresist layer 110 is coated on the top surface of the silicon substrate 100, the top surface of the silicon substrate 100 and the grooves 120 are both electroplated with a plating layer 130, the electric conduction socket 140 is arranged by penetrating the silicon substrate 100 and comprises an opening part for installing the probe 400 and a base part jointed with the space transformer 200, an interface device 600 is arranged between the printed circuit board 500 and the space transformer 200 and electrically connected with the two through the interface device 600, a pad 210 is arranged on the top of the space transformer 200 at a position corresponding to the electric conduction socket 140, a bump 300 is arranged between the pad 210 and the conductive socket 140, and the probe 400 is matched and plugged with the conductive socket 140.

Further, the number of the probes 400 and the conductive sockets 140 is plural, the bumps 300 are conductive members, and the plating layer 130 is a conductive plating layer.

Further, on the probe substrate of the plurality of conductive sockets 140 formed through the silicon substrate 100, a plurality of conductive sockets 140 may be formed by removing portions of the silicon substrate 100 by etching.

Further, the surface of the silicon substrate 100 is a polishing arrangement.

Further, the conductive socket 140 is disposed through one surface of the silicon substrate 100 in an open manner, and the other surface is disposed in a closed manner.

The present invention also provides a method for manufacturing a probe card, which includes a process of manufacturing a probe substrate in which a plurality of conductive sockets 140 penetrate a silicon substrate 100 through an MEMS process; a process of manufacturing the space transformer 200, which includes forming a plurality of pads 210 at positions corresponding to the plurality of conductive sockets 140; a step of disposing a plurality of bumps 300 having a conductive function between the plurality of conductive sockets 140 and the plurality of pads 210, respectively; and a step of collectively bonding the plurality of conductive sockets 140 and the plurality of terminals of the space transformer 200.

Specifically, the step of manufacturing the probe substrate includes a step of forming a plurality of grooves 120 in the silicon substrate 100, a step of forming a conductive material on one surface of the silicon substrate 100 on which the plurality of grooves 120 are formed, a step of polishing one surface of the silicon substrate 100, and a step of polishing the other surface of the silicon substrate 100.

The working principle of the invention is as follows:

manufacturing a Probe substrate for a Probe card

Fig. 2a to 2e are process flow diagrams illustrating a method for manufacturing a probe substrate for a probe card according to an embodiment of the present invention. A method of manufacturing a probe substrate in a MEMS manner according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, as shown in fig. 2a, as a semiconductor substrate, a photoresist layer 110 is coated on a silicon substrate 100 in a spin coating manner; next, as shown in fig. 2b, a mask defining a plurality of socket patterns is placed on the silicon substrate 100, and the photoresist layer 110 is exposed using an ultraviolet exposure apparatus, an X-ray exposure apparatus, an electron beam (E-beam), or the like.

After developing on the exposed photoresist layer 110, as shown in fig. 2b, the photoresist layer 110 is patterned according to a defined mask pattern, and then, as shown in fig. 2c, the silicon substrate 100 on which the photoresist pattern exposure is completed is subjected to a Dry etching (Dry etching) process, such as Deep silicon etching (Deep silicon etching), or Wet etching (Wet etching), so that a plurality of trenches 120 are formed on the silicon substrate 100 according to the exposed photoresist pattern. The mask used for the deep silicon etch is different and a hard mask such as a metal or silicon oxide film may be used in addition to the photoresist.

After the plurality of trenches 120 are formed, the photoresist pattern is removed by photoresist pattern ashing or a wet removal process, and as shown in fig. 2d, a plating layer 130 is formed on one surface of the silicon substrate 110 where the plurality of trenches 120 are formed by a plating process. In the electroplating process, a metal such as Cu or Ni may be used as a Seed layer (Seed layer), the plating layer 130 may be formed using a metal such as Ni, Ni alloy, Cu or alloy, and further, before the Seed layer is deposited, a silicon oxide film or a silicon nitride film may be formed on the silicon substrate 100, the silicon substrate 100 and the plating layer 130 may be subjected to an insulation process, after the plating layer (130) is formed, as shown in fig. 2e, the upper surface and the lower surface of the silicon substrate 110 may be polished by Chemical Mechanical Polishing (CMP), and when Polishing, the upper surface on which the silicon substrate plating layer 130 is formed may be polished until the silicon substrate 100 except for the inside of the trench 120 is exposed, the lower surface of the silicon substrate 100 without the plating layer 130 may be polished until the base of the plating layer 130 inside the trench 120 is exposed, and the Polishing process is finished, that is a probe substrate including the silicon substrate 100 and a plurality of conductive sockets 140 penetrating the silicon substrate 100 into a "U, the plurality of conductive sockets 140 formed through the silicon substrate 100 are to be inserted with probes 400, and the probe substrate functions as an intermediate joint for connecting the probes 400 mounted in the conductive sockets 140 and the space transformer 200, as described later.

Bonding probe substrate and space transformer

Fig. 3 shows a Space transformer 200 disposed opposite to a probe substrate, a plurality of pads 210 are formed on an upper surface and a lower surface of the Space transformer 200, the pads 210 on the upper surface of the Space transformer 200 correspond to the probes 400, pads (not shown) on the lower surface correspond to a printed circuit board 500, the pads 210 on the upper surface and the lower surface are electrically connected by an internal circuit of the Space transformer 200, the pads 210 formed on the surface of the Space transformer 200 where the probes 400 are mounted toward a wafer to be tested must have a high integration level as the pitch of the pads 210 of the wafer to be tested is narrowed, the pads 210 formed on the surface of the Space transformer 200 corresponding to the printed circuit board 500 have a low integration level, the pads 210 on both surfaces of the Space transformer 200 are electrically connected while the pads are equally spaced, the Space transformer 200 is manufactured as an mlc (multi Layer ceramic) substrate by a MEMS process, the pads 210 are formed on the upper and lower surfaces of the MLC substrate, and the contact hole of each MLC substrate is filled with filler such as silver paste (Agpaste) to contact each other, so that the substrates are stacked continuously and the corresponding pads 210 on the two surfaces are connected to each other, but the structure of the space transformer 200 is merely an example, and in the present invention, the pads on the two surfaces of the space transformer 200 are connected to each other through the MLC substrate. On one hand, in order to bond the probe substrate manufactured according to the process shown in fig. 2a to 2e to the space transformer 200, the bumps 300 are formed on the plurality of pads 210 of the space transformer 200, respectively, the bumps 300 may be formed on the pads 210 through an SPP (vapor Paste printing) process, or the bumps 300 may be formed in a tin-plating (vapor) manner after a photolithography process is performed on the upper surface of the space transformer 200 instead of the SPP process to form the bump 300 pattern.

Fig. 4a is a schematic view of the probe substrate of fig. 2e and the space transformer 200 of fig. 3 after bonding.

A probe substrate including a plurality of conductive sockets 140 penetrating the silicon substrate 100 is brought into contact with the space transformer 200 having bumps 300 formed on the pads 210, in this case, the bump 300 on the pad 210 is brought into contact with the base of the conductive socket 140 having a "U" shaped cross section on the probe substrate, at which time the bump 300 is heated, the probe substrate and the space transformer 200 are bonded to each other, the plurality of pads 210 on the upper surface of the space transformer 200 and the plurality of conductive sockets 140 on the probe substrate correspond to each other, when the space transformer 200 and the probe substrate are coupled, the conductive sockets 140 and the pads 210 are arranged one-to-one, and after the probe substrate and the space transformer 200 are coupled in this manner, the plurality of conductive sockets 140 of the probe substrate and the plurality of pads 210 of the space transformer 200 are easily bonded together by the bumps 300, and thereafter, as shown in fig. 4b, the silicon substrate 100 portion may also be removed from the probe substrate by wet etching.

As shown in fig. 4b, fig. 5 shows the assembly of the silicon substrate 100 removed after the probe substrate and the space transformer 200 are bonded, and as shown in fig. 5, conductive sockets 140 bonded by bumps 300 are formed on each pad 210 on the upper surface of the space transformer 200, and a probe 400 is mounted on each conductive socket 140.

According to an embodiment of the present invention, the conductive socket 140 is bonded to the space transformer 200, but the space transformer 200 may be omitted and the conductive socket 140 may be directly bonded to the PCB.

As described above, after the probe substrate including the plurality of conductive sockets is fabricated through the MEMS process, the probes are mounted on the conductive sockets 140, which does not significantly increase the overall thickness of the probe card as compared to the probe card directly mounted on the pads 210 of the space transformer 200, and at the same time, can solve the problems of the related art caused by the direct mounting of the probes on the space transformer 200.

In addition, the present invention employs the probe substrate in the form of a single structure manufactured in the MEMS process, thereby enabling to reduce the entire thickness of the probe card, compared to the prior art in which the probe substrate and the stiffener plate are used together to mount the probe.

Manufacturing a Probe card

Fig. 6 to 7 schematically illustrate a probe card fabricated using a probe substrate and a space transformer 200 bonded to each other. As shown in fig. 6, after the probe substrate and the space transformer 200 are bonded, the plurality of probes 400 are vertically inserted into the plurality of conductive sockets 140 of the probe substrate, and at this time, the probes 400 are fixed in the conductive sockets 140 by using conductive epoxy or solder paste (Soldering paste). Accordingly, the probes 400 mounted on the probe substrate are electrically connected to the pads 210 of the space transformer 200 through the conductive sockets 140, and since the conductive sockets 140 have a "U" -shaped cross-section with one side thereof being open and the other side being a closed structure, the probes 400 inserted into the openings of the conductive sockets 140 are electrically connected to the space transformer 200 only through the conductive sockets 140 and do not penetrate through the probe substrate to be exposed to the outside.

As described above, after the probe substrate formed with the plurality of conductive sockets 140 is bonded to the space transformer 200, the probe 400 is mounted to each of the conductive sockets 140, which can solve the problem that the entire expensive space transformer 200 is discarded due to improper installation of the probe 400 in the space transformer 200.

In addition, since the probe 400 is inserted into the conductive socket 140 having the "U" -shaped cross-section, the probe 400 is conveniently installed, and the bottom end of the probe is not directly contacted to the pad 210 of the space transformer 200 but the base portion of the conductive socket 140 flattened by a Chemical Mechanical Planarization (CMP) operation is collectively bonded to the pad 210 of the space transformer 200, so that it is not necessary to directly bond the pad 210 of the space transformer 200 and the probe 400 as in the prior art, thereby making it possible to solve the problem of difficulty in collectively arranging and collectively bonding, and is connected to the printed circuit board 500 through the electrical interface device 600 such as a spring block including a Pogo pin on the lower surface of the space transformer 200.

While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that the described embodiments may be modified in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are illustrative in nature and should not be construed as limiting the scope of the invention.

The points to be finally explained are: first, in the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" should be understood broadly, and may be a mechanical connection or an electrical connection, or a communication between two elements, and may be a direct connection, and "upper," "lower," "left," and "right" are only used to indicate a relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship may be changed;

secondly, the method comprises the following steps: in the drawings of the disclosed embodiments of the invention, only the structures related to the disclosed embodiments are referred to, other structures can refer to common designs, and the same embodiment and different embodiments of the invention can be combined with each other without conflict;

and finally: the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.

Claims

1. A probe card comprising a printed circuit board (500), characterized in that: the top of the printed circuit board (500) is provided with a space converter (200), the top of the space converter (200) is provided with a probe (400) and a probe substrate clamped between the space converter (200) and the probe (400), the probe substrate comprises a silicon substrate (100) and a conductive socket (140), the top of the silicon substrate (100) is provided with a plurality of grooves (120), the top surface of the silicon substrate (100) is coated with a photoresist layer (110), the top surface of the silicon substrate (100) and the grooves (120) are both electroplated with a plating layer (130), the conductive socket (140) penetrates through the silicon substrate (100) and comprises an opening part for mounting the probe (400) and a base part connected with the space converter (200), and an interface device (600) is arranged between the printed circuit board (500) and the space converter (200), the space converter and the conductive socket (140) are electrically connected through an interface device (600), a bonding pad (210) is arranged at the position, corresponding to the conductive socket (140), of the top of the space converter (200), a bump (300) is arranged between the bonding pad (210) and the conductive socket (140), and the probe (400) and the conductive socket (140) are matched and spliced.

2. A probe card according to claim 1, wherein: the number of the probes (400) and the number of the conductive sockets (140) are respectively provided with a plurality of the probes, the bumps (300) are conductive material members, and the plating layers (130) are conductive plating layers.

3. A probe card according to claim 2, wherein: on a probe substrate of the plurality of conductive sockets (140) formed through the silicon substrate (100), a plurality of conductive sockets (140) may also be formed by removing portions of the silicon substrate (100) by etching.

4. A probe card according to claim 1, wherein: the surface of the silicon substrate (100) is provided for polishing.

5. A probe card according to claim 1, wherein: the conductive socket (140) is disposed through one of the surfaces of the silicon substrate (100) in an open configuration, while the other surface is disposed in a closed configuration.

6. A method of manufacturing a probe card according to any one of claims 1 to 5, wherein: the method comprises a step of manufacturing a probe substrate in which a plurality of conductive sockets (140) penetrate a silicon substrate (100) by an MEMS process; a step of manufacturing a space transformer (200) which includes forming a plurality of pads (210) at positions corresponding to the plurality of conductive sockets (140); a step of disposing a plurality of bumps (300) having a conductive function between the plurality of conductive sockets (140) and the plurality of pads (210); and a step of collectively bonding the plurality of conductive sockets (140) and the plurality of terminals of the space transformer (200).

7. The method of claim 6, wherein the probe card comprises: the step of manufacturing the probe substrate includes a step of forming a plurality of grooves (120) in a silicon substrate (100), a step of forming a conductive material on one surface of the silicon substrate (100) on which the plurality of grooves (120) are formed, a step of polishing one surface of the silicon substrate (100), and a step of polishing the other surface of the silicon substrate (100).