TWI695985B - Vertical probe card and rectangular probe thereof - Google Patents

Abstract

The present invention discloses a vertical probe card and a rectangular probe thereof. The rectangular probe includes an upper contacting segment, a lower contacting segment, and a comb segment arranged between the upper contacting segment and the lower contacting segment. The comb segment includes a U-shaped portion and at least one teeth portion. The U-shaped portion includes a bottom base defining a first circuit channel and two lateral bases respectively connected to two opposite ends of the bottom base. The at least one teeth portion extends from the bottom base, and is arranged between the two lateral bases. The at least one teeth portion includes a head and a neck connected to the head and the bottom base, and a length of the neck is less than that of the head. The upper contacting segment and the lower contacting segment are configured to be staggeredly arranged with each other, and the comb segment can be bent to be an arc structure that causes the at least one teeth portion to be arranged on an inner side thereof, so that the head of the at least one teeth portion is connected to the two lateral bases for forming a second circuit channel.

Description

Vertical probe card and its rectangular probe

The invention relates to a probe card, in particular to a vertical probe card and its rectangular probe.

The existing vertical probe card includes a plurality of guide plates and a plurality of conductive probes passing through the plurality of guide plates, and each of the conductive probes will be pressed by the misalignment of the plurality of guide plates, thereby generating deformation. However, since the deformation portion of the conductive probe may have excessive concentration of stress, the problem of breakage is likely to occur.

Therefore, the inventor believes that the above-mentioned defects can be improved, and Naite devotes himself to research and cooperates with the application of scientific principles, and finally proposes a reasonable design and effectively improves the above-mentioned defects of the present invention.

An embodiment of the present invention is to provide a vertical probe card and a rectangular probe, which can effectively improve the defects that may occur in the existing vertical probe card (or rectangular probe).

The embodiment of the invention discloses a vertical probe card, which comprises: an upper guide plate and a lower guide plate, which are arranged at intervals from each other; and a plurality of rectangular probes, which are respectively penetrated on the upper guide plate and respectively The lower guide plate; wherein each of the rectangular probes is elongated and defines a length direction, and each of the rectangular probes includes: an upper contact section and a lower contact section, respectively located on the upper guide plate Opposite two outer sides of the lower guide plate; and at least one comb-shaped section between the upper contact section and the lower contact section, and at least one of the comb-shaped section includes: a U-shaped portion , Comprising a long base parallel to the length direction and a bottom base connected to two ends of the base base respectively; wherein the base base constitutes a first section of at least one of the comb-shaped sections A current channel; and a plurality of comb-tooth portions, formed from the bottom base portion extending in an extension direction and located between the two side base portions, and the plurality of comb-tooth portions are spaced apart from each other along the length direction Arranged in a row; wherein, each of the comb teeth includes a head and a neck connecting the head and the base, and the neck of each comb is at the length A length in the direction is less than a maximum length of the head in the length direction; wherein, in each of the rectangular probes, when the upper guide plate and the lower guide plate are misaligned with each other, the The upper contact section and the lower contact section are misaligned with each other, and at least one of the comb-shaped sections is bent into an arc-shaped configuration, a plurality of the comb tooth portions are located inside the arc-shaped configuration, and a plurality of the combs The heads of the teeth are in contact with each other and connected to the two side bases to jointly form a second current channel.

The embodiment of the present invention also discloses a rectangular probe of a vertical probe card, which is elongated and defines a length direction. The rectangular probe includes: an upper contact section and a lower contact section; and at least one comb-shaped section, It is located between the upper contact section and the lower contact section, and at least one of the comb-shaped sections includes: a U-shaped portion, including a base portion elongated and parallel to the length direction, and respectively connected Two side bases at both ends of the base base; wherein the base base constitutes a first current channel of at least one of the comb-shaped sections; and at least one comb tooth portion extending from the base base in an extending direction Formed by an extension and located between the two side bases; wherein at least one of the comb teeth includes a head and a neck connecting the head and the bottom base, and at least one of the comb teeth A length of the neck portion of the portion in the length direction is smaller than a maximum length of the head portion in the length direction; wherein, the upper contact section and the lower contact section of the rectangular probe can Are misaligned with each other so that at least one of the comb-shaped sections is bent into an arc-shaped configuration, and at least one of the comb-tooth portions is located inside the arc-shaped configuration, and the heads of at least one of the comb-tooth portions are connected The two side bases together form a second current channel.

In summary, the vertical probe card and the rectangular probe disclosed in the embodiments of the present invention can reduce the stress caused by bending with a comb-shaped section, so as to avoid the problem of fracture of the rectangular probe, and the The rectangular probe can transmit signals by connecting a plurality of heads of the comb-shaped section, so that the signals can be stably transmitted.

In order to understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention, but these descriptions and drawings are only used to illustrate the present invention, not to make any protection to the scope of the present invention. limit.

Please refer to FIG. 1 to FIG. 8, which are the embodiments of the present invention. It should be noted that this embodiment corresponds to the relevant quantity and appearance mentioned in the drawings, and is only used to specifically illustrate the implementation of the present invention. In order to facilitate understanding of the content of the present invention, rather than to limit the scope of protection of the present invention.

As shown in FIGS. 1 and 2, this embodiment discloses a vertical probe card, which includes a probe head 100 (probe head) and abutting on the probe head 100 side (such as: An adapter plate 200 (space transformer) on the top side of the needle 100, and the other side of the probe head 100 (such as: the bottom side of the probe head 100 in FIG. 1) can be used to bear against a test DUT (device under test, DUT) (not shown in the figure, such as: semiconductor wafer).

It should be noted that, in order to facilitate the understanding of this embodiment, the drawings only show the partial structure of the vertical probe card, so as to clearly show the structure and connection relationship of each element of the vertical probe card, but the present invention does not Limit to schema. The structure of each element of the probe head 100 and its connection relationship will be described below.

As shown in FIGS. 1 and 2, the probe head 100 includes an upper guide plate 1 (upper die), a lower guide plate 2 (lower die) spaced apart from the upper guide plate 1, and is clamped on the upper guide plate 1 a spacer plate (not shown) between the lower guide plate 2 and a plurality of rectangular probes 3. It should be noted that, in other embodiments not shown in the present invention, the spacing plate of the probe head 100 may also be omitted or replaced by other components. Furthermore, the rectangular probe 3 can also be used in conjunction with other components or separately.

Wherein, the upper guide plate 1 is formed with multiple upper perforations 11, the lower guide plate 2 is formed with multiple lower perforations 21, and the positions of the multiple lower perforations 21 correspond to the positions of the multiple upper perforations 11, respectively . Furthermore, the partition plate may have a ring structure and be sandwiched between the corresponding peripheral portions of the upper guide plate 1 and the lower guide plate 2 so that the upper guide plate 1 and the lower guide plate 2 can be spaced apart from each other in parallel, but The present invention is not limited to this. Since the partition plate has a low correlation with the improvement point of the present invention, the detailed structure of the partition plate will not be described in detail below.

Furthermore, the probe head 100 can be selectively in a needle implantation position (eg, FIG. 1) and a detection position (eg: FIG. 2). Wherein, when the plurality of upper through holes 11 of the upper guide plate 1 are located directly above the plurality of lower through holes 21 of the lower guide plate 2, the probe head 100 is in the position of needle implantation, which facilitates the detection of a plurality of rectangles The needle 3 passes through the upper guide plate 1 and the lower guide plate 2. When the upper guide plate 1 and the lower guide plate 2 are offset from each other (any upper hole 11 is located diagonally above the corresponding lower hole 21 ), the probe head 100 is in the detection position.

The plurality of rectangular probes 3 respectively pass through the (upper perforation 11) of the upper guide plate 1 and respectively pass through the (lower perforation 21) of the lower guide plate 2. In this embodiment, the rectangular probe 3 has an elongated conductive structure and defines a length direction L. For ease of description, in this embodiment, the rectangular probe 3 further defines an extension direction E orthogonal to the length direction L. The rectangular probe 3 has a substantially rectangular cross-section, and the rectangular probe 3 of this embodiment may be manufactured by micro-electromechanical system (MEMS) technology, but the invention is not limited thereto.

Since the structures of the plurality of rectangular probes 3 of the probe head 100 of this embodiment are substantially the same, the following description takes the single rectangular probe 3 as an example, but the present invention is not limited thereto. For example, in other embodiments not shown in the present invention, the plurality of rectangular probes 3 of the probe head 100 may also have different structures from each other. Furthermore, in order to facilitate understanding of the structure of the rectangular probe 3, the rectangular probe 3 when the probe head 100 is in the needle implantation position will be described below.

As shown in FIGS. 2 to 4, the rectangular probe 3 in this embodiment includes an upper contact section 31, a lower contact section 32, and a deformation section connected to the upper contact section 31 and the lower contact section 32 33. Instead, the rectangular probe 3 includes the upper contact section 31 and the deformation section 33 in sequence, as viewed from a direction along the adapter plate 200 toward the object to be measured (eg, from top to bottom in FIG. 1) 、和下名字段32。 And the lower contact section 32.

Wherein, as shown in FIG. 2, the upper contact section 31 and the lower contact section 32 are respectively located on opposite outer sides of the upper guide plate 1 and the lower guide plate 2, and the upper contact section 31 is fixed to the adapter plate The corresponding conductive contact of 200, and the lower contact section 32 is used to detachably abut (or press) the corresponding conductive contact of the object to be tested (not shown in the figure). One end of the deformation section 33 connected to the upper contact section 31 is penetrated and positioned on the upper guide plate 1 (corresponding to the upper perforation 11 ), and the other end of the deformation section 33 connected to the lower contact section 32 is penetrated On the lower guide plate 2 (corresponding to the lower perforation 21).

It should be added that in other embodiments not shown in the present invention, each of the upper guide plate 1 and the lower guide plate 2 may adopt a double guide plate structure that is arranged in a misalignment with each other, so that the rectangular probe 3 can It is held by the double guide plate structure corresponding to the upper guide plate 1 and the lower guide plate 2 respectively, and is accordingly positioned on the upper guide plate 1 and the lower guide plate 2.

As shown in FIGS. 3 to 5, in this embodiment, the rectangular probe 3 includes a plurality of combs formed in the deformation section 33 (that is, between the upper contact section 31 and the lower contact section 32) In this embodiment, three comb-shaped sections 331 and the comb-shaped section 331 of the rectangular probe 3 are described in this embodiment, but the present invention is not limited thereto. That is to say, the number of comb-shaped sections 331 of the rectangular probe 3 may be at least one.

Furthermore, since the structures of the plurality of comb-shaped sections 331 of the rectangular probe 3 in this embodiment are substantially the same or symmetrical, for ease of description, the following takes a single comb-shaped section 331 as an example, but the present invention is not limited Here. For example, in other embodiments not shown in the present invention, the plurality of comb-shaped sections 331 of the rectangular probe 3 may also have different structures from each other.

The comb-shaped section 331 includes a U-shaped portion 3311 and at least one comb-tooth portion 3312 located inside the U-shaped portion 3311. Wherein, the U-shaped portion 3311 includes an elongated base base 3313 parallel to the longitudinal direction L, and two side bases 3314 respectively (vertically) connected to both ends of the base base 3313. In this embodiment, a width W3313 of the bottom base 3313 in the extending direction E is at least 10% of a width W3314 of any side base 3314 in the extending direction E, and the bottom base 3313 is in the longitudinal direction A length L3313 on L is preferably between 30 microns and 200 microns. Furthermore, the bottom base portion 3313 constitutes a first current channel C1 of the comb-shaped section 331, so that a signal can be transmitted.

The comb teeth portion 3312 is formed from the bottom base portion 3313 extending along the extension direction E and is located between the two side base portions 3314, and the comb-shaped section 331 includes a plurality of comb teeth portions 3312 in this embodiment The plurality of comb-tooth portions 3312 are arranged in a row at intervals along the longitudinal direction L. In this embodiment, the plurality of comb-tooth portions 3312 are arranged at equal intervals, and the number of comb-tooth portions 3312 of the comb-shaped section 331 may be at least three (preferably 1 to 2), but The present invention is not limited to this.

In more detail, each comb-tooth portion 3312 includes a head 3315 and a neck 3316 connecting the head 3315 and the base portion 3313, and the neck 3316 of each comb-tooth portion 3312 in the longitudinal direction L A length L3316 is smaller than a maximum length L3315 of the head 3315 in the length direction L. Among them, the heads 3315 of the plurality of comb teeth 3312 are arranged at equal intervals, and the necks 3316 of the plurality of comb teeth 3312 are also arranged at equal intervals. Preferably, there is a distance between 5 microns (μm) and 8 microns, and the distance is not greater than the maximum length L3315 of any one of the heads 3315.

In this embodiment, the head 3315 is substantially circular, so the maximum length L3315 of the head 3315 is equivalent to its diameter; and the length L3316 of the neck 3316 is connected from the head 3315 to the bottom The two ends of the base portion 3313 are gradually shortened inward, but the shape of the comb tooth portion 3312 of the present invention can be adjusted and changed according to design requirements, and is not limited to the above.

From another perspective, as shown in FIG. 5, the outer surface of each rectangular probe 3 includes two first long side surfaces 3 a located on opposite sides and two second long side surfaces 3 b located on opposite sides. Wherein, each of the first long side surfaces 3a and each second long side surface 3b are parallel to the length direction L, and any one of the first long side surfaces 3a is orthogonal to the extending direction E and away from the plurality of heads 3315 The surface of the bottom base portion 3313 (such as the left side surface of the bottom base portion 3313 in FIG. 5) is one of the two first long side surfaces 3a, and each of the first long side surfaces 3a is far away from the bottom base portion 3313 The position of the end edge of the head 3315 (eg, the right end edge of the head 3315 in FIG. 5) corresponds to the other of the first long sides 3a.

It should be noted that a first distance D1 between the two first long sides 3a is greater than a second distance D2 between the two second long sides 3b; that is, the rectangular probe 3 There is a comb-shaped section 331 so that it can be bent in a thicker direction (as shown in FIG. 5 ). In addition, in another embodiment of the present invention (as shown in FIG. 6), the first distance D1 between the two first long sides 3a of the rectangular probe 3 may also be less than (or equal to) two The second distance D2 between the second long sides 3b.

In addition, the portion of the head 3315 formed with the maximum length L3315 is located in the region between the two first long sides 3a in this embodiment, but the present invention is not limited to this. For example, in other embodiments not shown in the present invention, the portion of the head 3315 formed with the maximum length L3315 may also be substantially aligned with the adjacent first long side 3a.

The above is the description of the single comb-shaped section 331 of the rectangular probe 3, and the connection relationship between the multiple comb-shaped sections 331 of the rectangular probe 3 will be described below. As shown in FIG. 1, in the two adjacent comb-shaped sections 331 of the rectangular probe 3, the surfaces away from the two bottom bases 3313 corresponding to the head 3315 are located on the rectangular probe 3 respectively The two first long sides 3a; that is to say, the bottom base 3313 in any two adjacent comb-shaped sections 331 of the rectangular probe 3 is arranged in a dislocation.

As shown in FIG. 2, FIG. 7 and FIG. 8, when the upper guide plate 1 and the lower guide plate 2 are offset from each other (that is, when the probe head 100 is at the needle side position), the upper contact section 31 The lower contact section 32 is misaligned with each other, and each comb-shaped section 331 is bent into an arc-shaped configuration, and the plurality of comb-tooth portions 3312 of each comb-shaped section 331 are located inside the above-mentioned arc-shaped configuration, and each comb-shaped The heads 3315 of the plurality of comb-tooth portions 3312 of the section 331 abut against each other and are connected to the two side bases 3314 to jointly constitute a second current channel C2. In addition, in other embodiments not shown in the present invention, when the number of the comb teeth portions 3312 of the comb-shaped section 331 is at least one, the at least one comb teeth portion 3312 is connected to the two side base portions 3314 to Together constitute the second current channel C2.

Furthermore, in each comb-shaped section 331, a gap G between the first current channel C1 and the second current channel C2 is formed between any two adjacent necks 3316, according to It is ensured that the heads 3315 of the plurality of comb-tooth portions 3312 can abut each other and be connected to the two side bases 3314.

From another point of view, when the upper guide plate 1 and the lower guide plate 2 are offset from each other, the multiple comb sections 331 of each rectangular probe 3 are sequentially reversely bent to form multiple arc-shaped structures, each The plurality of comb-tooth portions 3312 of each comb-shaped section 331 are located inside the corresponding arc-shaped structure, and there is an inflection point between any two adjacent comb-shaped sections 331 of each rectangular probe 3 ). In other words, the rectangular probes 3 located on the opposite sides of the above-mentioned inflection point can each use a comb-shaped section 331 to reduce the stress caused by bending, and simultaneously synchronize the phases of the multiple heads 3315 of the comb-shaped section 331 Received to transmit signals.

Furthermore, a length of each rectangular probe 3 in the longitudinal direction L is 3 mm to 4 mm in this embodiment, and when the upper guide plate 1 and the lower guide plate 2 are arranged in a misaligned manner, each The lower contact sections 32 of the rectangular probes 3 can be used to detachably abut the object to be measured and to be displaced by at least 100 microns through the plurality of comb-shaped sections 331. In other words, since the plurality of comb-shaped sections 331 can effectively reduce the stress required by the rectangular probe 3, the rectangular probe 3 of this embodiment can bear the relative length of the lower contact section 32 with a shorter length Higher displacement.

[Technical efficacy of embodiments of the invention]

In summary, the vertical probe card and the rectangular probe disclosed in the embodiments of the present invention can reduce the stress caused by bending with a comb-shaped section, so as to avoid the problem of fracture of the rectangular probe, and the The rectangular probe can transmit signals by connecting a plurality of heads of the comb-shaped section, so that the signals can be stably transmitted. Furthermore, the rectangular probe disclosed in the embodiment of the present invention is formed with a comb-shaped section so that it can be bent in a thicker direction, thereby effectively expanding the application range of the rectangular probe.

In addition, the rectangular probe disclosed in the embodiment of the present invention can be formed with comb-shaped segments on the rectangular probe parts on opposite sides of the inflection point, so that the comb-shaped segments can effectively reduce the rectangular probe The stress required by the needle allows the rectangular probe to bear the relatively high displacement of the lower contact section with a shorter length. Furthermore, since the length of the rectangular probe can be shortened by providing the comb-shaped section, the inductance value and the resistance value of the rectangular probe can be effectively reduced accordingly.

The content disclosed above is only a preferred and feasible embodiment of the present invention, and therefore does not limit the patent scope of the present invention. Therefore, any equivalent technical changes made by using the description and drawings of the present invention are included in the patent scope of the present invention. Inside.

100: Probe head

1: Upper guide

11: Upper perforation

2: Lower guide

21: Lower perforation

3: rectangular probe

3a: first long side

3b: second longest side

31: Upper contact section

32: Lower contact section

33: Deformation section

331: Comb section

3311: U-shaped part

3312: Comb teeth

3313: bottom base

3314: Side base

3315: Head

3316: neck

200: adapter board

L: length direction

E: Extension direction

C1: the first current channel

C2: Second current channel

D1: First distance

D2: Second distance

W3313, W3314: width

L3313, L3315, L3316: length

G: gap

FIG. 1 is a schematic plan view of the probe head of the vertical probe card of the present invention at the position of needle implantation.

2 is a schematic plan view of the probe head of the vertical probe card of the present invention at the detection position.

Fig. 3 is a schematic plan view of the rectangular probe in Fig. 1.

FIG. 4 is a partially enlarged schematic view of the IV site in FIG. 3.

5 is a partial schematic perspective view of a rectangular probe of the present invention.

6 is a partial perspective view of another aspect of the rectangular probe of the present invention.

7 is a schematic plan view of the rectangular probe in FIG. 2.

FIG. 8 is a partially enlarged schematic view of the site VIII in FIG. 7.

33: Deformation section

331: Comb section

3311: U-shaped part

3312: Comb teeth

3313: bottom base

3314: Side base

3315: Head

3316: neck

L: length direction

E: Extension direction

C1: the first current channel

C2: Second current channel

G: gap

Claims (9)

A vertical probe card, comprising: an upper guide plate and a lower guide plate, which are arranged at intervals from each other; and a plurality of rectangular probes, respectively penetrated on the upper guide plate and respectively penetrated on the lower guide plate ; Wherein, each of the rectangular probes is elongated and defines a length direction, and each of the rectangular probes includes: an upper contact section and a lower contact section, respectively located on the upper guide plate and the lower guide Opposite two outer sides of the plate; and at least one comb-shaped section, located between the upper contact section and the lower contact section, and at least one of the comb-shaped section includes: a U-shaped portion, including a long A bottom base that is shaped and parallel to the length direction and two side bases respectively connected to both ends of the base base; wherein the bottom base constitutes a first current channel of at least one of the comb-shaped sections; and A plurality of comb-teeth portions formed from the bottom base portion in an extension direction and located between the two side base portions, and the plurality of comb-teeth portions are arranged in a row at intervals along the length direction; wherein , Each of the comb teeth includes a head and a neck connecting the head and the base, and the neck of each comb teeth has a length in the length direction Less than a maximum length of the head in the length direction; wherein, in each rectangular probe, when the upper guide plate and the lower guide plate are arranged in a misalignment with each other, the upper contact section is The lower contact sections are misaligned with each other, and at least one of the comb-shaped sections is bent into an arc-shaped configuration, a plurality of the comb-tooth portions are located inside the arc-shaped configuration, and a plurality of the comb-tooth portions The heads are in contact with each other and connected to the two side bases to jointly form a second current channel; wherein, the outer surface of each rectangular probe includes two A long side and two second long sides on opposite sides; the number of at least one comb-shaped section included in each rectangular probe is plural; adjacent to each rectangular probe In the two comb-shaped sections, the surfaces away from the two base portions corresponding to the head are respectively located on the two first long sides of the rectangular probe. The vertical probe card according to claim 1, wherein in the arc-shaped structure formed by bending at least one of the comb-shaped sections of each rectangular probe, any two adjacent ones A gap between the first current channel and the second current channel is formed between the necks. The vertical probe card according to claim 1, wherein in at least one of the comb-shaped sections of each rectangular probe, a width of the bottom base in the extending direction is any At least 10% of a width of the side base in the extension direction, and a length of the bottom base in the length direction is between 30 microns and 200 microns. The vertical probe card according to claim 1, wherein in at least one of the comb-shaped sections of each of the rectangular probes, the heads of the plurality of comb teeth are equally spaced It is provided that there is a gap between any two adjacent heads between 5 micrometers (μm) and 8 micrometers, and the gap is not greater than the maximum length of any one of the heads. The vertical probe card according to claim 1, wherein in at least one of the comb-shaped sections of each of the rectangular probes, any one of the first long sides is orthogonal to the extending direction, The surface of the base base away from the plurality of heads is one of the first long sides of the two first long sides, and the distal edge of each head away from the base base The position corresponds to the other of the first long sides. The vertical probe card according to claim 5, wherein in each rectangular probe, a first distance between the two first long sides is greater than two of the second A second distance between the long sides. The vertical-type probe card according to claim 1, wherein, when the upper guide plate and the lower guide plate are arranged in misalignment with each other, the plurality of comb-shaped sections of each rectangular probe The sequence is reversely bent to form a plurality of arc-shaped structures, the plurality of comb-tooth portions of each comb-shaped section are located inside the corresponding arc-shaped structure, and any two of each rectangular probe There is an inflection point between each adjacent comb-shaped section. The vertical probe card according to claim 7, wherein the vertical probe card further includes an adapter plate fixed to the upper contact section of each rectangular probe; each of the A length of the rectangular probes in the longitudinal direction is 3 millimeters (mm) to 4 millimeters, and when the upper guide plate and the lower guide plate are arranged in misalignment with each other, the lower of each rectangular probe The contact section can be used to detachably abut an object to be measured and to be displaced by at least 100 microns through the plurality of comb-shaped sections. A rectangular probe of a vertical probe card is elongated and defines a length direction. The rectangular probe includes: an upper contact section and a lower contact section; and at least one comb-shaped section located on the upper contact section Between the lower contact section and at least one of the comb-shaped sections includes: a U-shaped portion, including a base portion elongated and parallel to the longitudinal direction, and two base portions respectively connected to the base portion Two side bases at the end; wherein, the base base constitutes a first current channel of at least one of the comb-shaped sections; and at least one comb tooth portion formed from the base base extending in an extension direction and located at two Between the side bases; wherein at least one of the comb teeth includes a head and a neck connecting the head and the bottom base, and at least one of the neck of the comb teeth A length in the length direction is less than a maximum length of the head in the length direction; Wherein, the upper contact section and the lower contact section of the rectangular probe can be misaligned with each other, so that at least one of the comb-shaped sections is bent into an arc-shaped configuration, and at least one of the comb-tooth portions is located at the The inside of the arc-shaped structure, and the head of at least one of the comb teeth is connected to the two side bases to form a second current channel; wherein, the outer surface of the rectangular probe includes The two first long sides on the opposite side and the two second long sides on the opposite side; the number of at least one comb-shaped section included in the rectangular probe is a plurality; In the two adjacent comb-shaped sections, the surfaces away from the two base portions of the corresponding head are respectively located on the two first long sides of the rectangular probe.

Images