Probe module

A probe module includes a substrate having a through hole, and at least four probe-needle rows arranged on the substrate. The probe-needle rows are arranged from a first side to a second side along a first direction. Each of the probe-needle rows has at least two needles arranged along a second direction. Each of the needles has a contact segment and an arm segment having an included angle with the contact segment. An end of the arm segment is connected to the substrate, and the other end of which extends toward the through hole to connect the contact segment. The lengths of the contact segments of the needles of each of the probe-needle rows are the same. The included angles of the needles of the probe-needle rows along the first direction are gradually increased from the first side to the second side.

RELATED APPLICATIONS

This application claims priority to Taiwan Application Serial Number 102102221, filed Jan. 21, 2013, which is herein incorporated by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a probe structure. More particularly, the present disclosure relates to a probe module having multi-tier needles with angle variation.

2. Description of Related Art

In a test of semiconductor chips, a tester needs to contact devices under test (DUT), such as chips, through probe cards. Test results of the devices under test can be obtained by signal transmissions and electrical signal analysis. A probe card often includes several precision needles arranged thereon. Each of the needles usually corresponds to a specific electrical connection pad of a chip (i.e. a device under test). When the needles contact the corresponding electrical connect (i.e., pads, bump, etc.), the test signals of the tester having the probe card can be correctly transmitted. Simultaneously, the control and analysis procedures of the tester and the probe card are operated in coordination to achieve the purpose of testing the electrical characteristics of the device under test.

However, along with the progress in electrical element, the density of the electrical concacts of the chip is gradually increased, such that the density and the tier number of the needles need to be increased as well.FIGS. 1A and 1Bare structure schematic views of multi-tier needle structures of conventional probe modules. Referring toFIG. 1A, a chip100has two electrical concacts100a,100bthereon, and the probe module has a first probe-needle row and a second probe-needle row. The first probe-needle row has a plurality of needles (12-1,12-2), and the second probe-needle row has a plurality of needles (12-3,12-4). The end portions12bof the needles are respectively connected to the electrical concacts100a,100b. An included angle is formed between the arm segment12dand the contact segment12eof each of the needles. As far as the needles at the same row are concerned, such as the second probe-needle row, the included angle θ1 of the needle12-3is smaller than the included angle θ2 of the needle12-4. Moreover, in the first probe-needle row, the included angle θ1 of the needle12-1is smaller than the included angle θ2 of the needle12-2. In addition, as far as the corresponding needles at different rows, the included angles of the needles are the same. For example, the needle12-1of the first probe-needle row and the needle12-3of the second probe-needle row have the same included angle θ1, and the needle12-2of the first probe-needle row and the needle12-4of the second probe-needle row have the same included angle θ2. Furthermore, inFIG. 1B, the included angles of the needles are the same, but the lengths of the contact segments of the needles are different.

SUMMARY

An aspect of the present invention is to provide a probe module having a multi-tier needle structure. Contact segments having a same length of needles of each of probe-needle rows and the corresponding needles having different bending angles of the different probe-needle rows are designed to proceed electrical tests to a chip having electrical concacts with high density and small pitches.

According to an embodiment of the present invention, a probe module includes a substrate and at least four probe-needle rows. The substrate has a through hole. The probe-needle rows are arranged on the substrate. The probe-needle rows are arranged from a first side to a second side along a first direction. Each of the probe-needle rows has at least two needles arranged along a second direction. Each of the needles has a contact segment and an arm segment. An end of the arm segment is connected to the substrate, and the other end of the arm segment extends toward the through hole to connect the contact segment. An included angle is formed between the contact segment and the arm segment. The lengths of the contact segments of the needles of each of the probe-needle rows are the same. The included angles of the needles of the probe-needle rows along the first direction are gradually increased from the first side to the second side.

According to another embodiment of the present invention, a probe module includes a substrate and at least four first probe-needle rows. The substrate has a through hole. The first probe-needle rows are arranged on the substrate. The first probe-needle rows are arranged from a first side to a second side along a first direction. Each of the first probe-needle rows has at least two needles arranged along a second direction. The numbers of the needles of at least two of the first probe-needle rows are different. Each of the needles has a contact segment and an arm segment. An end of the arm segment is connected to the substrate, and the other end of the arm segment extends toward the through hole to connect the contact segment. An included angle is formed between the contact segment and the arm segment. The lengths of the contact segments of the needles of each of the first probe-needle rows are the same. For the two adjacent first probe-needle rows, the included angle of the needle having the largest included angle of the first probe-needle row adjacent to the first side is smaller than or equal to the included angle of the needle having the smallest included angle of the first probe-needle row adjacent to the second side, such that the included angles of the needles of the first probe-needle rows along the second direction are gradually increased from the first side to the second side.

DETAILED DESCRIPTION

FIG. 2is a side and partial cross-sectional view of a probe module2according to an embodiment of the present invention. The probe module2includes a substrate20and at least four probe-needle rows21-24arranged on the substrate20. The substrate20has a through hole200having an edge201. The substrate20has an external structure202. In this embodiment, the four probe-needle rows21-24are arranged between the edge201of the through hole200and the external structure202of the substrate20, but the position of the probe-needle rows21-24is not limited in this regard. In order to strengthen the stability of the probe-needle rows21-24, the substrate20further has a fixing member26to maintain the positions of the probe-needle rows21-24. Moreover, the end portions of the needles at outside of the fixing member26may be soldered to the substrate20in accordance with the layout of the electrical concacts of the substrate20, and the arrangement of the needles may be different from the arrangement shown inFIG. 2. Therefore, the positions of the substrate20connected to the end portions of the needles are determined in accordance with practical requirements, and the present invention is not limited to the embodiment shown inFIG. 2.

FIG. 3is an enlarged perspective view of a partial region3shown inFIG. 2. The needles of the probe-needle rows21-24electrically contact the electrical concacts90of a to-be tested chip9to test the electrical characteristics of the to-be tested chip9. As far as the electrical concacts90at the same row are concerned, a pitch d between the two adjacent electrical concacts90is smaller than or equal to 40 μm. In this embodiment, the probe-needle rows21-24are arranged from a first side91to a second side92along a first direction X. Each of the probe-needle rows21-24has at least two needles arranged along a second direction Y. At least two needles are defined as a needle group, and each of the probe-needle rows21-24has a plurality of needle groups. The aforesaid arrangement of the needles depends on the positions of the tips (i.e. contact segments250) of the needles. The tip of the needle is referred to as a portion of the needle that is used to contact the electrical connection pad90of the to-be tested chip9. In this embodiment, the first side91along the first direction X is adjacent to the external structure202of the substrate20, and the second side92along the first direction X is adjacent to the edge201of the through hole200. In this embodiment, the probe-needle rows21-24respectively have the needle groups210a,220a,230a,240a. The numbers of the needle groups210a,220a,230a,240aalong the second direction Y are the same, and the needle groups210a,220a,230a,240aalong the first direction X correspond to each other. For example, the probe-needle row21has the needle groups210a-210nalong the second direction Y; the probe-needle row22has the needle groups220a-220nalong the second direction Y; the probe-needle row23has the needle groups230a-230nalong the second direction Y; and the probe-needle row24has the needle groups240a-240nalong the second direction Y. Moreover, the needle groups210a-210n,220a-220n,230a-230n,240a-240nare respectively correspond to each other along the first direction X. For example, the needle groups210a,220a,230a,240acorrespond to each other along the first direction X, and the other corresponding needle groups (e.g.,210n,220n,230n,240n) have the same design.

In this embodiment, each of the needle groups210a,220a,230a,240aincludes a first needle25aand a second needle25b. The first needles25aof the corresponding needle groups (210a-210n,220a-220n,230a-230n,240a-240n) of the probe-needle rows21-24are aligned with and correspond to each other along the first direction X, and the second needles25bof the corresponding needle groups (210a-210n,220a-220n,230a-230n,240a-240n) of the probe-needle rows21-24are aligned with and correspond to each other along the first direction X. Referring toFIGS. 3 and 4, each of the first and second needles25a,25bhas the contact segment250and an arm segment251. An end of the arm segment251is connected to the substrate20, and the other end of the arm segment251extends toward the through hole200to connect the contact segment250. An included angle is formed between the contact segment250and the arm segment251, and the lengths of the contact segments250of the first and second needles25a,25bof each of the probe-needle rows21-24are the same. For example, the lengths of the contact segments250of the first and second needles25a,25bof the probe-needle row21are the same, and the first and second needles25a,25bof the other probe-needle row (e.g.,22) have the same design. The aforesaid “same length” may have tolerance of height different. As shown inFIG. 5A, the two contact segments250of the first and second needles25a,25bof one of the needle groups have a height different Δd. The absolute value of the height different Δd is in a range from 0 to 1 mil (0.001 inch).

Referring back toFIGS. 3 and 4, in this embodiment, each of the needle groups (210a-210n,220a-220n,230a-230n,240a-240n) has two needles, but in another embodiment, each of the needle groups may has more than three needles. As shown inFIG. 5B, one of the needle groups having three needles as an example, the three needles are the first, second, and third needle25a,25b,25c. The absolute value of the height different of any two of the three needles is smaller or equal to 1 mil. For example:
|ha−hb|≦1 mil;
|ha−hc|≦1 mil; and
|hb−hc|≦1 mil.

As shown inFIGS. 3 and 4, the included angle described in the present invention is defined between the central line of the contact segment250and the central line of the arm segment251. In this embodiment, the distance between the two central lines of the two contact segments250of the two adjacent needles is smaller or equal to 40 μm.

The feature of the included angles between the contact segments250and the arm segments251of the needles is that the included angles of the corresponding first and second needles25a,25bof the corresponding needle groups (210a-210n,220a-220n,230a-230n,240a-240n) of the probe-needle rows21-24along the first direction X are gradually increased from the side of the external structure202of the substrate20to the edge201of the through hole200, such as the needle groups210a,220a,230a,240ashown inFIGS. 3 and 4. Referring toFIG. 4, each of the needle groups210a,220a,230a,240aof the probe-needle rows21-24has the first and second needles25a,25b. The positions of the first and second needles25a,25bof the needle groups210a,220a,230a,240aalong the second direction Y correspond to each other. The first and second needles25a,25bof the needle group210arespectively has the included angles θ1and θ2, the first and second needles25a,25bof the needle group220arespectively has the included angles θ3and θ4, the first and second needles25a,25bof the needle group230arespectively has the included angles θ5and θ6, and the first and second needles25a,25bof the needle group240arespectively has the included angles θ7and θ8. In this embodiment, the included angle relationship of the corresponding first and second needles25a,25bof the needle groups210a,220a,230a,240ais θ1<θ2<θ3<θ4<θ5<θ6<θ7<θ8. Therefore, the included angles are gradually increased from the side of the external structure202of the substrate20to the edge201of the through hole200. That is to say, the included angle θ3of the needle having the smallest included angle of the second probe-needle row is greater than the included angle θ2of the needle having the largest included angle of the first probe-needle row, and the other included angles have the same arrangement (e.g., the included angle θ5is greater than the included angle θ4). In addition, as shown inFIG. 3, the first and second needles25a,25bof the needle group210arespectively have the contact segment lengths T1, T2, the first and second needles25a,25bof the needle group220arespectively have the contact segment lengths T3, T4, the first and second needles25a,25bof the needle group230arespectively have the contact segment lengths T5, T6, and the first and second needles25a,25bof the needle group240arespectively have the contact segment lengths T7, T8. The relationship of the contact segment lengths is T7=T8>T5=T6>T5=T3>T4>T1=T2. As shown inFIGS. 3 and 4, in this embodiment, the probe-needle rows21-24have a first probe-needle row and a second probe-needle row, and the first probe-needle row is adjacent to the second probe-needle row. The contact segments of the needles of the second probe-needle row is larger than the contact segments of the needles of the first probe-needle row. For example, the first probe-needle row is the probe-needle row21, the second probe-needle row is the probe-needle row22, and the contact segment lengths T3, T4of the probe-needle row22are greater than the contact segment lengths T1, T2of the probe-needle row21. In this embodiment, the number of the needles of the second probe-needle row22is not equal to the number of the needles of the first probe-needle row21.

Furthermore, in this embodiment, the included angles of the first needles25aof the corresponding needle groups (210a-210n,220a-220n,230a-230n,240a-240n) of the probe-needle rows21-24are smaller than the included angles of the second needles25b. The absolute value of the angle difference between the included angles of the first and second needles25a,25bof each of the needle groups of the probe-needle row adjacent to the edge201of the through hole200is greater than or equal to 2 degrees. As shown inFIG. 3andFIG. 4, in this embodiment, the probe-needle row24is adjacent to the edge201of the through hole200, and the absolute value of the angle difference between the included angle θ7of the first needle25aand the included angle θ8of the second needle25bof each of the needle groups240a-240nof the probe-needle row24is |θ8−θ7|≧2°.

The angle difference between the included angles of the first and second needles25a,25bof each of the needle groups of the probe-needle row adjacent to the edge201of the through hole200is greater than or equal to the included angles of the first and second needles25a,25bof the corresponding needle group of the probe-needle row adjacent to the external structure202of the substrate20. As shown inFIG. 3andFIG. 4, in this embodiment, the probe-needle row24is adjacent to the edge201of the through hole200, and the absolute value of the angle difference between the included angle θ7of the first needle25aand the included angle θ8of the second needle25bof each of the needle groups240a-240nof the probe-needle row24is greater than or equal to the absolute value of the angle difference between the included angle θ1of the first needle25aand the included angle θ2of the second needle25bof the corresponding needle groups240a-240nof the probe-needle row21adjacent to the external structure202of the substrate20. That is to say, |θ8−θ7|≧|θ2−θ1|.

Moreover, another feature of the included angles of the needles of the present invention is that the angle difference between the included angle of the first needle of each of the needle groups of the probe-needle row adjacent to the edge201of the through hole200and the included angle of the second needle of the corresponding needle group of the adjacent probe-needle row is greater than or equal to 1 degree. As shown inFIG. 3andFIG. 4, in this embodiment, the probe-needle row24is adjacent to the edge201of the through hole200. For example, the absolute value of the angle difference between the included angle θ7of the first needle25aof the needle group240aof the probe-needle row24and the included angle θ6of the second needle25bof the corresponding needle group230aof the probe-needle row23adjacent to the probe-needle row24is greater than or equal to 1 degree. That is to say, |θ7−θ6≧1°.

In this embodiment, based on the aforesaid feature of the angle difference, the absolute value of the angle difference between the included angle of the first needle of each of the needle groups of the probe-needle row adjacent to the edge201of the through hole200and the included angle of the second needle of the corresponding needle group of the adjacent probe-needle row is greater than or equal to the absolute value of the angle difference between the included angle of the second needle of the corresponding needle group of the probe-needle row adjacent to the external structure202of the substrate20and the included angle of the first needle of the corresponding needle group of the adjacent probe-needle row. As shown inFIG. 3andFIG. 4, in this embodiment, the probe-needle row24is adjacent to the edge201of the through hole200. For example, the absolute value of the angle difference between the included angle θ7of the first needle25aof the needle group240aof the probe-needle row24and the included angle θ6of the second needle25bof the corresponding needle group230aof the probe-needle row23adjacent to the probe-needle row24is |θ7−θ6|. The absolute value of the angle difference between the included angle θ2of the second needle25bof the corresponding needle group210aof the probe-needle row21adjacent to the external structure202of the substrate20and the included angle θ3of the first needle25aof the corresponding needle group220aof the probe-needle row22adjacent to the probe-needle row21is |θ3−θ2|. Further, |θ7−θ6|≧|θ3−θ2|.

The arrangement of the included angle symbols θnof the needles having the aforesaid relationships will be explained in the following description. Referring toFIGS. 3 and 4, the included angle symbols are provided from the needle groups adjacent to the external structure202of the substrate20. The included angles symbols are provided to the needles in sequence from the original point O along the second direction Y. After the included angle symbols are provided to the needles of the needle group along the second direction Y, the included angle symbols are provided to the next needle group along the first direction X. Thereafter, the included angle symbols are provided to the needles of the needle group along the second direction Y. As a result, the included angle symbols θ1−θncan be completely provided to the needles of all the corresponding the needle groups. The aforesaid angle feature can obtain the following relationships:
θ1<θ3< . . . θn−3<θn−1
θ2<θ4< . . . θn−2<θn
|θn−θn−1|≧2°
|θn−1−θn−2|≧1°
|θ2−θ1|≧|θn−θn−1|
|θ3−θ2|≧|θn−1−θn−2|

The number of the probe-needle rows21-24shown in aforementionedFIGS. 2-4is four, but the present invention is not limited in this regard. Four or more than four probe-needle rows can also be suitable for the aforesaid included angle relationships. In addition, the number of the aforesaid needles of each of the needle groups is two, but the present invention is not limited in this regard. Two or more than two needles can also be suitable for the aforesaid included angle relationships.

For example, regarding to the number of the probe-needle rows is m (m≦9), and the number of each of the needle groups is a (in this embodiment, a=2). According to the aforesaid features, for matrix type needles, the included angle relationships of the corresponding needles of the needle groups can be obtained as the following relationships (1)-(3):
θ1a<θ2a. . . <θ(mmax−1)a<θmmaxa(1)
θ11<θ21. . . <θ(mmax−1)1<θmmax1(2)
θ12<θ22. . . <θ(mmax−1)2<θmmax2(3)

Wherein n=F(m, a), m is the number of the probe-needle rows, m≦9, a is the serial number of the needle of the needle groups of each of the probe-needle rows, and 1≦a. The aforesaid relationship (1) means that the included angles of the needles corresponding to the same needle group and serial number along the first direction are gradually increased. In the embodiment shown inFIGS. 2-4, a may be 1 or 2, such that the relationship (1) can be replaced by the relationships (2), (3). In another embodiment, the range of the maximum mmaxof the row number m is 4≦m≦9. Other relationships can be obtained as the following relationships:
|θm(a+1)−θma|≧2° and (a+1)≦amax(4)
|θ(m+1)1−θmamax|≧1°  (5)

Wherein amaxis the maximum of the serial numbers of each of the needle groups. The relationship (4) means that: regarding to the needles of the same probe-needle row, the absolute value of the angle difference between the two included angles of the two adjacent needles is greater than or equal to 2 degrees, and the limitation of the relationship (4) is (a+1)≦amax. The relationship (5) means that: regarding to the two adjacent probe-needle rows, the absolute value of the angle difference between the included angle of the needle having the smallest included angle of the probe-needle row (m+1) adjacent to the second side along the first direction and the included angle of the needle having the largest included angle of the probe-needle row m adjacent to the first side along the first direction is greater than or equal to 1 degree. Other relationships can be obtained as the following relationships:
(|θm(a+1)−θma|≧|θmmax(a+1)−θmmaxa|) and (a+1)≦amaxandm<mmax(6)
(|θ12−θ11|≧|θmmax2−θmmax1|)  (7)

The relationship (6) means that: regarding to the needles of the same probe-needle row (m<mmax), the absolute value of the angle difference between the two included angles of the two adjacent needles (a+1 and a) is smaller than or equal to the absolute value of the angle difference between the two included angles of the two corresponding needles (a+1 and a) of the probe-needle row mmax. In the relationship (6), if m=1, a=1, the relationship (6) can be replaced by the relationship (7). Other relationships can be obtained as the following relationships:
(|θ(m+1)1−θmamax|≧|θmmax1−θ(mmax−1)amax|) and (m+1)<mmax(8)
(|θ21−θ12|≧|θmmax1−θmmax−1)2|)  (9)

The relationship (8) means that: regarding to the two adjacent probe-needle rows (m and m+1 and m+1<mmax), the absolute value of the angle difference between the included angle of the needle having the smallest included angle of the probe-needle row (m+1) adjacent to the second side along the first direction and the included angle of the needle having the largest included angle of the probe-needle row (m) adjacent to the first side along the first direction is smaller than or equal to the absolute value of the angle difference between the included angle of the needle having the smallest included angle of the terminal probe-needle row (mmax) along the first direction and the included angle of the needle having the largest included angle of the probe-needle row (mmax−1) front of the terminal probe-needle row long the first direction. In the relationship (8), if m=1, a=1, the relationship (8) can be replaced by the relationship (9).

In addition, the first and second directions shown inFIG. 3are not limited to the two perpendicular directions X, Y at the same plane. In another embodiment,FIG. 6is a schematic view of a needle arrangement according to an embodiment of the present invention. The needle arrangement in this embodiment is that the first direction is an arc direction (θ), and the second direction is a radial direction (r). The coordinate system defined by such arc direction (θ) and radial direction (r) is shown inFIG. 6. The probe module has four probe-needle rows21-24, and each of the probe-needle rows21-24has a plurality of needle groups210a-210f. Regarding to the probe-needle rows21-24, the probe-needle rows21-24respectively have the corresponding needle groups210a,220a,230a,240a, and respectively have the corresponding first and second needles25a,25b. The relationships of the included angles of the needles are similar to the aforesaid embodiment, and the relationships of the included angles in this embodiment will not be described repeatedly.

FIGS. 7A and 7Bare schematic views of a needle arrangement according to an embodiment of the present invention. The structure of the needle arrangement is substantially similar to the embodiment shown inFIGS. 2-4. The difference between this embodiment and the embodiment shown inFIGS. 2-4is that the probe module further has a probe-needle row27. The probe-needle row27is arranged between the edge201of the through hole200and the probe-needle row24adjacent to the edge201of the through hole200. The probe-needle row27has a plurality of needles270a, and each of the needles270acorresponds to one of the needle groups. Moreover, the needle groups (e.g., the needle groups210a-240a) of the original probe-needle rows21-24correspond to each other, and an important feature in another embodiment is that a single needle270ais increased to correspond to the needle groups210a-240a. That is to say, according to the structure shown inFIGS. 2-4, the single needle270acan be increased to correspond to the corresponding needle groups. The aforesaid feature of the single needle corresponding to the needle groups can be applied to the arrangement of the needles in the design of the arc direction (θ) and the radial direction (r) shown inFIG. 6.

FIG. 8is a schematic view of an asymmetric needle arrangement according to an embodiment of the present invention. The asymmetric needle arrangement means that the numbers of the needles of the probe-needle rows are different, or means that the combination of a portion of the probe-needle rows having the same number of the needles and the other probe-needle rows having the different numbers of the needles. In this embodiment, the rectangular symbols shown inFIG. 8means that the positions of the electrical concacts90of the to-be tested chip9for correspondingly contacting the contact segments of the needles.

In another embodiment, the probe module has nine probe-needle rows40-48arranged along the first direction X. Each of the probe-needle rows40-44has a plurality of needles arranged along the second direction Y. Each of the probe-needle rows45-48has one needle. The probe-needle row40has the needles400-403, the probe-needle row41has the needles410-412, the probe-needle row42has the needles420-421, the probe-needle row43has the needles430-431, and the probe-needle row44has the needles440-441. The structure of the aforesaid needle is the same as the structure of the needle shown inFIG. 4. An included angle is formed between the arm segment and the contact segment of each of the needles. According the purpose of the present invention, the included angles of the needles of the probe-needle rows along the first direction X are gradually increased from the first side91to the second side92.

In this embodiment, each of the needles400-403has the same contact segment length L0and the needles400-403respectively have the included angles θ400, θ401, θ402, θ403. Each of the needles410-412has the same contact segment length L1, and the needles410-412respectively have the included angles θ410, θ411, θ412. Each of the needles420-421has the same contact segment length L2, and the needles420-421respectively have the included angles θ420, θ421. Each of the needles430-431has the same contact segment length L3, and the needles430-431respectively have the included angles θ430, θ431. The probe-needle row44has the needles440-441having the same contact segment length L4, and the needles440-441respectively have the included angles θ440, θ441. Furthermore, the needles450,460,470,480respectively have the contact segment lengths L5-L8, and the needles450-480respectively have the included angles θ450, θ460, θ470, θ480. The relationship of the contact segment lengths is L1<L2<L3<L4<L5<L6<L7<L8. The relationships of the included angles can be described in two parts. The relationships of the included angles along the second direction Y are:
θ400<θ401<θ402<θ403;
θ410<θ411<θ412;
θ420<θ421;
θ430×θ431; and
θ440<θ441.

The aforesaid relationships means that the included angles of the needles arranged along the second direction Y of the probe-needle rows40-44are gradually increased from the first side to the second side in the second direction Y. In another embodiment, regarding to the probe-needle row40, the first side of the second direction Y is a side of the needle400, and the second side of the second direction Y is a side of the needle403. However, the present invention is not limited in this regard. For example, the first side of the second direction Y may be a side of the needle403, and the second side of the second direction Y may be a side of the needle400.

In addition, in the two different and adjacent probe-needle rows, since the included angles along the first direction X are gradually increased, the included angle of the needle having the smallest included angle of the probe-needle row adjacent to the second side92of the first direction X is greater than the included angle of the needle having the largest included angle of the other probe-needle row adjacent to the first side91of the first direction X. The angle difference between the two included angles is greater or equal to 1 degree. The aforesaid angle difference will be described as the “adjacent probe-needle row angle difference” in the following description. Moreover, any one of the aforesaid adjacent probe-needle row angle difference (not the last two probe-needle rows adjacent to the second side) is smaller than or equal to the adjacent probe-needle row angle difference of the last two probe-needle rows adjacent to the second side92. Therefore, the angle relationships ofFIG. 8are:
θ410−θ403≧1°;
θ420−θ412≧1°;
θ430−θ421≧1°;
θ440−θ431≧1°;
θ450−θ441≧1°;
θ460−θ450≧1°;
θ470−θ460≧1°;
θ480−θ470≧1°; and
θ410−θ403≧θ480−θ470.

Although the last are relationship θ410−θ403≧θ480−θ470is the comparison between the probe-needle rows40,41and the probe-needle rows47,48, the adjacent probe-needle row angle difference of any two of the adjacent probe-needle rows42-46is smaller than or equal to θ480−θ470.

Furthermore, for the different needles of one of the probe-needle rows, the absolute value of the angle difference between the two included angles of the two adjacent needles is also greater than or equal to 2 degrees. Taking the first probe-needle row40as an example, the angle relationships are:
θ401−θ400≧2;
θ402−θ401≧2; and
θ403−θ402≧2;