Probe head with linear probe

A probe head includes a linear probe which is flattened at least one of tail, body and head portions thereof and thereby defined with first and second width axes, along which each of the tail, body and head portions is defined with first and second widths, and upper and lower die units having upper and lower installation holes respectively, wherein the tail and head portions are inserted respectively, which are offset from each other along the second width axis so that the body portion is curved. The first and second widths of the body portion are respectively larger and smaller than the first and second widths of at least one of the tail and head portions. As a result, the probes of the same probe head are consistent in bending direction and moving behavior and prevented from rotation, drop and escape.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to probe heads and probes of probe cards and more particularly, to a probe head with a linear probe.

2. Description of the Related Art

Referring toFIG. 1, a conventional probe head10equipped with a plurality of linear probes16is shown. The conventional probe head10primarily includes at least two upper dies12, at least two lower dies14and a plurality of probes16. For simplifying the drawing, only one probe16is shown inFIG. 1. The head portion162of each of the probes16, i.e. linear probes, is adapted to contact a conductive contact pad of a device under test (not shown), and the head portion162is inserted through the lower dies14. The tail portion164of each of the probes16is adapted to be abutted against a conductive contact pad of a circuit board or space transformer (not shown), and the tail portion164is inserted through the upper dies12. During the assembly of the probe head10, after the probes16are inserted through the dies12and14, the upper dies12and the lower dies14are horizontally displaced from each other to make the head portion162and tail portion164of each probe16offset from each other and thereby not located on the same imaginary straight line, so that the body portion166of each probe16is curved. In this way, when the probe16contacts the conductive contact pad of the device under test, the body portion166of the probe16can provide an elastically adjusting effect to cause the head portion162to be in contact with and electrically connected with the conductive contact pad of the device under test positively, and a buffering effect to avoid damage or excessive wear to the conductive contact pad of the device under test or the probe due to an excessive contact force.

The conventional linear probe, also called wire needle, is formed by directly cutting a metal wire having circular cross sections into an appropriate length and thus cylinder-shaped. Therefore, during the above-described assembly of the probe head10, the body portions166of the probes16may be inconsistent in the direction of the bending deformation due to the horizontal relative displacement of the upper and lower dies12and14. Besides, when the head portions162of the probes16are abutted against the conductive contact pads of the device under test, the body portions166of the probes16may be inconsistent in the moving behavior due to the elastic deformation thereof, and the entirety of each probe16is also liable to rotate a little bit so that the body portions166of the probes16are more inconsistent in bending direction.

However, the linear probe is widely used in the field of fine pitch, which means the pitch of the probes16of the probe head10is usually quite small. Therefore, the above-mentioned inconsistent deformation direction, inconsistent moving behavior and self-rotation of the probes16are all liable to cause the body portions166of the adjacent probes16to interfere with each other. In other words, the body portions166of the adjacent probes16may collide with each other, thereby not only deteriorating the aforesaid elastically adjusting effect and buffering effect but also causing wear to the body portions166. If the abrasion of the insulating layer on the surface of the body portions166causes electrical connection between the probes16colliding with each other, a short circuit may occur to damage the probe card or the device under test.

In addition, the conventional linear probe is liable to have the problem of probe drop, i.e. the probe16dropping from the downside of the lower die14, or probe escape, i.e. the probe16being escaped from the upside of the upper die12, during the assembly or maintenance of the probe card10. The conventional method of solving the problem of probe drop or probe escape is providing a stopper to the probe at an appropriate position thereof to restrict the probe in the upper and lower dies by the stopper being abutted against the upper and lower dies. However, the stopper of the conventional probe is usually formed by adding a protruding block on the outer peripheral surface of the original probe. Such method is not suitable for the linear probe manufactured by cutting a cylindrical metal wire.

SUMMARY OF THE INVENTION

The present invention has been accomplished in view of the above-noted circumstances. It is an objective of the present invention to provide a probe head with a linear probe, which can attain at least one of the effects of consistent bending direction of the probes of the same probe head, consistent moving behavior of the probes of the same probe head, avoiding self-rotation of the probe, avoiding probe drop and avoiding probe escape.

To attain the above objective, the present invention provides a probe head which includes a linear probe, a lower die unit having a lower installation hole, and an upper die unit having an upper installation hole. The linear probe includes a tail portion, a body portion and a head portion extending along a longitudinal axis in order. At least one of the tail portion, the body portion and the head portion is flattened and thereby defined with a first width axis perpendicular to the longitudinal axis, and a second width axis perpendicular to the longitudinal axis and the first width axis. Each of the tail portion, the body portion and the head portion is defined with a first width along the first width axis and a second width along the second width axis. The first width and the second width of the body portion are respectively larger than and smaller than the first width and the second width of at least one of the tail portion and the head portion. The head portion and the tail portion of the linear probe are inserted through the lower installation hole and the upper installation hole respectively. The lower installation hole and the upper installation hole are defined with a first central axis and a second central axis respectively. The second central axis is offset from the first central axis along the second width axis and thereby the body portion of the linear probe is curved. The upper die unit includes a first upper die and a second upper die. The first and second upper dies respectively have a first through hole and a second through hole for the head portion, the body portion and the tail portion of the linear probe to be inserted therethrough. The first and second through holes are offset from each other along the first width axis to collectively form the upper installation hole.

As a result, at least one of the tail portion and the head portion is different from the body portion in area moment of inertia because of the above-described difference in the first and second widths. For example, the area moment of inertia (Ix) of the body portion with respect to the first width axis (X-axis) is smaller than the area moment of inertia of (Ix) of at least one of the tail portion and the head portion with respect to the first width axis (X-axis). Because of such difference in area moment of inertia, the body portion is liable to elastic bending deformation in a specific direction when the linear probe is applied with a force along the second width axis (Y-axis). Therefore, setting the first and second widths of the tail portion, the body portion and the head portion can control the directions of the deformation and movement of the linear probe due to the relative displacement between the upper and lower die units and the contact between the head portion and the device under test in a way that the probes of the same probe head are consistent in bending direction and moving behavior thereof and thereby prevented from interference and short circuit. In particularly, the tail portion, the body portion and the head portion may, but unlimited to, be all flattened in a way that the long sides of the cross sections of the tail and head portions are perpendicular to the long sides of the cross sections of the body portion, such that the above-mentioned effects are optimized. For example, the linear probe may be formed in a way that a cylindrical needle is at least partially flattened to become the linear probe, and the direction in which the tail portion and the head portion are flattened is perpendicular to the direction in which the body portion is flattened, so that the first and second widths of the body portion are respectively larger than and smaller than the diameter of the needle and the first and second widths of each of the tail and head portions are respectively smaller than and larger than the diameter of the needle, thereby optimizing the above-mentioned effects.

Besides, in the condition that the body portion and the tail portion have the above-described difference in the first and second widths thereof, such as the condition that the body portion and the tail portion are flattened in the directions perpendicular to each other like the above-described manner or the condition that only one of the body portion and the tail portion is flattened and the other one is maintained with cylindrical shape with first and second widths both equal to the diameter of the needle, an upper stopping portion exists at the junction of the body portion and the tail portion, which can be abutted on the bottom surface of the upper die unit as long as the width of the upper installation hole defined along the first width axis is smaller than the first width of the body portion, such that the problem of probe escape is avoided.

Likewise, in the condition that the body portion and the head portion have the above-described difference in the first and second widths thereof, such as the condition that the body portion and the head portion are flattened in the directions perpendicular to each other like the above-described manner or the condition that only one of the body portion and the head portion is flattened and the other one is maintained with cylindrical shape, a lower stopping portion exists at the junction of the body portion and the head portion, which can be abutted on the top surface of the lower die unit as long as the width of the lower installation hole defined along the first width axis is smaller than the first width of the body portion, such that the problem of probe drop is avoided.

In addition, the at least one of the tail portion, the body portion and the head portion being flattened has cross sections having an elongated shape, such as an elongated shape with two arc sides. The upper installation hole and/or the lower installation hole may be shaped according to the flattened tail portion and/or head portion to have an elongated shape such as a rectangle, such that the linear probe is prevented from self-rotation. Besides, the tail portion and/or the head portion can move smoothly in the upper installation hole and/or the lower installation hole and release stress because of having the arc-shaped parts.

The above-mentioned upper installation hole with the elongated shape is formed by the first and second through holes having relatively larger areas, wherein the area of the first through hole and the area of the second through hole may be larger than the area of the lower installation hole, and the shape of each of the first and second through holes may be a circle or a square. Such upper installation hole is not only effective in preventing the probe from self-rotation and avoiding probe escape as mentioned above, but also convenient for the installation of the probe.

The above-mentioned lower installation hole may include a lower part and an upper part, and only the lower part is an elongated-shaped hole corresponding to the flattened head portion for preventing the probe from self-rotation. The upper part may be a circular hole with the diameter larger than or equal to the length of the elongated-shaped hole and larger than the width of the elongated-shaped hole and the first and second widths of the body portion. In this way, the circular upper part can reduce the wear of the head portion and the lower die unit, and the lower part is still effective in stopping the body portion to avoid the problem of probe drop.

DETAILED DESCRIPTION OF THE INVENTION

First of all, it is to be mentioned that same reference numerals used in the following preferred embodiments and the appendix drawings designate same or similar elements throughout the specification for the purpose of concise illustration of the present invention.

Referring toFIGS. 2-4, a linear probe20according to a first preferred embodiment of the present invention is formed in a way that a cylindrical needle, like the conventional linear probe16as shown inFIG. 1, is at least partially flattened to become the linear probe20. After the manufacturing and before the installation and the use, the linear probe20is straight and has a tail portion22, a body portion24and a head portion26extending along a longitudinal axis (Z-axis) in order. The technical term “flattened” mentioned in the entire specification and the claims of the present invention refers to that the linear probe is at least partially made into a flat shape in a specific processing manner. For example, the technical term “flattened” mentioned in the afore description that a cylindrical needle is at least partially “flattened” to become the linear probe20, refers to that at least a part of the originally cylindrical-wire-shaped needle is processed by flattening. The flattening may, but unlimited to, be performed in a mechanical processing manner like forging, pressing or rolling. Generally speaking, the length of the body portion24is larger than double of the length of the tail portion22, and the length of the body portion24is larger than double of the length of the head portion26.

In this embodiment, the tail portion22, body portion24and head portion26of the linear probe20are all flattened. Besides, the direction in which the body portion24is flattened is perpendicular to the direction in which the tail portion22and head portion26are flattened. There may, but unlimited to, be a non-flattened part28left between the tail portion22and the body portion24and another non-flattened part28left between the body portion24and the head portion26. In other words, when it is mentioned in the present invention that the tail portion22, body portion24and head portion26extend along the longitudinal axis (Z-axis) in order, it delimits the positional order and extending direction of the tail portion22, body portion24and head portion26without delimiting that the tail portion22, body portion24and head portion26have to be connected in order directly. Each of the non-flattened parts28is cylinder-shaped like the original needle, thereby having circular cross sections. Because the tail portion22, body portion24and head portion26are flattened, the cross sections thereof substantially have an elongated shape with two arc sides, like the tail portion22as shown inFIG. 11. However, for simplifying the drawing, the flattened portions shown in the figures of the present invention other thanFIG. 11are shaped as columns having non-square rectangular cross sections without arc parts.

Because the flattened tail portion22, body portion24and head portion26have approximately non-square rectangular cross sections, the linear probe20is defined with a first width axis (X-axis) perpendicular to the longitudinal axis (Z-axis) and a second width axis (Y-axis) perpendicular to the longitudinal axis (Z-axis) and the first width axis (X-axis) according to the shape of the flattened portions. The tail portion22, body portion24and head portion26are defined with first widths WX1, WX2and WX3along the first width axis (X-axis) and second widths WY1, WY2and WY3along the second width axis (Y-axis). Because the body portion24is flattened in the direction along the second width axis (Y-axis) from the original cylindrical needle, the first width WX2and the second width WY2of the body portion24are respectively larger than and smaller than the diameter of the needle, i.e. the diameter D of the non-flattened part28. The tail portion22and head portion26are flattened in the direction along the first width axis (X-axis) from the original cylindrical needle, so the first widths WX1and WX3of the tail portion22and head portion26are smaller than the diameter D of the needle and the second width WY1and WY3of the tail portion22and head portion26are larger than the diameter D of the needle. In other words, the first width WX2and the second width WY2of the body portion24are respectively larger than and smaller than the first width WX1and the second width WY1of the tail portion22, and respectively larger than and smaller than the first width WX3and the second width WY3of the head portion26.

Referring toFIGS. 5-11, the linear probe20of the present invention is primarily applied in a probe head30. The probe head30includes a lower die unit40, an upper die unit50and a plurality of linear probes20. The upper and lower die units50and40have a plurality of upper and lower installation holes52and42respectively for the installation of the linear probes20. The probe head30usually includes hundreds or even thousands of linear probes20, thereby also provided with hundreds or thousands of upper and lower installation holes52and42. However, for the simplification of the figures and the convenience of illustration, only three upper installation holes52, three lower installation holes42and two linear probe20are shown in the figures of the present invention. Besides, the upper and lower die units50and40shown inFIGS. 5 and 8are partially cut-off for the convenience of illustrating the corresponding shapes of the upper and lower installation holes52and42and the linear probe20.

In this embodiment, the lower die unit40includes a lower die44. However, the lower die unit40may be composed of a plurality of lower dies. Each of the lower installation holes42penetrates through the lower die44and is defined with a first central axis A1as shown inFIG. 9. The upper die unit50includes a first upper die53and a second upper die54, which are disposed above and parallel to the lower die44. The first and second upper dies53and54are provided therebetween with a gap56by a cushion spacer (not shown) disposed between the first and second upper dies53and54or a fastening clamp fastening the first and second upper dies53and54spacedly. It should be noticed that in other embodiments, the first and second upper dies53and54may be directly piled on one another without the aforesaid spacer and gap56therebetween. As shown inFIG. 5, the first and second upper dies53and54have a plurality of first and second through holes532and542respectively for the head portion26, body portion24and tail portion22of the linear probe20to be inserted therethrough. In this embodiment, each of the first and second through holes532and542is shaped as a square, each side of which is a little larger than the first width WX2of the body portion24and the second width WY1and WY3of the tail portion22and the head portion26. However, each of the first and second through holes532and542may be shaped as a circle with the diameter a little larger than WX2, WY1and WY3or other shapes adapted for the head portion26, body portion24and tail portion22to be inserted therethrough. In this way, it is convenient for each linear probe20to be inserted downwardly from the top of the first through hole532through the first and second through holes532and542and then the lower installation hole42, so that the head portion26of each linear probe20is inserted through the lower installation hole42and the tail portion22is inserted through the first and second through holes532and542. At this time, as shown inFIGS. 5-7, the first through holes532are coaxial with the second through holes542respectively and coaxial with the lower installation holes42respectively, and the linear probes20are still straight.

As shown inFIGS. 8-11, after the linear probes20of the probe head30are all inserted through the upper and lower die units50and40, the upper and lower die units50and40are displaced relative to each other along the second width axis (Y-axis), and the first and second upper dies53and54are displaced relative to each other along the first width axis (X-axis), so that the formerly coaxial first and second through holes532and542are offset from each other along the first width axis (X-axis) to collectively form the non-square rectangular upper installation hole52as shown inFIG. 11. Each of the upper installation holes52is defined with a second central axis A2passing through the center thereof, as shown inFIG. 9. For the same linear probe20, the associated first central axis A1and second central axis A2are offset from each other along the second width axis (Y-axis), so that the body portion24of each linear probe20is curved and thereby has the elastically adjusting function and buffering function.

With the feature that the first and second widths of the body portion24are respectively larger than and smaller than the first and second widths of the tail portion22and the head portion26, the area moment of inertia of the body portion24has significant and specific difference from the area moment of inertia of the tail portion22and the head portion26, and such difference in the area moment of inertia makes the body portion24liable to elastic bending deformation in a specific direction when the linear probe20is applied with a force along the second width axis (Y-axis). Specifically speaking, considering the condition that the cross sections of the tail portion22, body portion24and head portion26are non-square rectangular, the formula for the area moment of inertia Ixof the body portion24with respect to the first width axis (X-axis) is IX=WX2WY23/12, and the formulas for the area moment of inertia Ixof the tail portion22and the head portion26with respect to the first width axis (X-axis) are IX=WX1WY13/12 and IX=WX3WY33/12 respectively. It can be thus known that the area moment of inertia Ix of the body portion24is smaller than the area moment of inertia of Ix of the tail portion22and the head portion26. When the upper and lower die units50and40are displaced relative to each other along the second width axis (Y-axis) to apply a force along the second width axis (Y-axis) to the linear probe20, the body portion24is particularly liable to elastic bending deformation on the Y-Z plane, as shown inFIG. 9, while the tail portion22and the head portion26are particularly unbendable. Besides, the tail portion22and the head portion26have relatively larger strength for resisting the force due to the relative displacement of the upper and lower die units50and40, thereby prevented from the damage due to the friction between the portions22and26and the dies44,53and54, and preventing the dies44,53and54from fractures on the peripheries of the installation holes42and52.

As a result, setting the first and second widths of the tail portion22, body portion24and head portion26can control the directions of the deformation and movement of the linear probe20due to the relative displacement between the upper and lower die units50and40and the contact between the head portion26and the device under test in a way that the probes20of the same probe head30are consistent in bending direction and moving behavior thereof and thereby prevented from interference and short circuit. In particular, the size of the body portion24is more influential in the above-mentioned effects, which is adjustable according to the practical demanding conditions. The sizes of the tail portion22and the head portion26are not only adjustable for improving the above-mentioned effects, but also adjustable according to the size of the device under test.

Besides, the body portion24and the tail portion22have the above-described difference in first and second widths, and the upper installation hole52is shaped as a non-square rectangle from the first and second through holes532and542offset from each other along the first width axis (X-axis) so that the width WH1of the upper installation hole52defined along the first width axis (X-axis) as shown inFIG. 11is smaller than the first width WX2of the body portion24. Therefore, the body portion24needs no additional stopping portion, but itself can be abutted on the bottom surface of the upper die unit50so as to avoid the problem of probe escape. Likewise, the body portion24and the head portion26have the above-described difference in first and second widths, and the lower installation hole42is shaped as a non-square rectangle with the width WH2defined along the first width axis (X-axis) as shown inFIG. 8smaller than the first width WX2of the body portion24. Therefore, the body portion24needs no additional stopping portion, but itself can be abutted on the top surface of the lower die unit40so as to avoid the problem of probe drop. In addition, because the flattened tail portion22and head portion26are cross-sectionally elongated-shaped and inserted through the elongated-shaped upper and lower installation holes52and42, the linear probe20is prevented from self-rotation when contacting the device under test. Besides, the tail portion22and the head portion26can move smoothly in the upper and lower installation holes52and42and release stress because of having arc-shaped parts.

Referring toFIGS. 12-15,FIGS. 12-15show the linear probes according to second to fifth preferred embodiments of the present invention, in the condition as shown inFIGS. 12 and 14that the body portion24is flattened but the tail portion22is not flattened and thereby maintained with the cylindrical shape and the first and second widths WX1and WY1both equal to the diameter D of the needle, and in the condition as shown inFIGS. 13 and 15that the tail portion22is flattened but the body portion24is not flattened and thereby maintained with the cylindrical shape and the first and second widths WX2and WY2both equal to the diameter D of the needle. Under these conditions, the first width WX2of the body portion24is still larger than the first width WX1of the tail portion22. Therefore, the above-mentioned effect of avoiding probe escape can be attained in a way that the width WH1of the upper installation hole52is smaller than the first width WX2of the body portion24, wherein if the upper installation hole52is a circular hole, the width WH1thereof equals to the diameter thereof.

FIGS. 13, 14, 16 and 17show the linear probes according to the third, fourth, sixth and seventh preferred embodiments of the present invention, in the condition as shown inFIGS. 14 and 16that the body portion24is flattened but the head portion26is not flattened and thereby maintained with the cylindrical shape and the first and second widths WX3and WY3both equal to the diameter D of the needle, and in the condition as shown inFIGS. 13 and 17that the head portion26is flattened but the body portion24is not flattened and thereby maintained with the cylindrical shape. Under these conditions, the first width WX2of the body portion24is still larger than the first width WX3of the head portion26. Therefore, the above-mentioned effect of avoiding probe drop can be attained in a way that the width WH2of the lower installation hole42is smaller than the first width WX2of the body portion24, wherein if the lower installation hole42is a circular hole, the width WH2thereof equals to the diameter thereof.

In the second to seventh preferred embodiments of the present invention as shown inFIGS. 12-17, only one or two of the tail portion22, body portion24and head portion26are flattened. In such condition, the first and second widths of the body portion24are still respectively larger than and smaller than the first and second widths of at least one of the tail portion22and the head portion26. Therefore, setting the first and second widths can still make the area moment of inertia (Ix) of the body portion24with respect to the first width axis (X-axis) smaller than the area moment of inertia of (Ix) of at least one of the tail portion22and the head portion26with respect to the first width axis (X-axis), thereby resulting in consistent bending direction and moving behavior of the probes20of the same probe head30.

In the above-described first preferred embodiment, the lower installation hole42is provided with the area approximately just adapted for the head portion26to be inserted therethrough, thereby attaining the effects of avoiding probe drop and preventing the probe from self-rotation. Besides, the upper installation hole52is formed with an elongated shape a little larger than the tail portion22(the upper installation hole52is formed from the first and second through holes532and542offset from each other and each having an area larger than the lower installation hole42), thereby attaining the effects of avoiding probe escape, preventing the probe from self-rotation and convenience for the installation of the probe. However, the lower installation hole42is unlimited to be shaped as a non-square rectangle. As long as the lower installation hole42has an elongated shape, the effects of avoiding probe drop and preventing the probe from self-rotation can be attained by the lower installation hole42and the flattened head portion26collectively. In the condition that the head portion26is not flattened and maintained with the cylindrical shape, the lower installation hole42may be not elongated-shaped, but shaped as a circle, square, and so on, such that the effect of avoiding probe drop can be still attained. Likewise, the upper installation hole52is unlimited to be shaped as a non-square rectangle. As long as the upper installation hole52has an elongated shape, the effects of avoiding probe escape and preventing the probe from self-rotation can be attained by the upper installation hole52and the flattened tail portion22collectively. In the condition that the tail portion22is not flattened and maintained with the cylindrical shape, the upper installation hole52may be not elongated-shaped, but shaped as a circle, square, and so on, such that the effect of avoiding probe escape can be still attained. However, in the condition that the upper and lower installation holes52and42are elongated-shaped, the body portion24can be abutted on relatively larger areas of the bottom surface of the upper die unit50and the top surface of the lower die unit40around the upper and lower installation holes52and42, such that the effects of avoiding probe escape and probe drop are relatively better. No matter the tail portion22is flattened or not, the upper installation hole52is unlimited to be formed from two through holes collectively, which means the upper die unit50may include only one upper die where the upper installation hole52penetrates, as long as the upper installation hole52is adapted for the tail portion22to be inserted therethrough.

Referring toFIGS. 18-20,FIGS. 18-20show an eighth preferred embodiment of the present invention in the condition that the head portion26is flattened and thereby the cross sections thereof have an elongated shape. Under this condition, the lower installation hole42may be elongated-shaped at only a part thereof. Specifically speaking, the lower die unit40includes a top surface45and a bottom surface46opposite to the top surface45, and the top surface45faces toward the upper die unit50. The lower installation hole42includes an upper part421extending from the top surface45toward the bottom surface46, and a lower part422extending from the bottom end of the upper part421to the bottom surface46. The lower part422is an elongated-shaped hole for the head portion26to be inserted therethrough. For example, in this embodiment, the cross section of the lower part422of the lower installation hole42is substantially shaped as a non-square rectangle with arc chamfering. The upper part421is a circular hole and the diameter D′ thereof is larger than the length L and width W of the elongated-shaped hole422and also larger than the first width WX2and the second width WY2of the body portion24. The lower die unit40may be composed of first and second lower dies47and48piled on one another and made of the same material or different material, so that it is convenient to process the upper part421and the lower part422penetrating through the first and second lower dies47and48respectively.

In this way, the circular upper part421of the lower installation hole42can reduce the wear of the head portion26and the lower die unit40, and the body portion24can enter the upper part421to be stopped at the top end of the lower part422, i.e. the top surface of the second lower die48, so the lower part421of the lower installation hole42is still effective in avoiding probe drop and preventing the probe from self-rotation. The above-mentioned effects may be attained in a way that the diameter D′ of the upper part421of the lower installation hole42is designed to be equal to the length L of the elongated-shaped hole422.

It should be appreciated that in the entire specification and the claims of the present invention, the linear probe refers to that the probe is long and straight after the manufacturing and before the installation and the use, which means the linear probe is unlimited to the probe formed from the cylindrical wire needle being at least partially flattened like the probe in the above embodiments. For example,FIG. 21is a schematic perspective view showing a state in the manufacturing process of a linear probe20′ according to a ninth preferred embodiment of the present invention, wherein a plate60capable of being cut into the linear probe20′ is shown. The plate60is formed in a way that a board is shaped by an etching process of MEMS (microelectromechanical systems) or a mechanical cutting process to become the plate60having two thick lateral sections for forming the tail portion22′ and the head portion26′ and a thin middle section for forming the body portion24′. After that, the plate60is cut by laser along a cutting line CL as shown inFIG. 21, such that the linear probe20′ is formed and the tail, body and head portions22′,24′ and26′ thereof are all flattened in a way that the long sides of the cross sections of the tail and head portions22′ and26′ are parallel to Y-axis and the long sides of the cross sections of the body portion24′ are parallel to X-axis.