PROBE STRUCTURE AND PROBE DEVICE

A probe structure includes a tube body and a pin body. The tube body has a central axis and includes a first rigid section, a first spring section, a second rigid section, and a second spring section. The first spring section surrounds the central axis and extends in a direction along the central axis. Two ends of the first spring section connect to one end of the first rigid section and one end of the second rigid section. The first spring section and the second spring section are different in spring constant. The pin body passes through and is disposed in the tube body. The pin body has a head section protruding out of the first rigid section, and the head section is fastened to the first rigid section.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. §119(a) to Patent Application No. 104144813 filed in Taiwan, R.O.C. on Dec. 31, 2015, the entire contents of which are hereby incorporated by reference.

BACKGROUND

Technical Field

The instant disclosure relates to a probe structure and a probe device, in particular, to a probe structure and a probe device suitable for wafer testing in semiconductor industries.

Related Art

In the testing procedures for integrated circuit (IC) chips, a tester is electrically connected with an IC chip to be tested by a probe card. The test result of the IC chip can be obtained by signal transmission and signal analysis. A conventional probe card commonly includes a circuit board and a probe device, or the conventional probe card may further include a space transformer between the circuit board and the probe device. The probe device includes several probes corresponding to electrical contacts of the IC chip to be tested, so that the probes can be in contact with the electrical contacts at the same time.

FIGS. 1 and 2respectively illustrate an exploded view of a conventional probe structure11and a partial sectional view of a conventional probe card14. The conventional probe structure11includes a pin body12and an spring sleeve13fitting over the pin body12. The spring sleeve13has two spring sections138separated by a non-spring section. The conventional probe card14includes a circuit plate15and a probe device16. The circuit plate15may be a circuit board or a space transformer. The probe device16includes a probe holder17and a plurality of probe structures11. InFIG. 2, for the sake of convenience in description, parts of the circuit plate15, the probe holder17, and one probe structure11are illustrated.

Upon the assembling of the probe structure11, the pin body12is inserted into the spring sleeve13. Then, a combination portion132at one end of the spring sleeve13is fastened with the pin body12by compression and welding procedures. The combination portion132has two protrusions134formed during the compression and welding procedures. Each of the protrusions134is protruding from an outer tube surface136of an uncompressed portion of the spring sleeve13.

The probe holder17includes an upper guiding plate171, a middle guiding plate172, and a lower guiding plate173(or the probe holder17may include an upper guiding plate171and a lower guiding plate173and exclude from a middle guiding plate172). The upper guiding plate171, the middle guiding plate172, and the lower guiding plate173are stacked with each other along a vertical direction and define several assembling holes174, so that the probe structures11can be assembled in the assembling holes (InFIG. 2, one assembling hole174is shown). The assembling hole174is configured to be a round hole and the radius of the assembling hole174should be greater than a maximum distance between each of the protrusions134and the center of the probe structure11, so that the probe structure11can be assembled into the assembling hole174from a top surface175of the probe holder17, and the probe structure11can be rotated freely in the assembling hole174upon contacting the IC chip during the testing procedure.

When the probe device16is assembled, the circuit plate15is then positioned on the top surface175of the probe holder17. Next, a top of the spring sleeve13is electrically connected to an electrical contact of the circuit plate15, and a bottom of the pin body12is provided for contacting an electrical contact of a component to be tested. The spring sleeve13has the two spring sections138that are elastically compressible, a lower portion of the pin body12is fastened with the combination portion132at the lower end of the spring sleeve13, and a gap18is between the top of the pin body12and the circuit plate15(i.e., the top of the spring sleeve13). Therefore, when the bottom of the pin body12is abutted against the electrical contact of a component to be tested, the pin body12is retracted and the spring sleeve13is compressed. Accordingly, not only the probe structure11can be firmly in contact with and conducted with the electrical contact of the component to be tested, but also the electrical contacts of the component or the pin body12can be prevented from being damaged or excessively worn by the buffering function of the spring sleeve13.

Please refer toFIG. 3. When the assembling of the probe device16is done, the spring sleeve13is compressed by a length of x1, and the corresponding elastic force of the spring sleeve13in such condition is f1. When the tip of the pin body12(i.e., the bottom of the pin body12) slightly penetrates the surface of the pad (i.e., the electrical contact) of a component to be tested in a probing testing state, the spring sleeve13is compressed by a length of x2, and the corresponding elastic force of the spring sleeve13in such condition increases from f1to f2.

The compressible stroke of each of the two spring sections138of the spring sleeve13of the conventional probe structure11is further greater than a prepressing stroke required by the probe structure11upon the probe structure11is assembled with the probe holder17and the circuit plate15plus a compression stroke of the pin body12caused upon the pin body12is forced against a surface of the pad. In other words, during the probe testing step, the two spring sections138of the spring sleeve13can be compressed freely. Therefore, the relationship between the force F the pin body12applies to the surface of the pad and the compression X of the spring sleeve13is linear, as shown in FIG.3. The slope of the line shown inFIG. 3is the equivalent spring constant of the two spring sections138. For example, the spring constant (or called as Young's modulus) of the two spring sections138are respectively Kx and Ky, and the two spring sections138are in a series connection. Therefore, the equivalent spring constant of the two spring sections138is

The aforementioned prepressing procedure is provided for improving the flatness between the tips of the pin bodies12after the assembling step, i.e., allowing the tips of the pin bodies12to be on the same horizontal plane. Moreover, the spring constant of the spring sleeve13should not be too large; otherwise, the probe holder17may become warped after the prepressing procedure. However, in the probe testing step, the tip of the pin body12has to penetrate into the oxidized layer on the surface of the pad of the component to be tested. As a result, once the spring constant of the spring sleeve13is not large enough, the spring sleeve13has to be compressed by a longer stroke to provide a sufficient spring force and allow the tip of the pin body12penetrating into the oxidized layer on the surface of the pad. Conversely, when the spring constant of the spring sleeve13is large enough, once the spring sleeve13is slightly compressed, the spring sleeve13would provide a sufficient spring force to make the tip of the pin body12penetrate into the oxidized layer on the surface of the pad. In other words, the preference of the spring constant required in the prepressing procedure is just opposite from the preference of the spring constant required in the probe testing step.

SUMMARY

In view of these issues, in one embodiment, a probe structure comprises a tube body having a central axis and a pin body passing through and disposed in the tube body. The tube body comprises a first rigid section, a first spring section, a second rigid section, and a second spring section. The first spring section surrounds the central axis and extends in a direction along the central axis. One of two ends of the first spring section is connected to one end of the first rigid section. One of two ends of the second rigid section is connected to the other end of the first spring section. The second spring section surrounds the central axis and extends in the direction along the central axis. One of two ends of the second spring section is connected to the other end of the second rigid section. The first spring section and the second spring section are different in spring constant. The pin body has a head section protruding from the first rigid section, and the head section is fastened to the first rigid section.

In another embodiment, a probe structure comprises a tube body having a central axis and comprising an spring section. The spring section surrounds the central axis and extends in a direction along the central axis. The spring section comprises a plurality of first curled portions and a plurality of second curled portions. The first curled portions and the second curled portions are in a series connection and arranged alternately. A first distance between two ends of the first curled portion along the central axis is less than a second distance between one of the second curled portions along the central axis.

In yet another embodiment, a probe device comprises a probe holder and a probe structure comprising the tube body and the pin body. The probe holder comprises an upper surface, a lower surface, and a guiding channel. The guiding channel is defined through the probe holder from the upper surface to the lower surface. A connection between the guiding channel and the lower surface forms a neck section. The probe structure is received in the guiding channel. An outer diameter of the first rigid section of the tube body is greater than an inner diameter of the neck section, so that the first rigid section is abutted against the neck section, and the head section of the pin body is protruding out of the lower surface.

DETAILED DESCRIPTION

FIGS. 4 to 7Crespectively illustrate a schematic view of a probe structure20according to a first embodiment of the instant disclosure, a partial enlarged view of the portion5shown inFIG. 4, a partial enlarged view of the portion6shown inFIG. 4, a side view of a first spring section211of the probe structure20of the first embodiment, a developed view of one of first curled portions2111of the probe structure20of the first embodiment, and a developed view of one of second curled portions2112of the probe structure20of the first embodiment. In this embodiment, the probe structure20comprises a tube body21having a central axis C1. The tube body21can be divided into, from one end to the other end, a first rigid section221, a first spring section211, a second rigid section222, a second spring section212, and a third rigid section223.

The first spring section211comprises a plurality of first curled portions2111and a plurality of second curled portions2112. The first curled portions2111and the second curled portions2112are in a series connection in a head-to-tail manner and arranged alternately to form the first spring section211. The first spring section211surrounds the central axis C1and extends in a direction along the central axis C1. One of two ends of the first rigid section221is connected to one of two ends of the first spring section211, and the other end of the first rigid section221is a free end. Two ends of the second rigid section222are respectively connected to the other end of the first spring section211and one of two ends of the second spring section212. One of two ends of the third rigid section223is connected to the other end of the second spring section212, and the other end of the third rigid section223is a free end.

A first distance between two ends of one of the first curled portions2111along the central axis C1is less than a second distance W2between two ends of one of the second curled portions2112along the central axis C1. In this embodiment, the first distance is zero, the second distance W2is not equal to zero, and the first distance is not indicated by numerical. When the first distance is zero, the first curled portion2111surrounds the central axis C1on the same plane rather than extending in a direction along the central axis C1. As shown inFIG. 7A, the first curled portion2111substantially surrounds, from top view, a half circle of the central axis C1. The central points at two ends of the first curled portion2111are respectively P1and P2, and the vector formed by the connection of the two points P1, P2does not have components in the direction along the central axis C1. Namely, the first distance is zero. Likewise, when the second curled portion2112surrounds the central axis C1, the central points at two ends of the second curled portion2112are respectively Q1and Q2, and the absolute value of the component of the vector formed by the connection of the two points Q1, Q2in the direction along the central axis C1is the second distance. As shown inFIGS. 7B and 7C, when the first curled portion2111and the second curled portion2112are developed and flattened, the first curled portion2111is linear, but the second curled portion2112is curved or includes curved and linear patterns.

As shown inFIGS. 4 and 6, the second spring section212comprises a plurality of third curled portions2121. The third curled portions2121surround the central axis C1and extend in the direction along the central axis C1, and each of the third curled portions2121substantially surrounds a full circle of the central axis C1. In this embodiment, the spring constant of the second spring section212is greater than the spring constant of the first spring section211.

As illustrated by a side view of the first spring section211shown inFIG. 7, the first curled portion2111is a horizontal line, meaning that the component of the vector formed by the connection of the central points P1, P2at two ends of the first curled portion2111in the direction along the central axis C1, i.e., the first distance, is zero. The component of the vector formed by the connection of the central points Q1, Q2at two ends of the second curled portion2112in the direction along the central axis C1, i.e., the second distance W2, is nonzero. In other words, in the side view of the first spring section211, the slope of the first curled portion2111is zero, while the slope of the second curled portion212is greater than zero. In this embodiment, the first distance is configured as zero for illustrative purpose, but embodiments are not limited thereto. It is understood that, in this embodiment, the value of the component of the vector formed by the connection of the central pointes P1, P2at two ends of the first curled portion2111in the direction along the central axis C1is different from the value of the component of the vector formed by the connection of the central points Q1, Q2at two ends of the second curled portion2112in the direction along the central axis C1.

Please refer toFIGS. 8, 9, and 14.FIGS. 8 and 9respectively illustrate schematic views (1), (2) of a probe structure30according to a second embodiment of the instant disclosure, andFIG. 14illustrates a diagram showing the relationship between force (F) and compression stroke (X) of the probe structure according to the instant disclosure. In the second embodiment, the probe structure30further comprises a pin body31. The pin body31is passing through the tube body21, and the pin body31is disposed in the tube body21. The pin body31has a head section311and a tail section312. The head section311is protruding from the first rigid section221of the tube body21, an end surface of the tail section312is lower than the third rigid section223of the tube body21by a distance d1. As shown inFIG. 9, in this embodiment, the head section311of the pin body31is fastened with the first rigid section221of the tube body21by compression and welding to form a fastening portion29.

In this embodiment, when the probe structure30is further installed to a testing device, the tube body21is in a state that the tube body21is pre-compressed by a stroke of X1. When the tube body21is pre-compressed by a stroke of X1, the first spring section211is compressed to be in a state that the first spring section211cannot be compressed anymore and reaches or almost reaches to its dead point. In this embodiment, the first spring section211has two different curled portions, thus, a probe designer can design the first spring section211with proper spring constant easily. Accordingly, during the prepressing procedure, the probe structure30would not suffer severe buckling and become damaged. During the prepressing procedure of the assembling step, the compression performed by the tube body21and a behavior of an external force are determined by an equivalent spring constant Kededuced from the spring constant K1of the first spring section211and the spring constant K2of the second spring section212, wherein

In one embodiment, K2is ten times or more over K1.

During the probe testing step, the tube body21is further pressed (i.e., the pin body31is further pressed downward). Because the first spring section211is compressed to be in a state that the first spring section211cannot be compressed anymore and reaches or almost reaches to its dead point, the compression performed by the tube body21and the behavior of the external force in the probe testing step are determined by the spring constant K2of the second spring section212. Supposed that the total compressible stroke of the first spring section211is X1, when the first spring section211is prepressed by an extent greater than 90% of a force corresponding to a stroke of X1, yet the compression stroke is not reached to X1, the first spring section211is in the state that it almost reaches to its dead point. Therefore, combining the prepressing stage in the assembling step with the pressing stage in the probe testing step, the relationship between the force F suffered by the tube body21and the compression X of the tube body21is not linear; instead, as shown inFIG. 14, the line indicating the relationship between F and X has two different slopes. The compression X1shown inFIG. 14equals to the compression of the first spring section211upon being compressed to its dead point, and the slope of line corresponding to such instance is

The slope of the other line is K2. While in the prepressing stage, the first spring section211is in the state that it almost reaches to its dead point. Therefore, in an early period of the probe testing step, the slope of the line is still

and the slope of the line is changed into K2until the first spring section211is compressed to its dead point.

Please refer toFIGS. 10.FIG. 10illustrates a partial sectional view of a probe device40according to a third embodiment of the instant disclosure. The probe device40comprises a probe holder41and at least one probe structure30. The probe holder41comprises an upper surface41a,a lower surface41b,and a guiding channel41c.The guiding channel41cis defined through the probe holder41from the upper surface41ato the lower surface41b.A connection between the guiding channel41cand the lower surface41bforms a neck section41d.When the probe structure30is received in the guiding channel41c,because an outer diameter of the first rigid section221of the tube body21is greater than an inner diameter of the neck section41d,the first rigid section221is abutted against the neck section41dand not detached from the guiding channel41c.

In the testing, as illustrated inFIGS. 1 and 2, a circuit plate15is further disposed on the upper surface41aof the probe holder41. The probe structure30is received in the guiding channel41cand the probe holder41is assembled with the circuit plate15, and the third rigid section223of the tube body21is in contact with an electrical contact of the circuit plate15. When the probe structure30is received in the guiding channel41c,the head section311of the pin body31is protruding out of the lower surface41bof the probe holder41for probing a component to be tested.

Please refer toFIG. 11.FIG. 11illustrates a schematic view of a probe structure50according to a fourth embodiment of the instant disclosure. As shown inFIG. 11, the probe structure50comprises a tube body51. In this embodiment, in addition to the first rigid section221, the first spring section211, the second rigid section222, the second spring section212, and the third rigid section223provided in the first embodiment, the tube body51in the fourth embodiment further comprises a third spring section213. One of two ends of the third spring section213is connected to the third rigid section223. The third spring section213surrounds the central axis C2and extends in a direction along the central axis C2. One of two ends of the third spring section213is connected to the other end of the third rigid section223. In this embodiment, the spring constant of the third spring section213is greater than or equal to the spring constant of the second spring section212.

It is understood that, the relationship between the spring constant of the first spring section211and the second spring section212are not limited thereto. For instance, the spring constant K1of the first spring section211may be greater than the spring constant K2of the second spring section212. In this embodiment, the second spring section212comprises a plurality of first curled portions and a plurality of second curled portions, and the first spring section211merely comprises a plurality of third curled portions.

In other words, between the first spring section and the second spring section, the spring section with a smaller spring constant comprises a plurality of first curled portions and a plurality of second curled portions, and the spring section with a larger spring constant comprises a plurality of third curled portions. A first distance is between two ends of the first curled portion along the central axis. A second distance is between two ends of the second curled portion along the central axis. The first curled portions and the second curled portions are in a series connection and arranged alternately, and the first distance is less than the second distance.

In the foregoing embodiment, no matter which spring section has smaller spring constant, if a spring section comprises a plurality of first curled portions and a plurality of second curled portions, one end of one of the second curled portions of the spring section is connected to the second rigid section.

Please refer toFIGS. 12 and 13, respectively illustrate schematic views (1), (2) of a probe structure60according to a fifth embodiment of the instant disclosure. In this embodiment, the probe structure60comprises a first tube body61and a second tube body65. The first tube body61has a central axis C3and comprises a first rigid section621, a first spring section611, and a second rigid section622. The first spring section611surrounds the central axis C3and extends in a direction along the central axis C3. Two ends of the first spring section611are respectively connected to the first rigid section621and the second rigid section622.

Please further refer toFIGS. 12 and 7A. The structure of the first spring section611in this embodiment is approximately the same as that of the first spring section211in the first embodiment. The first spring section611comprises a plurality of first curled portions6111and a plurality of second curled portions6112. The first curled portions6111and the second curled portions6112are in a series connection and arranged alternately. A first distance between central points at two ends of one of the first curled portions6111along the central axis C3is less than a second distance W2between central points at two ends of one of the second curled portions6112along the central axis C3.

The second tube body65has a central axis C4, and an outer diameter of the second tube body65is greater than that of the first tube body61. The second tube body65comprises a third rigid section661, a second spring section651, and a fourth rigid section662. Two ends of the second spring section651are respectively connected to the third rigid section661and the fourth rigid section662. As shown inFIGS. 12 and 13, the fourth rigid section662of the second tube body65, the first rigid section621of the first tube body61, and the tail section312of the pin body31are fastened with each other by compression and welding to form a fastening portion69a.The second spring section651surrounds the central axis C4and extends in a direction along the central axis C4.

In the fifth embodiment, the first tube body61is in a series connection with the second tube body65, and the spring constant of the first spring section611of the first tube body61is greater than the spring constant of the second spring section651of the second tube body65. For example, the spring constant of the first spring section611may be ten times or more over the spring constant of the second spring section651. In this embodiment, when the probe structure50is applied to a testing device (i.e., installed to the testing device), the third rigid section661of the second tube body65is abutted against a neck section41dlike one shown inFIG. 10.

Please refer toFIGS. 15 and 16, respectively illustrate schematic views (1), (2) of a probe structure70according to a sixth embodiment of the instant disclosure. The probe structure70comprises a first tube body71and a second tube body75. In this embodiment, the first tube body71has a central axis C5. The first tube body71can be divided into, from one end to the other end, a first rigid section721, a first spring section711, a second rigid section722, a second spring section712, and a third rigid section723. The first spring section711comprises a plurality of first curled portions7111and a plurality of second curled portions7112. The first curled portions7111and the second curled portions7112are in a series connection in a head-to-tail manner and arranged alternately to form the first spring section711. The first spring section711surrounds the central axis C5and extends in a direction along the central axis C5. One of two ends of the first rigid section721is connected to one of two ends of the first spring section711, and the other end of the first rigid section571is a free end. Two ends of the second rigid section722are respectively connected to the other end of the first spring section711and one of two ends of the second spring section712. One of two ends of the third rigid section723is connected to the other end of the second spring section712, and the other end of the third rigid section723is a free end. The details about the first curled portion7111and the second curled portion7112in the sixth embodiment are approximately similar to that provided in the first embodiment, thus descriptions are omitted.

The turns of the second spring section712is different from the turns of the first spring section711. In this embodiment, the second spring section712is shorter than the first spring section711. The second spring section712comprises a plurality of first curled portions7121and a plurality of second curled portions7122. The first curled portions7121and the second curled portions7122are in a series connection in a head-to-tail manner and arranged alternately to form the second spring section712. The second spring section712surrounds the central axis C5and extends in the direction along the central axis C5. In this embodiment, the structure of the second spring section712is approximately the same as the structure of the first spring section711, except having different turns. In another case of this embodiment, between the first spring section711and the second spring section712, only one of them has a similar structure with the first spring section211in the first embodiment, and the other has a similar structure with the second spring section212in the first embodiment.

The second tube body75has a central axis C6, and an outer diameter of the second tube body75is greater than that of the first tube body71. The second tube body75comprises a fourth rigid section761, a third spring section751, and a fifth rigid section762. The structure of the second tube body75in this embodiment is approximately the same as the second tube body65in the fifth embodiment.

As shown inFIG. 16, the fifth rigid section762of the second tube body75and the second rigid section722of the first tube body71are fastened with each other by compression and welding to form a fastening portion69bbetween the third spring section751and the second spring section712. In this embodiment, when the probe structure70is applied to the testing device, the fourth rigid section761of the second tube body75having a greater diameter is abutted against a neck section41dlike one shown inFIG. 10. As illustrated inFIGS. 1 and 2, a circuit plate15is electrically connected to a top surface of the third rigid section723of the first tube body71and compresses the third spring section751, so that the third spring section751is compressed to its dead point or almost to its dead point. During the probe testing step, the first rigid section721directly presses on the surface of the pad of a component to be tested, and the first spring section711and the second spring section712of the first tube body71are compressed by the reaction force. In this embodiment, when the first spring section711is not in its dead point, the probing signal must be transmitted along the first curled portions7111and the second curled portions7112orderly. When the first spring section711is compressed to its dead point, adjacent first curled portions7111are closely in contact with each other. Therefore, the transmission path of the probing signal can be efficiently reduced as compared with a condition the first spring section711is not in its dead point. Accordingly, the probe structure70can be applied for high frequency signal testing.

In the foregoing embodiments, the tube body may be produced by lithography, and the spring sections are manufactured by exposure and developing procedures. Therefore, the intervals between adjacent spring sections are determined by the procedure parameters of the lithography. Upon having the same lithography procedure parameters, the intervals between adjacent spring sections are substantially the same. Moreover, in all the embodiments, the spring sections are formed by stripe structures (i.e. cross-section of spring section is not circular) rather than the coil spring of the conventional.

As above, the spring section comprising the first curled portions and the second curled portions is adjusted. In other words, the spring section as well as the first curled portions and the second curled portions of the spring section are defined in the embodiments, so that the spring section having proper spring constant can be provided. The spring section may be the first spring sections described in the embodiments, or the spring section may be an spring section comprising the first curled portions and the second curled portions.