JPH0671035B2 - A prober for measuring electrical characteristics of semiconductor wafers - Google Patents

Description

The present invention relates to a prober for measuring electrical characteristics of ICs, LSIs, etc. on a wafer.

(Prior Art) Conventionally, in order to measure the electrical characteristics of ICs, LSIs, etc. on a wafer shown in FIG. 6, a probe consisting of one signal line 3 and one ground 4 as shown in FIG. The prober 7 having the needle 5 soldered to the coaxial cable 6 as shown in FIG. 6 was used.

(Problems to be Solved by the Invention) By the way, since the prober 7 joins the probe needle 5 to the coaxial cable 6, a plurality of signal lines cannot be taken out. In other words, it is impossible to make multiple terminals with the probe needle 5 having a plane line and the coaxial cable 6. Further, since the signal line 3 of the probe needle 5 having a different shape and the coaxial cable 6 are soldered,
The characteristic impedance causes a mismatch, a reflected wave appears, and accurate electrical characteristics cannot be measured. In particular, accurate electrical characteristics cannot be measured in the high frequency region.

On the other hand, the development of high-density and high-speed ICs, LSIs, etc. has recently been advanced, and as a prober for evaluating these, stable characteristic impedance, multiple terminals, and reliable padding on the wafer have been developed. We need a prober that can make various contacts, and the development of this is urgent.

Therefore, the present invention is intended to provide a prober that can achieve stabilization with respect to setting of characteristic impedance, increase in number of terminals, and reliable contact, and that can accurately measure electrical characteristics even in a high frequency region.

(Means for Solving Problems) The prober of the first invention for solving the above problems is
A transmission cable is integrally provided in parallel in a plurality of rows on a dielectric body, and a side surface as a probe needle is curved and raised in a semicircular shape at the tip of the transmission cable of a flat cable formed by joining a conductor to the opposite surface. It is characterized in that a contact portion is provided.

The prober of the second invention for solving the above problems is
A contact portion in which a side face as a probe needle is curved in a semicircular shape at a tip end of the transmission line of a flat cable in which a plurality of columns of transmission lines are provided in parallel on a dielectric and conductors are joined to the opposite faces. Is provided, a dielectric is joined with the transmission line excluding the contact portion sandwiched therebetween, and a conductor is joined onto the dielectric.

(Embodiment) An embodiment of the prober of the first invention will be described with reference to FIG. Reference numeral 10 is a dielectric body made of polyimide and having a width of 10 mm and a thickness of 200 μ. A thickness of 3 μ in the longitudinal direction on the dielectric body 10 and a width of 150 μ.
The transmission lines 11 made of Cu are provided in parallel in three rows at intervals of 200μ, and the conductor 12 made of Cu having a thickness of 3μ is joined to the opposite surface to form the flat cable 13. The tip portion of each transmission line 11 of the flat cable 13 is raised to a height of 80 μ in a semicircular shape in side cross section, and a contact portion is formed.
It is 14.

FIG. 2 shows an embodiment of the prober of the second invention, which is the first embodiment.
On the dielectric 10 in the prober of the first invention shown in FIG.
A dielectric 10 ′ made of polyimide having a thickness of 200 μ is joined across a transmission line 11 except 14 and a conductor 12 ′ made of Cu having a thickness of 3 μ is joined on the dielectric 10 ′. is there.

As described above, in the probers 15 and 15 'of each embodiment, since the transmission lines 11 are provided in three columns in parallel on the dielectric 10, the transmission lines 11
Has a stripline structure, and the characteristic impedance of the transmission line 11 does not change and is constant at any part. Therefore, the probers 15 and 15 'of each embodiment are attached to the prober holder 18 supported by the arm 17 which is movable in the X, Y, and Z axis directions of the measuring instrument 16 as shown in FIGS. 3 and 4, respectively. The ends are connected to the connector 19 and connected to the measuring device 16, and the contact portions 14 at the tips of the probers 15 and 15 'are brought into contact with the pads 2 of the IC, LSI, etc. on the wafer 1 to obtain the electrical characteristics. As a result of measurement, in the high frequency region, in this example, accurate parameter measurement was possible at a high frequency of 30 GHz. Further, even when this measurement is repeated, since the raised contact portion 14 is provided at the tip of each transmission line 11, the IC, LSI, etc. on the wafer 1 are measured in the measurement of the electrical characteristics. The pad 2 is always reliably and stably contacted. Conductor 12
Is bonded to the dielectric 11 and the conductor 12 'is bonded to the dielectric 10', respectively, and the conductive layers are formed in two or three layers, so that the characteristic impedance is remarkably stable against setting.
Further, the transmission line 12 on the dielectric 10 is sandwiched between the dielectrics 10 ′, and the electrically shielded prober 15 ′ reduces noise from the outside, and moreover, the crosstalk between the transmission lines 11 is reduced. Is reduced.

The dielectrics 10 and 10 'in the prober of each of the above embodiments are
Is made of polyimide, but is not limited to this and may be polyester. In each of the above embodiments, the transmission line 11
Is three columns, but is not limited to this, and any number of columns may be used as long as there are two or more examples, and there are cases of several tens of columns and several hundreds of columns.

(Effects of the Invention) As can be seen from the above description, in the prober of the present invention, a plurality of transmission lines are provided in parallel on the dielectric of the flat cable, and the transmission lines have a strip line structure. Therefore, the setting of the characteristic impedance can be stabilized, the characteristic impedance can be made constant in any part of each transmission line, and a multi-terminal can be realized by a plurality of lines of transmission lines. Moreover, in the prober of the present invention, the tip end portion of the transmission line is provided with the contact portion whose side surface is curved in a semicircular shape and is raised, so that the transmission line is not consumed and the contact with the object to be measured is stable. Further, when each transmission line on the dielectric is sandwiched between the dielectrics and electrically shielded, noise from the outside is reduced, and moreover, crosstalk between the transmission lines is reduced. In addition, since a conductor is joined to the dielectric to form at least two conductive layers, the characteristic impedance is remarkably stable against setting.
Thus, high density and high speed I on semiconductor wafer
Accurate measurement of electrical characteristics in high frequency areas such as C and LSI,
It can be performed reliably and reliably.

[Brief description of drawings]

1 and 2 are partial perspective views showing an embodiment of the prober of the present invention, respectively, and FIGS. 3 and 4 are schematic views showing the use state of the prober of FIGS. 1 and 2, and FIG. FIG. 6 is a perspective view showing a conventional prober, and FIG. 6 is a schematic view showing a use state of the conventional prober.

Claims (2)

[Claims] 1. A flat cable having transmission lines integrally provided in parallel in a plurality of rows on a dielectric and having conductors joined to opposite sides thereof, and a side face as a probe needle has a semicircular shape at a tip end of the transmission line. A prober for measuring electrical characteristics of a semiconductor wafer, which is provided with a curved and raised contact portion. 2. Transmission lines are provided in parallel in a plurality of columns on a dielectric,
At the tip of the transmission line of the flat cable formed by joining a conductor to the opposite surface, a contact portion is formed in which the side face as a probe needle is curved in a semicircular shape and is raised, and the transmission line excluding this contact portion is sandwiched. A prober for measuring electrical characteristics of a semiconductor wafer, characterized in that a dielectric is bonded to the conductor and a conductor is bonded to the dielectric.