WO2005029575A1

WO2005029575A1 - Structure of probe needle for probe card

Info

Publication number: WO2005029575A1
Application number: PCT/KR2003/002198
Authority: WO
Inventors: Byung-June Jun
Original assignee: Byung-June Jun
Priority date: 2003-09-24
Filing date: 2003-10-20
Publication date: 2005-03-31
Also published as: KR100426073B1

Abstract

Disclosed is a probe needle structure for a probe card, characterized in that, as for the probe card used to inspect a semiconductor wafer, the probe needle structure coming into contact with a pad on a semiconductor chip is improved, whereby the probe card can be effectively manufactured even though the pads have very small size and intervals between them. Further, when a plurality of probe needles come into contact with the pads, needle pressure and movement amount are uniform, thus increasing the inspection reliability, prolonging the service life of the probe card, and reducing the time and effort required to manufacture the probe card.

Description

STRUCTURE OF PROBE NEEDLE FOR PROBE CARD

Technical Field

The present invention relates, in general, to the structure of a probe needle for a probe card for semiconductor wafer inspection. More particularly, the present invention relates to a probe needle structure for a probe card, characterized in that the probe needle structure which comes into contact with an inspecting pad present in a semiconductor chip on a semiconductor wafer is improved, whereby the probe card can be effectively manufactured even through the pads have very small size and intervals between them. Further, when a plurality of probe needles come into contact with pads, needle pressure or movement amount is uniform, therefore increasing the reliability of inspection, prolonging the service life of the probe card, and decreasing the time and effort required for manufacturing the probe card.

Background Art

According to conventional techniques, a probe card has been manufactured by fixing a probe needle structure having various heights to come into contact with inspecting pads present in a plurality of semiconductor chips on a wafer, using an epoxy member (insulator) . FIG. la shows a conventional structure of a probe card. As shown in the drawing, the probe card indicated by the reference numeral 10 includes a PCB 14 having a central aperture 12 and a plurality of probe needles 16 connected to a pattern present on a peripheral region of a lower surface of the PCB, and slantingly extending downwards from the peripheral region to the center aperture. Tips 18 of the probe needles 16 are positioned directly below the center aperture 12. A proximal end 17 of the probe needle 16 comes into contact with a lower portion of a via plug 22 passing through the PCB, and is connected to a card terminal 28 through a pattern composed of the via plug and a binding wire 26. The card terminal 28 is electrically connected to a testing apparatus not shown in the drawing to perform the inspection. The probe needle 16, having the probe tip 18 that is almost vertical, is supported by a probe needle- fixing portion 24. The probe needle-fixing portion is composed mainly of a ceramic ring and epoxy resin. Commonly, the tip 18 of the probe needle 16 moves slightly due to the elastic force of the probe needle when coming into contact with the pad of the semiconductor chip on a semiconductor wafer 20. At this time, testing is performed by the probe card 10 connected to the testing apparatus. On the other hand, to simultaneously test the semiconductor chips formed in an X axis of FIG. la, the part of the probe needle indicated by a circle in FIG. la has the same structure as in FIG. lb. Since FIG. lb is a schematic sectional view, although probe needles 32, 34, 36 and 38 seem to be in a short- circuit state, they are actually not. The probe needles arranged along a Y axis are merely seen to overlap. Simultaneous measurement of 8 rows of semiconductor chips arranged along an X axis can be accomplished by measuring every 4 rows from left and right sides at the same time. The structure of probe needles originating from the left side has four layers, as shown in FIG. lb. Also, the structure of probe needles originating from the right side is symmetrical with the structure depicted in FIG. lb. Upon manufacturing the probe card, since the probe needles are fixed using the epoxy member while being regularly stacked, the probe tips have various lengths, as in FIG. lb. For example, the third layer 36 and the fourth layer 38 have much longer probe tips than the first layer 32 and the second layer 34. Hence, when the probe tip comes into contact with the pad on the board for a practical test, the probe needle increases in the extent of movement (movement amount) by contact pressure (needle pressure) . That is, in cases where the probe needles are introduced at various heights (various layers) so as to avoid a short- circuit, the length of the probe tip of each layer, that is, the length of a movable portion (length of a free end) , varies, resulting in non-uniform needle pressure and movement amount upon contact. This causes noise during the performance of inspection, therefore generating an inspection error. Further, due to deformation of the probe tips, the probe card has shortened service life and may be frequently out of order. As for the conventional probe needle structure shown in FIG. lc, since the probe needles are introduced from only one direction and come into contact with the pads, intervals between neighboring pads, that is, pitches, become narrow, thus inevitably generating short-circuits. In a manufacturing process of the conventional probe card, the probe needles are arranged and then fixed using an epoxy resin, so that the probe tips as end portions of the probe needles come into contact with pads of semiconductor chips on a wafer. Thereby, the first layer 32 of FIG. lb is formed. The first layer functions to simultaneously test a first row of a plurality of chips formed in a Y axis perpendicular to a given plane. Although FIG. lb shows only the probe needles originating from the left side, a structure having probe needles originating from the right side is symmetrically provided, too. Accordingly, the first layer serves to simultaneously test the first row of the leftmost side and the eighth row of the rightmost side. Thereafter, a second layer 34 is formed on the first layer 32, thereby forming probe needles capable of testing a second row of chips at the right side of the first row. In this way, a third layer 36 and a fourth layer 38 are formed, and then arranged again on the ceramic ring before being fixed. However, the conventional manufacturing process is disadvantageous because every layer is fixed after being formed in order. That is, the second layer is formed after the first layer has been completed, and the third layer is formed following the formation of the second layer. Therefore, even though there are many workers, a period of time required to manufacture a single probe card cannot be shortened.

Disclosure of the Invention Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a probe needle structure for a probe card capable of simultaneously testing a plurality of chips, which has uniform needle pressure and movement amount. Another object of the present invention is to provide a probe needle structure for a probe card, which can be easily manufactured even though intervals between neighboring pads, that is, pitches, are narrow, in accordance with high integration of semiconductor devices. A further object of the present invention is to provide a probe needle structure for a probe card, which has a short manufacturing time and high productivity, as a result of a parallel manufacturing process made possible by separately manufacturing probe needle structures for inspecting a row of semiconductor chips and then assembling them. In order to accomplish the above objects, the present invention provides a probe card apparatus, comprising a probe needle structure which includes an insulating member having a column form, a plurality of first probe needles introduced toward a boundary between neighboring lateral surfaces of the insulating member, vertically extending downwards along a first surface of the insulating member, being horizontally bent, extending along a second surface of the insulating member, and then being bent downwards to form end portions of the probe needles, a plurality of second probe needles introduced toward a boundary between neighboring lateral surfaces of the insulating member, extending along a fourth surface of the insulating member, being vertically bent downwards, extending along a third surface opposite to the first surface of the insulating member, being horizontally bent, extending along a second surface of the insulating member, and then being vertically bent downwards to form end portions of the probe needles, and an epoxy member provided on outer surfaces of the insulating member, wherein the first probe needles and the second probe needles are fixed to the insulating member using the epoxy member. Further, the probe card apparatus of the present invention includes at least one probe needle structure, and the probe needle structure is fixed to a ceramic plate. The insulating member is made of a ceramic material. Although the insulating member of the present invention preferably has a square column, it may have various forms other than the square column. That is, the insulating member having a column form may have various rectangular cross-sections or cross-sections other than rectangular. In addition, the outer surfaces of the insulating member may be changed for easy arrangement and fixation of the probe needles. The insulating member used for the probe card is generally made of a ceramic material, or other insulating materials, such as sapphire or glass. The epoxy member used to fix the probe needles to the insulating member may have a variety of adhering means other than epoxy. The probe needles for the probe card of the present invention have a constant probe tip length, regardless of an introduction height of the probe needle. Compared to conventional probe cards, the present probe card has uniform needle pressure and movement amount. Thus, upon inspection, the possibility of being exposed to noise or generating leakage current decreases, resulting in increasing inspection reliability. Further, uniform needle pressure and movement amount of the probe needle lead to preventing the probe tip from deformation, hence prolonging the service life of the probe card.

Brief Description of the Drawings

FIGS, la, lb and lc are views showing a conventional probe card; FIGS. 2a, 2b and 2c are views showing a probe needle structure for a probe card, according to a first embodiment of the present invention; FIG. 3a is a view showing a plurality of probe needle structures separately manufactured and then assembled, according to the first embodiment of the present invention; and FIG. 3b is a view showing a plurality of probe needle structures separately manufactured and then assembled, according to a second embodiment of the present invention.

Best Mode for Carrying Out the Invention

First Embodiment FIG. 2a shows a sectional view of a probe needle structure for a probe card, according to a first embodiment of the present invention. From the drawing, it can be seen that an insulating member 50 having a square column has a rectangular cross-section, and probe needles surround outer surfaces of the insulating member and are fixed to the insulating member by an epoxy member. Referring to FIG. 2a, the probe needle structure for the probe card, according to the first embodiment of the present invention, comprises an insulating member 50 having a square column, and a plurality of first probe needles 54 introduced toward a boundary between neighboring lateral surfaces of the insulating member, vertically extending downwards along a first surface 50a of the insulating member, being horizontally bent, extending along a second surface 50d of the insulating member, and then being bent downwards, to form end portions of the probe needles. Further, the probe needle structure has a plurality of second probe needles 52 introduced toward a boundary between neighboring lateral surfaces of the insulating member, extending along a fourth surface 50b of the insulating member 50, being vertically bent downwards, extending along a third surface 50c opposite to the first surface 50a of the insulating member 50, being horizontally bent, extending along a second surface 50d of the insulating member, and then being vertically bent downwards, to form end portions of the probe needles. Additionally, the above structure has an epoxy member 56 which is provided on outer surfaces of the insulating member. The first probe needles 54 and the second probe needles 52 are fixed to the insulating member 50, using the epoxy member 56. FIG. 2b depicts the probe needle structure of FIG. 2a in three dimensions, in which two probe needles introduced from the same direction are bent near the edge line between the neighboring lateral surfaces of the insulating member to form the probe needle structure of the present invention. As apparent from FIG. 2b, the first probe needle 54 is provided along the first surface 50a and the second surface 50d of the insulating member 50, while the second probe needle 52 is provided along the fourth surface 50b, the third surface 50c and the second surface 50d of the insulating member 50. The probe needles as depicted in FIG. 2b are fixed to the outer surfaces of the insulating member, using the epoxy member. Since a plurality of probe needles are additionally provided even in a Y axis of FIG. 2b, every probe needle is arranged at a proper position so as not to generate short-circuit, and then fixed to the outer surfaces of the insulating member using an epoxy resin material. Thereby, the probe needle structure of the present invention has a cross-section shown in FIG. 2a, in which the plurality of probe needles are provided around the outer surfaces of the insulating member 50, and then fixed by the cured epoxy member 56. Although the insulating member 50 is represented in the square column in FIG. 2a, it may have various forms other than the square column. That is, the insulating member having a column form may have various rectangular cross-sections or cross-sections other than rectangular. Also, the outer surfaces of the insulating member may be changed so that the arrangement and fixation of the probe needles are easily performed. The insulating member for the probe card is generally made of a ceramic material, or other insulating materials, such as sapphire or glass. The epoxy member used to fix the probe needles to the insulating member may have a variety of adhering means other than epoxy. FIG. 2c shows the arrangement of a probe needle 62 coming into contact with a pad 60, in the probe needle structure according to the present invention. As in FIG. 2c, since the probe needles are arranged while being alternately introduced from opposite directions, pitches P between the probe needles become much wider. For instance, in cases where the pad has a constant size and interval, the pitch P between the probe needles doubles, compared to a conventional probe needle arrangement shown in FIG. lc. Thus, even though the pad decreases in size and the intervals between the pads decrease in accordance with the high integration of semiconductor devices, the probe card can be easily manufactured. Turning now to FIG. 3a, there is shown a partial cross-section of a probe card containing the probe needle structure according to the first embodiment of the present invention. In FIG. 3a, a probe needle structure 82, functioning to test the first row of chips to the left side, is formed by fixing the probe needle to one surface of the insulating member using an epoxy resin, as in the conventional technique. 3 probe needle structures 83, 84 and 85, serving to test a second row, a third row and a fourth row from the left side, are manufactured using the probe needle structure of the present invention. As seen in the drawing, the probe needle structure for the probe card of the present invention has uniform needle pressure and movement amount, because the probe tip has a constant length d, regardless of the introduction height of the probe needle. Every probe needle structure is separately manufactured, arranged on a ceramic plate 70, and then fixed thereto using the epoxy member 56, to obtain a final probe needle structure for a probe card. Although the ceramic plate preferably has a plate-type rectangular parallelepiped form as shown in FIG. 3a, it may be changed into various forms. For example, when a probe card capable of simultaneously testing all of the chips on a wafer is manufactured using the probe needle structure of the present invention, the ceramic plate may be in the wafer form or in other forms. Further, it is possible to replace the ceramic material of the ceramic plate with other insulating materials. In the case of manufacturing a probe card capable of simultaneously testing the total of 128 semiconductor chips arranged in 16 columns and 8 rows among semiconductor chips on a wafer, 8 probe needle structures shown in FIG. 2a are required. That is, there is provided one probe needle structure to each row. According to the present invention, every probe needle structure is separately manufactured and then assembled to complete the probe card. Thus, the probe card of the present invention is advantageous because it can be manufactured by the lowest number of workers due to the division of work. 8 probe needle structures, which are separately manufactured, are placed on an assembling jig for arrangement, and then arranged according to measurement positions using an inspecting device. Subsequently, the structures are fixed to the ceramic plate 70 using the epoxy member 56, thereby completing the probe card capable of simultaneously testing the total of 128 chips arranged in of 16 columns and 8 rows. Second Embodiment In FIG. 3a, there is illustrated the probe needle structure 82, serving to test the first row of chips, manufactured by introducing the probe needles from the same direction and then bending them once according to the conventional technique. The reason why the conventional probe needle structure may be applied is that the probe needle used to test the first row has a low introduction height, and thus, a long probe tip is not required. Alternatively, it is possible to form a probe card by manufacturing 4 probe needle structures according to the present invention and then fixing them to a ceramic plate. That is, as shown in FIG. 3b, the probe needle structure 82, serving to test the first row of chips, is replaced with one manufactured like the probe needle structures 83, 84 and 85 of the present invention. FIG. 3b shows a sectional view of a probe card assembled by fixing 4 probe needle structures of the present invention to a single ceramic plate. As in the first embodiment, the probe needle structure for the probe card, according to the second embodiment, has a constant probe tip length d, regardless of the introduction height of the probe needle, and thus, the needle pressure and the movement amount become uniform.

Industrial Applicability

As described above, the present invention provides a probe needle structure for a probe card, in which the probe card together with a testing apparatus is used to measure the electric properties of semiconductor devices manufactured through a semiconductor-manufacturing process. In a plurality of semiconductor chips formed on a wafer, there are provided a plurality of pads for the input or output of electric signals to measure the electric properties of the device. As such, the probe needles of the probe card are positioned on the pad for measurement. Therefore, the probe card and the related techniques are essentially required to manufacture semiconductor devices. Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A probe card apparatus, comprising a probe needle structure, the probe needle structure including: an insulating member having a column form; a plurality of first probe needles introduced toward a boundary between neighboring lateral surfaces of the insulating member, extending downwards along a first surface of the insulating member, being horizontally bent, extending along a second surface of the insulating member, and then being bent downwards, to form end portions of the probe needles; a plurality of second probe needles introduced toward a boundary between neighboring lateral surfaces of the insulating member, extending along a fourth surface of the insulating member, being bent downwards, extending along a third surface opposite to the first surface of the insulating member, being horizontally bent, extending along a second surface of the insulating member, and then being bent downwards, to form end portions of the probe needles; and an epoxy member provided on outer surfaces of the insulating member, wherein the first probe needles and the second probe needles are fixed to the insulating member using the epoxy member .

2. The probe card apparatus according to claim 1, wherein the probe needle structure is provided in a plural number, and fixed to a ceramic plate.

3. The probe card apparatus according to claim 1, wherein the insulating member is made of a ceramic material .