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Patent Issued for Vertical Micro Contact Probe Having Variable Stiffness Structure

May 28, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- According to news reporting originating from Alexandria, Virginia, by VerticalNews journalists, a patent by the inventors Kim, Jung-Yup (Daejeon, KR); Lee, Hak-Joo (Deajeon, KR); Kim, Kyung-Shik (Daejeon, KR), filed on April 30, 2009, was published online on May 13, 2014.

The assignee for this patent, patent number 8723541, is Korea Institute of Machinery & Materials (Daejeon, KR).

Reporters obtained the following quote from the background information supplied by the inventors: "Integration of semiconductor chips has been increased with the development of technologies. In general, complete semiconductor chips undergo electric inspection before packaged, and good products are packaged and bad products are abandoned, in accordance with the inspection result. A probe card that electrically connects a tester equipped with a built-in measurer with the pad of the semiconductor chips is used in the electric inspection.

"Electric inspection for line of center (LOC) elements of the related art has used a cantilever type probe 100 shown in FIG. 1.

"However, C4 (Controlled Collapse Chip Connection) type devices that can improve electric performance and increase integration are recently used in the non-memory field and communication field, the pad arrangement of the C4 devices generally has a non-uniform two-dimensional array and the pad pitch of the semiconductor chips is decreased with the high integration of the semiconductor chips, such that a vertical micro contact probe is required for this reason.

"In general, the shape of vertical micro contact probes is limited because these are manufactured by a process for semiconductors, such as electroplating. Further, the probes should have a structure for absorbing vertical displacement to overcome the step between the pads and should generate lateral force to remove native oxide on the electrode surface.

"A bellows shape micro contact probe 200 shown in FIG. 2 has been proposed to attenuate stress, under those conditions.

"However, in the bellows shape micro contact probe 200 of the related art, buckling or out-of-plane behavior still occurs, and is difficult to be applied when the step between pads is large, while it is difficult to reduce the pitch between the probes.

"Further, since a specific guide is used to prevent the buckling in the related art, the manufacturing cost increases and it is difficult to ensure a space between the probes.

"The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art."

In addition to obtaining background information on this patent, VerticalNews editors also obtained the inventors' summary information for this patent: "The present invention has been made in an effort to provide a vertical micro contact probe having advantages of reducing the contact area of the tip and preventing out-of-plane behavior by changing the tip shape of the vertical micro contact probe, and varying stiffness and allowing for automatic arrangement by providing the vertical micro contact probe with a stopper.

"An exemplary embodiment of the present invention provides a vertical micro contact probe that includes: a column formed by longitudinally continuously stacking a plurality of basic units; and a front end formed at the front end of the column and contacting an electrode pad of a semiconductor chip. The basic unit may includes a probe body alternately bending to the left and right and protrusions protruding from the probe body at the left and right sides from the center of the width direction, and contacting the adjacent probe body to support the probe body under compression.

"The gap between the protrusions and the probe body facing the protrusion may be set different at the longitudinal center of the column and at longitudinal both sides of the column.

"The gap may increase from the longitudinal center of the column toward the longitudinal both ends of the column.

"The gap may increase by a predetermined ratio from the longitudinal center of the column toward the longitudinal both ends of the column.

"The gap may increase by a predetermined value by stages from the longitudinal center of the column toward the longitudinal both ends of the column.

"The protrusions may be formed at the longitudinal center of the column.

"Prominences may further protrude from the probe body facing the protrusions.

"The protrusions may be arranged in two lines at the left and right sides from the center of the width direction of the column.

"The bending portions of the probe body may be rounded or formed at predetermined angle.

"The protrusions may have an elastic structure by protrusion shape.

"The protrusion may include an extender extending and bending in parallel with the probe body from the probe body, and a prominence formed at the end of the extender to contact the adjacent probe body under compression.

"The length of the extender of the protrusion may decrease from the longitudinal center of the column toward the longitudinal both ends of the column.

"The front end may have a plurality of contact portions and has a plurality of contact points between the front end and the semiconductor chip.

"According to the exemplary embodiments of the present invention, it is possible to prevent out-of-plane behavior while reducing the contact area of the front end, by changing the shape of the front end of the vertical micro contact probe. As the contact area of the front end is reduced, as described above, contact resistance can be reduced.

"Further, according to the exemplary embodiments of the present invention, it is possible to automatically arrange the vertical micro contact probe while changing the stiffness, by providing the probe with a stopper. Since the vertical micro contact probe can be automatically arranged, as described above, a guide for preventing buckling is not needed."

For more information, see this patent: Kim, Jung-Yup; Lee, Hak-Joo; Kim, Kyung-Shik. Vertical Micro Contact Probe Having Variable Stiffness Structure. U.S. Patent Number 8723541, filed April 30, 2009, and published online on May 13, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=68&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3400&f=G&l=50&co1=AND&d=PTXT&s1=20140513.PD.&OS=ISD/20140513&RS=ISD/20140513

Keywords for this news article include: Electronics, Semiconductor, Korea Institute of Machinery & Materials.

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Source: Electronics Newsweekly


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