JP3727040B2 - Probe card - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a probe card, and more particularly to a membrane type probe card.
[0002]
[Prior art]
In the semiconductor manufacturing process, before packaging IC chips formed on a semiconductor wafer (hereinafter, simply referred to as “wafer”), the electrical characteristics of each IC chip are inspected in the wafer state to screen non-defective IC chips in advance. Has an inspection process. In this inspection process, for example, a probe device is used. In general, the probe apparatus includes a loader unit that transfers a wafer and a prober unit that is adjacent to the loader unit and inspects the electrical characteristics of the wafer transferred from the loader unit. A main chuck that can move in the X, Y, Z, and θ directions is disposed in the prober section, and a probe card that faces the main chuck is fixed to the upper surface of the loader section.
[0003]
When inspecting using the probe device, the main chuck moves in the X, Y, Z, and θ directions while the wafer transferred from the loader portion is vacuum-sucked on the main chuck, and each IC chip of the wafer is moved. After aligning the electrode pad (for example, formed of aluminum) with the contact of the probe card, the main chuck is raised in the Z direction and the electrode pad and the contact are in electrical contact with each other. The electrical characteristics of each IC chip are inspected.
[0004]
Recently, as the diameter of a wafer increases, the integration density of IC chips increases rapidly, the wiring structure of the IC chips becomes ultrafine, and the arrangement of electrode pads becomes increasingly narrower. Along with this, the probe needles of the probe card are also narrowed. Therefore, there is a membrane-type probe card (hereinafter referred to as “membrane membrane”) as a probe card that can flexibly cope with a narrow pitch of electrode pads.
[0005]
For example, as shown in FIG. 6 , the membrane card includes a synthetic resin membrane 1 as a base material, a wiring pattern 2 made of a highly conductive metal such as copper formed on the membrane 1, and the wiring pattern 2. This is provided with a protruding contact 3 made of a highly conductive metal (for example, gold or gold alloy) provided at the end and a protective film 4 for protecting the wiring pattern 2. In this type of probe card, even if the electrode pad of the wafer is narrowed, the protruding contact 3 can be made according to the electrode pad, and even if the unevenness of the electrode pad is uneven, the membrane A relatively stable contact pressure can be ensured following the shape.
[0006]
However, since the electrode pad of the wafer is made of, for example, aluminum, the electrode pad is very easily oxidized, and the electrode pad is oxidized during the wafer manufacturing process or the transfer process to form an insulating oxide film. This oxide film reaches a film thickness of 900 to 1200 angstroms, for example. Therefore, it is necessary to remove the oxide film on the electrode pad when inspecting the wafer.
[0007]
When performing an inspection using the above-described membrane card, for example, as shown in FIG. 7 , the main chuck is raised in the Z direction and overdriven to increase the contact pressure of the protruding contact 3 and move in the X or Y direction. Then, the oxide film O is scraped off by the protruding contact 3 so that the protruding contact 3 and the electrode pad P are electrically connected.
[0008]
[Problems to be solved by the invention]
However, in the case of the conventional membrane card, since the tip of the protruding contact 3 is rounded as shown in FIG. 7 , the protruding contact 3 is difficult to bite into the electrode pad P. After the pressure is applied, the wafer W is moved in the X or Y direction and the oxide film O of the electrode pad P is scraped off and inspected, but the contact area between the protruding contact 3 and the electrode pad P is slight and sufficient contact There is a problem that it is difficult to ensure the resistance, and that the protruding contact 3 is rubbed, so that it is easily worn. Further, when the contact pressure of the protruding contact 3 is increased in order to ensure sufficient contact resistance, the protruding contact 3 bites too deeply into the electrode pad P when the oxide film O is scraped off, and the aluminum oxide reaches silicon. There is a risk that the electrical characteristics of the IC chip may be impaired.
[0009]
The present invention has been made to solve the above-mentioned problems, and sufficiently secures the contact resistance between the protruding contact and the electrode by a simple operation of merely pressing the protruding contact and the electrode of the object to be inspected. An object of the present invention is to provide a membrane-type probe card that can perform a highly reliable inspection and has excellent wear resistance.
[0010]
[Means for Solving the Problems]
The probe card according to claim 1 of the present invention includes a base material and a protruding contact formed on the surface of the base material , and the protruding contact and the electrode of the object to be inspected are electrically connected. In the probe card that contacts and inspects the electrical characteristics of the object to be inspected, the protruding contact is formed gradually and gradually from the base end portion to the tip end portion and has a flat surface at the tip end . And the screw blade was provided in the surrounding surface of the said contactor, It is characterized by the above-mentioned .
[0011]
The probe card according to claim 2 of the present invention is characterized in that, in the invention according to claim 1, the contact is formed of a material having a hardness higher than the hardness of the inspection electrode. .
[0013]
A probe card according to claim 3 of the present invention is the probe card according to claim 1 or 2 , wherein the contact is formed in a truncated cone or a truncated pyramid.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the embodiment shown in FIGS.
For example, as shown in FIGS. 1A and 1B, a probe card 10 according to this embodiment includes a membrane 11 made of a synthetic resin such as a polyimide resin or a silicon resin, and copper or the like on the surface of the membrane 11. A wiring pattern 12 made of a highly conductive metal, and a plurality of protruding contacts 13 formed on the end of the wiring pattern 12 in accordance with the arrangement of electrode pads of one or a plurality of IC chips on the wafer. And a protective film 14 made of a synthetic resin such as a polyimide-based resin for protecting the wiring pattern 12, and an electrical inspection of one or a plurality of IC chips is performed. Further, the wiring pattern 12 is formed over a plurality of layers if the number of the projecting contacts 13 is increased. The wiring pattern 12 and the protruding contact 13 in each layer are connected through a through hole or the like. The membrane 11 and the protective film 14 may be formed of the same material or different materials.
[0015]
Further, although not shown, the probe card 10 includes a printed wiring board and a support member. The membrane 11 is stretched at the central opening of the printed wiring board, and the wiring pattern 12 is connected to the wiring pattern of the printed wiring board. A support member is attached to the central opening to support the membrane 11 from the back surface and to apply a contact pressure to the membrane 11.
[0016]
For example, as shown in FIG. 1B, the protruding contact 13 is a quadrangular frustum that gradually becomes thinner from the base end portion to the tip end portion and has a substantially square flat surface 13A at the tip end. It is formed in a shape. As shown in FIG. 2, the protruding contact 13 includes a base portion 131 formed in a quadrangular pyramid shape with a material having a higher hardness than the electrode pad, for example, ore such as diamond, sapphire, quartz, and the like. The conductive film 132 is coated with a highly conductive metal such as gold, rhodium, or an alloy thereof. And the base end part of the electrically conductive film 132 is connected with the wiring pattern 12, and conduction | electrical_connection with an electrode pad is aimed through the electrically conductive film 13B. The protruding contact 13 is formed with a height from the wiring pattern 12 of, for example, 120 to 250 μm, and the side length of the flat surface 13A at the tip thereof is formed of, for example, 10 to 15 μm. In particular, when the side length of the flat surface 13A is 30 μm or more, the protruding contact 13 does not sufficiently bite into the electrode pad, and it is difficult to ensure sufficient contact resistance between the peripheral surface of the protruding contact 13 and the electrode pad. If it exceeds, the bite into the electrode pad may be difficult. Further, when the side length of the flat surface 13A is 8 μm or less, the protruding contact 13 bites into the electrode pad, but it is difficult to sufficiently secure the contact resistance between the peripheral surface of the protruding contact 13 and the electrode pad.
[0017]
Next, the operation will be described with reference to FIG. After placing the wafer on a main chuck (not shown) and performing a predetermined alignment, the main chuck is overdriven. Then, as shown in the figure, the wafer W rises in the Z direction and comes into contact with the protruding contact 13 of the probe card 10, and when the wafer W further rises, the protruding contact 13 has higher hardness than the electrode pad P. Therefore, a shearing force acts on the electrode pad P from the edge around the flat surface 13A at the tip, the surface is cut by the edge, and the protruding contact 13 starts to bite into the electrode pad P. As the wafer W subsequently rises, the electrode pad P is gradually spread around the peripheral surface of the protruding contact 13 and gradually bites into the position indicated by the solid line in FIG. In this state, the flat surface 13A of the protruding terminal 13 is in contact with the oxide film O and insulated from the electrode pad P, but the peripheral surface of the flat surface 13A is an innocuous portion where the electrode pad P is cut by the electrode pad P. This ensures complete contact resistance with aluminum and ensures good conduction with the electrode pad P. If the inspection is performed in this state, signals can be reliably transmitted and received between the protruding contact 13 and the electrode pad P, and a highly reliable inspection can be performed.
[0018]
As described below, according to the present embodiment, the protruding contact 13 of the probe card 10 is formed of ore such as diamond, sapphire, quartz or the like having a hardness higher than that of the electrode pad P, and a flat surface 13A is formed at the tip. Therefore, the shearing force acts on the electrode pad P from the edge of the flat surface 13A of the projecting contact 13 by a simple operation in which the projecting contact 13 is in pressure contact with the electrode pad P. P can be cut and bitten, and the peripheral surface of the protruding contact 13 can be in close contact with the solid aluminum of the electrode pad P to perform a highly reliable inspection. Further, in the present embodiment, since only the operation of overdriving the main chuck is sufficient, the operation of the main chuck is simple and its control is easy, and the protruding contact 13 does not rub against the electrode pad P. Abrasion resistance is greatly improved and life is extended.
[0019]
Compared with this, in the case of the conventional probe card shown in FIG. 7, the tip of the protruding contact 3 is round, so that it is sufficiently bite into the electrode pad P by simply overdriving the main chuck. First, the main chuck is moved laterally in the X or Y direction. Thus, even if the protruding contact 3 bites in, the tip thereof is round, so that sufficient contact resistance with the electrode pad P cannot be ensured.
[0020]
The contacts of the probe card 10 of the present invention may be those shown in FIGS. 4 (a) and 4 (b) to 5 (a) and 5 (b). The protruding contact 23 shown in FIGS. 4A and 4B is formed in a truncated cone shape, and the protruding contact 33 shown in FIGS. 5A and 5B is a quadrangular pyramid. It is formed in a trapezoidal shape and further has a screw blade formed on its peripheral surface. In particular, the protruding contact 33 shown in FIG. 5 bites into the inner peripheral surface of the electrode pad P with a screw blade, and the contact area is greatly increased, so that a more reliable inspection can be performed. .
[0021]
The present invention is not limited to the above embodiments. For example, the shape of the protrusion-like contactor may be any shape as long as it is gradually formed from the base end portion to the tip end portion and a flat surface is formed at the tip end. Moreover, although each said embodiment demonstrated what the protruding contact was comprised from the base | substrate part which consists of ores, such as diamond, and the electrically conductive film which coat | covers the surface, a base | substrate part has hardness higher than an electrode pad. If a conductive metal is used, the conductive film is not necessarily provided.
[0022]
【The invention's effect】
According to the first to third aspects of the present invention, sufficient contact resistance between the protruding contact and the electrode can be obtained by a simple operation of merely pressing the protruding contact and the electrode of the object to be inspected. Therefore, it is possible to provide a membrane type probe card that can perform a highly reliable inspection and is excellent in wear resistance.
[Brief description of the drawings]
FIG. 1 is an enlarged view of a part of an embodiment of a probe card according to the present invention. FIG. 1 (a) is a partial sectional view showing an essential part, and FIG. It is a fragmentary perspective view shown.
FIG. 2 is an enlarged cross-sectional view showing a configuration of a protruding contact shown in FIG.
3 is an operation explanatory view of a protruding contact of the probe card shown in FIG. 1. FIG.
4A and 4B are enlarged views showing a protruding contact according to another embodiment of the probe card of the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a side view.
5A and 5B are enlarged views showing a protruding contact according to still another embodiment of the probe card of the present invention, where FIG. 5A is a plan view and FIG. 5B is a side view.
FIG. 6 is a cross-sectional view corresponding to FIG. 1 showing a conventional membrane type probe card.
7 is an operation explanatory view of a protruding contact of the probe card shown in FIG. 6. FIG.
[Explanation of symbols]
10 Probe card 11 Membrane (membrane member)
12 wiring patterns 13, 23, 33 protruding contact 13A flat surface

Claims (3)

A substrate and a projecting contact formed on the surface of the substrate , and the projecting contact and the electrode of the object to be inspected are in electrical contact to inspect the electrical characteristics of the object to be inspected; In the probe card to be performed, the protruding contact is formed so as to be gradually narrowed from the base end portion to the tip end portion and has a flat surface at the tip end , and a screw blade is provided on the peripheral surface of the contact piece. A probe card characterized by that.   The probe card according to claim 1, wherein the contact is formed of a material having a hardness higher than that of the inspection electrode. The probe card of claim 1 or claim 2, characterized in that the formation of the contacts in the truncated cone or truncated pyramid.

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