JP3072423U - Probe tip cleaning sheet - Google Patents

Abstract

(57) [Summary] [Object] To remove foreign matter without changing the shape of the tip of the probe, and to prevent new foreign matter from adhering to the tip of the probe. A probe tip cleaning sheet for removing foreign matter adhering to the tip of a probe, comprising: a cleaning thin film having fine abrasive adhered to a surface thereof;
An elastic sheet 120 having elasticity provided below the cleaning thin film 110 and a substrate 130 provided below the elastic sheet 120 are provided. The cleaning thin film 110 applies a predetermined load to the tip of the probe 211. The elastic sheet 1 is made of a material that is depressed when pressed, but cannot be broken through by the tip of the probe 211.
Reference numeral 20 denotes the cleaning thin film 1 at the tip of the probe 211.
When the probe 211 is pressed with a predetermined load, the portion where the tip of the probe 211 is pressed is made of a material that is depressed.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a probe tip cleaning sheet for removing foreign matter attached to the tip of a probe.

[0002]

[Prior art]

 A probe of a probe card for measuring various electrical characteristics of a semiconductor chip formed on a semiconductor wafer is pressed into contact with a pad of the semiconductor chip (overdrive). For this reason, foreign matter such as aluminum powder scraped off from the pad adheres to the tip of the probe. This foreign matter tends to adhere to the tip of the probe especially in the case of a pad made of an alloy of aluminum and copper. If such foreign matter is not removed from the tip of the probe, conduction failure occurs between the probe and the pad, and electrical contact deteriorates, so that accurate measurement of characteristics becomes impossible. Also, if the probe is left for a long time, the contact resistance tends to increase.

In order to solve such a problem, every time probing is performed a predetermined number of times, the tip of the probe is cleaned to remove foreign matter. For this cleaning, a method using a ceramic plate and a method using a probe tip cleaning member that pierces the tip of the probe are known.

In the above method, that is, a method using a ceramic plate, a ceramic plate having the same shape as a semiconductor wafer is used. That is, the tip of the probe is overdriven on the ceramic plate as in the case of probing, and foreign substances such as aluminum powder are removed from the tip of the probe.

In the latter method, that is, in the probe tip cleaning member, the tip of the probe is cleaned by piercing the tip of the probe into the probe tip cleaning member.

[0006]

[Problems to be solved by the invention]

 However, the former method, that is, the cleaning of a probe using a ceramics plate, has the following problems. That is, when cleaning is performed a plurality of times, the tip of the probe is shaved. The tip of the probe is generally formed in a spherical shape so as to make smooth contact with the pad, but this tip is polished by a ceramic plate, and as a result, becomes flat. It is impossible for a probe with a flat tip to make smooth contact with the pad, causing problems such as a change in contact resistance and an increase in the amount of pad shaving. As described above, it is difficult for a semiconductor device manufacturer as a user to repair a probe having a flattened tip, and only a probe card manufacturer can do so. Therefore, users had to discard the flattened probe or ask the probe card manufacturer for correction.

In the latter method, that is, a method using a probe tip cleaning member, cleaning can be performed while maintaining the shape of the tip of the probe, that is, a spherical shape. However, the base material of the probe tip cleaning member is provided on the tip of the probe. For example, silicon rubber or urethane rubber may adhere. That is, although foreign matter adhering from the pad can be removed by cleaning, new foreign matter may adhere to the tip of the probe. In addition, since foreign matter such as aluminum powder removed from the tip of the probe remains inside the probe tip cleaning member and the ability to remove the foreign matter decreases, cleaning cannot be performed at the same location every time. Therefore, it is necessary to shift the position of the probe tip cleaning member every time cleaning is performed.

The present invention has been made in view of the above circumstances, and can remove foreign matter without changing the shape of the tip of the probe, and does not cause new foreign matter to adhere to the tip of the probe. It is intended to provide a probe tip cleaning sheet.

[0009]

[Means for Solving the Problems]

 The probe tip cleaning sheet according to the present invention is a probe removal cleaning sheet that removes foreign matter attached to the tip of the probe, and is approximately the same as or similar to the material forming the probe or the cleaning thin film having fine abrasive material fixed to the surface. A cleaning metal thin film made of a metal having a higher hardness and having a rough surface, an elastic sheet provided under the cleaning thin film or a cleaning metal thin film, and an elastic sheet provided under the cleaning metal thin film; And a substrate provided in a lower layer.

In addition, the cleaning thin film or the cleaning metal thin film is made of a material which is depressed when the tip of the probe is pressed with a predetermined load, but is not broken through by the tip of the probe. When the tip of the probe is pressed against the cleaning thin film or the cleaning metal thin film with the above-mentioned predetermined load, the portion where the tip of the probe is pressed is made of a concave material, and the substrate is formed by cleaning the tip of the probe with the cleaning thin film or the cleaning thin film. It is made of a material having rigidity that is not affected by the depression of the elastic sheet even when pressed against the metal thin film with the predetermined load.

[0011]

[Embodiment of the invention]

 FIG. 1 is a schematic explanatory view of cleaning a probe using a probe tip cleaning sheet according to an embodiment of the present invention, and FIG. 2 is a drawing of a probe tip cleaning sheet according to an embodiment of the present invention. FIG. 3A is a schematic enlarged cross-sectional view, FIG. 3B is a schematic plan view, and FIG. 3 illustrates cleaning of a probe using a probe tip cleaning sheet according to an embodiment of the present invention. FIG. 4 is a schematic view of a probe tip cleaning sheet according to another embodiment of the present invention, wherein FIG. 4A is a schematic enlarged sectional view, and FIG. 4B is a schematic view thereof. FIG. 5 is a schematic configuration diagram illustrating cleaning of the probe using the probe tip cleaning sheet according to the embodiment of the present invention, and FIG. 6 is a probe tip according to the embodiment of the present invention. Tip by leaning sheet is a schematic illustration showing the shape of the tip of the probe to be cleaned. The dimensional ratios of each part in each drawing are determined by the convenience of drawing, and are completely different from the actual dimensional ratios.

The probe tip cleaning sheet 100 according to the embodiment of the present invention is, as shown in FIG. 1, a probe tip cleaning sheet for removing foreign matter adhering to the tip of the probe 211, and the fine abrasive material 111 has a surface. A cleaning thin film 110 fixed to the substrate, a resilient elastic sheet 120 provided below the cleaning thin film 110, and a substrate 130 provided below the elastic sheet 120.

As shown in FIG. 2, the cleaning thin film 110 is formed by fixing the fine abrasive 111 on the surface of the thin film 112 with an adhesive or the like.

As the fine powder abrasive 111, alumina powder, silicon carbide powder, diamond powder, or the like is used, and the material, size, and the like are appropriately determined according to the material, dimensions, and the like of the probe 211. .

An important point of the cleaning thin film 110 is that the probe 211 has such a rigidity that the tip does not penetrate the cleaning thin film 110 when the probe 211 is pressed with a predetermined load. is there. This is delicately related to the characteristics of the elastic sheet 120 described later. However, when the tip of the probe 211 pierces the cleaning thin film 110, the probe 211 extends to the elastic sheet 120 below the cleaning thin film 110. This is because there is a risk that new foreign matter will adhere to the tip of the probe 211 as in the conventional probe tip cleaning member described above.

The thickness of the cleaning thin film 110 is preferably, for example, 100 μm or less.

On the other hand, the elastic sheet 120 is made of silicon rubber or urethane rubber having a uniform thickness. Here, the elastic sheet 120 has a uniform thickness for the following reason. That is, if the elastic sheet 120 having an uneven thickness is used, the tip of the probe 211 comes into contact with the probe tip cleaning sheet 100 at the time of cleaning of the probe 211, so that the cleaning operation is not performed during the cleaning operation. This is because an excessive load is applied to the probe 211 that has come into contact with the probe 211 first. Therefore, the thickness dimension of the elastic sheet 120 is desirably 1 mm or less.

As described above, the hardness that the elastic sheet 120 should have is delicately related to the characteristics of the cleaning thin film 110, but several grams to several tens of grams per one probe 211. It is desirable that the hardness is such that it is depressed by a load.

That is, the elastic sheet 120 is made of a material having such a hardness that when the tip of the probe 211 is pressed against the cleaning thin film 110 with a predetermined load, the portion where the tip of the probe 211 is pressed is depressed. It is. For example, as described above, silicon rubber, urethane rubber, or the like is used as the elastic sheet 120.

Further, when the elastic sheet 120 is formed of silicon rubber or urethane rubber, there is an advantage that the cleaning thin film 110 does not need to be bonded with an adhesive or the like. That is, only by putting the cleaning thin film 110 on the elastic sheet 120 made of silicon rubber, urethane rubber, or the like and bringing the cleaning thin film 110 into close contact therewith, the cleaning thin film 110 is fixed so as to be attracted to the elastic sheet 120. Therefore, the set is easy. Further, when the cleaning thin film 110 is bonded to the elastic sheet 120 with an adhesive or the like, if there is unevenness in the application of the adhesive or the like, even if the elastic sheet 120 having a uniform thickness is used. Also, irregularities are formed on the cleaning thin film 110 due to the unevenness, which hinders accurate cleaning. However, since no adhesive or the like is used, such a problem does not occur.

The predetermined load for pressing the probe 211 is several grams to several tens of grams per one probe 211, the cleaning thin film 110 is silicon carbide, the elastic sheet 120 is silicon rubber, and the probe 211 is tungsten. In this case, the weight is preferably about 3 to 10 grams.

On the other hand, as the substrate 130, for example, a metal plate, a ceramic plate, a silicon wafer, or the like is used. It is important that the substrate 130 has such a rigidity that it is not affected by the deformation of the elastic sheet 120, that is, the depression when the tip of the probe 211 is pressed.

As described above, the probe tip cleaning sheet 100 formed by laminating the cleaning thin film 110, the elastic sheet 120, and the substrate 130 in this order from the upper layer side has a semiconductor chip to be measured by a proper. It is formed in the same size and the same shape as the semiconductor wafer. Therefore, the thickness of the probe tip cleaning sheet 100 is set to about 0.8 mm to 2.0 mm.

Here, since the probe tip cleaning sheet 100 has the same size and the same shape as the semiconductor wafer on which the semiconductor chip to be inspected is formed, the following advantages are obtained.

First, a semiconductor wafer on which semiconductor chips to be measured are formed is set on a prober in a state where a plurality of semiconductor chips are held in one cassette, and each semiconductor wafer is taken out of the cassette one by one to obtain electrical characteristics. The measurement is performed. For example, if the probe tip cleaning sheet 100 is mixed at a predetermined ratio such as one probe tip cleaning sheet 100 for every 20 semiconductor wafers, the probe 211 Cleaning becomes possible. However, in this case, when the probe tip cleaning sheet 100 is taken out, it is necessary to move the probe 211 up and down a plurality of times unlike normal measurement, but the probe tip cleaning sheet 100 is taken out in advance. This can be done by inputting the order in which the probe 211 is to be input, or by detecting the cleaning sheet 100 at the probe tip by some means and moving the probe 211 up and down only in the case of the cleaning sheet 100 at the probe tip.

Next, cleaning of the probe 211 by the probe tip cleaning sheet 100 configured as described above will be described.

First, a prober 200 using a probe 211 that is cleaned by the probe tip cleaning sheet 100 before that will be described. As shown in FIG. 3, the prober 200 includes a probe card 210, a base portion 220 to which the probe card 210 is attached, and a suction table 230 for fixing a semiconductor wafer on which a semiconductor chip to be measured is formed. It is roughly divided.

The probe card 210 includes a plurality of probes 211 arranged corresponding to the arrangement of the pads of the semiconductor chip, a substrate portion 212 to which the probes 211 are attached, and the probe 211 attached to the substrate portion 212. And a probe support portion 213 for supporting. In the probe card 210, the probe 211 is vertically attached to the substrate section 212, and the tip of the probe 211 comes into vertical contact with the pad. The probe 211 has a substantially horizontal U-shaped curved portion 211A that is deformed when the tip is pressed against the pad and that secures a predetermined contact pressure between the pad and the probe 211. ing. The tip of the probe 211 is formed in a spherical shape as shown in FIG. Further, the probe 211 is formed of tungsten.

A wiring pattern 212 A connected to the probe 211 is formed on the substrate section 212 of the probe card 210, and the probe 211 is connected to a tester (not shown) via the wiring pattern 212 A.

The probe support portion 213 is for preventing the probe 211 from coming into contact with the adjacent probe 211 when the probe 211 is pressed against the pad. Each probe 211 has an independent through hole (not shown). (Omitted).

The suction table 230 provided below the probe card 210 is used to suction-fix not only the semiconductor wafer on which the semiconductor chip to be measured is formed but also the probe tip cleaning sheet 100.

Cleaning of the tip of the probe 211 using the probe tip cleaning sheet 100 by the prober 200 configured as described above is performed as follows. First, the probe tip cleaning sheet 100 is set at a predetermined position instead of the semiconductor wafer, that is, on the suction table 230 below the probe card 210. As for this set, in addition to the method of mixing the probe tip cleaning sheet 100 with the semiconductor wafer at a predetermined ratio as described above, a probe is separately provided from the semiconductor wafer on which the semiconductor chip to be measured is formed. The tip cleaning sheet 100 may be provided on the prober 200 so that the probe tip cleaning sheet 100 is set when the measurement of a predetermined number of semiconductor wafers is completed.

When the probe tip cleaning sheet 100 is set on the suction table 230, one or both of the probe card 210 and the suction table 230 on which the probe tip cleaning sheet 100 is set are moved up and down, and the probe The tip of 211 is repeatedly pressed against the surface of the probe tip cleaning sheet 100.

At this time, an appropriate value is selected as a predetermined load per one probe for pressing the probe 211 against the probe tip cleaning sheet 100 depending on a material of the cleaning thin film 110, the elastic sheet 120 and the probe 211.

As described above, the tip of the probe 211 is pressed against the probe tip cleaning sheet 100, and as shown in FIG. 1, the tip formed by the recess formed in the elastic sheet 120 without breaking through the cleaning thin film 110. Then, the state of being wrapped in the cleaning thin film 110 is repeated.

Since the fine powder abrasive 111 is fixed to the cleaning thin film 110, irregularities are formed on the surface thereof, and foreign matters adhering to the tip of the probe 211 are removed by the irregularities. Further, since the elastic sheet 120 is depressed according to the shape of the tip of the probe 211 by pressing the probe 211, even if the fine abrasive 111 is adhered to the surface of the cleaning thin film 110, the elastic sheet 120 may be a conventional ceramic sheet. It is unlikely that the tip of the probe 211 will be scraped off as described above.

When the cleaning of the probe 211 is completed, the probe tip cleaning sheet 100 is removed from the suction table 230, a new semiconductor wafer to be inspected next is set, and a new semiconductor wafer is formed. Measurements of the electrical characteristics of the semiconductor chip will be performed subsequently.

Further, in the probe tip cleaning sheet 100 described above, the cleaning thin film 110 constituted by adhering the fine powder abrasive 111 to the thin film 112 is used. Alternatively, a metal thin film 140 may be used. The metal thin film 140 for cleaning has a surface of a metal thin film 141 made of, for example, tungsten or the like formed into a rough surface 142 having irregularities by an appropriate means such as sandblasting or etching. Further, it is effective to perform a treatment such as plating the surface with rhodium.

The probe tip cleaning sheet using the cleaning metal thin film 140 has an elastic sheet 120 below the cleaning metal thin film 140 and a substrate 130 below the elastic sheet 120 in the same manner as described above. The elastic sheet 120 and the substrate 130 have the same characteristics as those described above.

Like the cleaning thin film 110 described above, the cleaning metal thin film 140 has such a rigidity that the tip of the probe 211 does not break through the cleaning metal thin film 140 when the probe 211 is pressed. Is important. When the tip of the probe 211 penetrates through the cleaning metal thin film 140, the tip of the probe 211 reaches the elastic sheet 120 under the cleaning metal thin film 140. This is because there is a possibility that new foreign matter may adhere to the tip.

The thickness of the cleaning metal thin film 140 is preferably 5 μm to 50 μm when the material of the cleaning metal thin film 140 is tungsten, and 20 μm to 50 μm when the material of the cleaning metal thin film 140 is palladium. 100 micron meters is desirable.

For example, when the above-described probe tip cleaning sheet 100 is used, the cleaning operation is performed about 10 times against the probe 211 whose tip has a contact resistance of 10Ω due to the attachment of foreign matter, that is, the tip of the probe 211 is pressed. By simply moving the probe 211 up and down, the experimental result was obtained that the contact resistance was reduced to 0.5Ω or less, and the measurement of the electrical characteristics of the semiconductor chips formed on the semiconductor wafer was not hindered. ing.

In the above description, the probe card 210 is an example of a so-called vertical operation type probe card in which the probe 211 is in vertical contact with the pad. However, as shown in FIG. The same applies to a so-called cantilever type probe card whose tip is bent and comes into contact with the pad at an angle. Further, as shown in FIGS. 6B and 6C, a probe 211 having a flat end may be used as long as it is a cantilever type probe card.

[0044]

[Effect of the invention]

 The probe tip cleaning sheet according to the present invention is a probe removal cleaning sheet for removing foreign matter adhering to the tip of the probe, and is provided below the cleaning thin film having fine abrasive particles fixed on the surface thereof and the cleaning thin film. And a substrate provided below the elastic sheet. The cleaning thin film is depressed when the tip of the probe is pressed with a predetermined load, but the cleaning thin film may not be provided depending on the tip of the probe. The elastic sheet is made of a material that does not break through, the elastic sheet is made of a material in which the portion pressed by the probe is depressed, and the substrate presses the tip of the probe against the cleaning thin film with the predetermined load. It is made of a material having rigidity that is not affected by the depression of the elastic sheet.

Accordingly, when the probe is pressed against the probe tip cleaning sheet, the tip of the probe is wrapped in the cleaning thin film, and foreign matter is removed by the fine abrasive adhered to the cleaning thin film. At this time, since the cleaning thin film and the elastic sheet are depressed according to the shape of the tip of the probe, the tip of the probe is not shaved unlike a conventional ceramics plate. Further, since the tip of the probe does not penetrate the cleaning thin film, the material constituting the elastic sheet does not adhere to the tip of the probe as new foreign matter. Therefore, a foreign matter can be removed without changing the shape of the tip of the probe, and a probe tip cleaning sheet can be obtained in which new foreign matter does not adhere to the tip of the probe.

Further, another probe tip cleaning sheet according to the present invention is a probe tip cleaning sheet for removing foreign matter adhering to the tip of the probe, and is made of a metal having the same or higher hardness as the material constituting the probe. A cleaning metal thin film having a roughened surface, an elastic sheet having elasticity provided below the cleaning metal thin film, and a substrate provided below the elastic sheet. The cleaning metal thin film is made of a material that is depressed when the tip of the probe is pressed with a predetermined load but cannot be broken through by the tip of the probe. When the probe is pressed against the thin film with the predetermined load, the tip of the probe is pressed or depressed. The substrate is made of a material having rigidity such that the depression of the elastic sheet is not affected even when the tip of the probe is pressed against the cleaning metal thin film with the predetermined load.

Even with such a probe tip cleaning sheet, when the probe is pressed against the probe tip cleaning sheet, the probe tip is wrapped in the cleaning metal thin film, similarly to the probe tip cleaning sheet described above. Foreign matter is removed by the rough surface of the cleaning metal thin film. At this time, since the metal thin film for cleaning and the elastic sheet are depressed according to the shape of the tip of the probe, the tip of the probe is not shaved unlike a conventional ceramic plate. Further, since the tip of the probe does not penetrate the metal thin film for cleaning, the material constituting the elastic sheet does not adhere to the tip of the probe as new foreign matter. For this reason, a probe tip cleaning sheet in which new foreign matter does not adhere to the tip of the probe can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of probe cleaning using a probe tip cleaning sheet according to an embodiment of the present invention.

2A and 2B are drawings of a probe tip cleaning sheet according to an embodiment of the present invention, wherein FIG. 2A is a schematic enlarged sectional view and FIG. 2B is a schematic plan view.

FIG. 3 is a schematic configuration diagram illustrating cleaning of the probe using the probe tip cleaning sheet according to the embodiment of the present invention.

FIG. 4 is a drawing of a probe tip cleaning sheet according to another embodiment of the present invention, wherein FIG. 4 (A) is a schematic enlarged sectional view and FIG. 4 (B) is a schematic plan view. .

FIG. 5 is a schematic configuration diagram illustrating cleaning of the probe using the probe tip cleaning sheet according to the embodiment of the present invention.

FIG. 6 is a schematic explanatory view showing the shape of the tip of the probe whose tip is cleaned by the probe tip cleaning sheet according to the embodiment of the present invention;

[Explanation of symbols]

 100 Probe tip cleaning sheet 110 Cleaning thin film 111 Fine abrasive material 120 Elastic sheet 130 Substrate 211 Probe

Continuing on the front page (72) Inventor Shinichiro Furusaki 2-5-113, Nishi-Nagasu-cho, Amagasaki-shi, Hyogo Japan Electronic Materials Co., Ltd. (72) Inventor Teruhisa Sakata 2-5-13-Nishi-Nagasu-cho, Amagasaki-shi, Hyogo No. Japan Electronic Materials Co., Ltd.

Claims (2)

[Utility model registration claims] 1. A probe-removing cleaning sheet for removing foreign matter adhering to the tip of a probe, comprising: a cleaning thin film having a fine powder abrasive fixed to a surface thereof; and an elastic sheet provided below the cleaning thin film having elasticity. And a substrate provided below the elastic sheet, wherein the cleaning thin film is made of a material which is depressed when the tip of the probe is pressed with a predetermined load, but is not broken through by the tip of the probe. The elastic sheet is made of a material in which the portion where the probe is pressed is depressed, and the substrate affects the depression of the elastic sheet even when the tip of the probe is pressed against the cleaning thin film with the predetermined load. A probe tip cleaning sheet, which is made of a material having rigidity that will not be removed. 2. A probe tip cleaning sheet for removing foreign matter adhering to the tip of a probe, wherein the cleaning metal is made of a metal having a hardness approximately equal to or larger than a material constituting the probe, and has a rough surface. A thin film, an elastic sheet having elasticity provided below the cleaning metal thin film, and a substrate provided below the elastic sheet. The elastic sheet is made of a material that dents when pressed with a load of the probe, but does not break through by the tip of the probe. The substrate is made of a material that is pressed or depressed, and the substrate is made of a metal thin film for cleaning. A probe tip cleaning sheet, which is made of a material having rigidity such that the depression of the elastic sheet is not affected even if the elastic sheet is pressed against the film with the predetermined load.