JP2000111577A - Probe card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To install a more number of probes than in the existing system, to keep the size of the probe constant, and to improve electrical characteristics by bringing one edge part of the probe into contact with one contact of an element to be measured, and by stopping deformation before the probe reaches an elastic deformation limit. SOLUTION: On an insulation substrate 1, a body 2 of a probe with elasticity is formed. At an edge 3 of the probe, a material with high hardness such as tungsten is jointed, and electric wiring 4 is formed. When needed, thousands of probes or more are formed. In an element 6 to be measured, a contact 5 is formed on the surface. In this case, when a working shelf where the element 6 to be measured is fitted is moved upward or a head plate where the body 2 of the probe is fixed is lowered, and the contact 5 of the element to be measured is brought into contact with the edge of 3 of the probe, the body 2 of the probe is subjected to elastic deformation. After that, when electrical measurement is advanced for completing, the body 2 of the probe is restored to its original shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a vertical probe card which is a kind of a probe card used for electrical inspection of a small electronic device, and a method of manufacturing the same. The present invention relates to the manufacture of a probe card (for example, a vertical micro probe card) for measuring the electrical characteristics of a manufactured electronic device.

[0002]

2. Description of the Related Art Generally, semiconductor integrated circuit devices (semi
conductor integrated circ
electric circuit elements (select devices)
In manufacturing a circuit device, a device is manufactured such that its overall or partial electrical characteristics are consistent with the design during the device fabrication process, after fabrication, and before attaching a lead frame. Will be tested. The equipment used for such a test is the probe equipment.
on), and a schematic diagram thereof is presented in FIG. A probe card is mounted on this equipment, and the probe card includes a measuring device for various electric signals in the probe equipment and a semiconductor wafer (wa) to be measured.
fer) and serves to connect electrical contacts (Pad) on one or more devices formed on the fer. The structure of the probe card is composed of two parts. One is a circuit board 12 on which a circuit for supporting the probe structurally and connecting the probe equipment and the probe is formed, and the other is a probe 13 attached to the substrate, and this probe is As shown in FIG. 8, it comes into direct contact with the element 6 to be measured.

[0003] The probe card is a headboard (HE
(AD PLATE) 10 attached to the lower surface of the insertion ring. A work shelf 14 is located below the probe card, and the work shelf is manufactured so as to be movable three-dimensionally in a horizontal direction (X and Y axis directions) and a vertical direction (Z axis direction). The measurement target element 6 is placed on this work shelf.

[0004] The measurement starts by fixing the priority measurement target element to the work shelf. Thereafter, the work shelf is moved in the X-axis direction and the Y-axis direction, and the probe of the probe card is arranged on the contact 5 of the element to be measured. Thereafter, the probe 13 is moved downward or the work shelf 14 is moved upward along the Z-axis direction so that contact between the probe and the contact 5 of the element to be measured occurs. Thereafter, the probe equipment generates an electrical signal for measuring the electrical characteristics of the element, and the electrical signal is transmitted through a so-called pogo pin (symbol 11) to the fixed substrate 12 of the probe card. Is transmitted to This signal travels from the circuit board to the probe and from the probe to the element to be measured through electrical wiring connected from the circuit board to the tip of the probe 13. Thereafter, the electrical response signal coming out of the element moves in the reverse order of the above order and is transmitted to the probe equipment.

The existing methods shown in FIGS. 7 and 8 are referred to as a horizontal type or a tungsten needle type. This method is a method in which a tungsten needle 13 having a sharpened end is fixed to a frame, and the tip is brought into contact with the contact 5 of the element to be measured to perform the measurement. However, the electrical contacts of recent semiconductor devices have become very small, and tens of contacts having a size of several tens of micrometers or less may be arranged at intervals of several micrometers per device. In the case of such an existing system,
Since the thickness of the tungsten needle used as a probe is in the range of several hundred micrometers, depending on the conventional probe,
It is impossible to measure adjacent contacts or measure all desired circuit patterns. Further, since the size of the contact is small, it is also difficult to install the probe so as to accurately contact a specific position of the fine contact.

The vertical system has been developed to improve such a point. In the vertical method, fine probes are arranged on the substrate, so many probes can be arranged at narrow intervals, and the probe length is short, so the electrical characteristics of the fabricated probe card are excellent. ing.

An important point in manufacturing the vertical probe is that all the installed probes should be in contact with the electrical contact (Pad) of the element to be measured. For this purpose, each probe pushes the contact with a pressure equal to or higher than a specific value so that the contact with the contact can be compensated, and the tips of the manufactured probes are arranged very evenly. The flatness must be excellent, and each probe must have a certain degree of elasticity or more. If the probe has elasticity and can be elastically deformed, if there is a small error in the flatness of the tip of the probe, or if there is an error in the position of the contact point of the element to be measured, for example, the element is formed. The required electrical measurements can be performed using a probe card even when the semiconductor wafer is not perfectly flat and slightly twisted. No. 4,961,052, U.S. Pat. No. 5,172,050, and U.S. Pat.
No. 3,347.

[0008]

However, since the existing probe card has a large and long probe, there is a problem that the arrangement coefficient and the position are limited, and the electric characteristics are not good. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a new type of probe card in which a large number of probes are installed according to an existing method, the size of the probes is kept constant, and the electrical characteristics are improved.

The present invention produces a vertical probe having the required mechanical properties, for example, appropriate elastic deformation and mechanical strength, and moves the probe to an appropriate position on a substrate. Provide a probe card attached at a density.
The probe attached to the probe card must be able to measure the electrical characteristics of the device under test by contacting the electrical contacts of the device under test. At this time, there should be no leakage current between the probes. Also, the probe must be restored to its original form after measurement, and must not deform during the fixed life of the card (eg, 300,000 contacts).

[0010]

For this purpose, there is provided a probe card for measuring the electrical characteristics of the device under test by bringing a plurality of probes into contact with the contacts of the device under test. A fixed and electrically insulated insulating substrate, a plurality of protruding probes fixed on the insulating substrate, having elasticity, and having a sharp end, and formed from the probe to the circuit board via the insulating substrate. The probe is manufactured by a method in which a pattern is defined by an optical lithography method, and then only a portion defined in the pattern is etched by an etching (etching) method. The two tips contact one contact of the device under test, and the insulating substrate provides a probe card that limits the deformation of the probe to stop before it reaches its elastic deformation limit.

A probe card for contacting a contact of a device to be measured and measuring an electrical characteristic thereof, comprising: a substrate made of an insulating material; a tip fixed to the substrate and in contact with a contact of the device to be measured. A probe part made of a semiconductor material, and a body made of a conductor and fixed to the probe part and transmitted from a contact point of the element to be measured. A probe card is provided that includes a wiring portion that conducts a signal and an electric signal transmitted to a contact point of a device to be measured.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example to which the present invention is applied. This probe card is manufactured by forming a probe 2 having elasticity on an insulating substrate 1, bonding a material 3 having a high hardness such as tungsten to a tip of the probe, and then forming a wiring 4. . Although only two probes are shown in FIG. 1, thousands or more probes can be formed as necessary. FIG. 2 is a side view of FIG. The element 6 to be measured has a contact 5 on its surface. At this time, the work shelf on which the element to be measured is mounted moves upward, or the head plate to which the probe is fixed descends, and the contact 5 contacts the tip 3 of the probe. The elastic deformation occurs as shown in FIG. Thereafter, the electrical measurement proceeds, and after the measurement is completed, the probe is restored to its original shape as shown in FIG.

The general manufacturing method is as follows.

For example, a single crystal silicon wafer (sin
gle crystal silicon wafer
r) Photolithography (photolithography)
After defining the pattern of the probe forming area using the HOG, the wet etching method is used.
Alternatively, unnecessary portions of the probe material are removed using dry etching. Thereafter, the probe material partially etched on a substrate made of a material such as glass or ceramic is, for example, melt-bonded (fusi).
on bonding or electrical bonding (anodi)
Bonding using c bonding or the like. Thereafter, an unnecessary portion of the probe material is wet-etched to form a tip portion and a main body portion of the probe.
Alternatively, the shape of the probe may be manufactured by removing it several times using dry etching. On the basic shape of the manufactured probe, a sputtering method (sputtering) and an evaporation method (evaporator) are applied.
) or chemical vapor deposition (chemica)
An electrically conductive layer and an electrically insulating layer are deposited using l vapor deposition (CVD) or the like, and an electrical circuit is formed using optical lithography and etching. The formed circuit includes a grounded wiring at an appropriate position to minimize electrical interference, and an insulating film and a conductive film may be formed above or below the circuit portion as necessary.
The tip 3 of the probe manufactured as shown in FIG.
That is, a material having a high hardness, for example, a tungsten film can be deposited on a portion of the device to be measured which is in contact with the contact. Alternatively, the tip 3 of a separate probe made of tungsten, that is, the portion that comes into contact with the contact point of the element to be measured,
If necessary, a material having high hardness, for example, a tungsten film can be deposited. Alternatively, the tip of the probe may be separately manufactured from tungsten and attached to the probe by a method such as welding.

A detailed example of the probe manufacturing method of the present invention is as follows.

A silicon oxide thin film or a silicon nitride thin film is formed on a silicon wafer having a <110> crystal direction by polishing both sides (polishing) by thermal decomposition chemical vapor deposition (thermal CVD) or physical vapor deposition (PV).
D), deposition using a method such as plasma enhanced chemical vapor deposition (PECVD), and photolithography.
Then, the pattern of the probe forming region is defined and etched by using the same as a mask for silicon etching. Anisotropic wet etching using KOH solution (a
The silicon layer is vertically etched to a depth of 5 to 500 micrometers using a nisotropic method. At this time, the etching depth may be larger or smaller than the height of a probe tip described later,
In order to eliminate the possibility that other parts except the tip of the probe hit the element to be measured, it is advantageous that the height is lower than the height of the probe. Thereafter, the etched surface of the silicon is brought into contact with a glass substrate, and then a pressure of 1 to 5 atm is applied to increase the humidity to 300 to 600 ° C.
And fusion bonding of silicon and glass substrate (fusi
on bond). Or, if the temperature is
After the temperature was raised to 00 ° C., a voltage of 100 V to 2000 V was applied so that a current of 1 mA to 100 mA flowed, and the silicon and the glass substrate were electrically bonded (anodic bond).
d) It is also possible. Immediately after bonding, the side surface formation of the element being manufactured is the same as in FIG. 4, and the etched portion 7 remains in the empty space. After the bonding, if the thickness of the bonded silicon is more than necessary, the side surface 21 opposite to the bonding surface 20 of silicon is polished to match the required thickness. The thickness of the silicon is determined according to the size of the probe to be manufactured. Then, a silicon oxide thin film or a silicon nitride thin film is formed on the side surface 21 of the bonded silicon by thermal decomposition chemical vapor deposition, physical vapor deposition, plasma chemical vapor deposition (Plas).
A method such as ma enhanced CVD) is used for the deposition, and the pattern of the probe tip forming region is defined and etched by an optical lithography method. The etched silicon oxide thin film or silicon nitride thin film is masked with a silicon etching mask (mas).
k), the tip 3 of the probe is made by vertically removing the silicon layer at a depth of 5 to 500 micrometers using an anisotropic wet etching method using a KOH solution. . Thereafter, a silicon oxide thin film or a silicon nitride thin film is entirely deposited by using a method such as thermal decomposition chemical vapor deposition, physical vapor deposition, or plasma chemical vapor deposition, and the probe main body forming area is formed using optical lithography. The pattern 2 is defined and etched to manufacture the main body 2 of the probe. The etching process is performed by vertically etching the silicon layer to a depth of 5 to 500 micrometers using, for example, an anisotropic wet etching method using a KOH solution. Through the above steps, the basic form of the probe is manufactured. On the other hand, in order to increase the electric conductivity of the probe, boron (boron) or phosphorus (p
hosthorus) by ion implantation (ion impl)
The step of adding the silicon probe to the silicon probe may be performed by a method such as an annealing method or a heat treatment method. Thereafter, wiring is formed from the tip 3 of the probe to the insulating substrate 1 by using a conductor deposition method such as a sputtering method, an evaporation method, or a chemical vapor deposition method and optical lithography. The wiring may be formed on the surface of the insulating substrate on which the probe is provided or on the surface opposite to the side surface on which the probe is provided, and may be penetrated through the insulating substrate or formed in multiple layers therein. The completed probe is adhered to the circuit board while being attached to the insulating substrate. There are various methods for connecting the circuit board and the wiring formed on the insulating substrate, and two examples are shown in FIGS. 5 and 6. FIG. 6 shows a method of forming a hole that penetrates an insulating substrate, filling the inside with a conductor, and connecting a wire. In FIG. 5, a wire is formed on the probe and the insulating substrate, and the wire is directly bonded to the wire (wire bob).
nding).

[0017]

As described above, according to the present invention, a probe having a very uniform height and precisely arranged probes can be set on a flat substrate, and the electric power of a large number of semiconductor elements can be reduced. Characteristic can be simultaneously and accurately measured.

Further, according to the present invention, since the length of the probe is short and the size of each probe is constant, it is possible to manufacture a probe card having excellent electric characteristics.

Further, according to the present invention, when the fabricated probe is made of single crystal silicon, it has very excellent elastic properties and restoring force, so that it can be fired during use (p.
There is an effect that almost no deformation occurs and the life of the probe card is extended.

[Brief description of the drawings]

FIG. 1 is a perspective view of a probe card of the present invention.

FIG. 2 is a side view of the probe card of the present invention.

FIG. 3 is a side view of a shape that is elastically deformed when the probe card of the present invention is used.

FIG. 4 is a side view showing a form in which a silicon wafer is first etched and then attached to an insulating substrate.

FIG. 5 is a diagram illustrating an example of connecting wires.

FIG. 6 is a diagram showing another example of connecting wires.

FIG. 7 is a schematic view of a probe device according to the related art.

FIG. 8 is an enlarged perspective view of a probe portion of a probe device according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating substrate 2 ... Probe main body 3 ... Tip of a probe 4 ... Electrical wiring 5 ... Contact of a device to be measured 6 ... Device to be measured 7 ... Cavity formed at the time of manufacturing the probe 8 ... Connected to the probe Electrode 9: gold (go1d) electric wire joined to the probe by wire joining method 10: probe-equipped head plate 11: pogo pin 12: circuit board 13: tungsten needle 14: work shelf

Continued on the front page (72) Inventor Ahn Yong-Gyeum Republic of Korea, Gyeonggi-do, Seongnam, Bun-dang, Yatapdong 266, Dongsinvila 904-403 (72) Inventor John Sam Wong Republic of Korea, Seoul, Seoul, Seoul, Songpag, Sinchondong , Missung Apartment 1-803 (72) Inventor Song Byung Chan South Korea, Seoul, Tokbyul, Gwang-Ak Kg, Boncheong-dong, Gwang-Ak Hyun De-Apartment 111-1401 (72) Inventor John Hapun South Korea, Gyeonggi-do, Suwon City, Gongsong, Homesildon, Elsie Samui Apartment 110-801

Claims (12)

[Claims] 1. A probe card for contacting a plurality of probes with a contact point of a device to be measured and measuring electrical characteristics of the device to be measured, the probe card being fixed on a circuit board and electrically insulated. An insulating substrate, a plurality of protruding probes fixed on the insulating substrate, having elasticity, and having a sharp end; and a conductive member formed from the probe through the insulating substrate to the circuit board. The probe includes a wiring portion, and the probe is formed by defining a pattern by an optical lithography method, and then etching by leaving only a portion defined in the pattern by an etching method, and one tip of the probe is measured by the measuring method. A probe card in contact with one contact of a target element, wherein the insulating substrate restricts the probe from stopping deformation before reaching the elastic deformation limit. 2. A probe card for contacting a contact point of a device to be measured and measuring an electrical characteristic of the device to be measured, wherein the substrate is made of an insulating material; A tip portion, which is in contact with the contact point of the element, includes a body portion connected to the tip portion and supporting the tip portion, a probe portion made of a semiconductor material, and a conductor, which is fixed to the probe portion. A probe card, comprising: a wiring portion for conducting an electric signal transmitted from a contact of the measurement target element and an electric signal transmitted to a contact of the measurement target element. 3. The probe card according to claim 1, wherein the probe is made of single crystal silicon. 4. The probe according to claim 3, wherein an impurity is implanted into the single crystal silicon by an ion implantation method or a thermal diffusion method in order to improve the electric conductivity of the probe. Needle card. 5. The probe card according to claim 1, wherein the probe is fixed to the insulating substrate by a fusion bonding method or an electric bonding method. 6. The probe card according to claim 1, wherein the insulating substrate is made of glass or ceramic. 7. The probe card according to claim 1, wherein the probe is manufactured using a wet etching method or a dry etching method together with an optical lithography method. 8. The probe card according to claim 7, wherein the dry etching is performed by reactive ion etching or isotropic dry etching. 9. The method according to claim 1, wherein the conductive wiring is deposited by sputtering, chemical vapor deposition, or sublimation deposition, and is patterned using an etching method or a lift-off method together with an optical lithography method. The probe card according to 1 or 2. 10. The probe according to claim 1, wherein the plurality of probes are structurally and electrically separated from each other, and are bonded to a substrate made of a material different from a probe material. Needle card. 11. The probe card according to claim 1, wherein the tip of the probe is plated with tungsten or tungsten silicide. 12. The probe card according to claim 1, wherein a tip of the probe is made of tungsten and is attached to the probe.