KR20090111142A - Resistive conduct line for MEMS probe and method for manufacturing thereof - Google Patents

Abstract

PURPOSE: A resistive conduction line for a MEMS probe and a manufacturing method thereof are provided to perform a stable property at a high temperature of a low temperature co-fired ceramic multilayer substrate. CONSTITUTION: A low temperature co-fired ceramic substrate(100) is prepared, and is sintered under 1000°C. A thick film resistance layer is formed on the low temperature co-fired ceramic substrate. An insulation film(7) is formed on the thick film resistance layer. A thin film conduction line(8) is formed on the insulation film and the thick film resistance layer. The thick film resistance layer is formed on a via hole pillar conductor prepared on a top part of the low temperature co-fired ceramic substrate.

Description

Resistive conduct line for MEMS probes and method for manufacturing the same

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a resistive conductor for a MEMS probe card and a method of manufacturing the same. Particularly, a low temperature cofired ceramic (hereinafter referred to as low temperature co-fired ceramics) substrate surface. The present invention relates to a resistive conductor for a MEMS probe card and a method of manufacturing the same, which easily design the required power power by using Ru ₂ 0 ₃ oxide having stable properties as a resistive conductor.

In general, a probe card used in an electronic device test apparatus is a device including a predetermined substrate and probes arranged on the substrate, and for measuring electrical characteristics of a microelectronic device (for example, a semiconductor device). Used.

The semiconductor device has pads formed on its surface for mutual signal transmission with an external electronic device. That is, the semiconductor device receives an electrical signal through the pads, performs a predetermined operation, and then transfers the processed result back to the external electronic device through the pads. In this case, the probe card forms an electrical path between the semiconductor device and an external electronic device (eg, a tester), thereby enabling electrical testing of the semiconductor device.

Meanwhile, as semiconductor devices are highly integrated, not only the pads of the semiconductor devices are miniaturized, but also the spacing therebetween is decreasing. Accordingly, the probe cards must also be made fine in response to the high integration of the semiconductor device, but the demand for such miniaturization makes the process of manufacturing the probe card difficult.

In other words, as the test equipment for semiconductor IC function test has increased in size and speed due to the development of semiconductor technology, MEMS probes to which a fine probe forming technology using semiconductor MEMS technology is applied in the conventional pin type have become important.

In addition, as the I / O pins of semiconductor ICs increase, probes also require multichannel probes.

When only one channel is shorted when the probe card is applied by the multi-junction pin, if excessive current flows excessively in one channel, a spark defect may occur at the probe terminal, which is a countermeasure.

Therefore, when the probe terminal is connected with a resistive conductive line, excessive current can be prevented from flowing suddenly and thus is applied as a useful method.

1 is a cross-sectional view and a plan view showing a structure of a resistive conductive line for a conventional MEMS probe.

As shown in FIG. 1, the structure of a resistive conductor for a conventional MEMS probe has a conductor 10 and a via filler conductor on an upper surface of a high temperature co-fired ceramics (HTCC) multilayer substrate. (11) is formed, and the thin film resistor 12 and the MEMS probe thin film conductive line 13 are formed on the conductive line 10. The resistance thus formed can control the speed and amount of current excessive current.

In addition, the resistive conductive line is formed by the via filler conductor 11, the thin film resistor 12, and the thin film conductive line 13.

In addition, the high temperature co-fired ceramic (HTCC) multilayer substrate is heat-treated at a temperature of 1500 ° C. or higher to form a multilayer wiring substrate. The insulating material of the high temperature cofired ceramic multilayer substrate uses 94% or more of alumina as a main raw material, a small amount of silica as an additive, and the electrical conductor mainly uses tungsten (W) capable of high temperature firing. High temperature co-fired ceramic multilayer substrates have excellent mechanical strength and chemical resistance properties, and have been applied to high integration packages by forming thin film conductive lines on the substrate surface. However, the electrical conductivity of high-temperature fired tungsten (W) conductors is lower than that of silver (Ag) or copper (Cu), so the disadvantages of high frequency characteristics are poor and the coefficient of thermal expansion is about twice that of silicon semiconductor devices. This is a major problem in these demanding applications.

In addition, since the thin film resistor 12 is connected in series in the X or Y direction to the conventional thin film conductive line 13 for the MEMS probe as described above, the circuit directivity is lowered. Tends to fall even further.

In addition, as shown in FIG. 1, since the thin film resistor 12 is designed to have the same or narrower width as the thin film conductive line 13, it is difficult to apply to a MEMS probe requiring high power.

In FIG. 1, 14 is a bump pad, 15 is an adhesive, 16 is a MEMS probe, and 17 is a probe tip.

Therefore, the present invention uses a low temperature co-fired ceramic (LTCC) multilayer substrate.

The LTCC multilayer substrate is heat-treated at a temperature below 1000 ° C. to form a multilayer wiring substrate. This LTCC multilayer substrate uses a lot of low melting point silica and uses a relatively small amount of alumina for use at low temperature below 1000 ° C. In the LTCC multilayer substrate, silver (Ag) or copper (Cu) having excellent electrical conductivity is used as the electrical conductor material while the firing temperature is 1000 ° C or lower.

However, despite the above advantages, the low temperature cofired ceramic multilayer substrate has a problem in its application to actual products due to the following disadvantages.

In particular, the surface of the low temperature cofired ceramic multilayer substrate is rough, making it difficult to form thin film resistors of tens to hundreds of nm thick.

An object of the present invention is to solve the above-mentioned conventional problems, it is easy to design the power power required using Ru ₂ 0 ₃ oxide having compatibility with LTCC multilayer substrate and LTCC process and stable at high temperature The present invention provides a resistive conductive line for a MEMS probe that can be manufactured and a method of manufacturing the same.

Another object of the present invention is to provide a resistive conducting wire for a MEMS probe and a method of manufacturing the same, which can easily produce resistive conducting wire for a MEMS probe.

In order to achieve the above object, a method of manufacturing a resistive conductive wire for a MEMS probe according to the present invention includes the steps of (a) preparing a low temperature cofired ceramic (LTCC) substrate fired at 1000 ° C. or lower, and (b) the low temperature cofired ceramic substrate. Forming a thick film resistive layer on the film; (c) forming an insulating film on the thick film resistive layer; and (d) forming a thin film conductive line on the insulating film and the thick film resistive layer. do.

In the method for manufacturing a resistive conductive line for a MEMS probe, the thick film resistive layer is formed on a via hole filler conductor provided on the low temperature co-fired ceramic substrate.

In the method for producing a resistive conductive line for a MEMS probe, the thick film resistive layer is formed on a conductive line provided on the low temperature cofired ceramic substrate.

In the method of manufacturing a resistive conductive wire for a MEMS probe, in the step (b), the thick film resistive layer is formed by a printing technique and then fired.

In addition, the method for producing a resistive conductive wire for a MEMS probe, characterized in that it further comprises the step of heat-treating the low temperature co-fired ceramic substrate before the step (b).

In the method of manufacturing a resistive conductive wire for a MEMS probe, the insulating film is a high dielectric material such as Al ₂ O ₃ , HfO ₂ , TiO ₂ , ZrO ₂ , Y ₂ O ₃ , Ta ₂ O ₅ , La ₂ O _3, or the like. It characterized in that the (K) (High-k) material.

In the method of manufacturing a resistive conductive line for a MEMS probe, the insulating film may be formed using an ion assistant PVD method, a PVD method using an E-Beam Evaporation technology, a PLD (Plus Laser Deposition) method, or the like. It is characterized in that formed in the aerosol deposition (Aerosol Deposition) method.

In the method for manufacturing a resistive conductive line for a MEMS probe, the thick film resistive layer is formed of Ru ₂ O ₃ oxide.

In the method for producing a resistive conductive line for a MEMS probe, the thin film conductive line is made of Ti, Pd, Cu or Al, Cu, Au as a composite metal.

In the method for producing a resistive conductive line for a MEMS probe, the thick film resistive layer, the insulating film, and the thin film conductive line may be formed by a wet etching method or an ion milling method.

In order to achieve the above object, the resistive conductive wire for MEMS probe according to the present invention is a thick film resistive layer formed on a low temperature co-fired ceramic (LTCC) substrate fired at 1000 ℃ or less, an insulating film formed on the thick film resistive layer and the And an insulating film and a thin film conductive line formed on the thick film resistive layer.

As described above, according to the resistive conductive line for the MEMS probe and the manufacturing method thereof according to the present invention, the effect that the power power can be easily designed and manufactured in the electronic device test apparatus is obtained.

Moreover, according to the resistive conducting wire for MEMS probe for MEMS probe card and its manufacturing method which concerns on this invention, the effect which can make it possible to have stable characteristic even at high temperature of LTCC multilayer board | substrate is acquired.

The above and other objects and novel features of the present invention will become more apparent from the description of the specification and the accompanying drawings.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated according to drawing.

2 is a view showing a manufacturing process of the resistive conductive line for a MEMS probe card according to the present invention.

Each process illustrated in FIG. 2 will be described with reference to FIGS. 3 to 12.

As shown in FIG. 3, in the present invention, an LTCC multilayer substrate 100 including N layers is provided (S10). The number of layers may vary depending on the substrate design and the like, and is generally composed of about 20 to 30 layers. At this time, the metal wiring metal used is mostly Ag and the composition can be changed if necessary. More than 60% to 70% of the ceramic material is glass and most of it is made of alumina. The thickness of the substrate is varied according to the customer's requirements, usually 4-7 mm. In Fig. 3, reference numeral 1 denotes a via hole (through hole) formed on the substrate, and reference numeral 2 denotes a conductive line formed in the substrate.

LTCC multilayer substrate 100 is printed by wiring to each of the N green sheets (layer), laminated all the layers are manufactured by simultaneous sintering at 1000 ℃ or less, preferably 850 ~ 900 ℃ about the surface of the substrate Since the and alumina components are separated and bonded to each other, the surface is rough. In order to form a thin film pattern, the substrate surface roughness requires roughness of about 1 μm or less, and thus, a mechanical polishing process is performed. In designing the substrate, it is desirable to form the substrate thicker than the polishing thickness in consideration of the warpage of the substrate, and then perform polishing. Usually, polishing is carried out at about 50 to 100 µm. Thereafter, the substrate surface is thermally annealed (S20).

Next, as shown in FIG. 4, a conductive line 3 and a via hole filler conductor 4 are formed on the LTCC multilayer substrate 100, and Ru ₂ 0 having stable characteristics as shown in FIG. 5. ₃ oxide is formed as the thick film resistive layer 5.

The thick film resistive layer 5 is formed by printing and then fired (S30).

Next, a high dielectric material such as Al ₂ O ₃ , HfO ₂ , TiO ₂ , ZrO ₂ , Y ₂ O ₃ , Ta ₂ O ₅ , La ₂ O _3, or the like is formed on the conductive line 3 and the thick film resistive layer 5. After surface cleaning to form an insulating film, which is a high-k material, laminating a dry PR photoresist (PR) on both sides of the substrate using a laminator equipment Step 1 is executed (S40). At this time, the pressure, temperature and speed of the laminator must be adjusted well to remove the pores. If pores occur in the PR, they must be reworked. It is important to make the PR as thick as possible. Generally 120 micrometers or more are used.

The process illustrated in FIG. 6 is a UV exposure process 1 (S50), for forming a pattern by irradiating light of a photosensitive agent. Mask1 is a process of designing a mask 1 pattern so that the light-receiving part is polymerized, and for example, by using a dual exposure equipment to sensitize the photoresist. Important variables here are the power of the UV light source and the exposure time. If the power of the light source is strong and the exposure time is long, it becomes under-develop and a larger pattern is formed than the desired pattern.If the UV light source is weak and the exposure time is short, it becomes over-develop. A pattern smaller than the desired pattern is formed.

The process shown in FIG. 7 is the development 1 process (S60), and the pattern 6 of the photosensitive agent is formed on a part of the surface of the thick film resistive layer 5. The formation of the pattern 6 enables the accurate pattern 6 to be obtained in a shorter time by spraying the developing solution through the nozzle on the substrate. Important variables here are the concentration of the developer, the temperature, the pressure of the injection being sprayed and the belt speed of the conveyor. If the variables of concentration, temperature, pressure and speed of the solution are not well controlled, it is difficult to obtain an accurate pattern.

Afterwards, if the residue of the photoresist on the developed substrate remains on the substrate, since the formation of an insulating film on the surface of the substrate is difficult, plasma equipment is used to remove traces of photosensitive residue remaining on the substrate. To perform a decom under vacuum O ₂ plasma gas. Here, the discom refers to an operation of additionally removing a small amount of photoresist residue remaining after the developing operation is not removed.

Next, a step of forming the insulating film 7 on both sides on the LTCC multilayer wiring board shown in FIG. 8 is performed (S70). The LTCC substrate contains a large amount of voids, and the chemical resistance is bad because the surface of the substrate is composed of a glass component. To compensate for this drawback, alumina and stabilized zirconia films with excellent insulation are formed on the LTCC substrate surface. In the present invention, Al ₂ O ₃ , ion assist PVD method, PVD method, PLD (Plus Laser Deposition) method or aerosol deposition method (Aerosol Deposition method) with a fast deposition rate. A stabilized ZrO ₂ or TiO ₂ film was formed at 5-10 μm. Preferably, an aerosol deposition method is used. At this time, the substrate temperature is room temperature, and the density of the carrier gas (He, O ₂ ), the pressure in the vacuum chamber and the structure and shape of the nozzle are well controlled to improve the density of the insulating film 7.

9 is a step (S80) of removing the insulating film 7 on the pattern 6 and PR as a photosensitive agent for the opening of the thick film resistive layer 5. The insulating film 7 is removed by mechanical scrubbing, and then removed using a PR strip device. In the PR strip, it is easy to remove PR by controlling the concentration of the stripper solution and the nozzle pressure well and simultaneously supplying ultrasonic waves. At this time, the control of the ultrasonic power is very important.

The process shown in FIG. 10 is a process (S90) for depositing the thin film conductive line 8 on the thick film resistive layer 5 and the insulating film 7. In order to improve the adhesion between the thin film conductive line 8 and the insulating film 7 and the thick film resistor 5, a Ti or Al metal layer having excellent adhesion is deposited by sputtering at a thickness of 2000 kPa to 5000 kPa, preferably 3000 kPa. And a Pd (palladium) metal layer serving as a barrier between the Cu layers directly on the Ti or Al metal layer is formed from 50 kPa to 200 kPa, preferably about 70 kPa, and finally the Cu metal layer, which is the main conductive wire, is 2500 kPa to 10000 kPa, preferably The film is formed over 9000 GPa to form a base metal layer.

Thereafter, a lamination process of coating the photosensitive agent for forming the thin film conductive line 8 on both sides of the substrate is performed (S100). The photoresist used in this case uses a PR of the same form or different form as the lamination 1 process depending on the type of the pattern or the working conditions.

Next, as the UV exposure 2 process (S110), a dry negative photosensitive agent is used, so that Mask 2 having a mask pattern different from Mask 1 is used. The working variable is the same as the UV exposure 1 condition, but the working condition has a different value depending on the PR thickness.

Next, PR developing process of the photosensitive agent is performed (S120). The developer equipment can use the same equipment and the working conditions are different.

Thereafter, if necessary, a PR decom process removes the remaining PR residues on the surface of the substrate, and this process generally uses an oxygen gas plasma. The thin film conductive line 8 as shown in FIG. 10 is formed by the above process.

In addition, the formation process of the thin film conductive line 8 is a plating process of forming a thick metal film by an electroplating method to thicken the metal wiring film in order to reduce the electrical conductivity of the thin film wiring and the electrical resistance of the high frequency line. In this case, the thin film conductive line 8 is made of Ti, Pd, Cu, and Au or Al, Cu, Ni, and Au as a composite metal. Cu is usually 10 to 25 µm as the main conductive wire, 2 to 4 µm for Ni metal, and less than 5 µm for Au metal. Metal thickness may vary depending on the application. At this time, the Ni metal may be selectively removed. This is because the Ni metal may be removed when the Au metal layer is 5 μm or more, preferably 5 μm to 10 μm to prevent diffusion of the interface between the Cu layer and the Au layer.

As described above, the via hole filler conductor 4, the thick film resistive layer 5, the insulating film 7 and the thin film conductive line 8 are completed for the resistive conductive line for the MEMS probe according to the present invention.

Next, as shown in FIGS. 11 and 12, the bump pad 14, the adhesive 15, the MEMS probe 16, and the probe tip 17 are used for the electronic device test apparatus according to the present invention. The probe card is completed.

Also, in the process of forming the thick film resistive layer 5, the insulating film 7, and the thin film conductive line 8, a wet etching method or an ion milling equipment using a chemical solution, and Ar, Xe or another Dry etching using a reactive gas may be used.

In order to remove by a wet etching method, a metal etching solution is selectively sprayed on both sides of the substrate by a spray method, and D.I water washing and drying are performed.

Under the wet etching method, an undercut phenomenon occurs, and in the case of a high-frequency component, an ion milling method capable of reducing the undercut phenomenon can form a high precision microstrip line. However, the dry etching method of ion milling is disadvantageous in that the equipment is expensive, but it is an essential process technology for producing precision parts.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

The present invention is used for a probe card used in an electronic device test apparatus.

1 is a cross-sectional view and a plan view showing a structure of a resistive conductive line for a conventional MEMS probe;

2 is a view showing a manufacturing process of the resistive conductive line for a MEMS probe according to the present invention;

3 to 12 show each process shown in FIG.

Claims (18)

(a) preparing a low temperature co-fired ceramic (LTCC) substrate fired at 1000 ° C. or less, (b) forming a thick film resistive layer on the low temperature cofired ceramic substrate, (c) forming an insulating film on the thick film resistive layer, and (d) forming a thin film conductive line on the insulating film and the thick film resistive layer. The method of claim 1, And the thick film resistive layer is formed on a via hole filler conductor provided on the low temperature cofired ceramic substrate. The method of claim 2, The thick film resistive layer is a method of manufacturing a resistive conductive line for a MEMS probe, characterized in that formed on the conductive line provided on top of the low temperature co-fired ceramic substrate. The method of claim 3, wherein In the step (b), the thick film resistive layer is formed by a printing method and the method of manufacturing a resistive conductive line for a MEMS probe, characterized in that the firing. The method of claim 4, wherein The method of manufacturing a resistive conductive line for a MEMS probe, further comprising the step of heat-treating the low temperature co-fired ceramic substrate before the step (b). The method of claim 5, The insulating film is made of a high-k material, which is a high dielectric material such as Al ₂ O ₃ , HfO ₂ , TiO ₂ , ZrO ₂ , Y ₂ O ₃ , Ta ₂ O ₅ , La ₂ O _3, etc. Method of making resistive conductors for MEMS probes. The method of claim 6, The insulating layer is formed by an ion assistant PVD method, a PVD method, an E-Beam Evaporation technology, a PLD (Plus Laser Deposition) method, or an aerosol deposition method, which has a high deposition rate. A method for producing a resistive conductor for a MEMS probe. The method according to any one of claims 1 to 7, The thick film resistive layer is a method of manufacturing a resistive conductive wire for MEMS probes, characterized in that formed of Ru203 oxide. The method of claim 8, The thin film conductive line is a composite metal, Ti, Pd, Cu or a method for producing a resistive conductive line for MEMS probes, characterized in that consisting of Al, Cu, Au. The method of claim 9, The thick film resistive layer, the insulating film and the thin film conductive line is a method of manufacturing a resistive conductive line for a MEMS probe, characterized in that formed by a wet etching method or an ion milling method. A thick film resistive layer formed on a low temperature cofired ceramic (LTCC) substrate fired at 1000 ° C. or lower, An insulating film formed on the thick film resistive layer; And a thin film conductive line formed on the insulating film and the thick film resistive layer. The method of claim 11, The thick film resistive layer further includes a via hole filler conductor provided on the low temperature cofired ceramic substrate, And the thick film resistive layer is formed on the via hole filler conductor. The method of claim 12, The thick film resistive layer is a resistive conductive line for a MEMS probe, characterized in that formed on the conductive line provided on top of the low temperature co-fired ceramic substrate. The method of claim 13, The thick film resistive layer is formed by a printing method and the resistive conductive line for the MEMS probe, characterized in that the firing. The method of claim 14, The insulating film is made of a high-k material, which is a high dielectric material such as Al ₂ O ₃ , HfO ₂ , TiO ₂ , ZrO ₂ , Y ₂ O ₃ , Ta ₂ O ₅ , La ₂ O _3, etc. Resistive conductor for MEMS probes. The method of claim 15, The insulating film is formed using an ion assistant PVD method, an PVD method, which is an E-Beam Evaporation technology, a PLD (Plused Laser Deposition) method, or an Aerosol Deposition method. Resistive conductors. The method according to any one of claims 11 to 16, The thick film resistive layer is a method of manufacturing a resistive conductive wire for a MEMS probe, characterized in that formed of Ru ₂ 0 ₃ oxide. The method of claim 17, The thin film conductive line is a composite metal resistive conductive line for MEMS probes, characterized in that consisting of Ti, Pd, Cu or Al, Cu, Au.

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