JP5996971B2 - Multilayer wiring board and probe card using the same - Google Patents

Description

  The present invention relates to a multilayer wiring board and a probe card using the same.

  Conventionally, multilayer wiring boards have been used as wiring boards used for mounting electronic components. Such a wiring board is made of, for example, a polyimide resin or the like on the upper surface of a circuit board made of a ceramic substrate or the like, and is formed by applying a resin precursor by a curtain coating method, a spin coating method, or the like and then heat-curing the resin substrate. Resin insulation layers and wiring conductor layers made of metals such as copper and aluminum, and formed by adopting thin film formation technology such as plating and vapor deposition methods and photolithography technology, are alternately stacked in multiple layers. The circuit conductor of the circuit board is electrically connected to the end surface of the through conductor exposed on one main surface side of the resin insulating layer, and the through conductor exposed on the other main surface side of the resin insulating layer An electrode of an electronic component such as a semiconductor integrated circuit element or a probe for performing an electrical inspection of the electronic component is connected to the end face of the semiconductor device. And an electronic component is electrically connected with the circuit conductor of a circuit board via a penetration conductor, and transmission / reception of a signal, an electrical test | inspection with respect to an electronic component, etc. are performed.

  In recent years, in such multilayer wiring boards for probe cards and the like, through conductors and connection pads formed in an insulating layer in accordance with the increase in the density of electronic components such as semiconductor elements (smaller in plan view). Since the area is increasing, it is becoming difficult to align the probe with the connection pad.

Japanese Patent Laid-Open No. 11-160356

  For example, a multilayer wiring board used for a probe card has a connection pad on the upper surface, and when the probe is pressed against the connection pad in the multilayer wiring board, a portion that overlaps with the through conductor connected to the connection pad in a plan view The probe may be pressed to a position shifted from the position of the probe, and the connection pad is pushed into the multilayer wiring board. As a result, the connection pad may be deformed or peeled off from the multilayer wiring board. there were.

A multilayer wiring board according to one aspect of the present invention includes a laminate, a connection pad, a through conductor, and a thin film conductor layer. The laminate is formed by laminating a plurality of resin insulating layers. The connection pad is provided on the upper surface of the stacked body. The through conductor is provided in the thickness direction of the multilayer body from the uppermost resin insulating layer. The thin film conductor layer is provided between the plurality of resin insulating layers at a position overlapping with the connection pad in plan view, and is connected to the connection pad through the through conductor. Through conductor, in between the connection pads and the thin film conductor layer, Ri Na overhang a portion of the thickness direction outward, has a larger convex portion than the connection pad in a plan perspective, it is formed integrally .

  According to another aspect of the present invention, a probe card includes a ceramic substrate having an upper surface, the multilayer wiring substrate having the above-described configuration laminated on the upper surface of the ceramic substrate, and a probe connected to a connection pad of the multilayer wiring substrate. I have.

In the multilayer wiring board according to one aspect of the present invention, a laminated body in which a plurality of resin insulating layers are laminated, a connection pad provided on the upper surface of the laminated body, and a thickness direction of the laminated body from the uppermost resin insulating layer And a thin-film conductor layer provided between the plurality of resin insulation layers at a position overlapping with the connection pad in plan view, and connected to the connection pad through the through conductor. between the pads and the thin film conductor layer, the through conductors, Ri Na overhang a portion of thickness outwards has a larger convex portion than the connection pad in a plan perspective, it is formed integrally As a result, when the probe is pressed against the connection pad, the connection pad remains within the multilayer wiring board even if the probe is pressed at a position displaced from the position overlapping the through conductor connected to the connection pad in plan view. As a result, the connection pad can be prevented from being deformed or peeled off from the multilayer wiring board, and the connection reliability between the multilayer wiring board and the probe is improved. Can be.

  According to another aspect of the present invention, a probe card includes a ceramic substrate having an upper surface, the multilayer wiring substrate having the above-described configuration laminated on the upper surface of the ceramic substrate, and a probe connected to a connection pad of the multilayer wiring substrate. By providing, connection reliability is improved.

(A) is sectional drawing which shows the multilayer wiring board and ceramic substrate in embodiment of this invention, (b) is sectional drawing which expands and shows the A section of the multilayer wiring board shown by Fig.1 (a). is there. (A) is sectional drawing which expands and shows the principal part of the modification of the multilayer wiring board in embodiment of this invention, (b) is a plane perspective view which shows the multilayer wiring board shown by Fig.1 (a). It is. It is sectional drawing which expands and shows the principal part of the other modification of the multilayer wiring board in embodiment of this invention.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

  A multilayer wiring board according to an embodiment of the present invention will be described with reference to FIGS. The multilayer wiring board 1 in this embodiment includes a multilayer body 2, connection pads 3, through conductors 4, and a thin film conductor layer 5.

  The laminate 2 is formed by laminating a plurality of resin insulating layers 2a. The resin insulating layer 2a is made of an insulating resin such as polyimide resin, polyphenylene sulfide resin, wholly aromatic polyester resin, BCB (benzocyclobutene) resin, epoxy resin, bismaleimide triazine resin, polyphenylene ether resin, polyquinoline resin, or fluorine resin. It consists of

For example, when the resin insulating layer 2a is made of a polyimide resin, a varnish-like polyimide precursor is applied to the upper surface of the ceramic substrate 11 described later by a coating method such as a spin coating method, a die coating method, a curtain coating method, or a printing method. Thereafter, it is cured with heat of about 400 ° C. to be polyimideized to form a thickness of about 10 μm to 50 μm. Alternatively, a resin adhesive such as a siloxane-modified polyamideimide resin, a siloxane-modified polyimide resin, a polyimide resin, a bismaleimide triazine resin, or an epoxy resin is dried on the lower surface of a sheet of about 10 μm to 50 μm made of the above resin with a dry thickness of about 5 μm to 20 μm. An adhesive layer is formed by applying and drying on a coating method such as a doctor blade method, and the adhesive layer is formed on the ceramic substrate 11 by heating and pressing. In any method, the plurality of resin insulation layers 2a are formed by forming the through conductors 4 and the thin film conductor layers 5 in the resin insulation layer 2a and repeating the above steps as many times as necessary for the resin insulation layers 2a. In the method using a resin for a film, a plurality of films can be pressed at once, and it is not necessary to apply and cure for each layer, so that the manufacturing process can be shortened.

In the multilayer body 2, the through conductors 4 are provided in the thickness direction of the multilayer body 2 from the uppermost resin insulating layer 2 a. For example, a through hole having a diameter of 20 μm to 100 μm is formed in the resin insulating layer 2a.
The through hole is formed by first forming a resist film having an opening in the resin insulating layer 2a and etching the resin insulating layer 2a located in the opening of the resist film or directly using a laser. It is formed by removing a part of. As the laser at this time, an excimer laser, a CO ₂ laser, or the like can be used. However, the shape of the inner wall of the through hole can be adjusted almost vertically, and the inner wall surface of the through hole can be formed with an ultraviolet laser that can be processed smoothly. Is desirable. Alternatively, in the case of a method of applying a varnish-like resin, a photosensitive resin is used, for example, a portion other than a portion where a through-hole is formed by exposure is cured, and a resin in a portion where the through-hole is formed is obtained. The through hole may be formed by removing by etching.

In the laminate 2, the connection pad 3 is provided on the upper surface, and the thin film conductor layer 5 is provided between the plurality of resin insulating layers 2 a at a position overlapping the connection pad 3 in a plan view, and the through conductor 4 is interposed therebetween. Are connected to the connection pads 3. The connection pad 3 and the thin film conductor layer 5 are formed on the entire main surface of the resin insulating layer 2a by a thin film forming method such as a vapor deposition method, a sputtering method, or an ion plating method, for example, with a thickness of about 0.1 μm to 3 μm. (Cr) -C
A base conductor layer made of a u alloy layer or a titanium (Ti) -Cu alloy layer is formed. Next, a resist film having a pattern-shaped opening of the connection pad 3 and the thin film conductor layer 5 is formed on the base conductor layer, and a metal having a low electrical resistance such as copper or gold is formed by plating or the like using the resist film as a mask. A main conductor layer having a thickness of about 2 μm to 10 μm is formed. Then, the resist film is peeled and removed, and the exposed portion of the underlying conductor layer is removed by etching, whereby the connection pad 3 and the thin film conductor layer 5 are formed. The surface of the connection pad 3 provided on the upper surface of the laminate 2 has a nickel plating layer with a thickness of about 1 to 10 μm and a gold plating with a thickness of about 0.1 to 3 μm for corrosion prevention and connectivity with a probe. Layers may be formed sequentially.

  Before forming the connection pad 3 and the thin film conductor layer 5, the through conductor 4 is made of, for example, a conductive paste mainly composed of metal powder such as copper and resin or melted solder or the like in the through hole of the resin insulating layer 2 a. By filling, a through hole filled with a conductor is formed as in the example shown in FIGS. Alternatively, when the connection pad 3 and the thin film conductor layer 5 are formed, the conductor layer may be formed in the through hole by plating such as copper or solder so that the connection pad 3 and the thin film conductor layer 5 may be formed simultaneously. . In this case, if the plating thickness at the time of forming the conductor layer is increased, the through holes can be filled with the conductor as in the examples shown in FIGS. When the through conductor 4 is formed simultaneously with the connection pad 3 and the thin film conductor layer 5, the through hole is larger on the upper surface side of the insulating resin layer 2 so that the conductor layer can be satisfactorily formed in the through hole. It is preferable to use a simple shape. The through hole having such a shape is controlled by etching conditions when the through hole is formed by etching, by adjusting the output of the laser when the through hole is formed by a laser, or by exposure condition or etching when using a photosensitive resin. It can be formed depending on conditions.

  In the multilayer wiring board 1 of the present embodiment, a laminate 2 formed by laminating a plurality of resin insulation layers 2a, a connection pad 3 provided on the upper surface of the laminate 2, and a laminate from the uppermost resin insulation layer 2a. A thin film that is provided between the plurality of resin insulating layers 2a at a position that overlaps with the connection pad 3 in a plan view and connected to the connection pad 3 through the through conductor 4 in the thickness direction of the body 2 Between the connection pad 3 and the thin film conductor layer 5, the through conductor 4 has a convex portion 6 that protrudes outward in the thickness direction, and is integrally formed. Yes.

In this way, the through conductor 4 has the convex portion 6 that projects a part in the thickness direction to the outside, and is formed integrally, so that when the probe is pressed against the connection pad 3, it is seen through in plane. Even if the probe is pressed to a position shifted from the position overlapping with the through conductor 4 connected to the connection pad 3, the connection pad 3 is effectively suppressed from being pushed into the multilayer wiring board 1, and as a result, It is possible to prevent the connection pad 3 from being deformed or peeled off from the multilayer wiring board 1, and the multilayer wiring board 1 can be improved in connection reliability.

The convex portion 6 is formed by forming a concave portion having the same shape as the convex portion 6 in the resin insulating layer 2a and filling the concave portion with the same material as the through conductor 4. In this case, for example, if a metal paste such as copper and a conductive paste containing resin as a main component or a melted solder are simultaneously filled in the concave portion and the through hole for forming the through conductor 4, the manufacturing process is simplified. And preferred. Alternatively, the conductor layer may be simultaneously formed by plating such as copper or solder in the recess and the through hole for forming the through conductor 4, and the manufacturing process is simplified, and the plating thickness when forming the conductor layer is preferable. If the thickness of the through hole is increased, the through hole can be filled with a conductor as in the example shown in FIGS. In order to form a concave portion having the same shape as the convex portion 6 in the resin insulating layer 2a, the surface of the exposed portion of the resin insulating layer 2a is removed by a laser such as an excimer laser or a CO ₂ laser, or the resin insulating layer is formed. A resist film having a pattern-shaped opening of the convex portion 6 is formed on the surface of 2a, and the surface of the exposed portion of the resin insulating layer 2a is removed by an etching method such as RIE (Reactive Ion Etching). What is necessary is just to overlap the resin insulation layer 2a which has and the other resin insulation layer 2a produced previously.

Further, as shown in FIG. 2 (b), by the convex portion 6 is larger than the connection pads 3 in a plan perspective, when pressing the probe to the connection pads 3, the periphery of the connection pads 3 in a plan perspective Even if the probe is pressed against the surface of the multi-layer wiring board 1, the protrusion 6 larger than the connection pad 3 in a plan view is surely suppressed from being pushed into the multilayer wiring board 1. deformed or it Ru can be effectively prevented that peeled off from the multilayer wiring board 1.

  In addition, as shown in FIGS. 1, 2A, and 3, when the convex portion 6 has a quadrangular shape in a cross-sectional view, the top surface of the convex portion 6 is flat, so that it can be seen through in plan view. Even if the probe is pressed to a position shifted from the position overlapping the through conductor 4 connected to the connection pad 3, it is pushed into the multilayer wiring board 1 while maintaining the shape of the connection pad 3 effectively. This is preferable because it can be suppressed.

  Further, as shown in FIG. 3, when the convex portion 6 is provided close to the connection pad 3 in the thickness direction of the multilayer body 2, a plane is formed when the probe is pressed against the connection pad 3. Even if the probe is pressed to a position where the probe is displaced from a position overlapping with the through conductor 4 connected to the connection pad 3 through fluoroscopy, the connection pad 3 is prevented from being pushed into the portion near the upper surface of the multilayer wiring board 1. As a result, it is possible to more effectively prevent the connection pad 3 from being deformed or peeled off from the multilayer wiring board 1, which is preferable.

The ceramic substrate 11 on which the multilayer wiring board 1 is laminated on the upper surface includes a ceramic insulating layer 11a. The ceramic insulating layer 11a includes an aluminum oxide (alumina: Al ₂ O ₃ ) sintered body, an aluminum nitride (AlN) sintered body, a silicon carbide (SiC) sintered body, a mullite sintered body, a glass ceramic, and the like. It is made of ceramics. When used for a probe card, an aluminum oxide (Al ₂ O ₃ ) sintered material or glass ceramics having a thermal expansion coefficient close to that of silicon (Si) forming a wafer is preferable. When the ceramic insulating layer 8 is made of such ceramics, when a probe is bonded onto the multilayer wiring board 1, the wafer bonded to the probe and the bonded portion of the probe and the multilayer wiring board 1 are joined together. This is preferable because the thermal stress due to the difference in thermal expansion is relatively small. Further, when used as a probe card, it is possible to effectively prevent thermal deformation with respect to a thermal load during measurement of electrical characteristics of a semiconductor element, and furthermore, heat is not retained inside due to high heat transferability.

The internal wiring 12 and the external wiring 13 of the ceramic substrate 11 are formed by simultaneous firing with the ceramic insulating layer 11a, tungsten (W), molybdenum (Mo), molybdenum-manganese (Mo-Mn) alloy, silver (Ag), It is made of metallization mainly composed of metal such as copper (Cu), gold (Au), silver-palladium (Pd) alloy.

  Such a ceramic substrate 11 is manufactured by the following method. For example, when the ceramic insulating layer 11a is formed of an aluminum oxide sintered body, first, an appropriate organic binder and solvent are added to and mixed with raw material powders of aluminum oxide, silicon oxide, magnesium oxide and calcium oxide, and the slurry is mixed. This is formed into a sheet shape by a doctor blade method or the like to produce a plurality of ceramic green sheets to be the ceramic insulating layer 11a.

  Next, a through hole is formed by a suitable punching process at a predetermined position where the internal through conductor of the ceramic green sheet is formed, and the through hole is filled with a conductive paste. Further, a conductor paste layer serving as an internal wiring layer is formed to a thickness of 10 to 20 μm at a predetermined position of the ceramic green sheet by a screen printing method or the like. The conductive paste is produced by kneading a metal powder having a high melting point such as tungsten (W), molybdenum (Mo), molybdenum-manganese (Mo-Mn) alloy, an appropriate resin binder, and a solvent.

Finally, these ceramic green sheets are superposed and pressure-bonded to produce a laminate, and this laminate is fired at a high temperature of about 1500 ° C. to 1600 ° C. to produce the ceramic substrate 11. On the surface of the external wiring 13 of the ceramic substrate 11, a nickel plating layer having a thickness of about 1 to 10 μm and a gold plating layer having a thickness of about 0.1 to 3 μm are sequentially formed for corrosion prevention and connectivity with an external circuit. Good. A similar plating layer may be formed on a portion of the internal wiring 12 (internal through conductor) exposed on the surface of the ceramic substrate 11.

  The probe card includes the ceramic substrate 11 having the above-described configuration, the multilayer wiring substrate 1 having the above-described configuration laminated on the upper surface of the ceramic substrate 11, and a probe connected to the connection pads 3 of the multilayer wiring substrate 1.

  For example, the probe is connected to the multilayer wiring board 1 of the present embodiment as follows. First, a plurality of female probes are formed on one surface of a silicon wafer by etching. Next, a metal made of nickel is applied to the surface on which the female mold is formed by plating, and the female mold is embedded with nickel, and nickel on the wafer other than the embedded portion is removed by processing such as etching. Then, a silicon wafer having a nickel probe embedded therein is produced. The nickel probe embedded in the silicon wafer is bonded to the connection pad 3 on the upper surface of the multilayer wiring board 1 with a bonding material such as solder. Then, by removing the silicon wafer with an aqueous potassium hydroxide solution, a probe card in which probes are connected to the connection pads 3 of the multilayer wiring board 1 laminated on the upper surface of the ceramic substrate 11 is obtained.

  In the multilayer wiring board 1 of the present embodiment, the through conductor 4 has a convex portion 6 that protrudes outward in the thickness direction between the connection pad 3 and the thin film conductor layer 5 and is integrally formed. As a result, when the probe is pressed against the connection pad 3, the connection pad 3 is multilayered even if the probe is pressed to a position shifted from the position overlapping the through conductor 4 connected to the connection pad 3 in a plan view. It is possible to effectively suppress being pushed into the inside of the wiring board 1, and as a result, the connection pad 3 can be prevented from being deformed or peeled off from the multilayer wiring board 1. The connection reliability can be improved.

The probe card of this embodiment includes a ceramic substrate 11 having the above-described configuration, a multilayer wiring substrate 1 having the above-described configuration laminated on the top surface of the ceramic substrate 11, and a probe connected to the connection pads 3 of the multilayer wiring substrate 1. And the connection reliability is improved.

DESCRIPTION OF SYMBOLS 1 ... Multilayer wiring board 2 ... Laminated body 2a ... Resin insulation layer 3 ... Connection pad 4 ... Through-conductor 5 ... Thin-film conductor layer 6 ... Convex
11 ... Ceramic substrate

Claims (3)

A laminate in which a plurality of resin insulation layers are laminated;
A connection pad provided on the upper surface of the laminate;
A through conductor provided in the thickness direction of the laminate from the uppermost resin insulation layer;
A thin film conductor layer provided between the plurality of resin insulation layers at a position overlapping with the connection pad in plan view, and connected to the connection pad via the through conductor;
In between the connection pad and the thin film conductor layer, the through conductors, Ri Na overhang a portion of the thickness direction outward, has a larger convex portion than the connection pad in a plan perspective, together A multilayer wiring board characterized by being formed. The multilayer wiring board according to claim 1 , wherein the convex portion has a quadrangular shape in a sectional view. A ceramic substrate having an upper surface;
The multilayer wiring board according to claim 1 or 2 , laminated on the upper surface of the ceramic substrate,
A probe card comprising: a probe connected to the connection pad of the multilayer wiring board.

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