JP2013131704A - Wiring substrate, probe card, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and thin wiring board which enables via conductors to be directly connected with surface wiring in a structure where recessed parts are formed on an upper surface of a ceramic wiring board and achieves high connection reliability.SOLUTION: Groove like recessed parts 9, each of which encloses one end part of surface wiring 5 so as to partially form a double portion, are formed on an upper surface of a ceramic wiring board 1, and an insulation resin 2a, leading from the one end part of the surface wiring 5 to the recessed part 9, penetrates into each recessed part 9. The surface wiring 5 is formed on the upper surface of the ceramic wiring board 1 passing through a clearance in the double portion of the recessed part 9. Since the surface wiring 5 can be formed on the surface of the ceramic wiring board 1 where the recessed parts 9 are formed, the size and the thickness of the wiring board are reduced. An area around a connection part between multiple via conductors 4 and one end of the surface wiring 5 is fixed by the recessed part 9 which is filled with the insulation resin 2a and is less likely to deform. Therefore, the structure makes the disconnection of the connection part less likely to occur.

Description

  The present invention relates to a wiring board used for a probe card or a wiring board for mounting electronic components such as a semiconductor element and a piezoelectric vibrator, and a probe card and an electronic apparatus using the wiring board.

  In recent years, along with miniaturization and higher density of electronic devices, not only semiconductor elements used in electronic devices but also packages, wiring boards on which the semiconductor elements are mounted, or electrical inspection of semiconductor elements The probe card is also required to have finer wiring and higher density. In order to meet such a demand, there is a so-called build-up type wiring board in which a multilayer wiring portion in which a plurality of thin film conductors and thin film insulating layers are formed on a ceramic substrate is formed. Such a wiring board has a thermal expansion coefficient of the insulating resin layer and a heat of the ceramic wiring board at a connection portion between the via conductor formed in the lowermost insulating resin layer and the surface wiring formed on the upper surface of the ceramic wiring board. Thermal stress due to the difference from the expansion coefficient is likely to be applied, and therefore, there is a problem that disconnection is easily caused between the via conductor of the lowermost insulating resin layer and the surface wiring on the upper surface of the ceramic wiring board.

  Therefore, in the conventional wiring board, a recess is formed on the upper surface of the ceramic wiring board so as to surround the connection portion between the via conductor and the connection terminal, and the insulating resin extending from the periphery of the connection portion to the recess is inserted into the recess. In addition, the insulating resin around the via conductor formed in the lowermost insulating resin layer is fixed by the recess to make it difficult to deform, and the thermal stress applied to the connection portion between the via conductor and the connection terminal is reduced and disconnected. (For example, refer to Patent Document 1).

JP 2011-009327 A

  However, the conventional wiring board is improved in that it easily breaks at the connection portion between the via conductor of the lowermost insulating resin layer and the upper surface of the ceramic wiring substrate, but surrounds the connection portion between the via conductor and the connection terminal. Since the concave portion is formed on the surface, the surface wiring directly connected to the connection terminal cannot be formed on the surface of the ceramic wiring board on which the concave portion is formed. Therefore, in order to form a wiring for development, it is necessary to further increase the ceramic insulating layer and the insulating resin layer, and there is a problem that the number of manufacturing steps increases and the wiring board becomes large.

  The present invention has been made to solve the above-mentioned problems, and its purpose is to provide an upper surface of a ceramic insulating layer in order to ensure the connection reliability between the via conductor of the insulating resin layer and the surface wiring of the upper surface of the ceramic wiring substrate. An object of the present invention is to provide a wiring board having high connection reliability that is reduced in size and thickness and capable of directly connecting a via conductor to a surface wiring in a wiring board in which a recess is formed.

In the wiring board of the present invention, a plurality of insulating resin layers and a plurality of wiring layers are alternately laminated on the upper surface of the ceramic wiring board, and the wiring layers positioned above and below the insulating resin layer are connected by via conductors. The plurality of via conductors formed in the lowermost insulating resin layer are electrically connected to one end of the surface wiring formed on the upper surface of the ceramic wiring substrate, and the other end of the surface wiring is A wiring board electrically connected to end portions of a plurality of internal wirings drawn from the inside of the ceramic wiring board to the upper surface, wherein a part of the wiring board is doubled on the upper surface of the ceramic wiring board. A groove-shaped recess is formed so as to surround one end of the surface wiring, and an insulating resin from one end of the surface wiring to the recess enters into the recess, and the surface wiring is formed of the ceramic. It is characterized in that the recess on the top surface of the wiring substrate is formed by through the gap portion of the doubled.

  A probe card according to the present invention includes the wiring board according to the present invention having the above-described configuration, and probe pins connected to the wiring layer on the upper surface of the uppermost insulating resin layer.

  An electronic device according to the present invention includes the wiring board according to the present invention having the above-described configuration and an electronic component connected to the wiring layer on the upper surface of the uppermost insulating resin layer.

  According to the wiring board of the present invention, a groove-like recess is formed on the upper surface of the ceramic wiring board so as to surround one end of the surface wiring so as to be partially duplicated. Insulating resin from one end to the recess enters, and the surface wiring is formed through the gap between the recesses doubled on the upper surface of the ceramic wiring board. The surface wiring can be formed on the surface of the ceramic wiring board with the recesses while ensuring the connection reliability between the via conductor and one end of the surface wiring by resin, so the number of ceramic insulating layers and insulating resin layers The wiring board can be reduced in size and thickness without increasing the number.

  According to the probe card of the present invention, the wiring board of the present invention having the above configuration and the probe pin connected to the wiring layer on the upper surface of the uppermost insulating resin layer are provided. Therefore, the probe card having such a wiring board can be reduced in size and thickness.

  According to the electronic device of the present invention, the wiring board of the present invention having the above-described configuration and the electronic component connected to the wiring layer on the upper surface of the uppermost insulating resin layer are provided. Since it becomes a small and thin wiring board which can form surface wiring on the surface of a board | substrate, the electronic device provided with such a wiring board can be reduced in size and thickness.

(A) is a top view which shows an example of embodiment of the ceramic wiring board in the wiring board of this invention, (b) is sectional drawing in the XX of (a). (A) is a top view which expands and shows the A section of Fig.1 (a), (b)-(d) is a top view which shows the other example of (a), respectively. It is a principal part expanded sectional view which shows the other example of embodiment of the wiring board of this invention.

A wiring board of the present invention and a probe card and an electronic device using the same will be described in detail with reference to the accompanying drawings. FIG. 1A is a top view showing an example of an embodiment of a ceramic wiring board according to the present invention, and FIG. 1B is a cross-sectional view taken along line XX in FIG. It is sectional drawing. The example shown in FIG. 1 shows a simplified example in which the wiring layer 3 on the outermost surface of the wiring board is 16 pieces, the insulating resin layer 2 is 3 layers, and the ceramic insulating layer 8 of the ceramic wiring board 1 is also 3 layers. . Depending on the number of terminals of electronic components mounted on the wiring board, the number of semiconductor elements on the wafer to be inspected by the probe card, the number of terminals of the semiconductor elements, and their arrangement, the insulating resin layer 2, the wiring layer 3, Via conductor 4, surface wiring 5, internal wiring 6, external wiring 7
The size and arrangement are set.

  In the example shown in FIG. 1, the via conductor 4 formed in the lowermost insulating resin layer 2 and one end of the surface wiring 5 are electrically connected, and the other end of the surface wiring 5 and the internal wiring are connected. The end of 6 is electrically connected. The ceramic wiring substrate 1 in which the internal wiring 6 and the ceramic insulating layer 8 are formed by simultaneous firing causes dimensional variations due to variations in sintering shrinkage in the production process, so that the internal wiring exposed on the ceramic wiring substrate 1 is exposed. Similarly, the position 6 also varies. In order to absorb this variation and to ensure the connection between the other end of the surface wiring 5 and the end of the internal wiring 6, the shape of the other end of the surface wiring 5 is changed from the end of the internal wiring 6. A wide pad shape is preferred. Similarly, the shape of one end portion of the surface wiring 5 may be a pad shape larger than the diameter of the via conductor 4.

  The ceramic wiring board 1 has an insulating base made of ceramics, an external wiring 7 formed on the surface thereof, and an internal wiring 6 formed inside. As shown in the example shown in FIG. 1, the insulating base is composed of a plurality of ceramic insulating layers 8 and the internal wiring 6 is developed, whereby the interval between the external wirings 7 on the lower surface of the ceramic wiring substrate 1 can be increased.

  The external wiring 7 on the lower surface of the ceramic wiring board 1 is for connecting the wiring board to an external circuit. The internal wiring 6 is for electrically connecting the external wiring 7 on the lower surface of the ceramic wiring substrate 1 to the wiring layer 3 formed on the insulating resin layer 2 and the like. There are a wiring layer and an internal through conductor that passes through the ceramic insulating layer 8 and connects the internal wiring layer and the internal wiring layer and the external wiring 7. In the example shown in FIG. 1, the end portion of the internal wiring 6 to which the other end of the surface wiring 5 is electrically connected is the upper end portion of the internal through conductor formed in the uppermost ceramic insulating layer 8.

The ceramic insulating layer 8 of the ceramic wiring board 1 includes an aluminum oxide (alumina: Al ₂ O ₃ ) sintered body, an aluminum nitride (AlN) sintered body, a silicon carbide (SiC) sintered body, and a mullite sintered body. Body, made of ceramics such as glass 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 the probe terminal is formed on the wiring board, the wafer and the wiring board joined together with the probe terminal, which are added to the probe terminal and the joint portion of the probe terminal, 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 surface wiring 5, the internal wiring 6, and the external wiring 7 of the ceramic wiring substrate 1 are formed by simultaneous firing with the ceramic insulating layer 8, tungsten (W), molybdenum (Mo), molybdenum-manganese (Mo-Mn) alloy, It is made of metallization mainly composed of metal such as silver (Ag), copper (Cu), gold (Au), silver-palladium (Pd) alloy.

  Such a ceramic wiring substrate 1 is manufactured by the following method. For example, when the ceramic insulating layer 8 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 8.

Next, through holes are formed by punching or laser processing using a mold or the like at a predetermined position where the internal through conductors of the ceramic green sheet are formed, and the through holes are filled with a conductive paste. Further, a conductive paste layer to be the surface wiring 5, the internal wiring layer, and the external wiring 7 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 the laminate is fired at a high temperature of about 1500 ° C. to 1600 ° C., thereby producing the ceramic wiring substrate 1. A nickel plating layer with a thickness of about 1 to 10 μm and a gold plating layer with a thickness of about 0.1 to 3 μm are sequentially formed on the surface of the external wiring 7 of the ceramic wiring board 1 in order to prevent corrosion and connect with external circuits. Good. A similar plating layer may be formed on the surface of the surface wiring 5 and the portion of the internal wiring 6 exposed on the upper surface of the ceramic wiring substrate 1 (the end of the internal wiring 6).

  If the ceramic insulating layer 8 is made of glass ceramics, when the ceramic green sheet is sintered at a temperature at which the ceramic green sheet is sintered, the constrained green sheet mainly composed of alumina or the like is laminated on both sides of the laminate and fired. The constrained green sheet is preferable because the ceramic green sheet suppresses the sintering shrinkage in the direction of the laminated surface, and the ceramic wiring substrate 1 having a small shrinkage in the plane direction and good shrinkage variation and good dimensional accuracy can be obtained.

  When the interval between the wiring layers 3 on the upper surface of the insulating resin layer 2 is large, it is not necessary to develop the internal wiring 6, and therefore the ceramic insulating layer 8 may be composed of one layer.

  When the ceramic insulating layer 8 is a single layer, first, a ceramic green sheet is laminated to produce a laminated body having a predetermined thickness, or a raw material powder added with an appropriate organic binder is die pressed. Then, a molded body is prepared and fired to produce an insulating substrate. Next, a through hole for forming the internal wiring 6 (internal through conductor) is formed in the insulating substrate by blasting or laser processing. The blasting is performed by placing a mask made of, for example, a resist film or the like having an opening in a portion where the through hole is formed on the upper surface of the insulating substrate. If at least the upper surface of the insulating substrate is polished flatly by polishing before or after the formation of the through-hole, the flatness of the wiring substrate can be improved and the insulating resin layer 2 can be satisfactorily formed. preferable. An insulating substrate having a through-hole is formed by punching or laser processing a ceramic green sheet or a laminate of ceramic green sheets, or by forming a through-hole with a mold during powder press molding. Can also be produced. In this case, since the positional displacement of the through hole for forming the internal wiring 6 due to firing shrinkage occurs, it is more preferable to form the through hole after the insulating base is manufactured as described above. And by filling the through-hole with the embedding method such as the printing method or the like, the conductor paste that becomes the internal wiring 6, by forming the conductor paste layer that becomes the surface wiring 5 and the external wiring 7 by the screen printing method, and by heat treatment, A ceramic wiring substrate 1 having a surface wiring 5, an internal wiring 6, and an external wiring 7 made of metallization is produced. Also in this case, a plating layer similar to the above may be formed on the surface of the external wiring 7 and the end of the internal wiring 6.

In the wiring board of the present invention, a groove-like recess 9 is formed on the upper surface of the ceramic wiring board 1 so as to surround one end of the surface wiring 5 so as to be partially doubled. It is important that the insulating resin 2 a that extends from one end of the wiring 5 to the recess 9 enters. For example, a plurality of groove-like recesses 9 are formed so as to surround each of the ends of the plurality of surface wirings 5 as in the example shown in FIG. With such a configuration, since the insulating resin around the via conductor 4 formed in the lowermost insulating resin layer 2 is fixed by the recess 9 and is not easily deformed, the connecting portion between the via conductor 4 and one end of the surface wiring 5 As a result, the connection stress between the via conductor 4 and one end of the surface wiring 5 is reduced, and the wiring board with high connection reliability is reduced.

  Further, in the wiring board of the present invention, it is important that the surface wiring 5 is formed through a gap between the upper surface of the ceramic wiring board 1 where the concave portions 9 are doubled. With such a configuration, the surface wiring 5 can be formed on the surface of the ceramic wiring substrate 11 in which the recesses 9 are formed. Therefore, the wiring substrate can be made thin without increasing the number of ceramic insulating layers 8 and insulating resin layers 2. In addition, it is possible to reduce the size of the wiring board without increasing the board area in order to secure the wiring for the surface wiring.

  FIG. 2 (a) is an enlarged top view of the main part showing the A portion of FIG. 1 (a) in an enlarged manner, and FIGS. 2 (b) to 2 (d) show the implementation of the respective wiring boards of the present invention. It is a top view which expands and shows the principal part of the other example of a form.

  As in the example shown in FIGS. 2A to 2D, the recess 9 is formed so as to surround one end portion of the surface wiring 5 so that a part of the recess 9 is doubled. Thus, since the recess 9 surrounds the entire circumference of the one end portion of the surface wiring 5 due to a part of the recess 9 being doubled, the insulating resin around the one end portion of the surface wiring 5 is removed. A wiring board having high connection reliability in which the thermal stress applied to one end portion of the surface wiring 5 is firmly fixed by the recess 9 and the disconnection between the via conductor 4 and one end portion of the surface wiring 5 is suppressed; Become. For example, if the groove-shaped recess 9 is divided around one end of the surface wiring 5, it is difficult to fix the insulating resin in the portion where the recess 9 is divided. As described above, it is important that the concave portion 9 is formed so as to surround one end portion of the surface wiring 5 so that a part thereof is doubled.

  The recess 9 may be a single annular groove having the same width as in the example shown in FIG. 2A, or the tip of the annular groove is narrow as in the example shown in FIG. It may be a tapered shape. As in the example shown in FIG. 2A, when the recess 9 is an annular groove having the same width, the insulating resin around the via conductor 4 connected to one end of the surface wiring 5 is all around the periphery. It will be fixed by the insulating resin 2a filled in the concave portion 9, and it will be fixed uniformly by the insulating resin 2a filled in the concave portion 9 and hardly deformed against stress from any direction in the plane direction. Since it becomes a thing, it is preferable. Furthermore, as in the example shown in FIG. 2 (b), when the recess 9 has an annular groove with a tapered tip, the recess 9 can be formed up to the tip of the bent portion of the surface wiring 5, Even if the surface wiring 5 is bent with a small radius, the insulating resin 2a filled in the recess 9 is more firmly fixed by the insulating resin 2a filled in the recess 9, and even if the surface wiring 5 is bent with a small radius, it is close to one end of the surface wiring 5. Since the recessed part 9 can be formed, it is preferable.

As described above, the shape of the recess 9 in the plan view as in the example shown in FIGS. 2A and 2B is a circular shape such as a circle, an ellipse, or an oval, but there is no particular limitation, and FIG. A polygonal ring shape such as a quadrangle or a hexagon as in the examples shown in (c) and (d) may be used. In the example shown in FIG. 2C, the concave portion 9 has a quadrangular shape and the corners are chamfered. When the concave portion is polygonal, the distance between the surface wiring 5 and the concave portion 9 can be easily made constant. At the same time, it is preferable to chamfer the corners because when the insulating resin 2a is filled in the recesses 9, there is no air trapped in the corners, and the insulating resin 2a can be reliably filled into the recesses 9. In the example shown in FIG. 2 (d), one end of the recess 9 extends in two directions: a direction toward the inside of the bent portion of the surface wiring 5, and a direction toward the outside. In this case, the surface wiring This is preferable because unnecessary electrostatic capacitance (floating capacitance) generated at the bent portion of 5 can be reduced.

The recess 9 depends on the insulating resin of the insulating resin layer 2 and the type of insulating resin in the recess 9, but the distance from the inner wall to the outer wall of the recess 9 in the opening of the recess 9, for example, FIG. In the case of the circular groove-like recess 9 as shown in the examples shown in a) and (b), the groove width should be about 0.1 mm to 0.5 mm and the depth should be about 0.03 mm to 0.5 mm. . If the distance from the inner wall of the recess 9 to the outer wall of the recess 9 is smaller than 0.1 mm, the distance in the recess 9 in the direction of the stress applied to the connecting portion between the via conductor 4 and one end of the surface wiring 5 Since the thickness of the insulating resin 2a is reduced, the insulating resin 2a is deformed or cracked in the vicinity of the opening of the recess 9, making it difficult to suppress the stress and making it difficult to fill the recess 9 with the insulating resin 2a. On the other hand, if it is larger than 0.5 mm, the size of the concave portion 9 becomes large, and the surface wiring 5 cannot be arranged with high density. If the depth of the recess 9 is shallower than 0.03 mm, the insulating resin 2a can easily come out of the recess 9 and the connecting portion between the via conductor 4 and one end of the surface wiring 5 is difficult to be fixed. In the case of the opening size as described above, it is difficult to fill the insulating resin 2a. Further, it is preferable that the distance between the outer concave portion 9 and the via conductor 4 at the portion where the concave portion 9 starts to be doubled is about 0.04 mm to 0.3 mm. If the distance from the connecting portion of the via conductor 4 to the recess 9 is smaller than 0.04 mm, the difference in thermal expansion between the via conductor 4 and the ceramic insulating layer 8 because the width of the ceramic insulating layer 8 around the via conductor 4 is narrow. As a result, cracks are likely to occur in the ceramic insulating layer 8. If the thickness is larger than 0.3 mm, the insulating resin 2 a around the connection portion is hardly fixed by the recess 9. In addition, the concave portion 9 being double means that the straight line connecting the center of the via conductor 4 and the end of the inner concave portion 9 intersects the outer concave portion 9, and the portion starting to become double Means a portion intersecting with the outer concave portion 9. In addition, when the gap between the concave portions 9 is double, that is, the interval between the inner concave portion 9 and the outer concave portion 9 is D, and the length where the concave portion 9 is double is L. , L is preferably larger than D. In this case, the stress applied to the connecting portion between the via conductor 4 and one end of the surface wiring 5 is preferably substantially equal to the case where the concave portions 9 are continuously connected in an annular shape.

  In order to form the concave portion 9 on the upper surface of the ceramic wiring substrate 1, the upper surface of the ceramic wiring substrate 1 or the insulating substrate manufactured as described above is processed into each shape of FIG. 2 by blasting, laser processing or etching processing. That's fine. For example, if the ceramic insulating layer 8 is glass ceramic, an etching resist having an opening in the shape of a plan view of the recess 9 is formed on the surface of the ceramic wiring substrate 1, and an etching process is performed by using ammonium fluoride or the like as an etching solution. Thus, the recess 9 can be formed. Similarly, in the case of blasting, a mask having an opening in the shape of a plan view of the recess 9 may be formed on the surface of the ceramic wiring substrate 1, and blasting may be performed by sandblasting or the like. In the case of laser processing, a hole to be a desired recess 9 can be formed by adjusting conditions such as laser output of laser processing. Or you may form the recessed part 9 by the punching process by a metal mold | die in the ceramic green sheet used as the ceramic insulating layer 8 in which the recessed part 9 of the ceramic wiring board 1 is formed.

One end portion of the surface wiring 5 on the upper surface of the ceramic wiring substrate 1 is electrically connected to a plurality of via conductors 4 formed in the lowermost insulating resin layer 2, and the other end portion of the surface wiring 5 is The ceramic wiring board 1 is electrically connected to ends of a plurality of internal wirings 6 drawn from the inside to the upper surface. The one end portion of the surface wiring 5 and the other end portion of the surface wiring 5 are electrically connected via the wiring portion (the routing portion) of the surface wiring 5. The size of one end portion of the surface wiring 5 is about 1.5 times the diameter of the via conductor 4, and the diameter is formed to be 100 μm to 150 μm. Further, it is preferable that the other end portion of the surface wiring 5 has a pad shape wider than the end portion of the internal wiring 6 as described above, and the other end portion of the surface wiring 5 has a diameter of about 0.3 mm to about 0.3 mm. It is formed to 0.5 mm. In this way, by making the other end portion of the surface wiring 5 have a large area, the position of the internal wiring 6 exposed on the ceramic wiring board 1 is also the same due to the dimensional variation due to the sintering shrinkage variation of the ceramic wiring board 1. Therefore, the variation can be absorbed and the connection between the other end of the surface wiring 5 and the internal wiring 6 can be ensured.

The surface wiring 5 on the upper surface of the ceramic wiring board 1 may be formed by simultaneous firing with the ceramic insulating layer 8 as with the external wiring 7, or the ceramic wiring board 1 without the surface wiring 5 is produced, After the upper surface is flattened by polishing or the like, it may be formed by a metallizing method such as a so-called Moriman method. Alternatively, a ceramic wiring board 1 having no surface wiring 5 is produced,
You may form by thin film formation methods, such as a vapor deposition method, sputtering method, and an ion plating method. Similarly, the external wiring 7 may be formed by a thin film forming method. In the case of the metallization method, for example, a conductor containing metal powder such as tungsten (W), molybdenum (Mo), manganese (Mn), and a suitable resin binder and solvent at a predetermined position of the ceramic wiring substrate 1 by screen printing or the like. It is produced by applying a paste and heat-treating it at a high temperature of 1400 ° C or higher. A plating layer similar to the above may also be formed on the surface of the surface wiring 5. In the case of the thin film forming method, a base conductor layer made of, for example, a chromium (Cr) -Cu alloy layer or a titanium (Ti) -Cu alloy layer having a thickness of about 0.1 μm to 3 μm is formed on the entire upper surface of the ceramic wiring substrate 1. A resist film having a pattern-shaped opening of the surface wiring 5 is formed thereon, and a main conductor having a thickness of about 2 μm to 10 μm made of a metal such as copper or gold by plating or the like using this resist film as a mask. Form a layer. Then, the resist film is peeled and removed, and the exposed portion of the underlying conductor layer is removed by etching, whereby the surface wiring 5 is formed. A nickel or gold plating layer may be further formed on the surface by plating.

  The insulating resin layer 2 is composed of polyimide resin, polyamideimide resin, siloxane modified polyamideimide resin, siloxane modified polyimide resin, polyphenylene sulfide resin, wholly aromatic polyester resin, BCB (benzocyclobutene) resin, epoxy resin, bismaleimide triazine resin, It is made of an insulating resin such as polyphenylene ether resin, polyquinoline resin, or fluorine resin.

In order to form the insulating resin layer 2 on the ceramic wiring substrate 1, for example, when made of polyimide resin, a varnish-like polyimide precursor is applied to the upper surface of the ceramic wiring substrate 1 by spin coating, die coating, or curtain coating. The film is applied by a coating method such as a printing method or the like, and then cured by heat at about 400 ° C. to form a polyimide, thereby forming 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 by a coating method such as a doctor blade method, and the adhesive layer is formed on the ceramic wiring substrate 1 by heating and pressing. In any method, the plurality of insulating resin layers 2 are formed by forming the via conductors 4 and the wiring layers 3 in the insulating resin layer 2 and repeating the above steps as many times as the number of necessary insulating resin layers 2. In the method using a film-shaped resin, 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.

Since the via conductor 4 is formed in the insulating resin layer 2, a through hole having a diameter of 20 μm to 100 μm is formed in this portion. This through hole is formed by first forming a resist film having an opening in the insulating resin layer 2 and etching the insulating resin layer 2 located in the opening of the resist film or using a laser to directly form the insulating resin. Formed by removing part of layer 2. An excimer laser, a CO ₂ laser, or the like can be used as the laser at this time, but the shape of the inner wall of the through hole can be adjusted to be nearly vertical, and the inner wall surface of the through hole can be processed smoothly, and is formed with an ultraviolet laser. It is desirable to keep it. 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.

  As the insulating resin 2 a extending from one end of the surface wiring 5 to the recess 9, the same insulating resin as that of the insulating resin layer 2 can be used. The insulating resin 2a may be the same as or different from the insulating resin of the insulating resin layer 2.

When the insulating resin 2a is different from the insulating resin of the insulating resin layer 2, the Young's modulus of the insulating resin 2a is preferably larger than the Young's modulus of the insulating resin of the insulating resin layer 2. In this case, since the insulating resin 2a is more difficult to deform, the insulating resin around one end of the surface wiring 5 is firmly fixed by the recess 9 to reduce the thermal stress applied to the one end of the surface wiring 5, and the via A wiring substrate having high connection reliability in which disconnection between the conductor 4 and one end of the surface wiring 5 is suppressed is obtained. For example, when the Young's modulus of the insulating resin 2a extending from the periphery of the connecting portion to the recess 9 is about twice or more the Young's modulus of the insulating resin of the insulating resin layer 2, for example, the polyamide imide is added to the insulating resin of the insulating resin layer 2. There is a case where a polyimide resin (Young's modulus: 12 GPa) is used for the insulating resin 2a from the periphery of the connecting portion to the recess 9 using a resin (Young's modulus: 3 GPa). As the insulating resin 2a extending from the periphery of the connecting portion to the concave portion 9, the same resin component as the insulating resin layer 2 is used as the resin component, and a filler made of insulating inorganic powder such as alumina or silica (SiO ₂ ) is added. A material having a large Young's modulus may be used. For example, by adding 30% by mass of fused silica powder as a filler to a polyamideimide resin having a Young's modulus of 3 GPa, the Young's modulus is about 10 GPa.

  When the insulating resin 2a is different from the insulating resin of the insulating resin layer 2, the insulating resin 2a is formed so as to protrude from the upper surface of the ceramic wiring substrate 1 as shown in FIG. 2 is covered with an insulating resin. In this case, the higher the height of the insulating resin 2a, the greater the stress applied in the lateral direction due to the thermal expansion of the lowermost insulating resin layer 2, so the height is equal to the thickness of the lowermost insulating resin layer 2. It is preferable to suppress it to 2/3 or less, and when the Young's modulus of the insulating resin 2a is less than twice the Young's modulus of the insulating resin of the insulating resin layer 2, it is 1/2 or less of the thickness of the lowermost insulating resin layer 2 It is preferable to keep it at a minimum.

  The insulating resin 2a can be formed by applying and curing a varnish-like insulating resin precursor to a portion from the periphery of one end of the surface wiring 5 to the recess 9 by a printing method or a dispensing method. Alternatively, a photosensitive varnish-like insulating resin precursor is applied to the entire upper surface of the ceramic wiring substrate 1 by a spin coating method or the like, and an opening that exposes a portion from one periphery of the surface wiring 5 to the recess 9 is exposed. The insulating resin 2a may be formed by forming a resist having, and exposing and curing. When the insulating resin 2a is the same as the insulating resin of the insulating resin layer 2, when the varnish-shaped insulating resin precursor is applied to the upper surface of the ceramic wiring substrate 1, the recess 9 is filled and cured at the same time. The insulating resin 2a can be formed at the same time. The insulating resin 2a may be formed beyond the recess 9 beyond the recess 9 in plan view.

First, the wiring layer 3 is formed by, for example, chromium (Cr) having a thickness of about 0.1 μm to 3 μm on the entire main surface of the insulating resin layer 2 by a thin film forming method such as vapor deposition, sputtering, or ion plating. ) -Copper (Cu) alloy layer or titanium (Ti) -copper (Cu) alloy layer. Next, a resist film having a pattern-shaped opening of the wiring layer 3 is formed on the underlying conductor layer, and the resist film is used as a mask to form a metal having a low electrical resistance such as copper or gold by plating or the like. A main conductor layer having a thickness of about 10 μm is formed. Then, the wiring layer 3 is formed by removing the resist film and removing the exposed portion of the underlying conductor layer by etching. A nickel or gold plating layer may be formed on the surface of the uppermost wiring layer 3 by plating.

  When the wiring layer 3 is formed with a recess having the same shape as the wiring layer 3 in the insulating resin layer 2 as in the example shown in FIG. 3 and the wiring layer 3 is formed in the recess, the upper surface of the insulating resin layer 2 is formed. Since there is no step between the wiring layer 3 and the upper surface of the wiring layer 3, the upper surface of the wiring substrate is flat even if a plurality of insulating resin layers 2 are stacked, and the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2. It is preferable because an electronic component and a probe pin can be connected better. In order to form a recess in the insulating resin layer 2, a resist film having a pattern-shaped opening of the wiring layer 3 is formed on the surface of the insulating resin layer 2, and the insulating resin layer is etched by an etching method such as RIE (Reactive Ion Etching). The surface of the exposed portion of 2 may be removed.

  The via conductor 4 is shown in FIG. 1 by filling the through hole of the insulating resin layer 2 with, for example, a conductive paste mainly composed of metal powder such as copper and resin before forming the wiring layer 3. As in the example, a through hole filled with a conductor is formed. The conductor paste is made of a metal powder such as copper, a resin, and a solvent, and is solidified by filling the through holes and then drying. Alternatively, when the wiring layer 3 is formed, it may be formed simultaneously with the wiring layer 3 by forming a base conductor layer and a main conductor layer also on the inner surface of the through hole. In this case, the via conductor 4 is formed by being attached to the inner surface of the through hole of the insulating resin layer 2, and the through hole is not filled with the conductor. When the plating thickness at the time of forming the main conductor layer is increased, the through holes can be filled with the conductor as in the example shown in FIG. When the via conductor 4 is formed at the same time as the wiring layer 3, the through hole is formed of an insulating resin layer as in the example shown in FIG. 1 so that the base conductor layer can be satisfactorily formed with a thin film on the inner surface of the through hole. It is preferable to make the shape such that the upper surface side of 2 is larger. 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, and when using a photosensitive resin, the exposure condition or etching is performed. Depending on conditions, a through hole having a desired size and shape can be formed.

  The probe card of the present invention comprises the above-described wiring board of the present invention and probe pins connected to the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2. The probe pin is produced, for example, as follows and attached to the wiring board of the present invention. First, a female die of a plurality of probe pins is formed on one surface of a silicon wafer by etching, a metal made of nickel is deposited on the surface on which the female die is formed by plating, and the female die is embedded and embedded with nickel. Nickel on the wafer other than nickel is removed by processing such as etching to produce a silicon wafer in which nickel probe pins are embedded. Nickel probe pins embedded in the silicon wafer are bonded to the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2 of the wiring substrate by a bonding material such as solder. Then, the probe card is obtained by removing the silicon wafer with an aqueous potassium hydroxide solution.

  The electronic device of the present invention includes the above-described wiring board of the present invention and an electronic component connected to the wiring layer 3 on the upper surface of the uppermost insulating resin layer 2. The electronic component is, for example, a semiconductor element such as an IC chip or a piezoelectric vibrator such as a crystal vibrator, and a passive element such as a chip capacitor is also mounted as necessary. Such an electronic component is connected to the wiring layer 3 by soldering, bonding with a conductive adhesive, or wire bonding.

DESCRIPTION OF SYMBOLS 1: Ceramic wiring board 2: Insulating resin layer 2a: Insulating resin from one end part of surface wiring to recessed part 3: Wiring layer 4: Via conductor 5: Surface wiring 6: Internal wiring 7: External wiring 8: Ceramic insulating layer 9: Recess

Claims (3)

A plurality of insulating resin layers and a plurality of wiring layers are alternately laminated on the upper surface of the ceramic wiring substrate, and the wiring layers positioned above and below the insulating resin layer are connected by via conductors, and the insulating resin in the lowermost layer The plurality of via conductors formed in the layer are electrically connected to one end of the surface wiring formed on the upper surface of the ceramic wiring board, and the other end of the surface wiring is connected to the interior of the ceramic wiring board. A wiring board that is electrically connected to ends of a plurality of internal wirings drawn from the upper surface to the upper surface of the ceramic wiring board, and surrounds one end of the surface wiring so that a part thereof is doubled The groove-like recess is formed, and the recess is filled with an insulating resin from one end of the surface wiring to the recess, and the surface wiring is located on the upper surface of the ceramic wiring board. Wiring board, characterized in that it is formed through a gap recess has a double portion. A probe card comprising: the wiring board according to claim 1; and a probe pin connected to the wiring layer on the upper surface of the uppermost insulating resin layer. An electronic device comprising: the wiring board according to claim 1; and an electronic component connected to the wiring layer on the upper surface of the uppermost insulating resin layer.

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