JP5383447B2 - Wiring board, probe card and electronic device - Google Patents

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 such a 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 addition, it is required that a high-frequency signal can be transmitted with an increase in the speed of the semiconductor element, and the probe card is also required to have excellent flatness.

  In order to meet such demands, fine patterning is possible, and as a substrate excellent in flatness and high frequency characteristics, a thin film conductor and a thin insulating layer are formed on a ceramic substrate flattened by polishing. There is a so-called build-up type wiring board in which the formed multilayer wiring portion is formed (see, for example, Patent Document 1). FIG. 5 is a cross-sectional view showing an example of a conventional wiring board. A conventional wiring board is formed by alternately laminating insulating resin layers 12 and wiring layers 13 on the upper surface of a ceramic wiring board 11 composed of a plurality of ceramic insulating layers 18, internal wirings 15 and external wirings 17. . The wiring layers 13 positioned above and below the insulating resin layer 12, and the wiring layer 13 on the upper surface of the lowermost insulating resin layer 12 and the connection wiring 16 on the upper surface of the ceramic wiring substrate 11 are connected by the via conductors 14. It was what was.

Japanese Patent Laid-Open No. 2004-214586

  However, the conventional wiring board has a thermal expansion coefficient of the insulating resin layer 12 at the connection portion between the via conductor 14 formed in the lowermost insulating resin layer 12 and the connection wiring 16 formed on the upper surface of the ceramic wiring board 11. And thermal stress due to the difference between the thermal expansion coefficients of the ceramic wiring substrate 11 were easily applied. This is because the connection wiring 16 on the upper surface of the ceramic wiring board 11 is thin, and the bonding strength between the ceramic wiring board 11 and the ceramic insulating layer 18 is higher than that of the insulating resin layer 12. Because the behavior shows behavior according to the behavior of the ceramic wiring board 11 (ceramic insulating layer 18), and the via conductor 14 is formed in the insulating resin layer 12, it shows behavior according to the behavior of the insulating resin layer 12. The position of the bonding interface between the via conductor 14 formed in the lowermost insulating resin layer 12 and the connection wiring 16 formed on the upper surface of the ceramic wiring board 11 is between the ceramic wiring board 11 and the insulating resin layer 12. This is because it substantially coincides with the position where the thermal stress increases.

  With respect to such a conventional wiring board, further miniaturization of the wiring layer 13 is required, and the connection portion between the via conductor 14 and the connection wiring 16 on the upper surface of the ceramic wiring board 11 has a diameter of, for example, about 50 μm or less. If it is small, the connection strength between the via conductor 14 and the connection wiring 16 formed on the upper surface of the ceramic wiring substrate 11 decreases. In addition, the electrical inspection of semiconductor elements is performed simultaneously with a probe card on a large number of semiconductor elements on the wafer. However, if the size of the wafer increases to reduce the cost of the semiconductor elements, the probe card must also be enlarged. When the wiring board for the probe card becomes large, the thermal stress applied to the connection portion with the connection wiring 16 on the upper surface of the ceramic wiring board 11 of the via conductor 14 becomes large. Therefore, there has been a problem that it is easy to break between the via conductor 14 of the lowermost insulating resin layer 12 and the connection wiring 16 on the upper surface of the ceramic wiring substrate 11.

  The present invention has been made in order to solve the above-mentioned problems, and its purpose is to further reduce the possibility of the wiring breaking even if a thermal stress is generated between the insulating resin layer and the ceramic wiring board. Another object of the present invention is to provide a highly reliable wiring board suitable for use as a probe card.

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. A wiring board in which the plurality of via conductors formed in the lowermost insulating resin layer and the ends of the plurality of internal wirings led out from the inside of the ceramic wiring board are electrically connected The insulating resin layer has an upper surface than the insulating resin so as to surround and surround each of the plurality of connection portions between the plurality of via conductors and the ends of the plurality of internal wirings on the upper surface of the ceramic wiring board. A plurality of convex portions made of a material having a high Young's modulus are formed, and the plurality of convex portions are provided independently of each other .

  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 material having a higher Young's modulus than the insulating resin of the insulating resin layer so as to surround and surround the connection portion between the via conductor and the end of the internal wiring on the upper surface of the ceramic wiring board. Since the projecting portion is formed, the connecting portion between the via conductor formed in the lowermost insulating resin layer and the end of the internal wiring is located inside the projecting portion, and the surrounding insulating resin is Since it is fixed by the convex part made of a material having a higher Young's modulus than the insulating resin and hardly deforms, the thermal stress applied to the connection part between the via conductor and the end part of the internal wiring is reduced, and the possibility of disconnection is reduced. It becomes a highly reliable wiring board.

  According to the probe card of the present invention, since the wiring board of the present invention having the above-described configuration and the probe pin connected to the wiring layer on the upper surface of the uppermost insulating resin layer are provided, a large-sized wafer corresponding to a large-sized wafer is provided. Even if it is a thing, it becomes a highly reliable probe card by which possibility that a wiring will fracture | rupture by a temperature change was reduced.

  According to the electronic device of the present invention, since the wiring board of the present invention having the above configuration and the electronic component connected to the wiring layer on the upper surface of the uppermost insulating resin layer are provided, the wiring breaks due to a temperature change. Therefore, a smaller and more reliable electronic device on which a smaller electronic component such as a semiconductor element with fine wiring is mounted is obtained.

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

  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. 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, The size and arrangement of the via conductor 4, the internal wiring 5 and the external wiring 7 are set.

  In the example shown in FIGS. 1 to 4, the via conductor 4 formed in the lowermost insulating resin layer 2 and the end of the internal wiring 5 are connected via a connection wiring 6. The ceramic wiring substrate 1 in which the internal wiring 5 and the ceramic insulating layer 8 are formed by simultaneous firing causes dimensional variations due to sintering shrinkage variations in the manufacturing process, so that the internal wiring exposed on the ceramic wiring substrate 1 is exposed. Similarly, the position 5 also varies. In order to absorb this variation and to ensure the connection between the via conductor 4 and the internal wiring 5, it is preferable to connect via the connection wiring 6. If the via conductor 4 of the lowermost insulating resin layer 2 is formed in conformity with the internal wiring 5 having a variation in position, the via conductor 4 and the end of the internal wiring 5 are not connected via the connection wiring 6. You may connect directly. In this case, the shape of the wiring layer 3 on the upper surface of the lowermost insulating resin layer 2 is made to be a shape corresponding to the positional variation of the internal wiring 5 of the ceramic wiring substrate 1 or large so as to absorb the positional variation. It is necessary to provide the connection wiring 6 because there is a possibility that productivity may be reduced and it may be difficult to route fine wiring.

  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 5 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 5 is developed, whereby the interval between the external wirings 7 on the lower surface of the ceramic wiring substrate 1 can be increased. 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 5, so the ceramic insulating layer 8 may be composed of one layer. When the ceramic insulating layer 8 is a single layer, the internal wiring 5 can be formed on the insulating base after the insulating base is manufactured. Therefore, the positional accuracy of the internal wiring 5 is high, and the connection wiring 6 can be made small. Can be omitted.

  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 5 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 FIGS. 1 to 4, the end portion of the internal wiring 5 to which the via conductor 4 formed in the lowermost insulating resin layer 2 is electrically connected is formed in the uppermost ceramic insulating layer 8. It becomes the upper end of the inner through conductor.

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 internal wiring 5 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, silver (Ag) , Copper (Cu), gold (Au), silver-palladium (Pd) alloy, etc.

  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 (alumina), silicon oxide, magnesium oxide and calcium oxide. Then, the slurry is formed into a mud shape and 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 internal wiring layer or 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 a portion of the internal wiring 5 exposed on the upper surface of the ceramic wiring substrate 1 (an end portion of the internal wiring 5).

  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 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 5 (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 5 due to firing shrinkage occurs, it is more preferable to form the through hole after the insulating base is manufactured as described above. Then, the conductive paste to be the internal wiring 5 is filled with the through holes by a filling method such as a printing method, and a conductive paste layer to be the external wiring 7 is formed by a screen printing method or the like, and heat treatment is performed, so The ceramic wiring substrate 1 having the wiring 5 and the external wiring 7 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 5.

  The connection wiring 6 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 connection wiring 6 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, the ceramic wiring substrate 1 without the connection wiring 6 may be produced and formed by a thin film forming method such as a vapor deposition method, a sputtering method, or 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 connection wiring 6. 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 connection wiring 6 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 the resist film as a mask. Form a layer. Then, the connection film 6 is formed by peeling off the resist film and removing the exposed portion of the underlying conductor layer by etching. A nickel or gold plating layer may be further formed on the surface by plating.

  The convex portion 9 on the upper surface of the ceramic wiring substrate 1 is formed so as to surround the connection portion between the via conductor 4 and the end portion of the internal wiring 5, and each of the plurality of connection portions is provided as in the example shown in FIG. Are formed of a material having a Young's modulus larger than that of the insulating resin of the insulating resin layer 2 so as to surround and be surrounded.

  The shape of the convex portion 9 in plan view may be one annular convex portion 9 as in the example shown in FIG. 2A, or the annular shape as in the example shown in FIG. The convex part 9 may be divided into a plurality of parts, or the convex part 9 may be disposed so as to surround the connecting part as in the example shown in FIG. As shown in the example shown in FIG. 2A, when the convex portion 9 is a ring-shaped protrusion, the insulating resin 2 around the via conductor 4 connected to the internal wiring 5 is all around the periphery. It will be fixed by the convex part 9, and it is preferable because it is fixed by the convex part 9 and hardly deforms against stress from any direction in the plane direction. In this case, the shape of the projection 9 in plan view is not particularly limited, and may be a circular shape such as a circle, an ellipse or an oval, or a polygonal ring such as a rectangle or a hexagon. Since the distance from the connecting portion to the convex portion 9 is equal to the via conductor 4 having a circular cross-sectional shape, the distance from the connecting portion to the convex portion 9 is equal, so that it is insulated against stress from a specific direction. Since the resin does not easily deform, and since there is no corner portion, it is easy to fill the insulating resin with the insulating resin, so that the connection portion as in the example shown in FIG. It is preferable that the convex portion 9 is formed in a circular shape.

  As shown in FIG. 2B and FIG. 2C, when the connection portions are surrounded by the plurality of projections 9, the interval between the plurality of projections 9 is preferably small. The length is preferably smaller than the length in the direction along the line connecting the center and the center of the connecting portion (in the example shown in FIG. 2C, the diameter of the convex portion 9). In addition, the shape of the plurality of convex portions 9 is not particularly limited, but each shape is the same and the size is the same, and it is specified by arranging them at equal intervals on the circumference centering on the center of the connecting portion. The insulating resin is not easily deformed by the stress from the direction. In this case, for example, in the case of the wiring board as shown in FIG. 1, the thermal stress in the direction from the respective connection portions toward the center of the wiring substrate is increased, so that each of the connection portions passes through the center of the wiring substrate. It is preferable to arrange the convex portions 9 on a straight line. Further, the shape (transverse cross-sectional shape) in plan view of each convex portion 9 when the convex portion 9 is composed of a plurality is not particularly limited, and is circular, elliptical, or oval as in the example shown in FIG. In addition to the circular shape, a polygonal shape such as a square or a hexagon may be used. In the same manner as described above, in consideration of the filling property of the insulating resin inside the convex portion 9, it is preferable that the corner has a large angle (90 ° or more) or has no corner.

  When a plurality of convex portions 9 are arranged, as shown in the example shown in FIG. 2D, the connecting portion is double-wrapped outside the concave portion 9, and the convex portion 9 is projected on the radiation from the center of the connecting portion. If it arrange | positions so that may be located, since the circumference | surroundings of a connection part can be surrounded without exception like the cyclic | annular convex part 9, it is preferable. In the example shown in FIG. 2D, the shape of the outer convex portion 9 and the shape of the inner convex portion 9 are different. For example, the outer convex portion 9 has an annular protrusion similar to the inner shape. The shape of the convex portion 9 may be the same on the inner side and the outer side, such as a shape that is divided into a plurality of parts.

  Although the convex portion 9 depends on the type of insulating resin of the insulating resin layer 2, its width (W shown in FIG. 3 (a)), specifically, in the example shown in FIGS. 2 (a) and (b). The distance from the inner (connecting portion side) surface to the outer surface of the convex portion 9 in the case of such an annular convex portion 9, or the convex shape in the case of the example shown in FIG. The diameter of the portion 9 is about 0.1 mm to 0.5 mm, and the height (H shown in FIG. 3A) is 1/3 of the thickness of the lowermost insulating resin layer 2 (T shown in FIG. 3A). It should be about ／. If the width W of the convex portion 9 is smaller than 0.1 mm, the thickness of the convex portion 9 in the direction of the stress applied to the connecting portion becomes small, so that the convex portion 9 is easily deformed, and the via conductor 4 and the internal wiring Therefore, it is difficult to suppress the stress applied to the connection portion with the end portion of 5. On the other hand, if the width W of the convex portion 9 is larger than 0.5 mm, the size of the convex portion 9 becomes large, and the wiring cannot be arranged with high density. When the height H of the convex portion 9 is lower than 1/3 of the thickness T of the insulating resin layer 2, the stress is applied to the inner side of the convex portion 9 through the insulating resin 2 having a lower Young's modulus above the convex portion 9. The connection portion between the via conductor 4 and the end portion of the internal wiring 5 is difficult to be fixed, while the height H of the convex portion 9 is higher than 2/3 of the thickness T of the insulating resin layer 2. Since the insulating resin layer 2 on the convex portion 9 becomes thin and the insulating resin layer 2 in this portion is easily broken, the wiring layer 3 on the upper surface may be broken. If the distance from the connecting portion of the via conductor 4 to the convex portion 9 (D shown in FIG. 3) is larger than 0.3 mm, the insulating resin around the connecting portion is difficult to be fixed by the convex portion 9, so that the distance is about 0.3 mm. Moreover, since the connection portion is located on the connection wiring 6, the convex portion 9 is formed outside the connection wiring 6.

The convex portion 9 is made of a material having a Young's modulus larger than that of the insulating resin of the insulating resin layer 2 and may be formed of glass, ceramics, resin, metallized metal, and a mixture thereof. The Young's modulus of the fixing material 9 is preferably about twice or more that of the insulating resin of the insulating resin layer 2. When the convex portion 9 is made of glass, ceramics, metallized metal, and a mixture thereof, the convex portion 9 has a Young's modulus larger than the insulating resin of the insulating resin layer 2 as described later (more than 10 times that of the insulating resin). Become. When the convex portion 9 is made of resin, for example, a polyamideimide resin (Young's modulus: 3 GPa) is used for the insulating resin of the insulating resin layer 2 and a polyimide resin (Young's modulus: 12 GPa) is used for the convex portion 9. Can be mentioned. The resin component of the convex portion 9 is the same as that of the insulating resin layer 2, and the Young's modulus is increased by adding a filler made of an insulating inorganic powder such as alumina or silica (SiO ₂ ). It 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. By adding such a filler, the thermal expansion coefficient of the convex portion 9 can be brought close to the thermal expansion coefficient of the ceramic insulating layer 8, and the bonding between the convex portion 9 and the ceramic insulating layer 8 becomes stronger. The reliability of fixing the insulating resin in the portion 9 can be increased.

  In the case where the convex portion 9 is made of a resin, for example, a liquid thermosetting resin may be formed on the ceramic wiring board 1 by printing and applying it in a predetermined shape by a screen printing method and curing by heating. When a photosensitive resin is applied to the upper surface of the ceramic wiring substrate 1 and formed on the convex portions 9 having a predetermined shape by photolithography, a sharp edge shape can be obtained as in the example shown in FIG. Alternatively, a photosensitive resin is applied to the upper surface of the ceramic wiring substrate 1, holes having the shape of the convex portions 9 are formed by photolithography, a mask is directly formed on the upper surface of the ceramic wiring substrate 1, and the holes are made liquid. The mask may be removed after filling with resin and curing.

  When the convex portion 9 is made of glass or ceramics, a paste mainly composed of these is printed on the ceramic wiring substrate 1 in a predetermined shape by a method such as a screen printing method, and the paste is applied to the upper surface of the ceramic wiring substrate 1. Just baked into. It is preferable to bake at a temperature lower than the firing temperature of the ceramic wiring board 1 so that the ceramic wiring board 1 is not warped by the heating at this time. For example, a low-melting glass, a low-melting glass paste mixed with a filler such as alumina powder for matching the thermal expansion coefficient with the ceramic insulating layer 8, a plasticizer, an organic solvent, and the like are used as the via conductor 4 and the end of the internal wiring 5. It is only necessary to print and apply on the upper surface of the ceramic insulating layer 8 by a method such as screen printing in a shape so as to surround and surround the connecting portions, and glaze at a temperature near the melting point of the low-melting glass.

  When the convex portion 9 is made of metallized metal, it can be formed in the same manner as the method for forming the connection wiring 6 by the metallization method described above, and the convex portion 9 is formed at the same time when the connection wiring 6 is formed by the metallization method. May be.

  When the convex portion 9 made of resin or glass is formed by a screen printing method or the like, the edge portion on the upper surface side of the convex portion 9 is likely to have an R (easily rounded) as shown in FIG. When R is attached to 9, the effect of fixing the insulating resin 2 is likely to be reduced. However, when the convex portion 9 is formed by adding 50% by volume or more filler to the insulating resin or glass, the filler is formed on the surface of the convex portion 9. It is preferable that the unevenness due to is formed because the effect of fixing the insulating resin is less likely to be lowered even if R is formed on the top of the convex portion 9. In addition, in the case of the convex part 9 which consists of metallization, even if it forms with a printing method, the unevenness | corrugation by a metallized metal is normally formed in the surface.

  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.

  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. Similar to the external wiring 7, a nickel or gold plating layer may be formed on the surface of the uppermost wiring layer 3 by plating.

  As shown in the example shown in FIG. 4, 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 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.

  Before forming the wiring layer 3, the via conductor 4 is formed by filling a through hole of the insulating resin layer 2 with a conductive paste mainly composed of metal powder such as copper and resin, as shown in FIGS. As shown in the example shown in FIG. 4, 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 examples shown in FIGS. When the via conductor 4 is formed at the same time as the wiring layer 3, the through hole is formed as in the example shown in FIGS. 1 to 4 so that the base conductor layer can be satisfactorily formed by a thin film on the inner surface of the through hole. It is preferable to make the shape so that the upper surface side of the insulating resin layer 2 becomes 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.

1: Ceramic wiring board 2: Insulating resin layer 3: Wiring layer 4: Via conductor 5: Internal wiring 6: Connection wiring 7: External wiring 8: Ceramic insulating layer 9: Projection

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 A wiring board in which a plurality of the via conductors formed in a layer and ends of a plurality of internal wirings led out from the inside of the ceramic wiring board are electrically connected;
The upper surface of the ceramic wiring board, the plurality of such via conductors and surrounding spaced apart each of the plurality of connecting portions between the ends of the plurality of internal wirings, the Young's modulus than that of the insulating resin of the insulating resin layer and a plurality of projections formed consisting of large material, the plurality of convex portions, the wiring board, characterized in that are provided independently of each other.   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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