JP4666830B2 - Multilayer wiring board and manufacturing method thereof - Google Patents

Description

【００６２】
表１からわかるように、多層配線層におけるバイア導体と導体配線層の接続部において、導体配線層凹部内に絶縁層中の熱硬化性樹脂を存在させることにより、高温放置、ＰＣＴ、温度サイクル、ホットオイル等の信頼性試験後において電気断線のない高信頼性の多層配線基板が作製できた。
【００６３】
【発明の効果】
以上詳述したように、本発明によれば、多層配線基板におけるバイア導体と導体配線層の接続性、特にコア基板の表面に形成された微細配線を有する多層配線層に形成された金属粉末を充填して形成されたバイア導体と導体配線層との接続性を高めることができ、これによって過酷な環境下においても優れた接続信頼性を有する多層配線基板を得ることができる。
【図面の簡単な説明】
【図１】本発明の多層配線基板の一例の概略断面図である。
【図２】本発明の多層配線基板の要部拡大断面図である。
【図３】本発明の多層配線基板におけるコア基板の製造方法の一例を説明するための工程図である。
【図４】本発明の多層配線基板における多層配線層の製造方法の一例を説明するための工程図である。
【符号の説明】
Ａ コア基板
Ｂ 多層配線層
１ 絶縁基板
２ 導体配線層
３、６ バイア導体
４ 絶縁層
５ 導体配線層
７ 凹部
８ 熱硬化性樹脂[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multilayer wiring board suitable for, for example, a multilayer wiring board and a package for housing a semiconductor element, and a manufacturing method thereof.
[0002]
[Prior art]
In recent years, electronic devices have been reduced in size, but in recent years, with the development of portable information terminals and the spread of so-called mobile computing for carrying and operating computers, there is a tendency for more compact, thin and high-definition multilayer wiring boards to be required. is there.
[0003]
Moreover, as represented by communication devices, electronic devices that require high-speed operation have been widely used. The demand for high-speed operation includes various requirements such as accurate switching for high-frequency signals. In order to cope with such an electronic device, a multilayer printed wiring board suitable for high-speed operation is required.
[0004]
In order to perform high-speed operation, it is necessary to shorten the length of the wiring and shorten the time required for propagation of the electric signal. In order to reduce the length of the wiring, there is a tendency to require a small, thin and high-definition multilayer wiring board in which the width of the wiring is reduced and the gap between the wirings is reduced.
[0005]
In order to meet such a demand for high-density wiring, a manufacturing method called a build-up method is used. The basic structure of the build-up method is classified into two types in the JPCA standard: (1) base + build-up method and (2) full-layer build-up method.
[0006]
(1) The base + build-up method is an exposure phenomenon after applying a photosensitive resin to the core substrate surface on which a conductor wiring layer or through-hole conductor is formed on the surface of an insulating substrate such as a double-sided copper-clad glass epoxy substrate. After forming the through hole, apply a plated layer such as copper to the entire surface of the photosensitive insulating layer, then apply a photosensitive resist to the plated layer, expose and develop the circuit pattern, and then etch the non-resist formation part Then, after forming a circuit, the resist is removed to produce a conductor wiring layer, and this process is repeated to form a multilayer.
[0007]
In addition, (2) a method for manufacturing all-layer build-up is, for example, as shown in Japanese Patent No. 2587593, by forming a through hole in the insulating sheet with a laser or the like and filling the through hole with a conductive paste. A wiring sheet is formed by electrically connecting conductor wiring layers formed on the surface, and the wiring sheet thus produced is repeatedly formed to be multilayered.
[0008]
[Problems to be solved by the invention]
However, (1) In the base + build-up method, a photosensitive epoxy resin or the like is frequently used as an insulating sheet. However, the epoxy resin originally has a low glass transition point and is made photosensitive, thereby increasing the water absorption rate and increasing the temperature. Since the reliability is likely to decrease due to deterioration of insulation properties when left at high humidity, a resin having a lower water absorption rate than an epoxy resin such as an allylated polyphenylene ether (A-PPE) resin or BT resin is used. Since the polarity is low, the wettability with a highly polar metal surface is deteriorated, the interface between the insulating layer and the conductor wiring layer is weakened, and it becomes very easy to pass moisture or the like that causes the characteristic deterioration. In addition, when the diameter of the through hole is reduced, problems such as an increase in the resistance of the via conductor have appeared remarkably, which has been a major obstacle for producing a high-density wiring board.
[0009]
In the (2) full-layer build-up method, the via conductor is formed by filling the through-hole with a conductive paste, but the via conductor is oxidized in a reliability test such as standing at high temperature or PCT, and the electric resistance is reduced. There is a problem of rising. Further, when the pitch of the via conductors is narrowed, there is a problem that the insulation resistance between the via conductors is lowered. This is because the interface between the conductor wiring layer or the via conductor and the insulating resin is weak, and it is easy to pass through what causes deterioration of moisture and the like. In addition, it is considered that water that has passed through the resin is generated because it directly enters the via conductor.
[0010]
Accordingly, the present invention aims to solve the problems in the conventional build-up method as described above. Specifically, the present invention improves the connection reliability between the via conductor and the conductor wiring layer, and is severe. It is an object of the present invention to provide a highly reliable multilayer wiring board that does not deteriorate characteristics even in a difficult environment and a method for manufacturing the multilayer wiring board that can be easily manufactured.
[0011]
[Means for Solving the Problems]
  The multilayer wiring board of the present invention includes an insulating layer containing at least a thermosetting resin, a conductor wiring layer embedded in the surface of the insulating layer, and a metal powder and an organic component in a through hole for connecting the conductor wiring layers. Conductor componentButIn a multilayer wiring board having a filled via conductor, a connection side of the conductor wiring layer with the via conductor is formed by an uneven surface,The surface roughness (Rz) of the uneven surface is 1 μm or more,The conductor wiring layerBottom part of 1/4 to 1/2 the height of the recessPresents thermosetting resin in the insulating layerThe thermosetting resin present in the bottom portion chemically reacts with the organic component in the conductor component.It is characterized by this.
[0012]
In particular, the via diameter at both ends of the via conductor is different, and the thermosetting resin in the insulating layer remains in the conductor wiring layer recess on the end side with a small diameter, so that the conductor wiring layer on the end side with a small via diameter is left. Connection reliability can be improved.
[0013]
  The multilayer wiring board of the present invention includes an insulating layer containing at least a thermosetting resin, a conductor wiring layer embedded on the surface of the insulating layer, and a metal powder and an organic component in the through hole for connecting the conductor wiring layers. And a via conductor filled with a conductor component including the first insulating layer and a second insulating layer having a thickness smaller than that of the first insulating layer. The conductor includes a first via conductor formed in the first insulating layer and a second via conductor formed in the second insulating layer and having a diameter smaller than that of the first via conductor, and the conductor wiring layer The connection side of the second via conductor is formed by an uneven surface, the surface roughness (Rz) of the uneven surface is 1 μm or more, and is 1/4 to 1/2 of the height of the recessed portion of the conductor wiring layer. On the bottom of the thermosetting tree in the second insulating layer There exists and is characterized by a thermosetting resin present in the bottom portion is an organic component and a chemical reaction in the conductive component of the second via conductor.
[0016]
  Furthermore, according to the method for manufacturing a multilayer wiring board of the present invention, (a) the upper surface side is not an uneven surface on the surface of the semi-cured first insulating sheet.The surface roughness (Rz) of the uneven surface is 1 μm or more.A step of forming a first conductor wiring layer; and (b) a second insulating sheet containing a semi-cured thermosetting resin on the surface of the insulating sheet is thermocompression bonded, and the first insulating sheet includes a first insulating sheet. A step of infiltrating the resin of the second insulating sheet to the bottom of the concave portion on the top surface of the conductor wiring layer; and (c) irradiating a predetermined portion of the second insulating sheet with a laser so that the first conductor wiring layer concave portion1/4 to 1/2 bottom part of heightForming a through-hole so that the thermosetting resin remains on the substrate, and filling the through-hole formed in (d) and (c) with a conductive paste containing metal powder and an organic component.The organic component of the conductor paste and the thermosetting resin remaining on the bottom portion are chemically reacted,A step of forming a via conductor; and (e) a step of forming a second conductor wiring layer on a surface of the second insulating sheet on which the via conductor is formed.
[0017]
In particular, in the step (b), thermocompression bonding is performed at a temperature of 80 ° C. or higher and a pressure of 10 kg / cm.²By performing the above, the resin of the second insulating sheet can be efficiently infiltrated to the bottom of the recess on the upper surface of the conductor wiring layer.
[0018]
Further, in the step (c), by setting the laser output to 0.05 to 0.5 mJ, the through hole is efficiently formed so that the thermosetting resin remains in the concave portion of the conductor wiring layer. Can do.
[0019]
Further, in the step (d), the organic component of the conductor paste chemically reacts with the semi-cured thermosetting resin in the second insulating sheet, thereby enabling strong connection.
[0020]
The multilayer wiring board of the present invention improves the connection reliability between the via conductor and the conductor wiring layer because the thermosetting resin in the insulating layer exists in the wiring layer recess in the connection portion between the via conductor and the conductor wiring layer. Therefore, it is possible to obtain a highly reliable multilayer wiring board without disconnection of the circuit including the via conductor and the conductor wiring layer and resistance change.
[0021]
Further, according to the manufacturing method of the present invention, since the through holes for connecting the conductor wiring layers are formed by laser irradiation, it is not necessary to use a photosensitive resin, and the glass transition point is high as an insulating layer material. Any insulating material having excellent material properties such as low water absorption can be selected. In addition, a through hole (blind via) is formed so that a semi-cured thermosetting resin remains in the concave portion of the conductor wiring layer at the connection portion between the via conductor and the conductor wiring layer. By causing a chemical reaction, a good electrical connection can be maintained even in a harsh environment.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
The multilayer wiring board of the present invention will be described together with the manufacturing method based on the drawings. FIG. 1 is a schematic cross-sectional view for explaining a multilayer wiring board according to the present invention.
[0023]
The multilayer wiring board of FIG. 1 includes a thin insulating layer 4 and a thin insulating layer 4 on the front and back of a core substrate A in which a conductor wiring layer 2 and a via conductor 3 are formed on the surface and inside of an insulating substrate 1 in which a plurality of insulating layers are stacked. A multilayer wiring layer B in which a conductor wiring layer 5 and a via conductor 6 having a fine pattern are formed is provided. Each of the via conductors 3 and 6 is formed by filling a through hole with a conductor component containing a metal powder and an organic resin.
[0024]
FIG. 2 shows an enlarged cross-sectional view of a main part of the multilayer wiring layer B in the multilayer wiring board of FIG. As shown in FIG. 2, the surface of the connection portion of the conductor wiring layer 5 in the multilayer wiring layer B with the via conductor 6 is formed by an uneven surface, and the bottom of the concave portion 7 of the uneven surface is in the insulating layer 4. It is important that the thermosetting resin 8 is present. According to the present invention, due to the presence of the thermosetting resin 8 in the recess 7, the organic component 6 a contained in the via conductor 6 and the thermosetting resin 8 in the recess 7 are firmly bonded, The connection reliability between the conductor wiring layer 5 and the via conductor 6 can be improved.
[0025]
In this connection portion structure, in order to reduce the connection resistance between the via conductor 6 and the conductor wiring layer 5 and improve the connection reliability, the depth of the concave portion 7 of the conductor wiring layer 5 is ¼ to 1/2. It is desirable that the thermosetting resin 8 be present at the bottom of 1/3 to 1/2.
[0026]
Further, when the via conductor 6 is formed of laser light, the via diameter is different between the incident side and the outgoing side of the laser light, and the diameter on the outgoing side is reduced, so that the connection reliability with the conductor wiring layer 5 is particularly deteriorated. Therefore, it is desirable that the connection portion with the conductor wiring layer 5 on the end portion side with the small via diameter has the above structure.
[0027]
Further, the surface roughness (Rz) of the concavo-convex surface of the conductor wiring layer 5 is desirably 1 μm or more, particularly 1.5 μm.
[0028]
Next, a method for manufacturing a multilayer wiring board according to the present invention will be described with reference to FIGS. FIG. 3 is a process diagram for explaining a method for manufacturing a core substrate, and FIG. 4 is a process diagram for explaining a method for forming a multilayer wiring layer B.
[0029]
According to the manufacturing method of the core substrate A of FIG. 3, first, the metal foil 21 is bonded to the surface of the resin film 22 via an adhesive (a). At this time, it is desirable to use a copper foil as the metal foil 21 in consideration of the ease of subsequent wiring formation, electrical resistance, and the like. Then, a photoresist 23 is further stuck on the surface of the metal foil 21 (b). Then, by exposing and developing the photoresist 23, the photoresist 24 remains in the conductor wiring portion (c). The negative type photoresist 24 is easier to process when the subsequent conductor wiring layer 25 is roughened. Thereafter, the conductive wiring layer 25 is formed by etching the metal foil 21 (d), and the photoresist 24 is removed (e). At this time, the cross section of the conductor wiring layer 25 formed on the surface of the resin film 22 is formed in a trapezoidal shape with an angle of formation (angle at both ends of the lower base) of 45 to 80 °, thereby improving adhesion to the insulating layer and embedding property. be able to. Such a trapezoidal conductor wiring layer 25 is preferably etched at 2 to 50 μm / min.
[0030]
Next, the surface of the conductor wiring layer 25 formed on the resin film 22 is desirably roughened to a surface roughness (Ra) of 0.2 μm or more. Depending on the type of metal, formic acid, NaClO₂, NaOH, Na₂PO_FourAlternatively, an acidic solution such as a mixed solution may be sprayed or dipped, and it is desirable to spray formic acid in particular because the surface roughness can be finely controlled.
[0031]
On the other hand, the insulating sheet 26 is prepared (f). The insulating sheet 26 is made of a thermosetting resin and an inorganic filler. The thermosetting resin constituting the insulating sheet 26 has a water absorption rate of 0.5% or less, particularly 0.3% or less, thereby preventing the resistance of the via conductor 28 from increasing due to the influence of moisture. Can do.
[0032]
Specifically, the thermosetting resin constituting the insulating sheet 26 is at least one selected from the group consisting of A-PPE (allylated polyphenylene ether), BT resin (bismaleimide triazine), polyimide resin, and polyamide bismaleimide. The resin is desirable. Further, as the inorganic filler of the insulating sheet 26, SiO₂, Al₂O_ThreeAt least one selected from the group of AlN is suitable, and the filler has a substantially spherical powder having an average particle diameter of 20 μm or less, particularly 10 μm or less, and optimally 7 μm or less. Moreover, in order to give the strength of the multilayer wiring board, it is desirable to include a fibrous woven fabric or non-woven fabric. It is desirable that at least one of the insulating layers forming the core substrate includes a fibrous filler.
[0033]
The inorganic filler is mixed at a volume ratio of organic resin: inorganic filler of 15:85 to 95: 5. In order to reduce the via pitch in order to produce a high-density wiring board, it is desirable to use a spherical filler rather than a fibrous filler.
[0034]
Next, a through hole 27 is formed in the insulating sheet 26 by irradiating laser light. The through hole 27 is processed by CO₂Laser, YAG laser, excimer laser, etc. can be used. Thereafter, a conductor paste is prepared by adding an organic component to a metal powder containing at least one selected from gold, silver, copper, aluminum, etc., and the via hole 27 is filled with the conductor paste to form a via conductor 28 (g ). It is desirable to use an organic component that is non-volatile and reacts with a thermosetting resin constituting the insulating layer. Moreover, although a normal-pressure printing machine etc. can be used as a filling method of a conductor paste, the filling rate can be raised more using a vacuum printing machine.
[0035]
Thereafter, the mirror image conductor wiring layer 25 produced on the resin film 22 is thermocompression bonded to both surfaces or one surface of the insulating sheet 26 on which the via conductors 28 are formed (h). Then, the resin film 22 having the pattern of the conductor wiring layer 25 having a mirror image is laminated on the surface of the B-stage insulating sheet 26 to obtain 3 kg / cm.²After applying the above pressure, the resin film 22 is peeled off (i), thereby transferring the conductor wiring layer 25 to the surface of the insulating sheet 26 and embedding the conductor wiring layer 25 in the surface of the insulating layer. 29 can be obtained (j).
[0036]
Next, the core board | substrate A can be produced by aligning and laminating | stacking the several wiring sheets 29-1-5 obtained by making it above as a position (k).
[0037]
The core substrate A may be heat-treated after the lamination process to completely cure the thermosetting resin in the insulating layer, or may be completely thermoset together with the formation of the multilayer wiring layer B described later. You can also.
[0038]
In forming the multilayer wiring layer B, which will be described later, the surface roughness Rz of the conductor wiring layer on the surface of the core substrate A is 1 μm or more, particularly 1 in order to improve the connectivity with the insulating layer and via conductor of the multilayer wiring layer B. It is desirable to roughen the surface to 5 μm or more. This rough surface processing varies depending on the type of metal, but formic acid, NaClO.₂, NaOH, Na₂PO_FourAlternatively, it is desirable to spray an acidic solution such as a mixed solution thereof by spraying or the like, and particularly to spray formic acid, because the surface roughness can be finely controlled.
[0039]
Next, a method of forming the multilayer wiring layer B on the front and back of the core substrate A will be described with reference to FIG. First, an insulating sheet 31 containing an uncured or semi-cured thermosetting resin is thermocompression bonded to the surface of the semi-cured core substrate A in which the conductor wiring layer 30 is formed on the surface produced as described above (b) ). The insulating sheet 31 is preferably made of a thermosetting resin and an inorganic filler. As the thermosetting resin and the inorganic filler, the same thermosetting resin and inorganic filler as those of the core substrate A are selected. In order to reduce the via pitch in order to produce a high-density wiring board, the multilayer wiring layer B is preferably made of a spherical filler rather than a fibrous filler.
[0040]
According to the present invention, when the insulating sheet 31 is thermocompression bonded to the surface of the core substrate A, the insulating sheet 31 in the concave and convex portions on the uneven surface of the surface of the conductor wiring layer 30 formed on the surface of the core substrate A. It is important to penetrate the thermosetting resin.
[0041]
In order to allow the thermosetting resin of the insulating sheet 31 to enter the recesses of the conductor wiring layer 30, the temperature is 80 ° C. or higher and 30 kg / cm, depending on the type of resin and the melt viscosity of the resin.²It is desirable to apply the above pressure.
[0042]
Further, the surface roughness (Rz) of the conductor wiring layer 30 on the surface of the core substrate A is 1.0 μm or more, desirably 1.5 μm or more. When the surface roughness (Rz) is smaller than 1.0 μm, peeling occurs between the insulating sheet or the via conductor.
[0043]
Next, the through-hole 32 is formed by irradiating a laser to the insulating sheet 31 thermocompression bonded to the surface of the core substrate A (c). The through hole 32 is processed in the same manner as the core substrate A with CO 2.₂Laser, YAG laser, excimer laser, etc. can be used. By this laser irradiation, the irradiated portion of the insulating sheet 31 is perforated by thermal decomposition. At this time, not all the thermosetting resin of the laser irradiated partial insulating sheet 31 is removed, but the conductor wiring layer 30 is removed. The reason described above is that the thermosetting resin in a semi-cured state remains at the bottom of 1/4 to 1/2, preferably 1/3 to 1/2 of the depth of the recess in the surface unevenness of Desirable from.
[0044]
The laser beam output at this time is 0.05 to 0.5 mJ, preferably 0.1 to 0.3 mJ. When the output of the laser beam exceeds 0.5 mJ, all the thermosetting resin in the recesses of the conductor wiring layer 30 is decomposed and removed. If it is less than 0.05 mJ, the thermosetting resin of the insulating sheet cannot be completely decomposed and removed, and it is difficult to form a through hole.
[0045]
Next, a conductor paste is embedded in the through hole 32 to form a via conductor 33 (d). The conductor paste is formed by adding an organic component to a metal powder containing at least one selected from gold, silver, copper, aluminum and the like. Moreover, although a normal-pressure printing machine etc. can be used as a filling method of a conductor paste, the filling rate can be raised more using a vacuum printing machine.
[0046]
At this time, the conductive paste has a semi-cured thermosetting resin in the insulating sheet 31 as an organic component, in other words, an organic substance that chemically reacts with the thermosetting resin remaining in the recesses on the surface of the conductive wiring layer 30. It is desirable to include ingredients. The connection reliability between the via conductor 32 and the conductor wiring layer 30 can be increased by reacting the organic component in the conductor paste with the thermosetting resin present in the recess of the conductor wiring layer 30. For example, when A-PPE is used as the thermosetting resin in the insulating sheet 31, triallyl isocyanurate (TAIC) can be suitably used as the organic component of the conductor paste. Moreover, when BT resin is used as the thermosetting resin in the insulating sheet 31, an epoxy resin can be suitably used as the organic component of the conductor paste. Considering the water absorption rate, heat resistance, and electrical characteristics of the resin, it is desirable to use a combination of A-PPE and TAIC.
[0047]
Thereafter, a conductor wiring layer 34 is formed on the surface of the insulating sheet 31 on which the via conductor 33 is formed (e). The conductor wiring layer 34 is formed in the same manner as in the production of the core substrate A by previously bonding a metal foil to the surface of the resin film 35 via an adhesive, and patterning the metal foil by a photoresist method. 34 is formed. Further, it is desirable that the surface of the conductor wiring layer 34 formed on the resin film 35 is roughened to a surface roughness (Ra) of 0.2 μm or more. Depending on the type of metal, formic acid, NaClO₂, NaOH, Na₂PO_FourAlternatively, it is desirable to spray an acidic solution such as a mixed solution by spraying or the like, in particular, formic acid, because the surface roughness can be finely controlled.
[0048]
After that, the mirror image conductor wiring layer 34 produced on the resin film 35 is applied to the surface of the insulating sheet 31 on which the via conductor 33 is formed at 100 to 150 ° C., 3 kg / cm²After applying the above pressure and thermocompression bonding, the conductor wiring layer 34 can be transferred and formed on the surface of the insulating sheet 31 by peeling the resin film 35.
[0049]
Thereafter, by repeatedly performing the processes (b) to (e) on the surface of the insulating sheet 31 on which the conductor wiring layer 34 is formed, an arbitrary number of multilayer wiring layers B can be stacked. (F). Finally, the multilayer wiring board of the present invention can be obtained by curing all at once while applying pressure at a temperature of 200 ° C. or higher.
[0050]
According to the present invention, in a multilayer wiring board, for example, a multilayer wiring board in which a multilayer wiring layer B made of a fine circuit is formed on the surface of a core substrate A, via conductors can be arranged at arbitrary positions in the multilayer wiring layer B. A high-density circuit can be formed in the wiring layer B. In addition, since the connection reliability between the via conductor and the conductor wiring layer can be improved in the multilayer wiring layer B, a multilayer wiring board having no conduction failure can be obtained even in a severe environment.
[0051]
Further, in the above manufacturing method, according to the transfer method, the patterning of the conductor wiring layer can be performed in parallel with the processing of the insulating layer. Therefore, a highly reliable multilayer wiring board can be manufactured in a short manufacturing process.
[0052]
【Example】
As an insulating layer of the core substrate, allylated polyphenylene ether (A-PPE) or BT resin was impregnated into a glass cloth to prepare a prepreg having a thickness of 100 μm as a first insulating sheet. Also, as the insulating resin of the multilayer wiring layer on the surface of the core substrate, A-PPE resin or BT resin is used similarly to the core substrate, and fused silica as an inorganic filler is prepared so as to have a volume ratio of 50:50. Was added to form a slurry. A second insulating sheet in a B stage state having a thickness of 40 μm was produced from this using a doctor blade method. These two kinds of insulating layers₂A conductive paste is prepared by forming a through hole of 100 μmφ in a prepreg used for a core substrate with a laser, and then mixing an organic component consisting of metal powder coated with silver on the copper surface and triallyl isocyanurate (TAIC), This conductor paste was filled in the through holes.
[0053]
On the other hand, a 12 μm thick electrolytic copper foil was bonded to a 38 μm PET film to prepare a film with a copper foil for transfer. A dry film resist was affixed to the copper foil surface, and exposure, development with sodium carbonate, and etching with ferric chloride were performed to form a conductor wiring layer having a trapezoidal formation angle of 60 °. Thereafter, the resist was removed with sodium hydroxide to form a wiring pattern on the PET film. Thereafter, the surface of the conductor wiring layer (side embedded in the prepreg) was roughened to a surface roughness Rz of 3.0 μm with 10% formic acid.
[0054]
Next, the wiring pattern prepared on the resin film is aligned and bonded to the prepreg on which the via conductor is formed, and is bonded at 130 ° C. and 50 kg / cm.²The conductor wiring layer was transferred to the surface of the prepreg by thermocompression bonding. Thereafter, the prepreg 4 layer onto which the conductor wiring layer was transferred was formed at 130 ° C., 50 kg / cm²A core substrate in a semi-cured state was prepared by laminating. Thereafter, the surface roughness (Rz) of the conductor wiring layer on the core substrate surface was changed to 0.8 to 3.4 μm using 10% formic acid.
[0055]
The second insulating sheet produced as described above on the front and back of the core substrate is 60 to 130 ° C. and 5 to 50 kg / cm.²Pasted together, CO₂A through hole of 50 μmφ was formed by laser. At this time, the laser output was 0.03 to 1.0 mJ.
[0056]
Next, a metal paste having a copper surface coated with silver and an organic resin were mixed to prepare a conductor paste. As the resin in the paste, TAIC was selected when the insulating sheet was A-PPE resin, and epoxy resin was selected when it was BT resin. The conductor paste was filled into the through holes using a vacuum printing machine to form a via conductor.
[0057]
Next, the second insulating sheet on which the via conductor is formed and the conductive wiring layer of the resin film formed in the same manner as the method for forming the conductive wiring layer of the core substrate are bonded together, and 130 ° C., 50 kg / cm.²The conductor wiring layer was transferred and formed on the surface of the insulating sheet.
[0058]
A multilayer wiring board having four insulating layers of the core substrate, five conductor wiring layers, one insulating layer on each side of the core substrate, one conductor layer, a total of six insulating layers, and seven conductor layers is manufactured. ℃, 20kg / cm²All the insulating layers were cured at once.
[0059]
In addition, as a wiring pattern for evaluation, a daisy chain was formed by connecting 800 via conductors in series with a conductive wiring layer to a multilayer wiring layer.
(Evaluation)
In the produced multilayer wiring board, the surface roughness (Rz) of the conductor wiring layer was measured with an atomic force microscope (AFM). Moreover, the penetration state of the thermosetting resin into the conductor wiring layer recess was determined by observing the cross section with SEM.
[0060]
1) 150 ° C., 1000 hours high temperature standing test, 2) 130 ° C., 85% RH, 2.3 atm, 200 hours PCT test, 3) −55 ° C. to 125 ° C., 1000 Temperature cycle test of cycle 4) Hot oil test of 100 cycles at 260 ° C. to 20 ° C. was performed. Before and after the above test, a daisy chain in which 800 via-hole conductors are connected in series with a conductor wiring layer has a resistance change of 10% or less. The substrate was tested.
[0061]
[Table 1]

[0062]
As can be seen from Table 1, in the connection portion between the via conductor and the conductor wiring layer in the multilayer wiring layer, the presence of the thermosetting resin in the insulating layer in the concave portion of the conductor wiring layer allows high temperature storage, PCT, temperature cycle, After a reliability test such as hot oil, a highly reliable multilayer wiring board without electrical disconnection could be produced.
[0063]
【The invention's effect】
As described above in detail, according to the present invention, the metal powder formed in the multilayer wiring layer having the fine wiring formed on the surface of the core substrate, particularly the connectivity between the via conductor and the conductor wiring layer in the multilayer wiring substrate is obtained. The connectivity between the filled via conductor and the conductor wiring layer can be enhanced, and thereby a multilayer wiring board having excellent connection reliability can be obtained even in a harsh environment.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an example of a multilayer wiring board according to the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of the multilayer wiring board of the present invention.
FIG. 3 is a process diagram for explaining an example of a manufacturing method of a core substrate in a multilayer wiring board according to the present invention.
FIG. 4 is a process diagram for explaining an example of a method for producing a multilayer wiring layer in a multilayer wiring board according to the present invention.
[Explanation of symbols]
A Core substrate
B multilayer wiring layer
1 Insulating substrate
2 Conductor wiring layer
3, 6 Via conductor
4 Insulation layer
5 Conductor wiring layer
7 recess
8 Thermosetting resin

Claims (7)

An insulating layer containing at least a thermosetting resin, and the conductive wiring layer buried in the insulating layer surface, the via conductor a conductor component in the through-hole containing a metal powder and an organic component in order to connect the conductive wiring layers are filled In a multilayer wiring board comprising:
The connection side of the conductor wiring layer with the via conductor is formed by a concavo-convex surface, the surface roughness (Rz) of the concavo-convex surface is 1 μm or more, and is 1/4 to 1 of the height of the concave portion of the conductor wiring layer. / 2 has a thermosetting resin in the insulating layer at the bottom portion, and the thermosetting resin in the bottom portion chemically reacts with an organic component in the conductor component . 2. The multilayer wiring board according to claim 1, wherein the via diameter is different at both ends of the via conductor, and the thermosetting resin in the insulating layer exists in the bottom portion of the conductor wiring layer recess on the end portion side having a small diameter. . An insulating layer containing at least a thermosetting resin, a conductor wiring layer embedded in the surface of the insulating layer, and a via conductor having a through hole filled with a conductor component containing a metal powder and an organic component for connecting the conductor wiring layers In a multilayer wiring board comprising:
The insulating layer includes a first insulating layer and a second insulating layer having a thickness smaller than that of the first insulating layer,
The via conductor includes a first via conductor formed in the first insulating layer, and a second via conductor formed in the second insulating layer and having a diameter smaller than that of the first via conductor,
The connection side of the conductor wiring layer with the second via conductor is formed by a concavo-convex surface, the surface roughness (Rz) of the concavo-convex surface is 1 μm or more, and ¼ of the height of the concave portion of the conductor wiring layer. The thermosetting resin in the second insulating layer is present at the bottom part of ˜1 / 2, and the thermosetting resin present in the bottom part chemically reacts with the organic component in the conductor component of the second via conductor. A multilayer wiring board characterized by (A) on the surface of the first insulating sheet in a semi-cured state, Ri upper surface side Do the uneven surface, a step of surface roughness of the concave convex (Rz) to form a first conductive wiring layer is 1μm or more (B) A second insulating sheet containing a semi-cured thermosetting resin is thermocompression-bonded to the surface of the insulating sheet, and the first insulating sheet reaches the bottom of the recess on the top surface of the first conductor wiring layer. (C) irradiating a predetermined portion of the second insulating sheet with a laser to ¼ to ½ of the height of the concave portion of the first conductor wiring layer ; a step of heat-curing resin on the bottom portion to form a through hole so as to leave, filled with a conductive paste containing a metal powder and an organic component in a through hole formed in (d) (c), organic conductor paste a thermosetting resin remaining in the bottom part and component are chemically reacted with, a via conductor A step of forming, (e) on the surface of the second insulating sheet the via conductor is formed, a method for manufacturing a multilayer wiring board, characterized by comprising a step of forming a second conductive interconnect layer 5. The method for manufacturing a multilayer wiring board according to claim 4 , wherein in the step (b), the thermocompression bonding is performed at a temperature of 80 ° C. or more and a pressure of 10 kg / cm ² or more. Wherein step (c), according to claim 4 or claim 5 method for manufacturing a multilayer wiring board, wherein the output of the laser is 0.05～0.5MJ. The said (d) process WHEREIN: The organic component of the said conductor paste chemically reacts with the thermosetting resin of the semi-hardened state in a 2nd insulating sheet, The Claim 4 thru | or 6 characterized by the above-mentioned. A method for manufacturing a multilayer wiring board.

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