JPS61127196A - Manufacture of multilayer wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application] The present invention relates to a method for manufacturing a multilayer wiring board, and is particularly applicable to printed circuit boards for computers and other devices that require high-density packaging.
The present invention relates to a high-performance and economical method of manufacturing a multilayer board used for a circuit module for SI mounting, etc.

[Prior art]

Conventionally, circuit boards used in computers, communication equipment, etc. are made by impregnating glass fiber with epoxy resin or polyimide resin, and have copper foil on both sides, as well as conductive patterns on the inner layer to increase wiring density. There are multilayer printed circuit boards that have multiple layers and the conductor patterns of each layer are connected by through-hole plating, or there are multilayer printed circuit boards that have 7 layers of metal patterns formed by printing on the surface of an inorganic insulating substrate such as alumina ceramic or glass. A so-called thin film wiring board is used, in which a metal pattern layer is formed on the surface of a film wiring board, or a resin base material or an inorganic insulating substrate by a method such as continuous plating or vapor deposition.

In the case of these methods, holes have been made in the insulating layer by drilling or punching to connect the upper and lower conductor pattern layers, and the holes have been filled with plating or conductive material. However, ultra-high-density wiring has become difficult due to the limits of miniaturization of drill diameters and punching pins.

In recent years, there has been a high demand for ultra-high-density wiring technology for high-speed calculations in ultra-large computers, and the dry etching and wet etching techniques used in LSI are being applied to form insulating layers and via holes (through holes). However, the process is complicated, making it extremely expensive and difficult to put into practical use. Also, since the insulating layer is etched using photoresist, it takes approximately
The via hole can only be formed with a taper angle of
The K to be secured is to μmK for large diameters, which is an impediment to high-density packaging.

In order to solve this drawback, attempts have been made to use photoresist as it is as an insulating layer.
-／／Ri6ri! It is disclosed in the publication No.

However, the disclosed resin has low heat resistance, so KL
It cannot withstand the heat required when mounting the SI, and has the drawback of lacking reliability.

Furthermore, it is highly conceivable to use a photosensitive polyimide precursor to impart the heat resistance of the photoresist.

However, Tokukai Akira! Hiro-/4cj7ri reference, Tokukai Sho! When the photosensitive polyimide precursor described in 7-/4♂ Rihiro λ publication etc. is used as an insulating layer of a multilayer wiring board,
These resins harden on the entire surface of copper used as a conductive material even without irradiation with ultraviolet rays, making it impossible to form via holes. It requires a pretreatment step to form a thin layer of Ti + Cr, making the process very complicated and making it difficult to put it into practical use.

Further, the photosensitive polyimide precursors disclosed in these publications are negative-type polymers whose ultraviolet irradiated portions are photocured.

In the case of a negative type, most of the part that becomes the insulating layer is photocured and the minute part of the via hole part is removed by development, so K, which forms ultrafine via holes, is inconvenient, and the part of the insulating layer that has been photocured is A portion of the surface was also removed with developer, and approximately
There was a drawback that the film thickness was reduced by 10%.

[Problems to be solved by the invention] The present invention eliminates the above-mentioned drawbacks and makes it possible to form via holes with extremely small diameters with high precision and to efficiently form multilayer wiring boards with excellent flatness. The present invention aims to provide a method for manufacturing wiring boards suitable for high-density packaging.

[Means for solving problems]

That is, the present invention includes (a) a first layer forming step of forming a conductive pattern on the surface of a support substrate; (b) a positive photosensitive polymer layer is provided on the surface of the first layer; An insulating layer forming process in which a hole for a via hole is formed by irradiation with light through the layer, and a hole for a via hole is formed by heat treatment of the layer to make it highly insulating. The present invention relates to a method for manufacturing a multilayer wiring board characterized by including a step of forming a wiring layer that is electrically connected to a lower layer circuit through a hole.

The first layer forming step of the present invention includes an alumina ceramic plate,
Plating or vapor deposition is applied to the surface of a supporting substrate selected from glass plates, metal plates such as aluminum or iron insulated with resin or enamel, glass cloth-based epoxy substrates, glass cloth-based polyimide substrates, polyimide films, etc. This is a process of forming a conductive pattern of steel and/or chromium, etc. using a method such as a method, a sputtering method, a pressure bonding method, or a coating method.

A specific example of conductor formation is shown below. The underlying substrate is cleaned with a cleaning agent selected from organic solvents, acids, and alkaline aqueous solutions, or the surface is cleaned/cleaned by plasma etching using a gas containing OH, CF4, etc.

Then, using sputtering equipment, chromium, steel, gold,
A single layer or multiple layers of a metal selected from nickel, aluminum, etc. are deposited on a base substrate. When sputtering is used, the adhesive strength between the base substrate and the conductor is excellent. It is also possible to form a conductor on the base substrate by vapor deposition. Furthermore, it is also possible to increase the thickness of the conductor by depositing a conductor metal such as steel on the conductor layer by electroplating or the like. An excellent method in terms of process is to form a copper layer on a base substrate by electroless plating, and then to form a conductor pattern by pattern plating using a metal resist.

Further advantageous methods include a method of laminating metal foil such as copper foil and forming a pattern by chemical etching, and a method of printing a conductive material by screen printing to form a pattern. In addition, in this first layer forming process, it is also possible to form not only a conductor but also a resistor pattern and a capacitor pattern using a paste commonly referred to as thick film ink to form a functional circuit on the first layer. .

The disconnection layer forming step of the present invention is a step of forming fine via holes using a positive photosensitive polymer as an insulating layer.
More specifically, it includes the following steps. That is, when a polymer with a functional group that is insoluble in a developer is irradiated with ultraviolet rays, the polymer itself changes to a structure that is soluble in the developer, or it chemically combines with a second component and dissolves in the developer. The polymer and/or composition to be changed is dissolved in a solvent such as dimethylformamide or N-methylpyrrolidone, and supported using a coating machine such as a spin coater, a roll coater, or a screen printer. It is applied onto a substrate and the solvent is removed using a hot air dryer or hot plate to form a coating film. Next, using a photomask, the via hole is irradiated with ultraviolet rays to harden it. Next, the exposed portion is developed and removed using a predetermined developer and rinse solution to form a via hole, and an insulating layer with excellent heat resistance is formed by heat treatment.

The positive photosensitive polymer that can be used in the present invention includes, for example, the general formula (al) [wherein X is a (λ+n)-valent carbocyclic group or a heterocyclic group, carbocyclic group or or 10-
C-NH-1R is a group having a carbon-carbon double bond, and W is -COOR when ROM is removed by heat treatment.
A group capable of reacting with a carbonyl group to form a ring, n is /, nine is λ, m is θ, /l or co, and C0OR and 2
are in an ortho position or an alternative position to each other. ] A composition comprising a polymer having a repeating unit represented by fbl/molecule, a compound having one mercapto group and seven or more carboxyl groups or sulfone groups per molecule (mercapto-shun), and a tel photopolymerization initiator. can be mentioned.

In the formula [Eq. Aromatic rings, viridi/, heterocyclic groups such as thiophene, and the general formula [ri1]k l is 0 or /SX, CHs, or CF3.

] and the like. Among these, a group represented by the general formula [H1] which is carbon σ3 or -C- is preferred, and a group represented by the formula %) [:) is more preferred.

Y in the general formula CI) is a di-, tri- or tetravalent carbocyclic group or heterocyclic group, such as a group having 10 to 10 carbon atoms derived from naphthalene, anthracene, etc. divalent aromatic hydrocarbon ring of lr, a heterocyclic group derived from pyridine, imidazole, etc. and the formula [Yl in the formula is Fl 1CHs , (CHs)zcH,
0CR3, Coon, “rohalogen atom, ・C0OH
, 5(hHt or NO2, Y, and Y6 are T(, CN
, halogen atom, CH3, OC city, 5O3H or 0
1 (is.) etc. Among these, groups with 1 carbon number
0-/Hiro's divalent aromatic hydrocarbon ring and Y2-gari SO! A group represented by the formula (US) in which -1-〇- or -S- and 1 and 1 are both hydrogen atoms is preferred, and a group represented by the formula -0-0-0-0=O÷・is preferred.

The above general formula CIl K Ohmaru W can be converted to ROH by heat treatment.
(R has the same meaning as above),
A group that can react with the carbonyl group of -COOR to form a ring, and as such, -Cg NH*
is suitable. Furthermore, n is preferably λ.

Furthermore, 1 R in the above general formula [I] is a group having a carbon-carbon double bond, and as such,
For example, the formula -Rt+CwCH hinoki 82
Cit ] [In the formula, R8 is a divalent hydrocarbon group having / to /2 carbon atoms, R2 and R4#i hydrogen atom. is a hydrocarbon group having carbon number / to r, R3 and RS are hydrogen atoms or methyl groups, 8 is an integer of IN Hiro, t and U are 0 or /. ] Aliphatic hydrocarbon group represented by the formula, alicyclic hydrocarbon group represented by the general formula [R+, R4 and t in the formula have the same meanings as above] [R+, Rz, t and An aromatic hydrocarbon group represented by 1 having the same meaning as above, a carbon-carbon dicarbon group represented by the general formula % formula % () [R1, R2 and R in the formula have the same meaning as above] Examples thereof include a group having a double bond and an ether bond, or a group having an ester bond conjugated with one double bond.

Among these, the general formula % formula %) [In the formula, R1 is a divalent hydrocarbon group having carbon number/~2, R;
is a hydrogen atom or an alkyl group having carbon number/-4, and g
is preferably a group represented by θ or /], more preferably an allyl group or a λ-allyloxyethyl group.

The polymer used as component (a) can be produced by polycondensation or polyaddition of a compound represented by the general formula and a compound represented by the general formula 22 Y Zt CM). An example of zl in the above general formula [v],! - is -COOH(M), Co CI CM2:l,
NCOCVs 1, Nu! (V4), -OH(Vs)
, and the abbreviations of the corresponding general formula [v] are shown within 0. In addition, examples of the general formula CVi'JK are CQCIC■1), C0OHC"lit)
, -NCO(Ms), MHz C'Vi4), and the abbreviations of the corresponding general formula C] are shown within 0. Note that X, R, Y and W have the same meanings as above.

By polycondensation or polyaddition reaction between the compound represented by the general formula [v] and the compound represented by the general formula (WE), -
2I and z2- react to form linked chain 2. zl and 2. A preferred combination with, producing 20
Table 7 summarizes the types and the names of the ring structures formed when the obtained polymers are heat-treated.

[Note) */II structure ■M: Imide ring QD: Quinagri/dione ring OD nioxazinedione ring In addition, in the combination of numbers / and - in Table 1, W
When is CONH2, an isoindoroquinazolinedione ring is formed by the heat treatment, and this structure is preferred because it exhibits particularly high heat resistance.

Moreover, the polymer of component (a) can also be produced by the following method. That is, a product obtained by reacting a compound represented by the general formula % formula % [X#- in the formula has the same meaning as above] with a compound represented by the general formula [■3] or CViJ The carboxyl group of
The polymer can be obtained by reacting with an epoxy compound represented by the general formula [R in the formula has the same meaning as above]. Preferred combinations and reaction formulas for this reaction are shown in formulas [■i], [■2] and [■3].

(The following is a blank space) 2" + Blind funnel Obtained by ring opening.

Examples of nucleic acid anhydrides [v6] include pyromellitic anhydride,! ,3:! Aψ-benzophene/tetracarboxylic dianhydride, 3. XIAψ-diphenyl ether tetracarboxylic dianhydride, J, 3: lA, II diphenyl tetracarboxylic dianhydride, J, J: lAll-diphenyl sulfone tetracarboxylic dianhydride, 2j, t
, 7-su7talentetracarboxylic anhydride, thiophene-2 7, 4/, J'-tetracarboxylic anhydride,
Examples include 2co-bis-(3,Hiro-biscarboxyphenyl)propane anhydride, and examples of alcohol ROH include allyl alcohol, crotyl alcohol, geraniol, nerol, citronellol, perillyl alcohol, hydroxymethylstyrene, etc. It can be mentioned. When these acid anhydrides are reacted with alcohol ROM, the reaction is accelerated by adding pyridine, dimethylaminopyridine, etc.

The combination of numbers/and λ in Table 7 above is one example of a preferred embodiment, and the diamines represented by the general formula CM, 1 used in this combination include, for example,
lA, <z'-diaminodiphenyl ether, pseudoψ-diaminobiphenyl, cedar diaminotoluene, Il, Hiro'-diaminobenzophenone, pseudohiro'-diaminodiphenylsulfone, phenylindane diamine, tA≠I-
Diaminodiphenylmethane, p-phenylenediami;'
, Itl-7 2-di-diamine, 4j-diaminonaphthalene, J, J'-dimethoxy-tAp'-diaminobipheny, j, j'-dimethyl-Ekahiro-cyaminobi'phekyl, 0-) luidine sulfone , 2-bis(Hiro-aminophenoxyphenyl)propane, bis(Hiro-aminophenoxyphenyl)sulfone, bis(4t-aminophenoxyphenyl)sulfide, 4≠-bis(Hiro-
aminophenoxy)benzene, 43-bis(≠-aminophenoxy)benzene, j, Hiro'-diaminodiphenyl ether, Z9-bis(4cm aminophenyl)anthracene-(10'), ? , butace(Hiro-aminophenyl)fluorene, 3,3'-diaminodiphenylsulfone, lAψ'-di(3-aminophenoxy)diphenylsulfone, lA4! ′-diaminobenzanilide,
J, <4'-diaminodiphenyl ether, each ψ'-[
t, 3-)unishinbis(/-methylethylidene)]
, 41. Ii4'-[/, Hiro-phenylene bis(/
-methylethylidene)), pseudoF'-(m-)unishindiisopropylide/)bis(m-)luidine), Kug'-
(p-phenylene diisoglohyritene) bis(m-toluidine) and the like.

Of the positive photosensitive polymer composition used in the present invention (
The mercap) IP compound used as component b) can be exemplified by the general formula %. However, m Fl is an integer of 7 or more, and US is an (m+/)-valent hydrocarbon group that does not contain a "reactive" unsaturated carbon-carbon bonding group and may contain a nitrogen or oxygen atom. "Reactive" herein means a group that produces an unsaturated carbon.

Mercaptoic acid D/'] and [v] are represented by the following general formula.

[In the formula, v and w are integers of 7 or more% XX7 is θ or an integer of 7 or more, 2 is Ol or /s R1+ is a hydrogen atom or a carboxyl group, A, B, C, D% E is a carbon atom or The nitrogen atom or sulfur atom, R, is a carboxyl group or a sulfonic acid group. ] Mercapto acids suitable for the present invention include 3-mercaptopropionic acid, thioglycolic acid, 2-mercaptopropionic acid, thiomalic acid, /2-mercaptotridecanoic acid, thiosalicylic acid, l-carboxymethyl-j-j mercapto -/, 2j, F-tetrazole, l-sulfoxymethyl-yo-mercap) -/, 23. Hiro-tetrazole, 2-carboxymethylthio-! -Mercaptothiadiazole and the like, but are not limited to these.

An example of a preferred specific mercapto acid is thiomalic acid. These mercapto acids have 0.6 l for the polymer.
-2θ% added, preferably! ~lj% is added.

Moreover, these mercapto acids can be used not only alone but also in combinations of several types.

In addition, (
The photopolymerization initiator used as component c) is benzophenone, acetophenone, acenaphthene-quinone, methyl ethyl ketone, parellophenone, hexaphenone, γ-
Phenylbutyrophenone, p-morpholinopropiophenone, dibenzosuberone, goomorpholinope/zopheno/, Hiro'-morpholinodeoxybenduin, p-diacetylbenzene, Hiro-aminobenzophenone, l'-methoxyacetophenone, benzaldehyde, α- Tetralone, teracetylphenanthrene, 2-acetylphenanthrene, 10-thioxanthenon, 3-acetylphenanthre/, 3-acetylindole, terfluorenone, l-indanone, /, J, j-triacetylbenzene, thioxanthin-terone, Xanthine-terone, 7-H-benzCd5)a/thracen-7-one, l-7taldehyde, fluore/-2-one, l'
-acetonaphthone! -acetonaphthone, 23-butanedione, Michler's ketone, benzyl, aromatic oximes and l-phenyl-y-mercapto/H-tetrazole, and the like, but are not limited to these.

When these positive-working photosensitive polymers are used, the developing solution used is an aqueous solution of inorganic alkalis such as sodium hydroxide, sodium metasilicate, or sodium phosphate, or an organic alkali such as tetramethylammonicum hydroxide. Examples include aqueous solutions of pudding and the like. In addition, these can be used not only in aqueous solutions but also in ethanol, ingropanol, N
, N-dimethylformamide, acetone, dimethyl sulfoxide, etc., and a mixed solution of water and an organic solvent that is miscible with water. In addition, other examples of developing solutions include:
Examples include, but are not limited to, ammonia water and a methanol solution of sodium methoxide.

Furthermore, since alkali metals may have an adverse effect on the properties, it is preferable to use an organic alkali developer as the developer. Further, immediately after the first development, it is preferable to perform a neutralization treatment using an acid such as dilute sulfur or acetic acid as a rinsing liquid.

The wiring layer forming process in the present invention refers to forming a wiring pattern of steel, chromium, etc. on the surface of the insulating layer by plating, sputtering, vapor deposition, etc., and at the same time making the via hole a conductor, forming a conductor pattern in the lower layer. This is the process of electrically connecting the More specifically, for example, in the case of a wiring layer formation method using a plating method, the support substrate or insulating layer is roughened by liquid honing or plasma etching to improve the wettability and adhesion of the surface of the layer and the inside of the via hole. Then, the entire surface is activated using organic silver salt, etc.
Electroless steel plating is applied to the entire surface to form a conductor.

Next, portions other than the wiring pattern are masked using photoresist, and the copper wiring pattern and the inside of the via hole are plated by electroplating. Next, the photoresist is peeled off and quick etching is performed with an aqueous ammonium persulfate solution to remove unnecessary electroless plated parts other than the wiring parts.

Instead of the electroless plating method in this method, there is also a method of forming a wiring pattern by sputtering or vapor deposition.

By repeatedly performing the formation of the insulating layer and the wiring layer, a multilayer wiring board having a plurality of wiring layers can be manufactured.

As explained above, in the manufacturing method of the present invention, a conductor pattern is formed in advance and then a polymer is formed, so that each layer becomes a flat layer. In particular, the polymer used to form the insulating layer of the present invention has a low viscosity even when mixed with a highly concentrated resin solution, so it has excellent coating film formation properties, greatly contributes to flattening, and can form a thick insulating layer. It has the advantage of being able to be formed in a single coating operation, and not only facilitates the mounting of LSI components, but also provides a board with excellent insulation resistance and connection reliability.

In addition, when forming the via hole conductor for connecting the upper conductor pattern and the lower conductor pattern, the insulating layer is directly formed by photoprocessing without using photoresist, making it possible to perform extremely fine processing under high pressure. It is simplified and costs can be reduced.

Furthermore, the conductor of the via hole part formed by one insulating layer is
In addition to serving the purpose of electrical connection, the implemented LS
It is effective as a conductor of heat generated from parts such as I,
Heat removal design is also possible in the multilayer wiring board of the present invention.

Next, an outline of the manufacturing process of a multilayer wiring board according to the present invention will be schematically shown using cross-sectional views.

1(a) to (j) are cross-sectional views showing specific examples of each process. FIG. 1(a) is a cross-sectional view showing a first wiring layer formed on a support substrate; , 2 is the first layer wiring pattern. The cross section of the photosensitive polymer 3 is shown after it has been coated and dried. (cl shows the step of curing the photosensitive polymer 3 by irradiating ultraviolet rays with an ultra-high pressure mercury lamp through a photomask. j shows the cured layer. Td) is a process in which the uncured part is removed and patterned using a liquid solution consisting of N-methylpyrrolidone and isopropyl alcohol, and then heat treatment is applied to impart heat resistance. 6 is the part that has been hardened by heat treatment, and 7 is for via holes. Indicates a hole.

(e) to (j) show the steps of forming a wiring pattern and a via hole conduction part. r represents a plating active layer formed by electroless plating or sputtering, ri represents a photoresist for a plating mask, /θ represents a plating mask cured with ultraviolet light, and // represents a conductive layer formed by electroplating.

〔Example〕

Next, examples will be shown.

Reference example: In a four-loaf flask equipped with a stirrer, a reflux condenser with a drying tube, and a thermometer, add 3 volumes of allyl alcohol.
3'-% g'-benzophenone tetracarboxylic dianhydride 1001 was added and stirred in an oil bath at 100°C for 3 hours. After cooling, allyl alcohol was distilled off from the reaction mixture using an evaporator and dried in vacuum to obtain 47179.
A solid was obtained. This product is designated as A-/.

Separable flask KXA-/2 units 2t1
γ-Butyrolactone 7/, Fd, pyridine zl- and lAg'-diaminodiphenyl ether♂? was added and stirred at room temperature for 30 minutes to obtain a homogeneous solution. Dicyclohexylcarbodiimide xo, tt was added to this solution under cooling with ice/water, and after stirring for 3 hours, ethanol! - was added and stirred for an additional 7 hours. The reaction mixture was passed through, and the p solution was added dropwise to stirring methanol in Step 21.
The precipitate formed was separated by decantation. Dissolve this precipitate in /l#td OTHFK and stir.
/do /, jllD io/exchange water pressure dropwise. The generated precipitate was air-dried for a time and then vacuum-dried. This product is B
-/.

This B-/ is 2, f1 is mercaptoic acid, thiomalic acid 3.2rf and Michler's ketone 101 are Hiro0tnt.
of N-methylpyrrolidone to form a polymer solution C-/
was prepared.

Reference example λ In reference example 1! , 1 pyromellitic anhydride instead of 3'-% Hiro'-benzophenonetetracarboxylic dianhydride? ! ! The reaction was carried out in the same manner except that 33rit was used. The obtained product is designated as A-u.

C-/3J,'I- in a separable flask with a volume of
f.

γ-Butyrolactone 3jOvt and pyridinej
Added YuJ-fRt and stirred at room temperature for 30 minutes to obtain a homogeneous solution.

This solution was added to thionyl chloride λ3 under cooling with ice/salt cryogen.
．． The mixture was stirred for 30 minutes at an internal temperature of 0 to -3°C. Furthermore, after removing the cryogen bath and stirring at room temperature for an hour and a half, tA
When a solution consisting of tf and γ-butyrolactone/7j1nt was added, the internal temperature rose to 30"C. After stirring for 12 hours, 10 minutes of ethanol was added and left to stand for 16 hours. The reaction mixture was stirred vigorously. Slowly drip it into Hirono's ion-exchanged water, allowing the precipitate to pass through.
Furthermore, after washing five times with JL ion-exchanged water, vacuum drying was performed.

This product is designated as B-1.

The obtained B-2 was 211, J-mercaptopropionic acid was 3.73? , benzyl/, O9z Michler's ketone/
, Of was dissolved in a mixed solvent of N-methylpyrrolidone/j- and cyclopentane/jtd, and the polymer solution C-
I got 2.

Example: After degreasing and cleaning a ceramic substrate of j0 square, thickness: IEII, it was treated with a spackling device (manufactured by Nichiden Aneba).

5PF-II-30H) to attach too much Cr and 2!00 A of Cu. After that, apply photoresist (Microposit TF-) for Metsukiresist.
Jo+ (manufactured by Sigley) was buttered to a thickness of 6 μm.

Next, put it in a sulfuric acid steel plating bath and perform copper plating at a current density of jOm~-, and the thickness! μm, line width! Opm.

A copper pattern with a land diameter of 100 μm and a pitch of j00 pm between each land was obtained. After removing the metal resist with a special remover, unnecessary - and Cr layers were quickly etched with an ammonium persulfate aqueous solution and a cerium nitrate aqueous solution.

The polymer solution C-/ prepared in Reference Example/ was applied to the obtained first layer wiring board using a spin coater at a rate of 100 Orpl.
/! After forming a film by rotating for I: seconds, it was dried for 10 minutes using a hot air dryer at 70°C.

Next, a positive photomask with white circles of VC71 μmφ and a grid spacing of 200 μm was placed in close contact with λ.
The film was exposed for 2 minutes using a mask aligner (exposure machine) equipped with an ultra-high pressure mercury lamp. After exposure, 0. z% sodium hydroxide in water/inoprobil alcohol solution in equal parts! The film was heated for 1 minute, followed by rinsing with 3000 dilute sulfur, washing with water, blowing with N2, and drying.

Thereafter, it was heat-treated at Hiroo 0°C for 2 hours in an open atmosphere in a Nzff atmosphere.

The thickness of the obtained insulating film was measured and found to be /jpm.

Next, the surface of the layer and the inside of the via hole were cleaned and roughened by liquid honing (-2Kf/cj). Next K.

This is followed by pretreatment for electroless plating (manufactured by Muromachi Chemical).

MK-200 and MK-330) and then electroless plating (MK-4jθ, Muromachi Chemical Co., Ltd.)
K immersion and electroless plating. Next, a second layer wiring pattern having a thickness of 5 μm was formed by electroplating in the same manner as in the first layer wiring pattern 1.

In the same way, insulating layer formation and wiring pattern formation were repeated nine times.
A multilayer wiring board was manufactured in which the wiring layer was a Hiro layer. This via hole! A multilayer wiring board with θO holes was subjected to a heat shock test of 100 times after being left in a dry heat at ≠20℃ for 60 minutes and left at room temperature at 23℃ for 10 minutes, and then the via hole connection reliability was evaluated. There were no abnormalities.

Example 2 Poly 1-solution C-λ was used, the via hole diameter was 30 μm
A 5-layer wiring board with (mask dimensions) was manufactured.

As a result of cutting this multilayer wiring board and observing the cross section of the via hole portion using a resin encapsulation method, it was found that via holes with a diameter of 20±tpm were formed with a taper angle of about 7j''.

〔Effect of the invention〕

The method of forming the insulating layer of the present invention using a positive photosensitive resin is as follows:
The via hole portion can be microfabricated and its shape can be formed steeply, and it is possible to manufacture a multilayer wiring board in which each layer is flattened and has excellent connection reliability.

[Brief explanation of drawings]

Figures 1) to (j) are schematic cross-sectional views showing a specific example of manufacturing a multilayer wiring board according to the present invention in the order of steps. In the figure, l...support substrate c...first layer wiring pattern 3...photosensitive polymer layer Hiroshi...positive photomask! ... Part B hardened by ultraviolet irradiation ... Insulating layer 7 hardened by heat treatment ... Hole t for via hole ... Plating active layer by electroless plating or sputtering method

Claims (1)

[Claims] (1) In the production of a multilayer wiring board, (a) a first layer forming step of forming a conductive pattern on the surface of a supporting substrate; (b) a positive photosensitive layer on the surface of the first layer; an insulating layer forming step of providing a polymer layer, irradiating light on the layer through a photomask, forming holes for via holes by developing, and heat-treating the layer to make it highly insulating; (c) further the layer; A method for manufacturing a multilayer wiring board, comprising the step of forming a wiring layer in which a conductor circuit is formed on the surface of the board and electrically connected to a lower layer circuit through a via hole. (2) The positive photosensitive polymer layer used in the insulating layer forming process is (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [X in the formula is a (2+n)-valent carbocyclic group or a heterocyclic group, Y is a (2+m)-valent carbocyclic group or a heterocyclic group,
Z is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ R is a group with a carbon-carbon double bond, W is a group that has a carbon-carbon double bond, and W is A group capable of reacting with the carbonyl group of -COOR to form a ring when ROH is eliminated, n is 1 or 2, m is 0, 1 or 2, and COOR and Z are mutually in the ortho or bery position. There is a relationship between ], (b) a compound having one mercapto group and one or more carboxyl or sulfonic acid groups per molecule (mercapto acid), and (c) a photopolymerization initiator. A method for manufacturing a multilayer wiring board according to claim 1, characterized in that: