DE102006037273B4 - Flattened, printed circuit board coated with resin - Google Patents

Abstract

A method of manufacturing a printed circuit board, comprising the steps of: applying a photo and thermosetting resin composition (105) to a surface and the through hole (103) of a printed circuit board having the through hole (103); performing the following steps (1) and (2); applying the photo and thermosetting resin composition (105) to the other surface of the printed circuit board; and sequentially performing the following steps (1) through (3) :( 1) flattening or leveling the surface of the applied resin with a platen roller (107, 108); (2) photocuring the applied resin; and (3) thermosetting the photocured resin.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a printed circuit board and a method for its production. The invention particularly relates to a printed circuit board in which both surfaces (front and back sides) are greatly flattened or strongly matched and (in particular the entire surface thereof) is coated with a resin and, for example, a flattened or matched and coated with resin Printed circuit board, a four-layer printed circuit board which can be used as the inner layer, and a double-sided printed circuit board which can be used as the outer layer, and a method for producing the same.

Description of the relevant prior art

As a method of manufacturing a flattened printed circuit board with plugged holes, a method is known in which a through hole of the printed circuit board is first plugged with a thermosetting resin composition and then the input resin is thermoset and a hardened one Part of the resin is removed from the surface of the printed circuit board by polishing to flatten the surface (Patent Document 1).

However, this method has a problem in that the number of manufacturing steps is increased by the polishing and that the polishing cost is increased. The method also has another problem in that the polishing causes the printed circuit board to deform (or change dimension).

Then a method of flattening the surface of the printed circuit board without polishing has been sought. As such a method, the method according to Patent Document 2 has been proposed. That is, in this method, the through hole of the printed circuit board is first plugged with a hardening resin [ 7A , 705 ]. Then the printed circuit board with hardening resists, sandwiched by thermal pressing with the printed circuit board at the hardening resists, is press-connected [ 7B , 727 ]. Thereafter, the applied resin and the hardening resist are fully hardened by high temperature heating [ 7C , 728 ].

With this method, however, it is difficult for the resist [ 7B , 727 at a recess [ 7B , 704a ] fully adheres between the circuits, particularly in a part with many circuits, even when vacuum pressing is performed. As a result, a gap is easily formed between the recess and the resist film, and in some cases, air remains in the gap. Therefore, on the surface of the resist film [ 7B , 725 ] the so-called "popcorn phenomenon", in which the remaining air is thermally expanded during the subsequent high-temperature heating and sometimes bubbles appear on the surface of the resist film.

On the other hand, because a large amount of the resist resin [ 7B , 727 ] is used to make a recess [ 7B , 704b ] is used between the circuits in a part with few circuits, sometimes a notch on the surface of the resist after thermosetting. [ 7C , 726 ].

Therefore, because a printed circuit board made by such a method has a surface with bubbles and notches and it is not completely flattened, the component attachability (bump bonding ability and the like) of the printed circuit board is reduced.

Furthermore, the surface of the printed circuit board has bubbles and notches, the thickness of an insulating layer, especially the thickness of an insulating layer formed on a conductive circuit layer [ 7C , 702 ] is not stabilized, causing a decrease in impedance characteristics such as an increase in fluctuation in impedance.

That is, in a peripheral bladder part [ 7C , 729 ] is the thickness [ 8A , 831 ] the insulating layer formed on the conductive circuit layer [ 8A , 802 ] gradually in Direction of a middle part of the bladder increased. On the other hand, in a notch peripheral part [ 7C , 730 ] the fat [ 8B , 831 ] the insulating layer formed on the conductive circuit layer [ 8B , 802 ] gradually decreased toward the central part of the notch.

• [Patentdokument 1] Offengelegte japanische Patentanmeldung ( JP-A) Nr. 2001-15909
• [Patentdokument 2] Offengelegte japanische Patentanmeldung ( JP-A) Nr. 2001-111214

Also, even in a multilayer printed circuit board made using such a printed circuit board as an inner layer or an outer layer that is not completely flattened, a decrease in component mounting ability (bump bonding ability and the like) and impedance characteristic or the like is caused.

• [Patent Document 1] Japanese Patent Application Laid-Open ( JP-A) No. 2001-15909
• [Patent Document 2] Japanese Patent Application Laid-Open ( JP-A) No. 2001-111214

In view of the above situation, it is an object of the present invention to produce a flattened resin-coated printed circuit board in which both surfaces of the printed circuit board are extremely flattened and the thickness of the printed circuit board in all areas (i.e., all portions and Parts) of the printed circuit board is fixed, thereby making the component attachability (bump bondability and the like) and the impedance characteristics (impedance stability and the like) excellent without the need for polishing. It is a further object of the present invention to provide a printed circuit board which has been made from such a printed circuit board and in which both surfaces are greatly flattened, e.g. a multi-layer printed circuit board (especially a four-layer printed circuit board) which is suitable as an inner layer, and a printed circuit board (in particular a double-sided printed circuit board) which is suitable as an outer layer.

SUMMARY OF THE INVENTION

In order to achieve the above object, the named inventors conducted investigations and, as a result, made the following invention.

• Aufbringen einer photo- und wärmehärtenden Harzzusammensetzung auf eine Oberfläche und das Durchgangsloch einer gedruckten Leiterplatte mit dem Durchgangsloch;
• nacheinander erfolgendes Durchführen der folgenden Stufen (1) und (2);
• Aufbringen der photo- und wärmehärtenden Harzzusammensetzung auf die andere Oberfläche der gedruckten Leiterplatte; und
• nacheinander erfolgendes Durchführen der folgenden Stufen (1) bis (3):
  1. (1) Abflachen bzw. Abgleichen der Oberfläche des aufgebrachten Harzes mit einer Druckwalze;
  2. (2) Photohärten des aufgebrachten Harzes; und
  3. (3) Wärmehärten des photogehärteten Harzes.

According to a first embodiment of the present invention, there is provided a method for producing a printed circuit board, comprising the steps:

• Applying a photo and thermosetting resin composition to a surface and the through hole of a printed circuit board having the through hole;
• successively performing the following stages (1) and (2);
• Applying the photo and thermosetting resin composition to the other surface of the printed circuit board; and
• successively performing the following stages (1) to (3):
  1. (1) flattening the surface of the applied resin with a pressure roller;
  2. (2) photocuring the applied resin; and
  3. (3) thermosetting the photocured resin.

• Aufbringen einer photo- und wärmehärtenden Harzzusammensetzung auf eine Oberfläche und das Durchgangsloch einer gedruckten Leiterplatte mit dem Durchgangsloch;
• nacheinander erfolgendes Durchführen der folgenden Stufen (1) bis (2);
• Aufbringen der photo- und wärmehärtenden Harzzusammensetzung auf die andere Oberfläche der gedruckten Leiterplatte;
• nacheinander erfolgendes Durchführen der folgenden Stufen (1) und (2);
• (A) zuerst erfolgende Durchführung der obigen Stufe (3), als Nächstes laminierendes Verpressen der gedruckten Leiterplatte und der Press-Bindungsmaterialien, wobei die gedruckte Leiterplatte sandwichartig zwischen den Press-Bindungsmaterialien angeordnet ist, um die Press-Bindungsmaterialien durch Pressen zu binden, oder
• (B) laminierendes Verpressen der gedruckten Leiterplatte und der Press-Bindungsmaterialien bei der Wärmehärtungstemperatur oder höher des photogehärteten Harzes, wobei die gedruckte Leiterplatte sandwichartig zwischen den Press-Bindungsmaterialien angeordnet ist, um die Press-Bindungsmaterialien durch Pressen zu binden, und auf diese Weise gleichzeitig die genannte Stufe (3) durchzuführen;
• Bilden eines Lochs von der Oberfläche des PressBindungsmaterials zu einer Leiterschicht, um einen Mikroweg zu bilden;
• Aufbringen einer Gesamtflächenplattierung;
• Bilden eines Strom- oder Schaltkreises von einer Plattierungsschicht; und
• Aufschichten eines Resists.

According to a second embodiment of the present invention, there is provided a method of manufacturing a multilayer printed circuit board, comprising the steps of:

• Applying a photo and thermosetting resin composition to a surface and the through hole of a printed circuit board having the through hole;
• successively performing the following stages (1) to (2);
• Applying the photo and thermosetting resin composition to the other surface of the printed circuit board;
• successively performing the following stages (1) and (2);
• (A) performing step (3) above first, next laminating pressing the printed circuit board and the press bonding materials, the printed circuit board being sandwiched between the press bonding materials to press-bond the press binding materials, or
• (B) laminating pressing the printed circuit board and the press bonding materials at the thermosetting temperature or higher of the photocured resin, the printed circuit board being sandwiched between the press binding materials to bond the press binding materials by pressing, and thus simultaneously perform said step (3);
• Forming a hole from the surface of the press bond material to a conductor layer to form a micro path;
• Applying total area plating;
• Forming a circuit or circuit from a plating layer; and
• Layering a resist.

According to a third embodiment of the present invention, there is provided a method of manufacturing a multilayer printed circuit board according to the second embodiment, wherein the resist has an opening.

• Aufbringen einer photo- und wärmehärtenden Harzzusammensetzung auf eine Oberfläche und das Durchgangsloch einer gedruckten Leiterplatte mit dem Durchgangsloch;
• nacheinander erfolgendes Durchführen der obigen Stufen (1) und (2);
• Aufbringen der photo- und wärmehärtenden Harzzusammensetzung auf die andere Oberfläche der gedruckten Leiterplatte; und
• nacheinander erfolgendes Durchführen der obigen Stufen (1) bis (3) und:
• Bilden einer Öffnung in der aufgeschichteten Harzschicht.

According to a fourth embodiment of the present invention, there is provided a method of manufacturing a printed circuit board, comprising the steps of:

• Applying a photo and thermosetting resin composition to a surface and the through hole of a printed circuit board having the through hole;
• sequentially performing steps (1) and (2) above;
• Applying the photo and thermosetting resin composition to the other surface of the printed circuit board; and
• successively performing the above stages (1) to (3) and:
• Form an opening in the layered resin layer.

According to a fifth embodiment of the present invention, there is provided a method for producing a printed circuit board according to the third or fourth embodiment, wherein a surface exposed through the opening or a surface at the opening is covered with a plating.

According to a sixth embodiment of the present invention, there is provided a method of manufacturing a printed circuit board according to any one of the first to fifth embodiments, wherein the surface of a conductive layer of the printed circuit board is roughened with the through hole.

According to a seventh embodiment of the present invention, there is provided a printed circuit board manufactured by the manufacturing method according to any one of the first to sixth embodiments.

By means of the invention, a flattened or balanced, resin-coated printed circuit board can be produced without the need for polishing, in which both surfaces are extremely flat and the thickness of the printed circuit board in all areas (i.e. all portions and parts) ) of the printed circuit board is fixed, whereby an excellent fastening ability of the components (bump binding ability and the like) and excellent impedance characteristics (impedance stability and the like) are obtained. Furthermore, the invention can provide a printed circuit board which has been made from such a printed circuit board and in which both surfaces are extremely flattened, for example a multilayer printed circuit board (in particular a four-layer printed circuit board) which is suitable as an inner layer and a printed circuit board (in particular a double-sided printed circuit board) which is suitable as an outer layer.

Figure list

• The 1 shows a manufacturing method of a flattened, resin-coated printed circuit board according to the invention (in particular Example 1);
• the 2nd shows a manufacturing method of a four-layer printed circuit board according to the invention (in particular Example 3);
• the 3rd shows a manufacturing method of a double-sided printed circuit board according to the invention (in particular Example 4);
• the 4th shows a manufacturing method of a four-layer printed circuit board according to an embodiment in which a four-layer printed circuit board according to the invention is modified and expanded;
• the 5 shows a manufacturing method of a four-layer printed circuit board according to a further embodiment, in which a four-layer printed circuit board according to the invention is modified and expanded;
• the 6 Fig. 11 shows a manufacturing process of a plugged printed circuit board according to Comparative Example 1, in which polishing is carried out;
• the 7 Fig. 11 shows a manufacturing process of a plugged printed circuit board in which a recess between circuits has not been previously filled with a resin according to a conventional method;
• the 8A shows a partial enlarged view of a bladder peripheral part and 8B Fig. 14 is a partially enlarged view of a notch peripheral part of a conventional printed circuit board with a notch and a bladder; and
• the 9A and 9B Fig. 14 shows partially enlarged cross sectional views of the vicinity of a bump bond part to show the occurrence of a bad bump connection when the bump connection of the BGA component is performed on a conventional four-layer printed circuit board with a notch and a bubble, the 9A FIG. 4 is a partial enlarged cross-sectional view showing poor bump bonding in the vicinity of the bubble on the surface of the four-layer printed circuit board, and wherein FIG 9B Fig. 3 is a partially enlarged cross-sectional view showing poor bump bonding in the vicinity of the notch on the surface of the four-layer printed circuit board.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the method of manufacturing the flattened resin-coated printed circuit board according to the invention, examples of the photo and thermosetting resin compositions (i.e., two-stage curing resin compositions in which primary curing by light irradiation is performed and secondary curing) are included by heating) includes those containing the following components [I] to [V].

1. [I]: Partial adducts of an epoxy resin with an unsaturated fatty acid
2. [II]: (meth) acrylates
3. [III]: Photo-crosslinking agent
4. [IV]: epoxy resins
5. [V]: latent curing agents

Preferred specific examples of photo- and thermosetting resin compositions are disclosed in Japanese Patent Application Laid-Open ( JP-A) No. 2003-105061 and 2004-75967 described.

The photo- and thermosetting resin composition contains a partial adduct of an epoxy resin with an unsaturated fatty acid as a component [I]. The epoxy number of the epoxy resin (hereinafter, sometimes referred to simply as the “raw material epoxy resin” for simplicity) as the raw material for the preparation of the component (I) is, for example, 130 to 400 and in particular 150 to 250. Examples of the raw material epoxy resins include epoxy resins of phenolic Novolak type, epoxy resins made from a polyfunctional phenol, epoxy resins with a naphthalene skeleton, epoxy resins of the glycidylamine type, epoxy resins with a triacine skeleton, epoxy resins of the glycidyl ester type and epoxy resins of the alicyclic type.

Preferred examples of the raw material epoxy resin include the individual compounds represented by the formulas [Chemical Formula I-E1] to [Chemical Formula I-E7] in Table 1. Particularly preferred examples include phenolic novolak type epoxy resins, epoxy resin Cresol novolak type, trisphenylmethane type epoxy resins, bisphenol A novolak type epoxy resins and dicyclopentadiene phenol type epoxy resins, at least one kind of which can be used.

In the formulas, "G" means a glycidyl group, except when "G" is used for a different definition.

The symbol n means an integer from 0 to 30 in the formulas [Chemical formula I-E1] to [Chemical formula I-E3]. The symbol n means an integer from 1 to 30 in the formulas [Chemical formula I-E4] to [Chemical formula I-E6]. The symbol n means an integer from 2 to 50 in the formula [Chemical Formula I-E7]. In the formula [Chemical formula I-E2], R ¹ and R ² each independently represent H or CH ₃ .

wobei jeder Rest von R¹ bis R³ unabhängig H oder CH₃ ist. Spezielle Beispiele für die ungesättigte Fettsäure schließen Acrylsäure, Methacrylsäure und Crotonsäure ein.Examples of unsaturated fatty acids as another raw material for the preparation of the component (I) include materials of the following formula [Chemical formula I-UFA].

wherein each radical from R ¹ to R ^{3 is} independently H or CH ₃ . Specific examples of the unsaturated fatty acid include acrylic acid, methacrylic acid and crotonic acid.

The component [I] can be produced by a usual manufacturing process. For example, the component [I] can be prepared by at least one kind of the raw material epoxy resin and at least one kind of the unsaturated fatty acid [for example, acrylic acid and / or methacrylic acid (hereinafter sometimes abbreviated as “(meth) acrylic acid” for the sake of simplicity)) If necessary, stir and mix with each other while heating.

The component [I] is obtained by partially adding the unsaturated fatty acid to the epoxy resin. That is, in the case of a partial adduct of the epoxy resin with the unsaturated fatty acid, at least one epoxy group remains in the epoxy resin after the addition of the unsaturated fatty acid. Specifically, the unsaturated fatty acid is preferably added to 20 to 80%, preferably 40 to 60% of the epoxy groups in the raw material epoxy resin. For an adduct in which the addition amount of the unsaturated fatty acid is less than 20% [which is sometimes referred to simply as an "adduct with less than 20% unsaturated fatty acid" and the like for convenience], there is occasionally adhesion in the primary photo-cured product. As a result, it is liable if a cover film described later is peeled off , the primary photo-cured product occasionally on the cover film. In contrast, in the case of an adduct with more than 80% unsaturated fatty acid, the toughness of the hardened product is deteriorated by reducing the epoxy groups, so that there is a tendency to crack.

Examples of the component [I] include adducts of a novolak-type epoxy resin with (meth) acrylic acid (specifically, an adduct of a cresol-novolak-type epoxy resin with acrylic acid, etc.) and the photo- and thermosetting resin composition may be at least one kind thereof contain.

Preferred examples of the component [I] include partial adducts of a phenol novolak type epoxy resin with acrylic acid, partial adducts of a cresol novolak type epoxy resin with acrylic acid, partial adducts of a trisphenylmethane type epoxy resin with acrylic acid, partial adducts of an epoxy resin of the bisphenol A novolak type with methacrylic acid, partial adducts of an epoxy resin of the dicyclopentadiene-phenol type with methacrylic acid and partial adducts of an epoxy resin of the phenol novolak type with crotonic acid, at least one type of which can be used.

The photo and thermosetting resin composition contains (meth) acrylates (i.e., acrylates and / or methacrylates) as component [II]. In the component [II], examples of the acrylates include esters of acrylic acids with hydroxy compounds. Examples of the methacrylates include esters of methacrylic acids with hydroxy compounds.

Examples of the above-mentioned acrylic acids and methacrylic acids include unsaturated fatty acids indicated by the formula [Chemical Formula I-UFA]. Specific examples of acrylic acids and methacrylic acids are acrylic acid, methacrylic acid and crotonic acid.

Examples of the above-mentioned hydroxy compounds include alcohols, (hemi) acetals or (hemi) ketals and hydroxy esters. Examples of the alcohols include lower alcohols, cyclic alcohols, polyhydric alcohols and aromatic alcohols, etc. In the hydroxy compounds, examples of the (hemi) acetal or (hemi) ketal condensates of the above alcohols (e.g. cyclic alcohols and polyhydric alcohols or the like) with formaldehyde or hydroxyaldehyde include. In the hydroxy compounds, specific examples of the hydroxy acid esters include ring opening adducts of caprolactone with furfuryl alcohol, neopentyl glycol, hydroxypivalate or the like.

Preferred examples of the ingredient [II] include the individual compounds represented by the formulas [Chemical Formula II-1] to [Chemical Formula II-9] according to Table 2, and particularly isobornyl acrylate, dicyclopentanyl methacrylate, hydroxypivalic acid neopentyl glycol diacrylate, tricyclodecanedimethanol acrylate, trimethylolpropanitro trityl acrylate, diphenyl tetrachylacetate, diphenyl acrylate, diphenyl acrylate, diphenyl acrylate, trimethylol propane tra-phenyl acrylate, diphenyl acetonitrile acrylate, diphenyl tetra acrylate, diphenyl tetra acrylate, diphenyl acrylate, diphenyl tetra acrylate, trimethylol propane trenta acrylate, diphenyl tetra acrylate, diphenyl acrylate, diphenyl tetra acrylate, diphenyl acrylate, one, at least one type of which can be used.

The photo- and thermosetting resin composition contains a photo-crosslinking agent as component [III]. Examples of the component [III] include a component that allows a primary curing reaction by irradiation with light such as ultraviolet light or the like having a wavelength of 200 to 400 nm.

Specific examples of the component [III] include hydroxy ketones, benzyl methyl ketals, acylphosphine oxides, amino ketones, benzoin ethers, benzoyl compounds, thioxanthones, biimidazoles, dimethylaminobenzoate, sulfonium salts, anthraquinones, acridones, acridines, carbazoles and titanium complexes, at least one of which can be used.

Preferred examples of the ingredient [III] include the individual compounds represented by the formulas [Chemical Formula III-1] and [Chemical Formula 111-2] shown in Table 3, and at least one kind thereof can be used.

The photo- and thermosetting resin composition contains an epoxy resin as a component [IV]. Examples of the epoxy resin include crystalline epoxy resins and / or liquid epoxy resins. In the component [IV], crystalline epoxy resins having a melting point of, for example, 80 to 110 ° C., in particular 90 to 105 ° C., are preferred. Furthermore, the viscosity (mPa · s) of the crystalline epoxy resins is preferably 50 or less, in particular 0.1 to 20, at the melting point to the melting point plus 20 ° C. Also preferred is a crystalline epoxy resin that is sparingly soluble in the photo and thermosetting resin composition.

Examples of crystalline epoxy resins include biphenyl-type, diphenyl-type, hydroquinone-type, biphenyl-novolak-type and fluorine-type crystalline epoxy resins, and at least one type thereof can be used.

wobei R für H oder CH₃ steht und wobei mindestens eine Art davon enthalten sein kann.Examples of biphenyl type crystalline epoxy resins include a compound represented by the following formula [Chemical Formula IVc-1].

where R is H or CH ₃ and at least one type of which may be contained.

worin X für O oder S steht und R¹ und R² jeweils unabhängig voneinander für H, CH₃ oder t-Butyl stehen und wobei mindestens eine Art davon enthalten sein kann.Examples of biphenyl type crystalline epoxy resins include a material having the following formula [Chemical Formula IVc-2].

wherein X is O or S and R ¹ and R ^{2 are} each independently H, CH ₃ or t-butyl and at least one type of which may be included.

worin n den Wert 0, 1 oder 2 hat und wobei mindestens eine Art davon enthalten sein kann.Examples of hydroquinone type crystalline epoxy resins include one indicated by the following formula [Chemical Formula IVc-3].

wherein n has the value 0, 1 or 2 and at least one type of which may be included.

worin n den Wert 1 oder 2 hat und wobei mindestens eine Art davon enthalten sein kann.Examples of crystalline biphenyl novolak type epoxy resins include one having the following formula [Chemical Formula IVc-4].

wherein n has the value 1 or 2 and at least one type of which may be included.

Examples of fluorine type crystalline epoxy resins include one having the following formula [Chemical Formula IVc-5].

Preferred examples of crystalline epoxy resins include tetramethylbiphenyl epoxy resins, hydroquinone diglycidyl ether and di (p-glycidylphenyl) ether, at least one kind of which may be included.

In the case of component [IV], the liquid epoxy resin is a liquid or semi-solid epoxy resin at normal temperature. Examples include an epoxy resin with a flowability Normal temperature. It is preferable that the liquid epoxy resin has a viscosity (room temperature, mPa · s) of 20,000 or less, for example, and particularly preferably 1,000 to 10,000.

worin n den Wert 0 oder 1 hat und wobei mindestens eine Art davon enthalten sein kann.Specific examples of the liquid epoxy resin include a bisphenol A type epoxy resin indicated by the following formula [Chemical Formula IV1-1].

wherein n has the value 0 or 1 and at least one type of which can be contained.

wobei n den Wert 0 oder 1 hat und wobei mindestens eine Art davon enthalten sein kann.Furthermore, specific examples of the liquid epoxy resin include a bisphenol F type epoxy resin indicated by the following formula [Chemical Formula IV1-2].

where n has the value 0 or 1 and at least one type of which may be included.

Furthermore, specific examples of a liquid epoxy resin include a naphthalene-type resin, a diphenylthioether (sulfide) -type resin, a trityl-type resin, an alicyclic-type resin, a resin made from the following alcohols, a resin of A diallyl-bis-A type, a methylresorcinol type resin, a bisphenol AD type resin and an N, N, O-tris (glycidyl) -p-aminophenol, and at least one kind thereof may be contained.

Preferred examples of the liquid epoxy resin include a bisphenol A-type epoxy resin, a bisphenol F-type epoxy resin, N, N, O-tris (glycidyl) -p-aminophenol, and a bisphenol AD-type epoxy resin, at least one of which Kind of it can be included.

The photo- and thermosetting resin composition contains a latent curing agent as an ingredient [V]. A secondary curing reaction is accomplished by heating component [V]. For the component [V], for example, the starting temperature of the secondary curing reaction is preferably 150 to 300 ° C and particularly preferably 150 to 200 ° C.

Specific examples of the component [V] include dicyandiamide (DICY), imidazole, a BF ₃ amine complex, amine adduct hardener, amino acid anhydride (polyamide) adduct hardener, hydrazide hardener, carboxylates (salts) of amine hardener and onium salts, at least one type of which may be included.

In the component [V], specific examples of the amine adduct curing agent include an adduct of an imidazole type curing agent [2-ethyl-4-methylimidazole, 2-methylimidazole, 2,4-diamino-6- (2'-methylimidazolyl- (1H ) -ethyl-S-triazine or the like] or an amine curing agent (diethylamine or the like) with an epoxy compound with urea or an isocyanate compound, examples of the hydrazide curing agents include adipic acid dihydrazide (ADH) and sebacic acid dihydrazide (SDH) the carboxylates (salts) of the amine curing agents include nylon salts and the ATU (3,9-bis (3-aminopropyl) -2, 4,8,10-tetraoxaspiro [5,5] undecane) adipic acid salt. Examples of the onium salts include sulfonium salts, ammonium salts and phosphonium salts.

Preferred examples of the ingredient [V] include the compounds of the formulas [Chemical Formula V-1] to [Chemical Formula V-3] in Table 4, which may include at least one kind thereof.

Various additives can be added to the photo- and thermosetting resin composition if necessary. Examples of the additives include fillers, organic / inorganic colorants, flame retardants and anti-foaming agents, at least one kind of which may be included.

With regard to the composition of the photo- and thermosetting resin, 100 to 300 parts by weight of component [I] from 100 to 300 parts by weight (in particular 150 to 250 parts by weight) of component [II], 1 to 50 parts by weight. Parts (in particular 5 to 15 parts by weight) of component [III], 50 to 200 parts by weight (in particular 60 to 120 parts by weight) of component [IV], 1 to 50 parts by weight (in particular 5 to 20 parts by weight) of the component [V] and 200 to 500 parts by weight (in particular 250 to 350 parts by weight) of the filler are preferred.

The photo- and thermosetting resin composition can be produced, for example, by mixing the individual constituents [I] to [V] and, if necessary, the additive, the mixture being uniformly dispersed and the foam-dispersed mixture being defoamed in vacuo. The order of addition or the like of the ingredients is not particularly limited, and each ingredient can be added sequentially or all of the ingredients can be added at once.

It is preferred that the photo and thermosetting resin composition prepared as above have a resin viscosity (Pa · s, room temperature) of 10 to 50 in view of the application properties to the printed circuit board or the like, with viscosities of 15 to 30 being particularly preferred become.

The invention is described in detail below with reference to the drawings.

In the manufacturing method of the flattened, resin-coated printed circuit board according to the invention, a printed circuit board with a through hole [ 1A , 103 ] used as a printed circuit board. Examples of the through holes include all types of holes that penetrate the printed circuit board. Specific examples of the through holes include through holes, component holes, and other through holes. Examples of the types of the printed circuit board include double-sided printed circuit boards. Examples of the double-sided printed circuit boards include a rigid printed circuit board, a flexible printed circuit board and a rigid, flex printed circuit board.

Regarding the printed circuit board with a through hole, the surface of the conductive layer [ 1A , 102 ] preferably roughened to enhance the adhesion of a conductive layer and a resin layer and the like. Examples of the conductive layer include a conductor metal layer, particularly a circuit layer, a plating metal layer and a metal foil layer formed on the inner wall of the through hole. Examples of the roughening treatments include a treatment with a black oxide, also called a "CZ treatment" (treatment with a chemical roughening agent manufactured by MECetchBOND CO., LTD.), A black reduction treatment, and plating a needle-shaped alloy and physical processing (sandblasting, blasting, polishing with leather or the like).

When manufacturing the flattened resin-coated printed circuit board of the present invention, the photo- and thermosetting resin composition is first applied to a surface and the through hole of the printed circuit board.

The photo and thermosetting resin composition can be applied, for example, by screen printing (mask printing or the like using a polyester screen or a stainless steel screen, etc.), metal mask printing, roller coating printing, and the like.

The generation of bubbles in the applied resin can be prevented by using a vacuum printing machine. Furthermore, the resin can be defoamed by heating the applied resin (e.g., at 80 to 120 ° C for 10 to 60 minutes) to reduce the viscosity of the resin.

Although the entire area of the printed circuit board with the resin layer [ 1B , 105 ] is covered by the above application according to the invention, in particular a recess (a recess or the like between the circuits) [ 1B , 104 ] formed on the surface of the printed circuit board and a through hole also with the resin applied [ 1B ] filled (the hole is plugged). Conventionally, a resist, a prepreg, a semi-hardened resin, an adhesive sheet and the coating material are coated without first filling the gap between the circuits of the printed circuit board with the resin.

However, if the inter-circuit recess has not been previously filled, then it is difficult to fill the recess with the coating material, and the filling tends to be insufficient even if the inter-circuit recess is filled with the material for the Layer is filled by a vacuum press. Particularly when a line and a space in a high density circuit are narrow, it is difficult to fill the gap between the circuits with the coating material. Therefore, a gap is formed to a small extent in the gap between the circuits, and air is sometimes left in the gap. As a result, when the printed circuit board is treated at a high temperature (e.g., at 200 to 300 ° C) by melting or the like in the case of fixing the components in a post-treatment process, the remaining air expands and sometimes blistering ( what is called a "popcorn phenomenon") of the coating surface [ 6E , 625 and 7C , 725 ].

On the other hand, if the space between the circuits is larger, the space can be completely filled with the resin. However, when the space is completely filled with the resin, a coating material for a large volume of space between the circuits is used for filling, and as a result, sometimes a notch is formed on the surface of the layered resin layer [ 6E , 626 and 7C , 726 ]. Both the bubble above and the notch on the coated surface significantly affect the flatness of the printed circuit board.

Therefore, in order to maintain the high flatness of the printed circuit board, it is important not only to fill the through hole of the printed circuit board but also the recess on the surface of the printed circuit board (the recess between the circuits or the like) with the photo- and thermosetting resin composition .

1. (1) eine Stufe der Abflachung der Oberfläche des aufgebrachten Harzes; und
2. (2) eine Stufe der Photohärtung des aufgebrachten Harzes.

In the method according to the invention for producing the flattened, printed circuit board coated with resin, the above-mentioned photo- and thermosetting resin composition is applied and filled. Then the following stages (1) and (2) are carried out in order:

1. (1) a step of flattening the surface of the applied resin; and
2. (2) a step of photocuring the applied resin.

Specifically, in step (1), the above-mentioned coated and filled printed circuit board is sandwiched between two cover films [FIG. IC, 106]. The cover film can be removed from the printed circuit board after a primary photocuring, which will be described later, and preferably penetrates the irradiation light well. Specific examples of the cover film include a PET film, a PEN film, a PP film and a PE film. The film thickness of the cover films can be, for example, 10 to 200 (typically 25 to 100) μm.

Then, the printed circuit board covered with the above cover film is subjected to a pressure roller. The pressure rolling can be carried out, for example, using a laminator or the like become. That is, the printed circuit board covered with the above cover film is first sandwiched between two rollers [ 1D , 107 ].

In this case, an interval between the rollers is preferably set so that the layer thickness of the resin applied to the printed circuit board circuit [ 1I , 111 ] Is 0.1 to 10 (especially 0.1 to 5) µm after curing the resin. Furthermore, the thickness of the resin layer applied to a base material of the printed circuit board is [ 1I , 112 ], preferably the thickness of a circuit copper foil plus 0.1 to plus 10 (in particular plus 0.1 to plus 5) µm after curing of the resin. If the layer thickness of the hardened resin is too small, in some cases the roughened copper foil may not be covered to a sufficient extent. On the other hand, when the hardened resin layer is polished to expose the surface of the copper foil or when an opening to be described below is to be formed, an excessive layer thickness of the hardened resin sometimes leads to difficulties in the polishing treatment or the treatment Achieving an opening occur. As a result, problems such as the occurrence of variations in the dimensions of the printed circuit board or the resin remaining in the opening occasionally arise. There may also be a large tolerance between the intended value and the actual value of the impedance.

The two rollers are moved on the entire surface of the respective cover films applied to both surfaces of the printed circuit board while maintaining the above roller interval [ 1D , 108 ].

Specifically, as the lamination conditions, a lamination pressure of 0.01 to 10 (typically 0.1 to 1) MPa, a lamination speed of 0.1 to 10 (typically 0.3 to 3) m / minute, a lamination temperature of room temperature to 150 ° C (typically 25 to 100 ° C) can be used.

In the method according to the invention for producing the flattened, printed circuit board coated with resin, process (2) is carried out after carrying out process (1). Both sides of the printed circuit board are preferably irradiated with light in process (2). In this case, both sides (front and back) of the printed circuit board can be irradiated with light at the same time and they can also be irradiated with light in succession. The applied resin is irradiated with light on the way through the cover film, and as a result, primary photosetting of the applied resin occurs [ 1E , 109 ].

As for the irradiation with light, the resin can be irradiated with light having a characteristic range of the absorption wavelength of the component [III] specifically with ultraviolet light with a wavelength of 200 to 400 nm at -20 to 80 ° C, the irradiation light amount being 0, 5 to 10 J / cm ² . The photocuring can also be carried out using a submerged exposure device described in US Pat JP-A Nos. 9-6010 and 10-29247 , be performed.

After photocuring the above resin, each of the cover films on both surfaces of the printed circuit board is peeled off and removed.

In the process of the present invention for producing the flattened resin-coated printed circuit board, steps (1) and (2) are completed as described above, and then the photo- and thermosetting resin composition [ 1F , 105 ] also applied to the other surface of the printed circuit board. The resin can be applied to a surface of the printed circuit board in the same manner as in the previously described application.

• 3) eine Stufe der Wärmehärtung des photogehärteten Harzes.

Then stage (1) [ 1G , 1H ] and step (2) are carried out in succession as described above. The following step (3) is then carried out in the process for producing the flattened, resin-coated printed circuit board according to the invention:

• 3) a step of thermosetting the photocured resin.

In step (3), the resin applied, which has been primarily photo-cured in step (2), is then thermoset secondarily to fully cure the resin [ 1I , 110 ]. The excellent properties in terms of heat resistance, resistance to solder and adhesion of the cured resin and the printed circuit board or the like are obtained by the full curing.

The heating temperature in the step (3) is preferably not lower than the starting temperature of the reaction (starting temperature of the secondary thermosetting) of the component [V] of the photo- and thermosetting resin composition. Specifically, the resin is preferably heated at 120 to 300 ° C (especially 140 to 200 ° C) for 30 to 200 minutes.

As already described above, because it is not necessary to carry out the heat-pressing in the production according to the invention of the flattened, resin-coated printed circuit board (that is, it is not necessary to heat and press at the same time deformation) of the resin can be prevented and deterioration of the flatness of the printed circuit board can also be prevented.

In the flattened resin-coated printed circuit board of the present invention obtained in the above manner, the maximum value of the difference in projection or protrusions and the recess in the surface is generally 3 (typically 1) µm or less.

In the flattened resin-coated printed circuit board [ 1 ] made in the above manner, the recess (especially the recess between the circuits and the like) and the through hole of the printed circuit board are filled with the hardened resin, and the flattened resin-coated printed circuit board is hardened Resin layer (film) covered with extreme flatness and uniform surface.

Therefore, the thickness of the flattened resin-coated printed circuit board of the present invention is over the entire area of the printed circuit board. uniform regardless of the circuit density, and the thickness of the applied resin layer formed on the conductive circuit layer (circuit copper foil) is fixed.

A multilayer printed circuit board (particularly a four-layer printed circuit board) which can be used as an inner layer material or the like of the multilayer printed circuit board can be manufactured by using the above-mentioned flattened resin-coated printed circuit board according to the invention as the material.

That is, in the multilayer printed circuit board of the present invention, the photo and thermosetting resin composition is first applied to a surface and the through hole of the printed circuit board. Steps (1) and (2) are carried out sequentially, and the photo and thermosetting resin composition is then applied to the other surface of the printed circuit board. After the sequential execution of the stages (1) and (2), the following stage A is carried out.

A) Performing step (3) and laminating pressing of the printed circuit board, the printed circuit board being sandwiched between press bond materials in order to press-bond the press bond materials to the printed circuit board.

In the above step (A), the above-mentioned flattened resin-coated printed circuit board according to the invention is obtained as described above in a step where step (3) has been completed.

Then, the flattened, resin-coated printed circuit board with the flattened, resin-coated printed circuit board is sandwiched between the press bond materials [ 2A , 213 ] arranged, laminated and pressed, whereby the press bond materials with the flattened, resin-coated printed circuit board according to the invention are connected by pressing or the flattened, resin-coated printed circuit board according to the invention is sandwiched between press bond materials [ 2A , 213 ], subjected to lamination and pressing, whereby the press bond materials are connected to the flattened, resin-coated printed circuit board according to the invention by pressing. Examples of the press bond materials include a prepreg, a copper foil with a resin, a semi-hardened resin film, an adhesive foil, a dry film and a resist, and typical examples thereof include the prepreg. The thickness of the press bond material can be, for example, 50 to 100 μm. If necessary, a variety of press bond materials can be used.

If the press bond material is a semi-thermally hardened resin, then the lamination compression is preferably carried out with heating. If the photo and thermosetting Resin composition is heated to the secondary thermosetting temperature or higher (particularly, the reaction start temperature of the component [V] or more) of the photo- and thermosetting resin composition, then step (3) in the above manufacturing process for the flattened resin-coated printed circuit board can be omitted become.

That is, in this case, the photo- and thermosetting resin composition is first applied to a surface and into the through hole of the printed circuit board. Steps (1) and (2) are carried out one after the other. Then, the photo and thermosetting resin composition is applied to the other surface of the printed circuit board, steps (1) and (2) are carried out in order, and then the following step (B) is carried out.

B) Laminating compression of the printed circuit board at the thermosetting temperature of the photo-hardened resin or higher, the printed circuit board being sandwiched between the press bond materials, whereby the press bond materials are press bonded simultaneously and step (3) is carried out.

At step (B) above, the press bond (and perfect thermosetting) of the press bond material and the secondary thermosetting [i.e. the step (3)] of the photo-cured resin is carried out simultaneously by laminating at the heat curing temperature or above.

In stages (A) and (B), the lamination press conditions are preferably, for example, 120 to 200 ° C (in particular 135 to 180 ° C), 30 to 180 (in particular 60 to 150) minutes, the pressure being 10 to 100 (in particular 15 to 40) kp / cm ² .

For example, the lamination molding can be performed by an open type laminator, a vacuum laminator, or the like. Furthermore, such laminators can e.g. a hydraulic press and an autoclave press. Furthermore, the hydraulic press can be of the vacuum type, the frame type, the box type and the like.

In the manufacture of the multilayer printed circuit board of the present invention, after performing step (A) or (B) above, a hole is drilled in the conductor layer (e.g., circuit or circuit layer) from the surface of the press bond material to provide a micro path [FIG. B, 214] of a blind hole. The micro path is used as a conformal path for the interlayer connection to the circuit layer formed in a post process. For example, the hole can be drilled using a method using a laser (UV laser, CO ₂ laser, excimer laser, Nd: YAG laser or the like) or a plasma treatment. It is preferred that the diameter of the micro path is, for example, 10 to 200 (in particular 20 to 70) μm.

Then, in the method according to the invention for producing the multilayer printed circuit board, the entire area is plated [ 2C , 215 ]. It is preferred that the entire surface be plated on both surfaces. The exposed surface (the surface of the press bond material, the surface of the inner wall of the micro path, the exposed surface of the conductor layer opened by the micro path, or the like) is covered with the plating layer by the entire surface plating. The plating layer is used for the interlayer connection or the circuit or circuit formation of the post-process and the like.

With regard to the plating of the entire surface, it is first preferable to perform electroless plating to make a layer called an underlayer, and further to perform electrolytic plating. Examples of the term “plating” in electroless plating and electrolytic plating include plating with copper, plating with nickel, plating with gold, plating with nickel-gold, and plating with solder. The plating agent can also be the same, or two types can be combined. It is preferable that the layer thickness of the electroless plating is 0.1 to 10 (particularly 0.5 to 5) µm and that the layer thickness of the electrolytic plating is 10 to 50 (particularly 15 to 30) µm.

Then, in the method of manufacturing the multilayer printed circuit board of the present invention, a circuit or circuit [ 2D , 216 ] of the above-mentioned total area plating layer. For example, the circuit or the circuit can be formed by a subtractive method, an additive method or the like.

Thereafter, in the method according to the invention for producing the multilayer printed circuit board, the surface is covered with a resist [ 2E , 217 ]. Examples of the resist include a solder resist, a polyimide resist and a polyimide film. A typical example is a solder resist.

The resist can be applied, for example, by a photographic method in which exposure and development are carried out using a photosensitive resist ink or a dry film and a printing method using a resist ink or the like.

An opening part can be formed on the resist if necessary. In this case, the exposure / development of the ink is carried out so that a resist pattern is obtained which has an opening part. In particular, the opening of the resist to achieve a support part [ 2E , 218 ] and / or a contact part [ 2E , 219 ] are formed in the multilayer printed circuit board. In this case, the multilayer printed circuit board is covered with a resist material, except for the pad and or contact part.

A plating [ 2F , 220 ] and / or a contact plating [ 2F , 221 ] can also be applied to the surface of the support and / or the surface of the contact part, exposed from the opening of the resist, in order to improve the abrasion resistance. With regard to the plating and / or the contact plating, for example, nickel can be plated and then gold can also be plated on. The layer thickness of the plating is preferably 0.1 to 20 (in particular 0.5 to 10) μm.

Regarding the multilayer printed circuit board [ 2F ] According to the invention made in the manner described above, regardless of the circuit density of a core part (that is, a part corresponding to the flattened resin-coated printed circuit board used as the material), no bubbles and Notches exist on the entire surface and that an extremely excellent flatness is obtained. The thickness of the insulating layer (the hardened resin layer and the layer of the press bond material) formed on the conductive circuit layer (circuit copper foil) of the core part is also extremely fixed.

The printed circuit board (especially the double-sided printed circuit board) which can be used as a base material for an outer layer or the like of the multi-layer printed circuit board can be manufactured by using the flattened resin-coated printed circuit board as the material. That is, in the method of manufacturing the printed circuit board of the present invention, the photo and thermosetting resin composition is applied to a surface and filled in the through hole of the printed circuit board, and steps (1) and (2) are carried out sequentially. The photo- and thermosetting resin composition is then applied to the other surface of the printed circuit board, and steps (1) to (3) are carried out in order to first obtain a flattened resin-coated printed circuit board according to the present invention [ 3A ].

The opening is then formed in the layer of the coated resin (hardened resin) of the flattened resin-coated printed circuit board. From this point of view, the coated resin layer acts as a resist [ 3B ].

The opening of the layered resin layer may be formed by a method using a laser (a UV laser, a CO ₂ laser, an excimer laser, an Nd: YAG laser or the like) or a plasma treatment as described above . Specifically, the opening of the layered resin layer can be formed by applying a platen [ 3B , 318 ] and / or contact part [ 3B , 319 ] is placed in the printed circuit board. Furthermore, a plating [ 3C , 320 ] and / or a contact plating [ 3C , 321 ] applied to the surface of the support and / or the surface of the contact part.

Referring to the printed circuit board of the present invention [ 3C ] made in the manner described above, there are no bubbles and nicks on the surface, and extremely excellent flatness is obtained. Therefore, the printed circuit board has excellent location accuracy when high-density microcomponents are mounted, and the entire printed circuit board has a uniform thickness regardless of the circuit density, and the entirety (all faces) of the printed circuit board is covered with a flat resin layer (especially a solder) -Resist film) covered. As a result, the printed circuit board also has excellent entry properties of the underfill when BGA (ball grid arrangement) is mounted with a close spacing, for example BGA, the spacing of which is 100 µm or less.

The invention has been described above. However, those skilled in the art can easily modify and extend the invention. For example, in the manufacturing method of the multilayer printed circuit board of the present invention, “a plating resist [ 4A , 422 ] are formed and the plating [ 4B , 415 ] can be applied to a part that is not covered with the plating resist to form the circuit [ 4C , 416 ] ”Instead of“ applying a total area plating and forming the circuit from the plating layer. ”

Furthermore, the multilayer printed circuit board with the desired number of layers can be produced by repeating the individual production steps in the method for producing the multilayer printed circuit board according to the invention.

Furthermore, in the method according to the invention for producing the multilayer printed circuit board, the term “copper foil with resin” [ 5A , 523 and 524 ] can be used as a designation for the "press binding material". In this case, the "total surface plating" of the post-treatment process can also be omitted ( 5 ).

The desired plugged-hole multilayer printed circuit board, in which the number of layers is larger and the layer structure is more complicated, can be manufactured by suitably making a plurality of flattened resin-coated printed circuit boards, multilayer printed circuit boards, and printed ones Printed circuit boards of the invention can be combined as a base material for the inner layer or as a base material for the outer layer and that the assembly is then laminated.

Furthermore, in any manufacturing method according to the present invention, another adhesive sheet and a different coating material or a copper sheet with the resin can be used instead of the prepreg, and as a result, a multilayer printed circuit board with plugged holes having the desired structure can be manufactured.

Furthermore, although step (1) has been described with a platen roller using the cover film in the manufacturing method of the present invention, other objects (a shape, a plate, a film and others) other than a film can be used.

[Examples]

In the following, the invention will be further described specifically in the examples with reference to the drawings.

<Production of photo- and thermosetting resin composition>

- Production example 1

The ingredients listed below were stirred and mixed. Then the resulting mixture was uniformly dispersed in a three-roll mill. The obtained uniform dispersion was defoamed in vacuo to prepare a photo- and thermosetting resin composition (Production Example 1)

• 40% (Meth)acrylsäureaddukt eines Epoxyharzes vom Dicyclopentadienphenol-Typ (100), Dicyclopentanylmethacrylat (30), Trimethylolpropantriacrylat(70), Dipentaerythrithexaacrylat (80), 2-Methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-on (10), Diethylthioxanthon (1), Epoxyharz vom Bisphenol A-Typ¹⁾ (80), Epoxyharz vom Bisphenol AD-Typ (20), Dicyandiamid (10), Siliciumdioxid (250), Oberflächenbehandeltes kolloidales Siliciumdioxid (6) und Polydimethylsiloxan (3).

Photo and thermosetting resin composition (parts by weight):

• 40% (meth) acrylic acid adduct of a dicyclopentadiene phenol type epoxy resin (100), dicyclopentanyl methacrylate (30), trimethylolpropane triacrylate (70), dipentaerythritol hexaacrylate (80), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane 1-one (10), diethylthioxanthone (1), bisphenol A type ¹ epoxy resin (80), bisphenol AD type epoxy resin (20), dicyandiamide (10), silicon dioxide (250), surface-treated colloidal silicon dioxide (6) and polydimethylsiloxane (3).

1) The mixture of the liquid epoxy resin (86% by weight) with n = 0 and the liquid epoxy resin (14% by weight) with n = 1 in the formula [Chemical formula IV1-1]. The average molecular weight was 380

<Production of thermo / thermosetting resin composition>

- Production example 2

The ingredients listed below were stirred and mixed. Then the resulting mixture was uniformly dispersed in a three-roll mill. The obtained uniform dispersion was defoamed in vacuo to prepare a photo- and thermosetting resin composition (Production Example 2).

• Epoxyharz vom Triphenylmethan-Typ (19), N,N,O-Tris(glycidyl)-p-aminophenol (28), Dicyandiamid (2), Epoxyharz-Aminaddukt (1), Aluminiumhydroxid (49), Bentonit (0,5), Polydimethylsiloxan (0,5).

Thermo / thermosetting resin composition (parts by weight):

• Triphenylmethane type epoxy resin (19), N, N, O-tris (glycidyl) -p-aminophenol (28), dicyandiamide (2), epoxy resin amine adduct (1), aluminum hydroxide (49), bentonite (0.5) , Polydimethylsiloxane (0.5).

<Manufacturing the Printed Circuit Board>

- Example 1

There was a double-sided printed circuit board [thickness of a copper circuit: 40 microns, line / distance (L / S) 20 microns / 40 microns, diameter of the through hole after plating 100 microns], the circuit layers [ 1A , 102 ] on both surfaces of a base material [thickness. 0.930 mm, [ 1A , 101 ] and a copper plating was formed on the inner wall of the through hole [ 1A , 103 ] used. A double-sided printed circuit board was used, and the surface of a conductive layer (circuit and copper plating of the inner wall of the through hole) was previously subjected to a roughening treatment called "MECetchBOND CZ-8101" (manufactured by MECetchBOND CO. LTD., Roughening chemicals) .

Screen printing was made on the photo and thermosetting resin composition (Production Example 1) [ 1B , 105 ] was applied in accordance with the printing conditions shown in Table 5 below, and the photo and thermosetting resin composition was applied to the entire surface of one surface (previous side) of the above printed circuit board. The through hole and the recess between the circuits [ 1B , 104 ] was filled and the hole was closed with the photo and thermosetting resin composition. Table 5 Printing conditions Sieve Mesh: V280, thickness of the emulsion: 15 µ Squeegee Hardness 90, 9.5 mm, width 3 mm left and 20 ° cut Printing conditions Pressure during printing (kp) 75 Pushing (mm) 1.5 Arrangement angle of the squeegee (°) 85 Speed of the squeegee (mm / s) 15 Off contact (mm) 10th Gap (mm) 3.5

The printed circuit board was then heated in a box dryer to 80 ° C for 30 minutes, placing the printed circuit board on a horizontal stand to reduce the viscosity and remove bubbles in the applied resin. The applied photo- and thermosetting resin composition (Production Example 1) was inspected by a microscope at 50 × magnification, and the microscopic inspection confirmed the absence of bubbles between circuits or between the circuits.

Then, the printed circuit board was subjected to a laminator, the printed circuit board being sandwiched between PET films [ 1C , 106 ], which had a film thickness of 100 µm. In the printed circuit board covered with the film, sandwiched between two rollers [ 1D , 107 ] made of stainless steel, were arranged (lamination pressure: 0.1 MPa, lamination speed: 0.5 m / min, lamination temperature: 100 ° C), the rollers were moved on the film [ 1D , 108 ]. In this way, the coated resin layer formed on the surface of the printed circuit board was flattened and thinned [ 1D ].

Then, the above printed circuit board was subjected to light irradiation at an exposure of 1200 mJ / cm ² using a high pressure mercury arc lamp to produce a primary photo-cured material [ 1E , 109 ]. The above-mentioned PET films, which had been coated on both surfaces, were peeled off and removed [ 1E ].

Then, the back surface (following surface) of the above printed circuit board was also treated in the same manner as in the previous page. That is, screen printing was applied to the photo- and thermosetting resin composition (Production Example 1) [ 1F , 105 ] was applied in accordance with the printing conditions shown in Table 5, and the photo- and thermosetting resin composition was applied to the entire area of the other sides (following surface) of the above printed circuit board. The gap between the circuits [ 1F , 104 ] was filled with the photo and thermosetting resin composition.

The printed circuit board was then heated in a box dryer to 80 ° C for 30 minutes, placing the printed circuit board on a horizontal stand to reduce the viscosity and remove bubbles in the applied resin. The applied photo- and thermosetting resin composition (Production Example 1) was inspected by a microscope at 50 × magnification, and the microscopic inspection confirmed the absence of bubbles between circuits or between the circuits.

The printed circuit board was then sandwiched between PET films [ 1G , 106 ] with a film thickness of 100 µm. With the printed circuit board covered with the film sandwiched between two rollers [ 1G , 107 ], made of stainless steel, was arranged (lamination pressure: 0.1 MPa, lamination speed: 0.5 m / min, lamination temperature: 100 ° C), the rollers were moved on the film [ 1G , 108 ]. In this way, the resin layer formed coated on the surface of the printed circuit board was flattened and thinned. [ 1H ].

Then, the above printed circuit board was subjected to light irradiation at an exposure of 1200 mJ / cm ² using a high pressure mercury arc lamp to produce a primary photo-cured material. The above-mentioned PET films, which had been coated on both surfaces, were peeled off and removed [ 1E ].

Thereafter, the printed circuit board was heated at 150 ° C for 30 minutes to carry out the secondary thermosetting of the photo-hardened resin [ 1I , 110 ], whereby a flattened resin-coated printed circuit board (Example 1) according to the invention was obtained, the total thickness of which was 1.018 mm [ 1I ] amounted to.

- Example 2

A double-sided printed circuit board [thickness of a copper circuit: 40 µm, (L / S) 20 µm / 40 µm, diameter of the through hole after plating: 100 µm] was used in which circuit layers on both surfaces of a base material with a thickness of 0.930 mm, and copper plating was formed on the inner wall of the through hole. A double-sided printed circuit board was used, the surface of a conductive layer (circuit and copper plating of the inner wall of the through hole) had previously been subjected to a roughening treatment with the designation “MECetchBOND CZ-8101”.

Screen printing was applied to the photo and thermosetting resin composition (Production Example 1) under the printing conditions shown in Table 5 below using a vacuum printing machine, and the photo and thermosetting resin composition was applied to the entire surface of one surface (previous surface) of the above circuit board . The through hole and the gap between the circuits was filled and the hole was plugged with the photo and thermosetting resin composition.

Then the printed circuit board was subjected to a laminator, the printed circuit board being sandwiched between PET films having a film thickness of 100 µm. With the circuit board covered with the film sandwiched between two rollers made of stainless steel (lamination pressure: 0.1 MPa, lamination speed: 0.5 m / min, lamination temperature: room temperature), the rollers were moved on the film. In this way, the applied resin layer formed on the surface of the printed circuit board was flattened and thinned.

Then, the above printed circuit board was subjected to light irradiation at an exposure of 1200 mJ / cm ² using a high pressure mercury arc lamp to produce a primary photo-cured material. The above-mentioned PET films, which had been coated on both surfaces, were peeled off and removed.

Then, the back surface (following surface) of the above printed circuit board was also treated in the same manner as the previous surface. That is, screen printing was applied to the photo- and thermosetting resin composition (Production Example 1) under the printing conditions shown in Table 5 below using a vacuum printing machine, and the photo- and thermosetting resin composition was applied to the entire area of the other surface (following surface) the above circuit board applied. The gap between the circuits was filled with the photo and thermosetting resin composition.

Then the printed circuit board was sandwiched between PET films with a film thickness of 100 µm. With the printed circuit board covered with the film sandwiched between two stainless steel rollers (lamination pressure: 0.1 MPa, lamination speed: 0.5 m / min, lamination temperature: room temperature), the rollers were moved on the film. In this way, the applied resin layer formed on the surface of the printed circuit board was flattened and thinned.

Then, the above printed circuit board was subjected to light irradiation at an exposure of 1200 mJ / cm ² using a high pressure mercury arc lamp to produce a primary photo-cured material. The above-mentioned PET films, which had been coated on both surfaces, were peeled off and removed.

Thereafter, the printed circuit board was heated at 150 ° C for 30 minutes to perform secondary thermosetting of the photocured resin, whereby a flattened resin-coated printed circuit board (Example 2) according to the invention with a total thickness of 1030 mm was produced.

- Example 3

The above printed circuit board (Example 1) was used as a base material for producing a four-layer printed circuit board. That is, first both surfaces of the above printed circuit board (Example 1) were prepregs [ 2A , 213 ] covered with a thickness of 0.1 mm, so that the printed circuit board was sandwiched between the prepregs.

Thereupon, the above-mentioned printed circuit board was heated and pressed in vacuo in accordance with the pressing conditions in Table 6 in order to bind the prepregs by pressing. Table 6 Hours minutes) Temperature (° C) Pressure (kp / cm ² ) Remarks Before the start Room temperature 0 Start at 10 135 15 Rise in temperature / rise in pressure 10 to 30 135 30th Increase in pressure 30 to 130 180 30th Rise in temperature / rise in pressure 130 to 159 Room temperature 30th cooling down 159 to 160 Room temperature 0 Lowering the pressure

Then, a laser was irradiated from the surface of the prepreg of the above printed circuit board to expose a circuit layer [ 2 B and 202 ], whereby a micro path (path diameter: 70 pm) was formed [ 2 B , 214 ] [ 2 B ].

Then, copper plating (first electroless copper plating and then electrolytic copper plating) was carried out on both surfaces of the above printed circuit board and the surface of the inner wall of the micro path [ 2C , 215 ] and the surface of the path and prepreg were covered with the copper foil to form a double-sided copper plating laminate. The plating thickness of the electroless copper plating and the electrolytic plating were 1 µm and 14 µm, respectively.

Then a circuit [ 2D , 216 ] formed on both surfaces of the above double-sided copper plating laminate as follows. First, an etching resist was formed by a dry film (laminate) process. That is, the dry film was laminated on both surfaces of the above double-sided copper plating laminate, and a negative type film (pattern mask) was overlaid thereon. The dry film was then exposed and cured using an ultra high pressure mercury lamp.

Then, a carrier film of the dry film was peeled off, and a developing solution (1% sodium carbonate solution) was sprayed from a spray nozzle onto the exposed surface of the resist, and development was carried out. The surface of the resist was then washed to form a resist pattern.

Then etching was performed. That is, an iron (III) chloride solution (36% by weight) was sprayed on both surfaces of the above resist covered with the double-sided copper plating laminate from the spray nozzle, and unnecessary copper foil was released and removed. A 3% sodium hydroxide solution was sprayed from the spray nozzle after the above etching was completed, and the etching resist was washed away, causing the etching resist to swell.

After forming the circuit as described above, a solder resist ink was applied to form a solder resist [ 2E , 217 ]. That is, an ultraviolet ray / thermosetting acrylate / epoxy resin was first applied by screen printing to both surfaces with a circuit formed thereon by a doctor blade (doctor blade hardness: 75) by way of a 150 mesh tetron screen.

Then, after the resin was pre-baked, a negative film was adhered to the resin in a hot air drying oven, and the resin was exposed (300 mJ / cm ² ) and cured. The resin was developed using a 1% sodium carbonate solution (30 ° C, 2.5 kg / cm ² ) to cover an opening (pad part [ 2E , 218 ]) and a contact part [ 2E , 219 ] to build. The resin was then heated to 150 ° C for 30 minutes and thermoset.

Then the edition part [ 2E , 218 ] and the contact part [ 2E , 219 ] first applied to electrolytic nickel and then gold plating was performed [ 2F , 220 and 221 ].

As described above, a four-layer printed circuit board (Example 3) [ 2F ] according to the invention, in which the thickness of the insulating layer formed on a circuit-rich part in the core part was fixed (uniform) and wherein the thickness of the insulating layer formed on a circuit-poor part was fixed (uniform was). There were no bubbles or nicks on the entire surface. All of the material was flat.

- Example 4

The above printed circuit board (Example 2) was used as the base material to produce a double-sided printed circuit board. That is, the covering hardened resin layer [ 3A , 310 ] of the above printed circuit board (Example 2) was first irradiated with a laser to cover a copper foil of a circuit layer in a platen part [ 3B , 318 ] and a contact part [ 3B , 319 ] [ 3B ] exposed.

Then the edition part [ 3C , 318 ] and the contact part [ 3C , 319 ] first applied to electrolytic nickel and then subjected to electrolytic gold plating [ 3C , 321 ].

As described above, a double-sided printed circuit board (Example 4) according to the present invention was manufactured in which the thickness of the insulating layer formed on a circuit-rich part was fixed (uniform), the thickness of the insulating layer was was formed on the circuit-poor part, was fixed (was uniform), and had no bubbles and nicks on the entire surface. The entire compilation was flat and the total thickness was 1.030 mm [ 3C ].

- Comparative example 1

A double-sided printed circuit board [copper circuit thickness: 40 µm, (L / S) 20 µm / 40 µm, diameter of the through hole after plating: 100 µm] was used, in which circuit layers [ 6A , 602 ] on both surfaces of a base material [ 6A , 601 ] with a thickness of 0.930 mm. Copper plating was formed on the inner wall of the through hole. A double-sided printed circuit board was used in which the surface of a conductive layer (circuit and copper plating of the inner wall of the through hole) had previously been subjected to a roughening treatment with MECetchBOND CZ-8101.

Screen printing was performed on a thermosetting resin composition (Production Example 2) [ 6A , 605 ] on the above printed circuit board according to the printing conditions shown in Table 5. Only the through hole was filled and the hole was plugged in with the resin without the gap between the circuits being filled with the resin.

Then, after the above printed circuit board was heated at 130 ° C for 60 minutes to form a primarily thermosetting resin [ 6B , 609 ] [ 6B ], both surfaces of the above printed circuit board are first polished with a No. 400 ceramic abrasive material and then further 4 times with the No. 600 abrasive material [ 6C ] polished.

Then both surfaces of the above printed circuit board were covered with prepregs [ 613 ], the printed circuit board being sandwiched between the prepregs. The thickness of the prepreg was 0.1 mm.

Then, the above printed circuit board was subjected to a vacuum heating pressing process under the pressing conditions shown in Table 6, and the press bonding of the prepreg and secondary heat setting of the primary thermosetting resin were carried out simultaneously to produce a printed circuit board [ 6E ] (Comparative Example 1)

The following defects were observed in the printed circuit board (Comparative Example 1) obtained. That is, the filling due to the prepreg was insufficient in the circuit-rich part of L / S = 20 µm / 40 µm. This left air between the circuits and the surface swelled [ 6E , 625 ].

Furthermore, although the filling was perfect due to the prepreg in the low-circuit part of L / S = 20 µm / 200 µm, there was a notch due to the filling and the consumption of the prepreg between the circuits [ 6E , 626 ].

- Comparative Example 2

The above printed circuit board (Comparative Example 1) was used as a base material for producing a four-layer printed circuit board. That is, the four-layer printed circuit board (Comparative Example 2) was manufactured in the same manner as in Example 3, except that the material of Comparative Example 1 was used as the printed circuit board instead of the material of Example 1.

However, there were bubbles [ 6E , 625 ] and notches [ 6E , 626 ] on the surface of the printed circuit board (Comparative Example 1) of the base material (core base material). This caused bubbles to form [ 9A , 925 ] and notches [ 9B , 926 ] also on the surface of the four-layer printed circuit board produced in this way (comparative example 2).

<Production of a printed circuit board with a BGA component formed thereon as a bump>

- Production example 1 and comparative production example 1

The bump bonding of the bump [mean value of the height of the bump: 33.4 μm and standard deviation of the height of the bump: 1.5] in a BGA component and the support part of the four-layer printed circuit board (each of Example 3 and Comparative Example 2) was carried out to produce a BGA component with a printed circuit board mounted thereon (each of Manufacturing Example 1 and Comparative Manufacturing Example 1)

<Determining the Characteristic Properties of the Printed Circuit Board>

The individual printed circuit boards were subjected to measurement and tested for the thickness of the cured film of the respective resins applied to the circuit and the base material (each of Examples 1 and 2). Further, the maximum bubbles and the maximum notches on the surface of the (four-layer) printed circuit board (each of Examples 1 and 2, Comparative Example 1, Manufacturing Example 1 and Comparative Manufacturing Example 1), the standard deviation (amount of variation in thickness in each part of the printed circuit board) the flatness of the (four-layer) printed circuit board (each of Examples 1 and 2, Comparative Example 1, Manufacturing Example 1 and Comparative Manufacturing Example 1), the average of the height of the bump (Manufacturing Example 1 and Comparative Manufacturing Example) 1) after assembly of the BGA component and the bump-binding ability (production example 1 and comparative production example 1).

9,2 13,2 Beurteilung der Bondhügel-Bindungsfähigkeit ○ × The BGA device used for the determination had a size of 16.0 mm × 16.0 mm, a plate thickness of 0.4 mm, a bump distance of 75 μm and a number of bumps of 148. Table 7 example 1 Example 2 Comparative Example 1 Cured film thickness of applied resin (µm) On the circuit 4th 10th - On the base material 44 50 - Maximum bubble value on the surface of the printed circuit board (µm) 0.2 0.3 25th Maximum notch value on the surface of the printed circuit board (µm) 0.8 0.9 40 Standard deviation of the flatness of the surface of the printed circuit board 0.41 0.26 15.6 Table 8 Production Example 1 Comparative Production Example 1 Four-layer printed circuit board used Example 3 Comparative Example 2 Maximum bubble value on the surface of the four-layer printed circuit board (µm) 0.2 7 Maximum notch value on the surface of the four-layer solution (µm) 0.6 13 Standard deviation "s" of the flatness of the surface of the four-layer printed circuit board 0.35 1.6 Average h of the height of the bump of the BGA component (µm) 33.4 33.4 Average "h '" of the height of the bump after mounting the BGA component (µm) 22.0 22.0 (h-h ') 11.4 11.4 $$\sqrt{{\left(6s\right)}^{\mathrm{2nd}}+{\left(6p\right)}^{\mathrm{2nd}}}$$

9.2 13.2 Assessment of bond hill binding ability ○ ×

In Tables 7 and 8, “bubble value” and “notch value” mean the height of the bubble or the depth of the notch when using a surface part (i.e., a flattened surface part) as a reference surface, in which there are no bubbles and notches on the surface of the ( four-layer) printed circuit board was done.

The thickness of the cured film of the applied resin, the bubbles and the notches on the surface, and the height of the bump after mounting the BGA component were measured by the cross-sectional method. The standard deviation of the flatness of the surface of the printed circuit board (Examples 1 and 2 and Comparative Example 1, respectively) was calculated by applying a grid with an interval of 2 mm on the surface of the printed circuit board and the total thickness of the printed circuit boards were measured in the intersections of 25 pieces which had been placed in the vertical direction and in the horizontal direction. The standard deviations of the flatness of the surface of the four-layer printed circuit board (each of Example 3 and Comparative Example 2) were calculated by measuring the total thickness in each plating part on the surface.

(1) ○ $$\left(h-h\text{'}\right)\leqq \sqrt{{\left(6s\right)}^2+{\left(6p\right)}^2}$$

(2) × The hillock binding ability was determined as follows. If the mean "h" (= 33.4 pm) of the height of the bump before the bond bump, the mean "h" of the height of the bond bump after the bond bump (after assembly of the BGA component), the standard deviation "s" of Flatness of the surface of the four-layer printed circuit board and the standard deviation "p" (= 1.5) of the height of the bump before the bump bond met the condition of equation (1) in Table 9, then the bump bond ability was considered as "(good bump Binding ability) ”. If the parameters satisfied the relationship of equation (2), then the bump bond ability was referred to as “x (poor bump bond ability)”. In equation (1) or (2), the left-hand side represents the amount of the bump smashed (hereinafter sometimes also referred to as "bump-shattering" for the sake of simplicity) and the right side represents the total sum fluctuation amount (hereinafter sometimes referred to as " Fluctuation "means) the fluctuation in the flatness of the surface of the four-layer printed circuit board and the fluctuation in the height of the bump. Table 9 equation evaluation $$\left(H-H\text{'}\right)>\sqrt{{\left(6s\right)}^{\mathrm{2nd}}+{\left(6p\right)}^{\mathrm{2nd}}}$$

(1) ○ $$\left(H-H\text{'}\right)\leqq \sqrt{{\left(6s\right)}^{\mathrm{2nd}}+{\left(6p\right)}^{\mathrm{2nd}}}$$

(2) ×

Tables 7 and 8 clearly show the following. That is, the flattened resin-coated printed circuit boards (Examples 1 and 2) and the four-layer printed circuit board (Example 3) according to the present invention have less concavity and convexity on the surface of the printed circuit board (because the sum of the maximum bubble value and of the maximum notch value is small) than the conventional (four-layer) printed circuit board (Comparative Example 1 and Comparative Manufacturing Example 1), and an extremely flattened surface (since the standard deviation of flatness is smaller).

Furthermore, when the BGA component is mounted (bump-bonded) on the four-layer printed circuit board (Example 3) according to the present invention (Manufacturing Example 1), the "fluctuation" is absorbed by the "shattering of the bump" can be (since the total amount of shattering of the bump or the total amount of shattering of the bump is greater than the total amount or the total amount of fluctuations), so that all bumps are bound with certainty.

On the other hand, when the BGA component is mounted (bump-bonded) on the conventional four-layer printed circuit board (Comparative Example 2) (Comparative Manufacturing Example 1), the "fluctuation" cannot be absorbed by the "shattering of the bump" (since the Amount or the extent of the shattering of the bump is smaller than the total amount or the total amount of fluctuations), so that some bumps cannot be bound.

That said, as in 9A if the bubble is too large, a bump is shown 932a that in the bubble 925 exists, cannot be crushed to the extent that plating 920 on a bump 932b can be tied (because of the amount or extent of the "shattering of the bump" of the bump 932a has already reached a limit). As a result, a bump bond of the bump can 932b and plating 920 not be carried out.

Likewise, as in 9B shown if the notch is too big, the bump 932a cannot be smashed to an extent that the plating 920 that in the notch 926 exists with the bump 932b can be connected (this is because the amount or the extent of the "shattering of the bump" of the bump 932a has already reached the limit). As a result, a bump bond of the bump can 932b with the plating 920 not be carried out.

Claims (7)

A method of manufacturing a printed circuit board, comprising the steps of: Applying a photo and thermosetting resin composition (105) to a surface and the through hole (103) of a printed circuit board having the through hole (103); successively performing the following stages (1) and (2); Applying the photo and thermosetting resin composition (105) to the other surface of the printed circuit board; and successively performing the following stages (1) to (3): (1) flattening or leveling the surface of the applied resin with a pressure roller (107, 108); (2) photocuring the applied resin; and (3) thermosetting the photocured resin. A method of manufacturing a multilayer printed circuit board, comprising the steps of: applying a photo and thermosetting resin composition (105) to a surface and the through hole (103) of a printed circuit board having the through hole (103); successively performing the following stages (1) and (2); Applying the photo and thermosetting resin composition (105) to the other surface of the printed circuit board; successively performing the following stages (1) and (2); (A) first performing the following step (3), next laminating the printed circuit board with press-binding materials (106, 213), the printed circuit board being sandwiched between the press-binding materials (106, 213), or (B) laminating the printed circuit board with the press bonding materials (106, 213) at the thermosetting temperature or higher of the photo-hardened resin, the printed circuit board being sandwiched between the press binding materials (106, 213) so as to in this way to carry out said step (3); Forming a hole from the surface of the press bond material to a conductor layer to form a micro path (214); Applying total area plating (215); Forming a circuit or circuit (216) from a plating layer; and layering a resist (217); (1) flattening or leveling the surface of the applied resin with a pressure roller (107, 108); (2) photocuring the applied resin; and (3) thermosetting the photocured resin. Method of manufacturing a multilayer printed circuit board according to Claim 2 wherein the resist (217) has an opening. A method of manufacturing a printed circuit board, comprising the steps of: Applying a photo and thermosetting resin composition (105) to a surface and the through hole (103) of a printed circuit board having the through hole (103); successively performing the following stages (1) and (2); Applying the photo and thermosetting resin composition (105) to the other surface of the printed circuit board; and successively performing the following steps (1) to (3) and: forming an opening in the layered resin layer (310): (1) flattening or leveling the surface of the applied resin with a pressure roller (107, 108); (2) photocuring the applied resin; and (3) thermosetting the photocured resin. Process for manufacturing a printed circuit board according to Claim 3 or 4th , wherein a surface (218, 219, 318, 319) exposed through the opening is covered with a plating (220, 221, 320, 321). Method of manufacturing a printed circuit board according to one of the Claims 1 to 5 roughening the surface of a conductive layer of the printed circuit board with the through hole (103). Printed circuit board, manufactured according to the manufacturing process according to one of the Claims 1 to 6 .

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