JPH09232703A - Chip mounted printed-wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relax a stress between a bare chip and a resin-impregnated glass- cloth laminated board by a method wherein conductor circuits are formed on an insulative resin layer on the resin-impregnated laminated board and bumps on a chip component are connected with electrodes on the conductor circuits. SOLUTION: An internal layer board 1 of a glass epoxy laminated board having conductor circuits 2 is prepared and the circuits 2 are blackened. Then, the resin layer side of a copper-clad insulating sheet formed with a resin layer 3 is superposed on one surface of this board 1 and laminating of the insulating sheet and the board 1 is conducted to form a copper-clad laminated board panel. Microscopic holes are provided in prescribed positions on a copper foil on the surface of the layer 3 by selective etching and a resin composition under the holes is dissolved to form blind via holes. Then, an electroless copper plating and an electrical copper plating are applied to the blind via holes to form plated blind via holes 8. Then, after the copper foil on the surface of the layer 3 is etched, an electroless gold plating is applied to the copper foil to provide conductor patterns and electrodes 4 for bump connection use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip mounting printed wiring board suitable for high density mounting. In particular, the present invention provides a printed wiring board that is excellent in connection reliability of a semiconductor chip by relaxing thermal stress due to heating when mounting a semiconductor bare chip.

[0002]

2. Description of the Related Art As electronic devices have become smaller and more multifunctional,
Currently, printed wiring boards are moving toward higher densities. For example, thinning conductor circuits and increasing the number of layers; reducing the diameter of through holes including through via holes, blind via holes, and interstitial via holes such as balled via holes; and high-density mounting by surface mounting of small chip components. Is mentioned.

For high-density mounting, a multi-chip module MCM-L using an organic material, MCM-C using ceramic for higher-density mounting, and ceramics, silicon wafers, metals regardless of the substrate material are used. MCM-D and the like in which circuits are multilayered on a board are often used. These are selected and designed in consideration of the need for high density and economy. That is, MCM-L, MCM-C, MC
The mounting density increases as the size becomes MD, but it is expensive.

When price is important, it is preferable to use MCM-L. In that case, MCM-L usually uses a resin-impregnated glass cloth laminate such as a glass epoxy laminate, a glass cloth polyimide laminate or a bismaleimide laminate, which is a versatile base material. However, the semiconductor bare chip and the above-mentioned laminated plate are not compatible with each other in thermal expansion and contraction rates. For example, the coefficient of thermal expansion of glass epoxy base material is 1.5 × 10 ^-5 / ° C and that of silicon is 2.6 × 10 ^-4 / ° C.
The difference is an order of magnitude, and the stress during contraction also increases.

A typical MCM-L is one in which a solder bump or a gold bump of a bare chip is connected to a conductor circuit on a laminated plate and the bare chip is covered with a sealant. In this step, if heating is performed at 140 ° C. to 170 ° C. for several tens of minutes, shrinkage stress remains in the resin after cooling, and warping / twisting occurs as MCM, and cracking easily occurs in the resin. In addition, the stress is concentrated on the bump connection portion and the damage tends to occur, so that the reliability of bare chip mounting cannot be sufficiently obtained.

On the other hand, generally, in the case of making an insulating resin flame-retardant, a brominated compound is usually added. In that case, ionic impurities such as bromine ions and chlorine ions mixed in during the production of brominated compounds are present in the resin, and the ion migration due to high temperature moisture absorption causes a problem of corrosion of aluminum wiring of the semiconductor bare chip. It was

[0007]

SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned drawbacks of the conventional method and provides a highly reliable chip-mounted printed wiring board.

[0008]

According to the present invention, a layer of an insulating resin having rubber elasticity when heated is formed on one surface or both surfaces of a resin-impregnated glass cloth laminate, and a conductor is formed on the insulating resin layer. A chip mounting printed wiring board formed by forming a circuit and connecting bumps of a chip component to the pads of the conductor circuit achieves the first purpose of stress relaxation between the bare chip and the resin-impregnated glass cloth laminate. is there.

That is, when a bare chip having a bump such as solder or gold plating is mounted on a pad composed of a conductor circuit of a printed wiring board, the bump is heated and pressed to be connected. In that case, since the insulating resin becomes rubber-like when pressed in a heated state, each pad of the conductor circuit follows even if there are variations in the height of the bumps, and stress is not concentrated even after cooling. The bump connection reliability will be improved. In addition, after the bare chip is mounted, when it is heated up to about 150 ° C. when it is covered with the sealant, there is an insulating resin layer which becomes rubber-like on the laminated plate, and the insulating resin layer is formed on the insulating resin layer. There is no stress concentration on the pad made of the conductor circuit during heating, the stress is dispersed by the insulating resin even during cooling, cracks are less likely to occur in the encapsulant, and damage to the bump connection portion due to stress concentration can be prevented.

The insulating resin having rubber elasticity when heated is solid at room temperature and has a dynamic viscoelastic modulus E ′ of 1 × 10 ⁹ dyn / cm ² or less at 140 ° C. or higher.

In a second aspect of the present invention, a layer of an insulating resin having rubber elasticity when heated is formed on one or both sides of an inner layer substrate composed of a resin-impregnated glass cloth laminate having a conductor circuit on the surface, A conductor circuit on the surface is formed on a resin layer, the conductor circuit on the inner layer substrate and the conductor circuit on the surface are connected by plating through the insulating resin layer, and the conductor circuit on the surface is formed. It is a chip mounting printed wiring board having a blind via hole formed by connecting a bump of a chip component to an electrode.

The high-density multilayer printed wiring board provided with the blind via holes described above can be mounted on bare chips, and the connection reliability of bumps can be improved by the stress relaxation effect of the insulating resin between layers as described above. become.

The third aspect of the present invention is (1) acrylic acid and / or methacrylic acid (hereinafter referred to as "(meth) acrylic") as the insulating resin having rubber elasticity when heated, which constitutes the first or second aspect of the present invention. Acid)) and a (meth) acrylic acid ester as a main component (hereinafter referred to as “unmodified acrylic polymer”), which is a constituent (meth) acrylic. A polymer obtained by adding a compound having a glycidyl group and a C = C unsaturated double bond to a part of a carboxyl group derived from an acid (hereinafter referred to as "first component"), (2) C = C at the terminal A polymerizable compound having an unsaturated double bond (hereinafter referred to as "second component"),
And (3) an alkali-soluble resin composition comprising a polymerization initiator capable of initiating the polymerization of a C = C unsaturated double bond by heating and / or irradiation with an active energy ray (hereinafter referred to as "third component") Therefore, the blind via hole is formed very easily by the method of dissolving the resin composition with an alkali as described below, and stress relaxation is possible, and the blind via hole has high reliability. A chip-mounted printed wiring board is obtained.

A fourth aspect of the present invention provides an insulating resin having rubber elasticity when heated according to the first or second aspect of the present invention, including (1) the unmodified acrylic polymer as a constituent component thereof (meth). A polymer obtained by adding a compound having a glycidyl group and a C = C unsaturated double bond to a part of a carboxyl group derived from acrylic acid and a halogenated phenyl compound having a glycidyl group (hereinafter referred to as "first 'component"). (2) the second component, (3) the third component, and
(4) An alkali-soluble resin composition comprising an inorganic ion exchanger having a —OH group (hereinafter referred to as “fourth component”) is used. In the fourth aspect of the present invention, it is possible to obtain a chip-mounted printed wiring board which has a flame retardant composition and can prevent corrosion of bare chips, and which has a highly reliable blind via hole.

When flame retardancy is imparted to the insulating resin composition by selecting the 1'component, halogen and the like are mixed as impurities, so that the purity of the composition is lowered and the insulation reliability and the conductor Problems such as corrosion easily occur. Therefore, the problem can be solved by further adding an inorganic ion exchanger having an —OH group to trap impurity ions.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The unmodified acrylic polymer in the third or fourth aspect of the present invention is, for example, methyl acrylate and / or methyl methacrylate (hereinafter “acrylate and / or methacrylate” is referred to as “(meth) acrylate”). ), Butyl (meth) acrylate, hexyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate or tetrahydrofurfuryl (meth) acrylate and the like, and (meth) acrylic acid Is dissolved in a solvent, preferably an alcohol solvent such as isopropyl alcohol, ethylene glycol monoethyl ether or propylene glycol monomethyl ether, at a desired composition ratio, and azobisisobutyronitrile or And the initiator benzoyl peroxide and the like, can be obtained by copolymerizing.

The unmodified acrylic polymer includes (meth)
As monomers other than acrylic acid and (meth) acrylic acid esters, vinyl monomers such as styrene and acrylonitrile other than these are used in a proportion of 25 mol% or less of all monomers constituting the unmodified acrylic polymer. Copolymerization is also possible, and it is preferable to use styrene among vinyl monomers because heat resistance is increased.

The preferred molecular weight of the unmodified acrylic polymer (styrene-equivalent weight average molecular weight by gel permeation chromatography) is 10,000 to 100,
000, more preferably 20,000 to 70,000
It is. If the molecular weight is too small, the heat resistance and moisture resistance will decrease, and if the molecular weight is too large, the alkali solubility will decrease.

Further, the ratio of (meth) acrylic acid to (meth) acrylic ester is such that the acid value of the final resin composition is within the range of 0.5 to 3.0 in view of alkali solubility. Considering that a part of the acid is used for addition with an ethylenically unsaturated compound having a glycidyl group and a halogenated phenyl compound having a glycidyl group, (meth) acrylic acid is an unmodified acrylic acid. 25-60 of all the monomers that make up the base polymer
Preferably it is mol%. In addition, in the resin composition of the third or fourth aspect of the present invention, the term "alkali-soluble" means that the conditions used for usual removal of a solder resist or the like, that is, 30 to 30% by using an aqueous solution of sodium carbonate of 0.1 to 1% by weight.
Dissolves at 40 ° C.

The first component of the third or fourth aspect of the present invention comprises a carboxyl group derived from (meth) acrylic acid copolymerized in an unmodified acrylic polymer, a glycidyl group and a C = C unsaturated double bond. A compound having a bond is added. Further, when flame retardancy is required, it is preferable to add a halogenated phenyl compound having a glycidyl group to the above compound to form the first component. These compounds will be described below.

Examples of the compound having a glycidyl group and a C = C unsaturated double bond include glycidyl (meth) acrylate, allyl glycidyl ether, vinylbenzyl glycidyl ether and 4-glycidyloxy-3,5-.
Glycidyl (meth) acrylate is preferred among these, from the viewpoint that the addition reaction to the acid is easy. In the present invention, it is considered that the heat resistance and the humidity resistance are significantly improved because the compound cross-links with the second component in a state of being added to the unmodified acrylic polymer.

The addition amount of the compound having a glycidyl group and a C = C unsaturated double bond is preferably 10 to 25 mol% of all the monomers constituting the unmodified acrylic polymer. If it is less than 10 mol%, heat resistance and moisture resistance will not be sufficiently exhibited, and if it exceeds 25 mol%, the amount of (meth) acrylic acid in the unmodified acrylic polymer will be too large, and the physical properties of the polymer will be low. Both of them are not preferable because they decrease.

The addition amount of the halogenated phenyl compound having a glycidyl group is preferably 5 to 25 mol% of all the monomers constituting the unmodified acrylic polymer.
If it is less than 5 mol%, the flame retardancy is not sufficiently exerted, and 2
If it exceeds 5 mol%, the solder heat resistance is deteriorated, which is not preferable.

Examples of the halogenated phenyl compound having a glycidyl group include a compound having two or more glycidyl groups in one molecule such as dibromophenylglycidyl ether, tribromophenylglycidyl ether, dichlorophenylglycidyl ether and dibromocresylglycidyl ether, and tetra A compound having two or more glycidyl groups in one molecule, such as diglycidyl ether of bromobisphenol A, can be mentioned. The latter compound is used in the addition reaction process to (meth) acrylic acid and a plurality of compounds in one molecule can be used. It is more preferable to use the former compound because the reaction of the glycidyl group of (1) causes gelation and the reaction is difficult to control. In addition, as the halogen atom, bromine is preferable because a small amount of halogen atom can provide good flame retardancy.

In order to impart flame retardancy to the insulating resin of the present invention, a glycidyl ether of a brominated phenol compound and (meth) acrylic acid are used as the first component instead of the first 'component. Although the reaction product can be blended and used, it is more preferable to use the 1'component because it has poor compatibility with the resin. It is also possible to further enhance the flame retardancy by blending the reaction product with an insulating resin containing the first 'component.

Next, the polymerizable compound having a C = C unsaturated double bond at the terminal as the second component will be described. It has an acryloyl group and / or a methacryloyl group (hereinafter referred to as “(meth) acryloyl group”), an allyl group or a vinyl group at the terminal, and is polymerized by irradiation with active energy rays such as ultraviolet rays and / or heating. It is a compound capable of causing (crosslinking).

Specifically, methyl (meth) acrylate having one double bond, butyl (meth) acrylate, 2-
Ethylhexyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth)
Examples thereof include monofunctional (meth) acrylates such as acrylate or 2-hydroxy-3-phenoxypropyl (meth) acrylate; and compounds having a vinyl group such as styrene or acrylonitrile. With two double bonds, 1,3-butanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and bisphenol A type epoxy can be used. Examples thereof include di (meth) acrylates such as di (meth) acrylate or urethane (meth) acrylate; and allyl compounds such as diallyl phthalate or diallyl ether of bisphenol A. Also,
When the number of double bonds is 3 or more, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. may be mentioned.

When a compound having three or more double bonds is used among the above-mentioned polymerizable compounds, the crosslink density is increased and the heat resistance is increased, but the resin after curing is hard and brittle, and it is difficult to form a copper foil or a substrate. Adhesion becomes poor. On the other hand, in the case of a compound having two or less double bonds, the adhesion is improved, but the heat resistance is deteriorated. Therefore, 3 or more compounds and 2 or less compounds
It is preferable to mix and blend in the range of 0 parts by weight / 70 parts by weight to 70 parts by weight / 30 parts by weight. Further, from the viewpoint of compatibility with the first component or the first component, urethane (meth) acrylate or polyethylene glycol di (meth) acrylate is used as the compound having two double bonds, and trimethylolpropane is used as the compound having three double bonds. Tri (meth) acrylate or pentaerythritol tri (meth) acrylate is preferred. The blending amount of the second component is 20 based on the total amount of the first component or the first ′ component and the second component.
The range of ˜50 wt% is preferable from the viewpoint of heat resistance and adhesion.

Among the polymerization initiators as the third component, as the polymerization initiator by active energy rays, aromatic ketones such as benzophenone, Michler's ketone, xanthone, thioxanthone or 2-ethylanthraquinone; acetophenones as acetophenone, trichloroacetophenone, 2 -Hydroxy-2-methylpropiophenone, 1
-Hydroxycyclohexyl phenyl ketone, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-diethoxyacetophenone, etc .; examples of the diketone include benzyl or methylbenzoyl formate, and the amount thereof is the first component or the first 'component and 0.5 based on 100 parts by weight of the total amount of the second component
-10 parts by weight is preferred. If the amount is less than 0.5 part by weight, curing is insufficient and the heat resistance is poor. If the amount is more than 10 parts by weight, a large amount of decomposed products remain in the composition and a plasticizer effect is exhibited, and the heat resistance tends to be poor. When the curing is performed using an electron beam among the active energy rays, this polymerization initiator may be omitted.

The heating initiator may be an organic peroxide type or an azobis type initiator, and one having a high decomposition initiation temperature is preferable for obtaining storage stability. Examples are dicumyl peroxide, t-butyl cumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane or 2,5-dimethyl-2,5-di (t-butylperoxide). (Oxy) hexyne and the like. The blending amount thereof is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the total amount of the first component or the first 'component and the second component. If the amount is less than 0.5 part by weight, curing is insufficient and the heat resistance is poor. If the amount is more than 10 parts by weight, a large amount of decomposed products remain in the composition and a plasticizer effect is exhibited, and the heat resistance tends to be poor.

Any means of active energy rays or heating may be used to cure the insulating resin composition. However, since heat resistance is not sufficiently increased only by active energy rays in many cases, curing by heating is not recommended. It is preferable to use them together.

In order to impart flame retardancy to the insulating resin composition of the present invention, phosphorus or phosphorus is used in addition to the main component being a polymer having a halogenated phenyl compound having a glycidyl group introduced into its side chain. It is preferable to add a small amount of the flame retardant. By adding a small amount of phosphorus or a phosphorus-based flame retardant, which originally has a poor flame retardant function, a synergistic effect regarding flame retardancy occurs, the required introduction amount of a halogenated phenyl compound is reduced, and heat resistance of the resin composition and Good flame retardancy can be provided without impairing electrical insulation.

Here, the phosphorus-based flame retardant is a phosphorus compound that is often used as an additive for imparting flame retardancy. As a phosphoric acid ester-based compound, triphenyl phosphate, tricresyl phosphate, and cresyl phosphate are used. Examples thereof include dil diphenyl phosphate or tributyl phosphate, and examples of the halogen-containing phosphate ester include trischloroethyl ethyl phosphate, tris dichloropropyl phosphate, tris (tribromophenyl) phosphate and the like. Furthermore, red phosphorus, which is pure phosphorus itself, can be used instead of the compound.

The total content of halogen and phosphorus in the insulating resin composition used in the present invention is the total amount of the first component or the first 'component, the second component, the third component and the phosphorus or phosphorus flame retardant. 2 to 20% by weight of halogen and 0.2 to 5% by weight of phosphorus are preferable. If the halogen content is less than 2% by weight, the flame retardancy is insufficient, and
If it exceeds 5% by weight, the soldering heat resistance becomes poor. When the content of phosphorus is less than 0.2% by weight, the flame retardancy is also insufficient, and when it exceeds 5% by weight, heat resistance, moisture resistance and electric insulation deteriorate. The more preferable halogen content is 8 to 15% by weight, and the more preferable phosphorus content is 0.5.
~ 2% by weight. Among the halogens, bromine is most preferable from the viewpoint of flame retardancy as described above.

Further, the insulating resin composition used in the present invention may be added with an inorganic filler such as talc or calcium carbonate which is usually used, or an additive such as a leveling agent or a defoaming agent. .

In the fourth aspect of the present invention, an inorganic ion exchanger having an —OH group is blended as a fourth component into the insulating resin composition consisting of the first component, the second component and the third component, The effect of preventing failure due to corrosion of the metal conductor can be preferably added.

As the ion exchanger, all ion exchangers,
There are organic ion exchangers or inorganic ion exchangers,
An inorganic ion exchanger having an —OH group having excellent heat resistance is suitable. More specifically, by including an inorganic cation exchanger having an —OH group and an inorganic anion exchanger having an —OH group together, the influence of ionic impurities can be more effectively prevented. The ion trapping action of the inorganic ion exchanger having a —OH group is as follows.

[0038] Inorganic cation exchanger for metal ion capturing RO ^- H ^+, a metal ion M ⁺ OH ^- expressed in hydroxyl type, the ion exchange is as follows, to produce water as a result. RO ⁻ H ⁺ + M ⁺ OH ⁻ → RO ⁻ M ⁺ + H ₂ O (a) The reaction for trapping the above-mentioned ions is an ion exchange reaction, but as a characteristic of the inorganic ion exchanger, the reverse reaction is unlikely to occur. Generally, the ions that have been once captured are difficult to release. It is considered that this is because the bond between O and M after the RO ^- H ⁺ bond becomes RO ^- M ⁺ has a strong covalent bond.

For ionic impurities such as halogen.
R ′ ⁺ OH ⁻ , an inorganic anion exchanger having a —OH group,
When the halogen ion is represented by the acid form of H ⁺ X ^−, the following reaction occurs, resulting in the production of water. R ′ ⁺ OH ⁻ + H ⁺ X ⁻ → R ′ ⁺ X ⁻ + H ₂ O (b) In the case of a neutral salt, the above reactions (a) and (b) occur simultaneously.

The amount of the inorganic ion exchanger to be blended with the insulating resin composition of the fourth aspect of the present invention is, based on the resin composition.
0.1 to 15% by weight is preferable, and 0.1 is more preferable.
10 to 10% by weight. The particle size of the inorganic ion exchanger is preferably fine in order to increase the rate of ion trapping and the intended contact with the trapped ion exchanger, and the average particle size is preferably 10 μm or less, more preferably 5 μm or less.

As the inorganic ion exchanger used,
Antimonic acid (Sb ₂ O ₅ · nH ₂₎ having high selectivity for metal ions such as gold, silver, copper, lead, platinum and cadmium
O), niobate (Nb ₂ O ₅ · nH ₂ O) and hydrous oxides of pentavalent metals typified by tantalic acid; insoluble tetravalent typified by zirconium phosphate having high selectivity for copper and aluminum. Metal phosphates; hydrous metal oxides represented by hydrated bismuth oxide nitrate and hydrous lead oxide having high selectivity for halogen ions, apatites represented by lead hydroxyapatite bismuth oxide hydrated nitrate, hydrotalcites, etc. Can be mentioned.

Others such as thallic acid, molybdic acid and tungstic acid are used for capturing metal ions, and hydrous iron oxide, hydrous tin oxide, hydrous aluminum oxide, hydrous zirconium oxide and hydrous titanium oxide are used for capturing halogen ions. To be Among these inorganic ion exchangers, hydrous oxides of pentavalent metals represented by antimonic acid are excellent in capturing ions of silver, copper, cadmium, lead, gold and platinum, particularly silver ions. Arsenite, a tetravalent metal typified by zirconium arsenite, is excellent in capturing copper ions.

On the other hand, hydrated bismuth nitrate, hydrated lead, lead hydroxyapatite and lead oxyhydroxide are useful for capturing halogen ions.
Those in which some of the groups are replaced with NO ₃ groups are particularly excellent.
As these inorganic ion exchangers, those for trapping metal ions may be used alone, or those for trapping halogen ions may be used in combination. However, when used in the insulating resin composition on the blackened inner layer substrate, the metal ion scavenger may affect the corrosion of copper oxide during the blackening treatment, so that only the halogen ion scavenger is used. Is preferred. Further, as the inorganic ion exchanger having an —OH group, a composite containing two or more kinds of metal elements (for example, manganese antimonate or tin antimonate) or a mixture thereof can be used.

In the chip-mounted printed wiring board of the present invention, a method of forming an insulating resin layer having rubber elasticity during heating on a resin-impregnated glass cloth laminated board or an inner layer substrate formed of the laminated board is the laminated board. Alternatively, a method of applying an insulating resin to the inner layer substrate and drying and laminating a copper foil, and a copper clad insulating sheet in which an insulating resin is applied to the copper foil are created, and the sheet is applied to the laminated plate or the inner layer substrate. A method of laminating may be mentioned, but the latter method is preferable because the steps are simple.

In the chip-mounted printed wiring board of the present invention, the thickness of the insulating resin layer having rubber elasticity when heated is preferably 30 to 70 μm. If it is less than 30 μm, the insulating property is insufficient, and if it exceeds 70 μm, the solder heat resistance becomes poor, which is not preferable. Incidentally, when a copper clad insulating sheet is prepared by applying a resinous resin to a copper foil and the sheet is laminated on a resin-impregnated glass cloth laminate or an inner layer substrate made of the laminate, the copper foil of the insulating resin is used. The coating thickness on the
-100 μm (thickness after drying) is suitable.

In the method for manufacturing a chip-mounted printed wiring board having a blind via hole according to the second, third and fourth aspects of the present invention, the blind via hole can be provided by various methods, but the insulating resin is alkali-soluble. In the case of, the following method is preferable because the steps are simple. That is,
A copper clad laminate panel is prepared by laminating a surface copper foil on an inner layer substrate via an insulating resin, and a fine hole is formed at a predetermined position of the copper foil on the surface by selective etching, and a resin under the fine hole is formed. It is a method of forming a blind via hole by dissolving a composition with an alkali. In addition, in the second aspect of the present invention, when the insulating resin is insoluble in alkali, the blind via hole can be formed by ordinary drilling.

As a method of forming a plating in the blind via hole, there can be mentioned a usual method of performing electroless copper plating and electrolytic copper plating, but a direct plating method can also be used.

[0048]

EXAMPLES The present invention will be described in more detail with reference to examples. It should be noted that FIGS. 1 to 3 are provided for explaining the method for manufacturing the chip-mounted printed wiring board.

Example 1 (Synthesis of First Component) 40 parts by weight of n-butyl methacrylate, 15 parts by weight of methyl methacrylate, 15 parts by weight of styrene, 10 parts by weight of hydroxyethyl methacrylate, 20 parts by weight of methacrylic acid and 2 of azobisisobutylnitrile. The mixture of 1 part by weight was added dropwise to 120 parts by weight of propylene glycol monomethyl ether kept at a temperature of 80 ° C. in a nitrogen gas atmosphere over 5 hours. After aging for 1 hour, 0.5 part by weight of azobisisobutylnitrile was further added and the mixture was aged for 2 hours to synthesize a methacrylic resin having a carboxyl group. Next, while blowing in air, 20 parts by weight of glycidyl methacrylate, 1.5 parts by weight of tetrabutylammonium bromide, and 0.15 parts by weight of hydroquinone as a polymerization inhibitor were added and reacted at a temperature of 80 ° C. for 8 hours to give a molecular weight of 50,000. ~ 70,
000, acid value 1.8 meq / g, unsaturated group concentration 1.14
A base resin having a mol / kg carboxyl group was synthesized.

(Preparation of Insulating Resin Composition A) 50 parts by weight of the above-mentioned first component, and polyethylene glycol diacrylate as a second component (Aronix M- manufactured by Toagosei Co., Ltd.)
260) 20 parts by weight and 20 parts by weight of urethane acrylate (Aronix M-1600 manufactured by Toagosei Co., Ltd.),
1.5 parts by weight of dicumyl peroxide (Parkmill D manufactured by NOF CORPORATION) as a thermal polymerization initiator in the third component,
2-methyl- [4- (methylthio) as a photopolymerization initiator
3 parts by weight of [phenyl] -2-morpholino-1-propanone (Irgacure 907 manufactured by Ciba-Geigy) and 2 parts by weight of a photopolymerization accelerator ethyl p-dimethylaminobenzoate (Kayacure EPA manufactured by Nippon Kayaku Co., Ltd.) are mixed well. Then, the insulating resin composition A was prepared. When the dynamic viscoelastic spectrum of the composition was measured, it was as shown in FIG. 4 and was E ′ = 10 ^8.5 dyn / cm ² at 140 ° C. The dynamic viscoelastic spectrum in FIG. 4 was measured using a viscoelastic spectrometer VES-FIII manufactured by Iwamoto Seisakusho Co., Ltd. under the conditions of an initial load of 30 g and a frequency of 10 Hz.

(Preparation of Printed Wiring Board) The insulating resin composition A described above was printed on a matte surface of a copper foil having a thickness of 18 μm by a bar coater, dried in an oven at 90 ° C. for 10 minutes, and having a thickness of 70 μm. A copper-clad insulating sheet having the resin layer 3 formed was prepared.

The resin side of the above copper clad insulating sheet was overlaid on the unclad 0.6 mm thick glass epoxy laminate 1 and
A copper clad laminate panel was prepared by laminating with a metal roll at ℃. After selective etching of copper foil, electroless gold plating is applied to form conductor circuit pattern and pitch 8
A printed wiring board provided with electrodes 4 for bump connection of 0 μm was prepared (FIG. 2).

(Creation of Printed Wiring Board) Semiconductor Chip 5
Bump bonder Panase manufactured by Matsushita Electric Industrial Co., Ltd.
Stud bumps 6 made of gold having a pitch of 80 μm were formed by rtASTB. Next, flip chip bonder Pan
After the conductive adhesive 9 was transferred to the stud bumps using the assert FCB-S, the electrodes 4 of the printed wiring board were aligned and then mounted to prepare a printed wiring board on which a semiconductor chip was mounted.

Next, a gap between the printed wiring board and the semiconductor chip was filled with a sealing agent 7 made of a thermosetting epoxy resin filled with a spherical silica filler by a capillary phenomenon. Then, the sealing agent was cured by heating at 150 ° C. for 30 minutes.

The printed wiring board on which the semiconductor chip 5 thus prepared is mounted is subjected to a temperature cycle of 125 ° C. for 30 minutes and −65 ° C. for 30 minutes.
The test was conducted up to 500 cycles with one minute as one cycle, but the electrical continuity of the bump connection portion was normal. 121 ° C 9
7%, 2 atm pressure cooker test (hereinafter “P
"CT". As a result, no abnormality was found in the aluminum wiring around the semiconductor bump. UL9
When the combustion test of No. 4 was performed, it was 94V-1.

Example 2 The insulating resin composition A prepared in Example 1 was printed on a matte surface of a copper foil having a thickness of 18 μm by a bar coater, and the temperature was 90 ° C.
It was dried in an oven for 10 minutes to prepare a copper-clad insulating sheet on which a resin layer 3 having a thickness of 70 μm was formed.

An inner layer substrate 1 of a glass epoxy laminate having a thickness of 0.6 mm having a conductor circuit 2 of 35 μm was prepared, and the conductor circuit was blackened by a usual method. Next, lay the resin side of the copper clad insulation sheet on one side of this inner layer substrate,
Lamination was performed with a metal roll at 0 ° C. to prepare a copper clad laminate panel. A fine hole is formed at a predetermined position of the copper foil on the surface by selective etching, and the resin composition under the fine hole is alkali-dissolved at 40 ° C. using 0.1 wt% sodium carbonate to form a blind via hole. did. Next, electroless copper plating and electrolytic copper plating were performed to form plated blind via holes 8. Then, the copper foil on the surface was selectively etched and then electroless gold plated to prepare a printed circuit board having a conductor circuit pattern and electrodes 4 for bump connection with a pitch of 80 μm (FIG. 3).

A semiconductor chip was mounted on the printed wiring board of this embodiment in the same manner as in Example 1 to prepare a printed wiring board having the semiconductor chip mounted thereon as shown in FIG.

The wiring board was subjected to a temperature cycle of 125 ° C. for 30 minutes,
The test was conducted up to 500 cycles with one cycle of −65 ° C. for 30 minutes, but the electrical continuity of the bump connection portion was normal. Then, a DC voltage of 50 V was applied between the conductor circuit of the inner layer substrate and the outer layer electrode and treated for 3,000 hours under the conditions of 85 ° C. and relative humidity of 85%, but there was almost no deterioration in insulation resistance and the resistance was 10 ¹² to 10 ¹³ Ω. there were. 121 ° C 97%, 2 atm P
As a result of CT, no abnormality was found in the aluminum wiring around the semiconductor bump. When the UL94 combustion test was performed, it was 94V-1 level.

Example 3 (Synthesis of 1'component) 30 parts by weight of n-butyl methacrylate, 13 parts by weight of methyl methacrylate, 10 parts of styrene
Parts by weight, 5 parts by weight of hydroxyethyl methacrylate, 42 parts by weight of methacrylic acid and 1 part by weight of azobisisobutyronitrile in 120 parts by weight of propylene glycol monomethyl ether kept at a temperature of 80 ° C. under a nitrogen gas atmosphere for 5 hours. It dripped over. After aging for 1 hour, 0.5 part by weight of azobisisobutylnitrile was added and aging was performed for 2 hours to give a molecular weight of 50,000 to 7
10,000 carboxyl group-containing methacrylic resins were synthesized. Next, while blowing air, a mixture of dibromophenyl glycidyl ether and dibromocresyl glycidyl ether (Broc-C manufactured by Nippon Kayaku Co., Ltd.) 50
Parts by weight, 20 parts by weight of glycidyl methacrylate, 1.5 parts by weight of tetrabutylammonium bromide, and 0.15 parts by weight of hydroquinone as a polymerization inhibitor, and reacted at 80 ° C. for 8 hours to give an acid value of 2.0 meq / g. A 1'component having a carboxyl group having an unsaturated equivalent of 0.83 mol / kg was synthesized.

Of the monomers constituting the 1'component, the amount of methacrylic acid was 50.7 mol% of all the monomers, of which 14.6 mol% was added with glycidyl methacrylate to give 16.1 mol%. Is added with dibromophenyl glycidyl ether and dibromo cresyl glycidyl ether, and the remaining 20.0 mol% is present as unmodified acid.

(Preparation of Insulating Resin Composition B) First '
50 parts by weight of the component, and polyethylene glycol diacrylate as the second component (Aronix M manufactured by Toagosei Co., Ltd.)
-260) 20 parts by weight and urethane acrylate (Aronix M-1600 manufactured by Toagosei Co., Ltd.) 20 parts by weight, and dicumyl peroxide (Perky Mill D manufactured by NOF CORPORATION) as a thermal polymerization initiator in the third component 1 0.5 parts by weight, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone (Irgacure 907 manufactured by Ciba-Geigy) as a photopolymerization initiator, and triphenyl phosphate as a phosphorus-based flame retardant. 1
4.4 parts by weight were mixed well to prepare a flame-retardant insulating resin composition. The bromine content of this composition is 8.4.
The weight% and the phosphorus content are 1.0% by weight. 1.0 parts by weight of a mixture of titanium antimonate as an inorganic ion exchanger having —OH and lead hydroxide phosphate for capturing halogen ions (weight ratio 6: 4) was added to pentaerythritol triacrylate in advance, and 3 The insulating resin composition was prepared by thoroughly mixing with a main roll or the like. When the dynamic viscoelastic spectrum of the insulating resin composition was measured,
Lower than that of the insulating resin composition A, E ′ at 130 ° C. = 10 ^8.5 dyn / cm ² , E ′ at 140 ° C.
= 10 ^8.3 dyn / cm ² .

The insulating resin composition B was printed by screen printing on the matte surface of a 18 μm-thick copper foil that had been mat-treated and dried in an oven at 90 ° C. for 10 minutes.
A copper clad insulating sheet having a resin layer 2 having a thickness of μm was prepared.

Next, a printed wiring board was prepared in the same manner as in Example 2, and the same semiconductor chip 5 as in Example 1 was mounted to prepare a printed wiring board on which the semiconductor chips were mounted.

The printed wiring board was subjected to a temperature cycle of 125 ° C.
The test was conducted up to 500 cycles with one cycle consisting of 30 minutes and −65 ° C. for 30 minutes, but the electrical continuity of the bump connection portion was normal. Then, a DC voltage of 50 V is applied between the conductor circuit of the inner layer substrate and the outer layer electrode at 85 ° C. and a relative humidity of 85%.
However, there was almost no deterioration in insulation resistance and the resistance was 10 ¹² to 10 ¹³ Ω. As a result of performing PCT at 121 ° C. 97% and 2 atm, no abnormality was found between the semiconductor bumps. When UL94 combustion test is performed, 94V-0
Met.

Comparative Example 1 A print in which a copper foil of a 0.6 mm-thick glass epoxy laminate having a copper foil circuit of 35 μm was electrolessly plated with gold to provide a conductor circuit pattern and electrodes for bump connection with a pitch of 80 μm. A wiring board was created.

As in Example 2, a semiconductor chip was mounted on the printed wiring board of this comparative example to prepare a printed wiring board on which the semiconductor chip was mounted. The printed wiring board was tested up to 100 cycles with a temperature cycle of 125 ° C. for 30 minutes and −65 ° C. for 30 minutes as one cycle, but defective electrical continuity of the bump connection portion occurred.

Comparative Example 2 Of the insulating resin composition B of Example 3, the fourth component, —OH
An insulating resin composition C excluding the inorganic ion exchanger having a group was prepared and applied to a matte surface of a 18 μm copper foil to obtain 90
A copper clad insulating sheet was prepared by drying at 10 ° C. for 10 minutes.

In the same manner as in Example 2, a printed wiring board provided with electrodes for bump connection having a pitch of 80 μm was prepared. Then, as in Example 1, a semiconductor chip was mounted on the printed wiring board of this comparative example to prepare a printed wiring board having the semiconductor chip mounted thereon.

The printed wiring board was subjected to a temperature cycle of 125 ° C.
The test was conducted up to 500 cycles with 30 minutes and -65 ° C. 30 minutes as one cycle, but there was no abnormality in the electrical continuity of the bump connection portion. However, as a result of applying a DC voltage of 50 V between the conductor circuit of the inner layer substrate and the outer layer electrode and treating it at 85 ° C. and a relative humidity of 85% for 500 hours, the insulation resistance between the layers is initially 10 ¹³ to 10 ¹⁴ Ω. It fell to 10 ¹¹ to 10 ¹² Ω. Further, as a result of performing PCT at 121 ° C. 97% and 2 atm, dendritic dendrites were observed in the aluminum wiring around the semiconductor bumps.

[0071]

As described above, since the insulating resin used in the printed wiring board of the present invention has a small residual heating stress, the printed wiring which is a semiconductor made of an inorganic material and an organic material having different thermal expansion coefficients when a semiconductor chip is mounted is used. The connection reliability of the board is high, and the aluminum wiring of the semiconductor does not corrode.
Therefore, a highly reliable printed wiring board can be obtained, which is of high industrial utility value.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a chip-mounted printed wiring board according to Embodiment 2 of the present invention.

FIG. 2 is a schematic cross-sectional view showing a printed circuit board provided with a conductor circuit pattern and electrodes for bump connection in Example 1 of the present invention.

FIG. 3 is a schematic cross-sectional view showing a printed circuit board provided with a conductor circuit pattern and electrodes for connecting bumps according to a second embodiment of the present invention.

FIG. 4 is a dynamic viscoelastic spectrum diagram obtained by measuring the insulating resin composition in Example 1 of the present invention.

[Explanation of symbols]

 1 Interior board 2 Conductor circuit 3 Resin layer 4 Electrode 5 Semiconductor chip 6 Bump 7 Sealant 8 Plating blind via hole 9 Conductive adhesive

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H05K 1/18 H01L 23/14 R (72) Inventor Hideki Hiraoka 1-1 Funami-cho, Minato-ku, Nagoya-shi, Aichi Toagosei Co., Ltd. Nagoya Research Institute (72) Inventor Masahiro Fujiwara 1 1 Funami-cho, Minato-ku, Aichi Prefecture Nagoya City Toagosei Co., Ltd. Nagoya Research Institute

Claims (4)

[Claims] 1. A resin-impregnated glass cloth laminate is formed on one or both sides with an insulating resin layer having rubber elasticity when heated, and a conductor circuit is formed on the insulating resin layer. Chip-mounted printed wiring board consisting of bumps of chip parts connected to the electrodes of. 2. An insulating resin layer having rubber elasticity when heated is formed on one or both sides of an inner layer substrate made of a resin-impregnated glass cloth laminate having a conductor circuit on the surface, and the insulating resin layer is formed on the insulating resin layer. A conductor circuit on the surface is formed, and the conductor circuit on the inner layer substrate and the conductor circuit on the surface are connected by plating by penetrating the insulating resin layer, and the electrode of the surface conductor circuit is connected to the electrode of the chip component. Chip mounted printed wiring board having blind via holes formed by connecting bumps. 3. The insulating resin having rubber elasticity when heated is (1) a linear polymer containing acrylic acid and / or methacrylic acid and acrylic acid ester and / or methacrylic acid ester as main components. A polymer in which a compound having a glycidyl group and a C = C unsaturated double bond is added to a part of a carboxyl group derived from acrylic acid and / or methacrylic acid which are its constituents, (2)
A polymerizable compound having a C = C unsaturated double bond at the terminal, and (3) a polymerization initiator capable of initiating the polymerization of the C = C unsaturated double bond by heating and / or irradiation with an active energy ray The chip-mounted printed wiring board according to claim 1 or 2, which is an alkali-soluble resin composition. 4. The insulating resin having rubber elasticity when heated is (1) a linear polymer containing acrylic acid and / or methacrylic acid and acrylic acid ester and / or methacrylic acid ester as main components. , A compound having a glycidyl group and a C = C unsaturated double bond, and a halogenated phenyl compound having a glycidyl group are added to a part of the carboxyl groups derived from acrylic acid and / or methacrylic acid which are its constituents. Polymer, (2)
A polymerizable compound having a C = C unsaturated double bond at the terminal,
(3) A polymerization initiator capable of initiating the polymerization of a C = C unsaturated double bond by heating and / or irradiation with an active energy ray, and (4) an inorganic ion exchanger having an -OH group, which is alkali-soluble. The chip-mounted printed wiring board according to claim 1 or 2, which is a resin composition.