TWI443018B - A lamination system for manufacturing circuitized substrates - Google Patents

Description

Lamination system for manufacturing circuitized substrates

The present invention generally relates to laminating a photopolymerizable dry film (sometimes referred to as a photoresist) onto a substrate. In particular, the wet lamination process and compositions of the present invention result in improved photoresist properties with respect to improved wet lamination fluid compositions and methods.

When a dry film photoresist is applied to the substrate: 1. Unwanted internal bubbles may occur, especially when the lamination interface is irregular or non-planar; and 2. Undesired residues (eg, anti-tarnish residues, For example, when the surface of the substrate is copper or stainless steel, it may hinder dry film adhesion. And if so, the final product may have circuit patterns of circuit lines that are susceptible to undesirable cracking or other defects.

In general, wet lamination (application of a photoresist dry film to a copper laminate) is known. See, for example, U.S. Patent No. 4,976,817 to Correa et al. However, with each new generation of board design, the circuit pattern tends to be smaller and therefore less able to withstand internal bubbles and undesirable surface residues. Accordingly, there is a need for a wet lamination system for dry film photoresists having improved properties, particularly associated with undesirable internal bubbles and undesirable surface residues.

The present invention relates to a lamination system that can be used to make a circuitized substrate. This lamination system includes a dry film photoresist and a laminate substrate comprising a metal (eg, copper or stainless steel) or a non-metallic surface. The lamination process of the present invention further includes a laminating fluid comprising water and a surface energy modifier.

In one embodiment of the invention, a dry film photoresist is applied to the copper surface of a copper laminate using conventional or non-conventional wet lamination. During the wet lamination process, a wet lamination fluid is applied between the dry photoresist film and the surface of the substrate. The wet laminating fluid is used to fill any irregularities in the two layers of the surface to be laminated together, thereby suppressing internal bubbles between the two layers. Subsequently, the wet laminating fluid is volatilized or removed.

The wet laminating fluid of the present invention is water based and has water up to 50, 60, 70, 80, 90, 95, 96, 97, 98, 99, 99.5 or 99.9 wt%. In one embodiment, prior to incorporation of the laminating fluid, the water component: 1. is sufficiently free of unnecessary ionic forms to have at least 10 ⁰ , 10 ¹ , 10 ² , 10 ³ , 10 ⁴ , 10 ⁵ , 10 ⁶ , 10 ⁷ , 10 ⁸ or 10 ⁹ Ohms resistivity; and 2. Contains dissolved oxygen, the content of which is less than 15, ¹⁴ , 12, 11, 10, 9, ⁸ , ⁷ , ⁶ , 5, ⁴ , 3, 2, 1 or 0.1 ppm.

According to the present invention, the wet lamination fluid of the present invention comprises at least one surface energy modifier. In one embodiment, the surface energy modifying agent is one or more of the following:

Organic alcohol

2. Organic phosphate

3. Fluorinated alcohol, such as:

Wherein R is hydrogen, alkyl and n is a positive integer of up to 25.

4. An anionic surfactant, such as a surfactant based on a sulfate anion, a sulfonate anion or a carboxylate anion, comprising:

a. sodium dodecyl sulfate (SDS)

b. Sodium lauryl ether sulfate (sodium lauryl ether sulfate)

c. ammonium lauryl sulfate, and

d. alkylbenzene sulfonate

e. fatty acid salt

f. sodium dodecyl sulfate (SDS), ammonium lauryl sulfate, and other alkyl sulfates

5. Cationic surfactants, such as:

a. Cetyltrimethylammonium bromide (CTAB), also known as cetyltrimethylammonium bromide, and other alkyltrimethylammonium salts

b. Cetylpyridinium chloride (CPC)

c. Polyethoxylated tallow amine (POEA)

d. Benzalkonium chloride (BAC)

e. Benzyl ethoxylated ammonium chloride (BZT)

6. Zwitterionic (amphoteric) surfactants, such as:

a. dodecyl betaine

b. Dodecyl dimethyl amine oxide

c. Coconut amidinopropyl propyl betaine

d. coconut-based amphoteric glycinate, and

7. Nonionic surfactants, such as:

a. alkyl poly(ethylene oxide),

b. Copolymers of poly(ethylene oxide) and poly(propylene oxide) (commercially known as Poloxamers or poloxamines)

c. Alkyl polyglucosides, including:

a) octyl glucoside

b) mercapto maltoside

d. Fatty alcohols, including:

a) cetyl alcohol

b) oleyl alcohol, and

e. coconut amide, and

8. Ether, such as:

a. glycol ethers, including: ethylene glycol mono-dibutyl ether, ethylene glycol monophenyl ether (phenyl diol), diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol single Butyl ether, diethylene glycol dibutyl ether, diethylene glycol monophenyl ether, propylene glycol monobutyl ether, propylene glycol monophenyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monobenzene Ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, and diethylene glycol monoethyl ether acetate.

b. Derivatives of glycol ethers, including: propylene glycol methyl ether acetate and propylene glycol diacetate.

In one embodiment, the surfactant is present (and optionally included) 0.0001, 0.001, 0.005, 0.01, 0.02, 0.05, 0.08, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9. Between 1.0, 2.0, 3.0 and 4.0 Moh/L. Generally, the level of surfactant that can be used should be sufficient to effectively wet the dry film of the photoresist, and this will generally depend on the nature of the particular surfactant and dry film photoresist surface selected. However, too much surfactant can cause undesirable foaming and/or flocculation during the lamination process. In one embodiment, an antifoaming agent is added during lamination to ensure that there is no unwanted foam.

In one embodiment, the fluid pH is generally controlled, for example, by adding a basic compound such as sodium hydroxide or potassium hydroxide at an optimum pH. In one embodiment, it is desirable to maintain the pH of the laminating fluid of the present invention within (and optionally include) any range between: 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0 , 10.0, 11.0, and 12.0. The pH of the laminating fluid of the present invention can be adjusted using any known acid, base or amine, especially an acid or a base which does not contain a metal ion, such as ammonium hydroxide and an amine, or nitric acid, phosphoric acid, sulfuric acid or an organic acid to avoid introduction. Undesired metal components into the process.

In one embodiment, the surface energy modifier is present between 0.0001 and 3.0 moles per liter and the fluid pH is between 3 and 11.

In one embodiment, the laminate fluid of the present invention comprises a binder. Useful combinations of reagents include, but are not limited to, acids such as citric acid, lactic acid, malonic acid, tartaric acid, succinic acid, acetic acid, oxalic acid, and other acids, as well as amino acids and amine sulfates, phosphoric acid, phosphonic acids, and salts thereof. The amount of the cross-linking agent is between (and optionally included) between any of the following: 0.1, 0.2, 0.5, 0.7, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, and 10.

In another embodiment, the laminating fluid comprises an organic amine based compound. Useful organic amine based compounds include alkyl amines, alcohol amines, amino acids, urea, urea derivatives, and mixtures thereof. Preferred organic amine based compounds are long chain alkyl amines and alcohol amines. The term "long-chain alkylamine" represents an alkylamine having 7 to 12 or more carbon atoms including, for example, decylamine and dodecylamine. Examples of useful alkanolamines include, but are not limited to, monoethanolamine and triethanolamine. Examples of useful urea derivatives include, but are not limited to, biuret. Preferred organic amine based compounds are long chain alkyl amines, dodecylamine. A preferred alcoholamine is triethanolamine.

The content of the organic amine based compound is between (and optionally included) between any of the following: 0.1, 0.2, 0.5, 0.7, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, and 10% by weight.

In one embodiment, the laminating fluid of the present invention comprises a film former. Useful film formers are nitrogen-containing cyclic compounds such as:

1. Thiazole, such as:

A. imidazole,

b. benzotriazole,

c. benzimidazole,

d. benzothiazole and

e. 2-mercaptobenzothiazole;

f. methylimidazole;

2. an oxazole such as 4H-oxazol-5-one;

3. benzopyrazole, such as carbazole;

4. A mixture thereof and a derivative thereof having a hydroxyl group, an amine group, an imido group, a carboxyl group, a thiol group, a nitro group and an alkyl substituent, and urea, thiourea or the like.

The film former concentration can vary over a relatively wide range, for example, between (and optionally included) any of the following: 0.01, 0.02, 0.05, 0.07, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8, 0.9, 1.0, 2.0, and 3.0 wt%.

In one embodiment, the film former is benzotriazole ("BTA"). However, benzotriazole and substituted benzotriazoles tend to have very low solubility in water, and in order to provide a sufficient concentration of benzotriazole in an aqueous solution, it is usually necessary to neutralize the benzoate with at least one molar equivalent of oxidant. Triazole (1 mole of non-acid oxidant is equivalent to 1 mole of benzotriazole). Useful oxidizing agents for use in the laminating fluids of the present invention include one or more inorganic or organic per-compounds. A peroxy compound as defined by Hawley's Condensed Chemical Dictionary is a compound comprising at least one peroxy group (--O--O--) or a compound comprising an element in its highest oxidation state. Examples of compounds containing at least one peroxy group include, but are not limited to, hydrogen peroxide and its adducts such as urea hydrogen peroxide and percarbonate, organic peroxides such as benzamidine peroxide, peracetic acid, peroxidation Third butyl, monopersulfate (SO ₅ ⁼ ), dipersulfate (S ₂ O ₈ ⁼ ), and sodium peroxide.

Examples of compounds containing an element in its highest oxidation state include, but are not limited to, periodic acid, periodate, hyperbromic acid, perbromate, perchloric acid, perchlorate, perboric acid, perborate And permanganate. Examples of non-peroxy compounds that meet electrochemical potential conditions include, but are not limited to, bromate, chlorate, chromate, iodate, iodic acid, and cerium (IV) compounds such as cerium ammonium nitrate.

Preferred oxidizing agents are peracetic acid, urea hydrogen peroxide, hydrogen peroxide, monopersulfuric acid, dipersulfuric acid, salts thereof, and mixtures thereof, including mixtures of urea and hydrogen peroxide.

The oxidant content is between (and optionally included) any of the following: 0.3, 0.5, 0.8, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10, 12, 14, 15, 16, 17, 18, 19, 20, 25 and 30 wt%.

In addition to water, the wet laminating fluid of the present invention may include a cosolvent such as:

1. Alcohol, such as:

a. isopropanol,

b. 2-butoxy-ethanol-1,

c. isobutanol, and

d. 1-propanol

Ketone, such as

a. methyl isobutyl ketone, and

b. isophorone,

3. Hydrocarbon solvents, such as

Benzene

bC _5-10 paraffin

The amount of non-aqueous solubilizing agent is between (and optionally included) between any of the following: 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15 or 20 wt %. A non-aqueous co-solvent promotes the dry film surface of the wet photoresist.

Instance

Perform laboratory tests and obtain the following results.

1. A dry film photoresist called "MX Advance 115" is applied to the stainless steel surface in 3 different lamination conditions (dry lamination = conventional, wet lamination = use of deionized water, and wet lamination) -S contains organic alcohol as an additive to deionized water).

Figure 1 is an analytical diagram of the separation line.

Significant improvements in dry film adhesion were observed when using this novel fluid technique.

2. A dry film photoresist called "MX-5040" is applied to a copper surface containing some amount of rust inhibitor. As shown in the analytical chart below, the wet lamination-S shows some improvement in terms of separation line resolution. In addition, both wet lamination and wet lamination-S provide excellent image quality without dry film ridges (see Figures 2 and 3).

Figures 2 and 3 show the dry film ridges on the dry laminate due to the rust inhibitor.

The above discussion of the invention is merely illustrative, and thus is not limiting. Any limitation of the invention is provided only by the scope of the following claims.

Figure 1 is a diagram of a separation line of a dry film photoresist applied to a stainless steel surface under three lamination conditions: i. dry, ii. deionized water, and iii. deionized water containing organic alcohol.

Figure 2 shows the dry film photoresist in three lamination conditions: i. dry, ii. deionized water, and iii. deionized water containing organic alcohol, applied to the copper surface (containing anti-rust coating) Analyze the graph offline.

Fig. 3 is a view showing an excellent image quality of a copper wire formed by applying a dry film photoresist to a copper surface (containing a rust-preventive coating film) using deionized water containing organic alcohol.

(no component symbol description)

Claims (9)

A laminating system wherein: a. a laminating fluid comprising water and a co-solvent in an amount between 0.1 and 20% by weight of the fluid, the co-solvent being an alcohol, a ketone, a hydrocarbon or Combining; b. the fluid comprises a surface energy modifier having a content between 0.0001 and 4.0 moles per liter, and the pH of the fluid is between 3 and 11, wherein the surface energy modifying agent comprises one of the following or a variety of: (a) organic alcohol, (b) organic phosphate, (c). fluorine-containing alcohol, (d) anionic surfactant, wherein the anionic surfactant is selected from: sulfate anion, sulfonate a surfactant composed of an anion or a carboxylate anion, (e) a cationic surfactant, (f) a zwitterionic (amphoteric) surfactant, and (g) a nonionic surfactant, and (h) An ether; wherein the laminating fluid further comprises: c. a film former having a content of between 0.01 and 3.0% by weight, and d. a non-acid oxidizing agent in an amount of between 0.3 and 30% by weight. The lamination system of claim 1, wherein the nonionic surfactant comprises one or more of the following: a. alkyl poly(ethylene oxide), b. a copolymer of poly(ethylene oxide) and poly(propylene oxide), c. an alkyl polyglucoside comprising: a) octylglucoside b) mercapto maltoside d. fatty alcohol, including: a Cetyl b) oleyl alcohol, and e. coconut decylamine. The lamination system of claim 1, wherein the film former is a nitrogen-containing cyclic compound. The lamination system of claim 3, wherein the nitrogen-containing cyclic compound comprises one or more of the following: (1) thiazole: (2) oxazole; (3) benzopyrazole; and (4) the above (1) a mixture of (3) and a derivative thereof having a hydroxyl group, an amine group, an imido group, a carboxyl group, a thiol group, a nitro group and an alkyl substituent, and urea, thiourea. The lamination system of claim 4, wherein the (1) thiazole of the nitrogen-containing cyclic compound comprises one or more of the following: a. imidazole; b. benzotriazole; c. benzimidazole; d. Thiazole e. 2-mercaptobenzothiazole; and f. methylimidazole. The lamination system of claim 1, wherein the non-acid oxidant is a peroxy compound comprising one or more inorganic or organic substances. The lamination system of claim 6, wherein the peroxy compound is a compound comprising at least one peroxy group. The lamination system of claim 6 wherein the peroxy compound is a compound comprising an element in its highest oxidation state. The laminate system of claim 6, wherein the non-acid oxidant is a non-peroxy compound selected from the group consisting of: bromate, chlorate, chromate, iodate, iodic acid, and cerium (IV). A group of compounds.