A browning additive and a method for browning an IC substrate using the same

Abstract

The present invention discloses a browning additive and an IC carrier browning method using the same, and relates to the technical field of IC carrier production and manufacturing. The browning additive is composed of the following components per 100 parts by weight: 1.0-3.0 parts of a first corrosion inhibitor, 1.0-3.0 parts of a second corrosion inhibitor, 0.5-2.0 parts of a cross-linking agent, 0.5-2.0 parts of a plasticizer, 0.2-1.0 parts of an oxidant, and the remainder is water; the mass ratio of the first corrosion inhibitor to the second corrosion inhibitor is 1: (0.5-2.0). The browning additive of the present invention can form a layer of organic metal film on an uneven surface of active microscopic rough copper, effectively improving the uniformity and bonding strength of the copper surface after browning, so that it has low roughness, high peel strength, low insertion loss and good heat resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of IC carrier board production and manufacturing, and particularly to a brownification additive and an IC carrier board brownification method using the same. Background Art

[0002] In recent years, as the integrated circuit industry continues to move towards smaller size and higher integration, IC packaging has also developed in the direction of super multi-pins, ultra-small size, and narrow pitch. The IC carrier board is developed based on the HDI board, with the characteristics of high density, high performance, and thin and light. It is an upgrade of the traditional integrated circuit packaging lead frame and is used in various chip packaging links, playing a key role in supporting, connecting, dissipating heat, and protecting the chip.

[0003] The brownification process is to generate an organic metal conversion film on the surface of the inner-layer copper film through the micro-etching effect of the brownification solution, enhance the bonding force with the substrate, and improve the thermal shock resistance and delamination resistance of the laminate. Most brownification solutions use an acidic system of sulfuric acid plus hydrogen peroxide, and then add specific organic substances. When brownifying, an uneven and active microscopic roughness is formed on the copper surface, increasing the contact area with the resin during lamination. The functions of brownification mainly include removing oils and impurities on the surface to ensure the cleanliness of the board surface; after brownification, a uniform fluff will be formed on the copper surface of the substrate, increasing the bonding force between the substrate and the resin, helping to avoid problems such as delamination and explosion of the board, thereby improving the reliability and stability of the circuit board; by removing oxides on the metal material of the circuit board, increasing the adhesion of the surface metal material, thereby improving the yield of the next process; for the deformation welding of lead-containing solder, an oxide film will be formed on the surface of the circuit board, which can increase the solderability of the circuit board surface and is beneficial for welding; the brownification of the circuit board will form an oxide film, because the copper oxide contains a certain amount of CuO and Cu 2 O, and these oxides have certain electrical conductivity, which can help improve the electrical conductivity of the circuit board.

[0004] Currently, there are also some technical solutions related to brownification. For example, Patent CN111826645A discloses a brownification solution for the inner-layer copper foil of a circuit board, whose components include an aqueous sulfuric acid solution, zinc sulfate, hydrogen peroxide, 2-mercaptobenzothiazole, 4-carboxybenzotriazole, sodium chromate, dodecylbenzenesulfonic acid, and polyvinyl alcohol, which can solve the defects of poor peel strength performance of the board after brownification, weak tolerance to high-temperature thermal shock, uneven micro-etching, and poor interlayer bonding force. Patent CN110527996A provides a brownification solution and its preparation method and application. The brownification solution contains anhydrous copper sulfate, sulfuric acid, chloride, benzotriazole, citric acid and its derivatives, nitric acid, and hydrogen peroxide. This brownification solution has a high copper loading capacity, less precipitation in the solution, a long service life, and less pollution. At the same time, it can effectively solve the problems of poor brownification of different copper crystals and exposed copper in the brownification of the repair wire alloy.

[0005] After continuous research and improvement, the existing brownification technology has also overcome the blackening problem in the original process. The board shows advantages such as strong acid resistance, no pink ring, high peel strength, low operating temperature, safety and high efficiency. The brownification technology has obvious advantages in production and manufacturing and will become the mainstream in the inner layer surface treatment process of printed circuit boards. With the rapid development of the PCB industry and the continuous improvement of market demand, the IC packaging substrate market has grown rapidly. The technical difficulty of IC carriers is generally higher than that of PCBs. Compared with ordinary PCBs, IC carriers have the advantages of thinner board bodies, easier deformation, smaller via hole diameters and line widths / line pitches. At the same time, their technical and production requirements are more stringent, which puts higher requirements on the densification and refinement of PCBs. Although the existing brownification technology has made good development progress, the existing technology is difficult to meet the standards of IC carrier production, resulting in a decline in production yield. Therefore, there is an urgent need for a brownification solution for IC carriers to meet the production requirements of modern IC carriers and high-frequency signal transmission. Summary of the Invention

[0006] Aiming at the shortcomings of the existing technology, the present invention provides a brownification additive for the brownification production process of IC carriers, which contains effective components such as corrosion inhibitors, cross-linking agents, plasticizers, oxidants, etc. The effective components can form an organic metal film on the uneven active micro-rough copper surface, effectively improving the uniformity and bonding force of the copper surface after brownification, making it have low roughness, high peel strength, low insertion loss and good heat resistance, meeting the production requirements of the IC carrier brownification process.

[0007] The object of the present invention is achieved through the following technical solutions.

[0008] A brownification additive is provided. By weight, every 100 parts are composed of the following components: 1.0 - 3.0 parts of a first corrosion inhibitor, 1.0 - 3.0 parts of a second corrosion inhibitor, 0.5 - 2.0 parts of a cross-linking agent, 0.5 - 2.0 parts of a plasticizer, 0.2 - 1.0 parts of an oxidant, and the balance is water;

[0009] The structural formula of the first corrosion inhibitor is as follows:

[0010] ;

[0011] Among them, R is F, Cl, Br or I;

[0012] The second corrosion inhibitor is selected from at least one of guar gum (CAS No.: 9000 - 30 - 0), locust bean gum (CAS No.: 9000 - 40 - 2), and alginate (CAS No. 83 - 85 - 2);

[0013] The mass ratio of the first corrosion inhibitor to the second corrosion inhibitor is 1:(0.5 - 2.0).

[0014] Preferably, the crosslinking agent is selected from at least one of bis(bipyridine)-4'-methyl-4-carbonylpyridine ruthenium-N-succinimidyl ester bis(hexafluorophosphate) (CAS No.: 136724-73-7), N-succinimidyl 4-(azidosulfonyl)benzoate (CAS No.: 1427502-22-4), and N-hydroxysuccinimidyl 3-maleimidopropionate (CAS No.: 55750-62-4).

[0015] Preferably, the plasticizer is selected from at least one of oxazole-2-carboxamide (CAS No.: 884539-45-1), oxazole-4-carboxamide (CAS No.: 23012-13-7), and oxazole-5-carboxamide (CAS No.: 158178-93-9).

[0016] Preferably, the oxidizing agent is selected from at least one of N-allylbenzylamine (CAS No.: 4383-22-6), 4-vinylbenzylamine (CAS No.: 50325-49-0), and N-benzylidene butylamine (CAS No.: 780-25-6).

[0017] Preferably, the first corrosion inhibitor is obtained by mixing 1,2-diphenylethylenedione, p-anisidine, p-halobenzaldehyde, and acetic acid in water, reacting at 60-70 °C for 4-6 hours, adjusting the pH of the reaction solution to 7-8 after the reaction, and then extracting with ethyl acetate.

[0018] Preferably, the mass ratio of 1,2-diphenylethylenedione, p-anisidine, p-halobenzaldehyde, and acetic acid is (2-3):(2-3):(2-3):1, and more preferably, the mass ratio is 2:2:2:1.

[0019] The preparation method of the above-mentioned brownification additive: Weigh the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer, the oxidizing agent, and the remaining water in sequence and add them into a reaction kettle, stir and mix evenly at room temperature to obtain the brownification additive, and store it sealed for later use.

[0020] The present invention also provides a method for brownifying an IC carrier board, which sequentially includes the following steps:

[0021] Activation: The IC carrier board is subjected to activation treatment with an activation solution; the activation solution is an aqueous solution of the above-mentioned brownification additive with a mass concentration of 3-4%.

[0022] Brownification: The IC carrier board is subjected to brownification treatment with a brownification solution; the brownification solution is composed of the following components in mass fractions: 3-5% of the above-mentioned brownification additive, 4-6% of sulfuric acid, 2-3% of hydrogen peroxide, and the balance is water.

[0023] Preferably, the activation treatment of the IC substrate with the activation solution is specifically as follows: spraying the IC substrate with the activation solution, with a spraying pressure of 1.5 ± 0.5 kg / cm 2 , and the time is 35 - 50S.

[0024] Preferably, the brownification treatment of the IC substrate with the brownification solution is specifically as follows: spraying the IC substrate with the brownification solution, with a spraying pressure of 1.5 ± 0.5 kg / cm 2 , and the time is 35 - 50S.

[0025] Further, in the above IC substrate brownification method, before the activation step, pickling, degreasing, and water washing are also included.

[0026] In the brownification additive of the present invention, the corrosion inhibitor includes a first corrosion inhibitor and a second corrosion inhibitor. By utilizing the synergistic effect between the components, the adsorption coverage and adsorption stability are increased, and the adsorption rate is changed, thereby effectively improving the corrosion inhibition efficiency and achieving a better brownification effect. Secondly, the corrosion inhibitor participates in the formation of the organic metal film, that is, a uniform and dense organic metal oxide layer is formed on the copper surface; the crosslinking agent in the present invention has the function of promoting crosslinking and coupling, and has a strong adsorption force with the copper surface, which is conducive to forming a multi-layer composite film on the copper foil surface, thereby significantly improving the quality of the organic metal film; the plasticizer in the present invention has strong chemical activity. On the one hand, it is easy to form a coordination bond with metallic copper and strongly adsorb on the copper foil surface. On the other hand, it has a strong polymerization effect with the semi-cured resin. At the same time, the non-polar group part can form a hydrophobic protective film on the metal surface to inhibit the erosion of the corrosive medium; the oxidant in the present invention can form a rough surface with a moderate depth and uniform consistency on the copper foil surface in an acidic medium, providing favorable conditions for the formation of the organic metal film on the copper foil surface of the copper surface, and being conducive to increasing the contact area between the copper foil surface and the resin during lamination.

[0027] Therefore, the brownification additive of the present invention can form an organic metal film on the uneven active micro-rough copper surface, effectively improving the uniformity and bonding force of the copper surface after brownification, making it have low roughness, high peel strength, low insertion loss, and good heat resistance. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is the reaction formula of the first corrosion inhibitor of the present invention;

[0030] Figure 2 SEM image of the IC substrate after the brownification process of Example 1 of the present invention;

[0031] Figure 3 SEM image of the IC substrate after the brownification process of Comparative Example 13 of the present invention. Detailed implementation manners

[0032] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] The first corrosion inhibitor of the present invention is prepared by mixing 1,2-diphenylethanedione, p-anisidine, p-halobenzaldehyde and acetic acid in water, reacting at 60 - 70 °C for 4 - 6 hours. After the reaction, the pH of the reaction solution is adjusted to 7 - 8 with sodium bicarbonate solution, and then extracted with ethyl acetate to obtain the first corrosion inhibitor; the mass ratio of 1,2-diphenylethanedione, p-anisidine, p-halobenzaldehyde and acetic acid is (2 - 3):(2 - 3):(2 - 3):1, and more preferably, the mass ratio is 2:2:2:1. To further verify the effects of the first corrosion inhibitor and the brownification additive of the present invention, in the following examples or comparative examples, the preparation method of the first corrosion inhibitor used is as follows:

[0034] By mass fraction of raw materials, 5% of 1,2-diphenylethanedione (CAS No.: 134 - 81 - 6), 5% of p-anisidine (CAS No.: 104 - 94 - 9), 5% of p-halobenzaldehyde (where the halogen can be F, Cl, Br, I; p-fluorobenzaldehyde, CAS No.: 459 - 57 - 4; p-chlorobenzaldehyde, CAS No.: 104 - 88 - 1; p-bromobenzaldehyde, CAS No.: 1122 - 91 - 4; p-iodobenzaldehyde, CAS No.: 15164 - 44 - 0), 2.5% of acetic acid (CAS No.: 64 - 19 - 7) and the balance of water are added to a three-necked flask and heated at 65 °C for 5 hours. After the reaction, the pH of the reactants is adjusted to 7 with sodium bicarbonate solution (CAS No.: 144 - 55 - 8), and then extracted with ethyl acetate (CAS No.: 141 - 78 - 6) to obtain the first corrosion inhibitor, and its structural formula is:

[0035] .

[0036] The reaction formula of the first corrosion inhibitor is as Figure 1 shown.

[0037] Example 1

[0038] Weigh the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer, the oxidant and the balance of water in sequence according to the following formula in 100 parts by weight, add them into a reaction kettle, stir and mix at room temperature for 30 minutes to obtain the brownizing additive of this example, and store it sealed for later use.

[0039] 1.5 parts of the first corrosion inhibitor, and its structural formula is:

[0040] ;

[0041] 1.5 parts of the second corrosion inhibitor, specifically guar gum;

[0042] 1.0 part of the crosslinking agent, specifically bis(bipyridine)-4'-methyl-4-carbonylpyridine ruthenium-N-succinimidyl ester bis(hexafluorophosphate);

[0043] 1.0 part of the plasticizer, specifically oxazole-2-carboxamide;

[0044] 0.5 part of the oxidant, specifically N-allylbenzylamine;

[0045] The balance is distilled water.

[0046] Example 2

[0047] Weigh the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer, the oxidant and the balance of water in sequence according to the following formula in 100 parts by weight, add them into a reaction kettle, stir and mix at room temperature for 30 minutes to obtain the brownizing additive of this example, and store it sealed for later use.

[0048] 1.5 parts of the first corrosion inhibitor, and its structural formula is:

[0049] ;

[0050] 1.5 parts of the second corrosion inhibitor, specifically locust bean gum;

[0051] 1.0 part of the crosslinking agent, specifically N-succinimidyl 4-(azidosulfonyl)benzoate;

[0052] 1.0 part of the plasticizer, specifically oxazole-4-carboxamide;

[0053] 0.5 part of the oxidant, specifically 4-vinylbenzylamine;

[0054] The balance is distilled water.

[0055] Example 3

[0056] Weigh the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer, the oxidant and the balance of water in sequence according to the following formula in 100 parts by weight, add them into a reaction kettle, stir and mix at room temperature for 30 minutes to obtain the brownizing additive of this example, and store it sealed for later use.

[0057] 1.5 parts of the first corrosion inhibitor, and its structural formula is:

[0058] ;

[0059] 1.5 parts of the second corrosion inhibitor, specifically sodium alginate;

[0060] 1.0 part of the crosslinking agent, specifically N-hydroxysuccinimide 3-maleimidopropionate;

[0061] 1.0 part of the plasticizer, specifically oxazole-5-carboxamide;

[0062] 0.5 part of the oxidant, specifically N-benzylidene butylamine;

[0063] The balance is distilled water.

[0064] Example 4

[0065] Weigh the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer, the oxidant and the balance of water in accordance with the following formula in 100 parts by weight and add them to a reaction kettle, and stir and mix at room temperature for 30 minutes to obtain the brownizing additive of this example, and store it sealed for later use.

[0066] 3.0 parts of the first corrosion inhibitor, and its structural formula is:

[0067] ;

[0068] 3.0 parts of the second corrosion inhibitor, specifically guar gum;

[0069] 2.0 parts of the crosslinking agent, specifically bis(bipyridine)-4'-methyl-4-carbonylpyridine ruthenium-N-succinimide ester bis(hexafluorophosphate);

[0070] 2.0 parts of the plasticizer, specifically oxazole-2-carboxamide;

[0071] 1.0 part of the oxidant, specifically N-allylbenzylamine;

[0072] The balance is distilled water.

[0073] Example 5

[0074] Weigh the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer, the oxidant and the balance of water in accordance with the following formula in 100 parts by weight and add them to a reaction kettle, and stir and mix at room temperature for 30 minutes to obtain the brownizing additive of this example, and store it sealed for later use.

[0075] 1.0 part of the first corrosion inhibitor, and its structural formula is:

[0076] ;

[0077] The second corrosion inhibitor is 1.0 part, specifically guar gum;

[0078] The crosslinking agent is 0.5 part, specifically bis(bipyridine)-4'-methyl-4-carbonylpyridine ruthenium-N-succinimidyl ester bis(hexafluorophosphate);

[0079] The plasticizer is 0.5 part, specifically oxazole-2-carboxamide;

[0080] The oxidizing agent is 0.2 part, specifically N-allylbenzylamine;

[0081] The balance is distilled water.

[0082] Example 6

[0083] Weigh the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer, the oxidizing agent and the balance of water in sequence according to the following formula of 100 parts by weight, add them to a reaction kettle, and stir and mix at room temperature for 30 minutes to obtain the brownizing additive of this example, and store it sealed for later use.

[0084] The first corrosion inhibitor is 2.0 parts, and its structural formula is:

[0085] ;

[0086] The second corrosion inhibitor is 1.0 part, specifically guar gum;

[0087] The crosslinking agent is 0.5 part, specifically bis(bipyridine)-4'-methyl-4-carbonylpyridine ruthenium-N-succinimidyl ester bis(hexafluorophosphate);

[0088] The plasticizer is 0.5 part, specifically oxazole-2-carboxamide;

[0089] The oxidizing agent is 0.2 part, specifically N-allylbenzylamine;

[0090] The balance is distilled water.

[0091] Example 7

[0092] Weigh the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer, the oxidizing agent and the balance of water in sequence according to the following formula of 100 parts by weight, add them to a reaction kettle, and stir and mix at room temperature for 30 minutes to obtain the brownizing additive of this example, and store it sealed for later use.

[0093] The first corrosion inhibitor is 1.0 part, and its structural formula is:

[0094] ;

[0095] The second corrosion inhibitor is 2.0 parts, specifically guar gum;

[0096] 0.5 parts of crosslinking agent, specifically bis(bipyridine)-4'-methyl-4-carbonylpyridinium ruthenium-N-succinimidyl ester bis(hexafluorophosphate);

[0097] 0.5 parts of plasticizer, specifically oxazole-2-carboxamide;

[0098] 0.2 parts of oxidizing agent, specifically N-allylbenzylamine;

[0099] The balance is distilled water.

[0100] Example 8

[0101] Weigh the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer, the oxidizing agent and the balance of water in sequence according to the following formula of 100 parts by weight, add them to the reaction kettle, and stir and mix at room temperature for 30 minutes to obtain the brownizing additive of this example, and store it sealed for later use.

[0102] 1.5 parts of the first corrosion inhibitor, and its structural formula is:

[0103] ;

[0104] 1.5 parts of the second corrosion inhibitor, specifically guar gum;

[0105] 1.0 part of crosslinking agent, specifically bis(bipyridine)-4'-methyl-4-carbonylpyridinium ruthenium-N-succinimidyl ester bis(hexafluorophosphate);

[0106] 1.0 part of plasticizer, specifically oxazole-2-carboxamide;

[0107] 0.5 part of oxidizing agent, specifically N-allylbenzylamine;

[0108] The balance is distilled water.

[0109] In the process of exploring the brownizing effect of brownizing additives with different formulas in the present invention, brownizing additives of the following comparative examples were also prepared.

[0110] Comparative Example 1

[0111] The brownizing additive of Comparative Example 1 is different from that of Example 1 only in that: it does not contain the first corrosion inhibitor.

[0112] Comparative Example 2

[0113] The brownizing additive of Comparative Example 2 is different from that of Example 1 only in that: it does not contain the second corrosion inhibitor.

[0114] Comparative Example 3

[0115] The brownizing additive of Comparative Example 3 is different from that of Example 1 only in that: it does not contain the crosslinking agent.

[0116] Comparative Example 4

[0117] The browning additive of Comparative Example 4 is different from that of Example 1 only in that it does not contain a plasticizer.

[0118] Comparative Example 5

[0119] The browning additive of Comparative Example 5 is different from that of Example 1 only in that it does not contain an oxidant.

[0120] Comparative Example 6

[0121] The browning additive of Comparative Example 6 is different from that of Example 1 only in that the first corrosion inhibitor is 0.8 parts.

[0122] Comparative Example 7

[0123] The browning additive of Comparative Example 7 is different from that of Example 1 only in that the second corrosion inhibitor is 0.8 parts.

[0124] Comparative Example 8

[0125] The browning additive of Comparative Example 8 is different from that of Example 1 only in that the crosslinking agent is 0.2 parts.

[0126] Comparative Example 9

[0127] The browning additive of Comparative Example 9 is different from that of Example 1 only in that the plasticizer is 0.2 parts.

[0128] Comparative Example 10

[0129] The browning additive of Comparative Example 10 is different from that of Example 1 only in that the oxidant is 0.1 parts.

[0130] Comparative Example 11

[0131] The browning additive of Comparative Example 1 is different from that of Example 1 only in that the first corrosion inhibitor is 2.5 parts, the second corrosion inhibitor is 1.0 part, and the mass ratio of the first corrosion inhibitor to the second corrosion inhibitor is 1:0.4 (lower than the scope defined in the present invention).

[0132] Comparative Example 12

[0133] The browning additive of Comparative Example 12 is different from that of Example 1 only in that the first corrosion inhibitor is 1.0 part, the second corrosion inhibitor is 2.5 parts, and the mass ratio of the first corrosion inhibitor to the second corrosion inhibitor is 1:2.5 (higher than the scope defined in the present invention).

[0134] Comparative Example 13

[0135] The brownification additive of Comparative Example 13 is the brownification additive of the prior art (Chinese Patent Application CN110527996 A), and the specific components include: sulfuric acid with a mass concentration of 200 g / L; hydrochloric acid with a mass concentration of 50 mg / L; a mixture of benzotriazole and methyl imidazole-4-carboxylate (mass ratio 5:2) with a mass concentration of 6 g / L; a mixture of citric acid and sodium citrate (mass ratio 3:1) with a mass concentration of 15 g / L; nitric acid with a mass concentration of 20 g / L; hydrogen peroxide with a mass concentration of 20 g / L; and the solvent is distilled water.

[0136] The brownification additive of the above-mentioned examples or comparative examples is used for the brownification of an IC substrate (test sample), and the brownification process flow is: S1 pickling → S2 water washing → S3 degreasing → S4 water washing → S5 activation → S6 brownification → S7 water washing → S8 drying. Specifically as follows.

[0137] The S1 pickling process is to treat the IC substrate with an acidic solution to clean the surface impurities. The process parameters of the pickling process are: in a spray mode, the degreasing tank solution contains 2% sulfuric acid by mass fraction, and the balance is distilled water; the pickling tank is 2.0 m long, the tank solution temperature is 25 ± 5 °C, the linear speed is 3.0 ± 0.5 m / min, and the pressure is 1.5 ± 0.5 kg / cm 2 ;

[0138] The S2 water washing process is to wash the IC substrate that has undergone the S1 pickling process. The process parameters of the water washing process are: in a spray mode, the water washing tank is 2.0 m long, the tank solution temperature is 25 ± 5 °C, the linear speed is 3.0 ± 0.5 m / min, and the pressure is 1.5 ± 0.5 kg / cm 2 ;

[0139] The S3 degreasing process is to soak the IC substrate that has undergone the S2 water washing process in an alkaline solution for degreasing; the process parameters of the degreasing process are: in a spray mode, the degreasing tank solution contains 2% sodium hydroxide by mass fraction, and the balance is distilled water; the degreasing tank is 2.0 m long, the tank solution temperature is 25 ± 5 °C, the linear speed is 3.0 ± 0.5 m / min, and the pressure is 1.5 ± 0.5 kg / cm 2 ;

[0140] The S4 water washing process is to wash the IC substrate that has undergone the S3 degreasing process with DI water. The process parameters of the water washing process are: in a spray mode, the water washing tank is 2.0 m long, the tank solution temperature is 25 ± 5 °C, the linear speed is 3.0 ± 0.5 m / min, and the pressure is 1.5 ± 0.5 kg / cm 2 ;

[0141] The S5 activation process is to treat the IC carrier board that has gone through the S4 water washing process with an activation solution. The process parameters of the activation process are as follows: using the spraying method, the activation solution in the activation tank contains 3% by mass of the browning additive of the embodiment or comparative example of the present invention, and the balance is distilled water (to prevent other chemical solutions from being brought into the browning tank and causing pollution); the length of the activation tank is 2.0 m, the activation temperature is 25 ± 5 °C, the linear speed is 3.0 ± 0.5 m / min, and the pressure is 1.5 ± 0.5 kg / cm 2 ;

[0142] The S6 browning process is to treat the IC carrier board that has gone through the S5 activation process with a browning solution. The process parameters of the browning process are as follows: using the spraying method, the browning solution in the browning tank contains 5% by mass of sulfuric acid, 2.5% by mass of hydrogen peroxide, 3% by mass of the browning additive of the embodiment or comparative example of the present invention, and the balance is distilled water; the length of the browning tank is 2.0 m, the temperature of the tank solution is 25 ± 5 °C; the linear speed is 3.0 ± 0.5 m / min, and the pressure is 1.5 ± 0.5 kg / cm 2 ;

[0143] The S7 water washing process is to wash the IC carrier board that has gone through the S6 browning process with DI water to clean the surface impurities. The process parameters of the water washing process are as follows: using the spraying method, the length of the water washing tank is 2.0 m, the temperature of the tank solution is 25 ± 5 °C, the linear speed is 3.0 ± 0.5 m / min, and the pressure is 1.5 ± 0.5 kg / cm 2 ;

[0144] The S8 drying process is to dry the IC carrier board after the S7 water washing process. The process parameters of drying are as follows: the temperature is 70 ± 5 °C, the length of the drying section is 2.0 m, and the linear speed is 4.0 ± 0.3 m / min.

[0145] The IC carrier boards (test samples) treated by the browning processes of the above embodiments or comparative examples are subjected to the following performance tests. The specific test methods are as follows.

[0146] Roughness: Use a roughness measuring instrument to measure the roughness value Ra of the copper surface after browning. The lower the Ra value, the more uniform the surface.

[0147] Peel strength: Take a substrate of 10 cm * 10 cm, etch off the copper foils on both sides, and then take a 10 cm * 10 cm 1OZ copper foil and fix it on the substrate; press the IC carrier board (test sample) treated by the browning process of the embodiment or comparative example onto the 1OZ copper foil, cut out a test sample of 5 cm * 5 cm size, and use a tensile testing machine to test its peel strength. The greater the peel strength, the better the bonding force between the copper surface and the resin.

[0148] Insertion loss: Use a network analyzer to test the insertion loss (unit: db / inch) of the transmission line of each embodiment or comparative example IC substrate under the test frequency of 25 GHz. The lower the insertion loss, the better the integrity of signal transmission.

[0149] Thermal stress test: First, the IC substrate (test sample) treated by the browning process is pretreated. The pretreatment condition is to bake the IC substrate in an oven at 125℃ for 4h; after pretreatment, a tin immersion test is performed. The tin immersion test condition is to put the IC substrate in a 288℃ tin solution for 10s, and then place it in a ventilated place to cool naturally to room temperature; repeat the tin immersion test 6 times to observe whether the IC substrate has delamination, fracture, or explosion. If not, the test result is qualified, otherwise it is unqualified.

[0150] Reflow test: First, pre-treat the IC substrate (test sample) after the browning process. The pre-treatment condition is to bake the IC substrate in an oven at 125℃ for 4h; after pre-treatment, put the IC substrate into the reflow machine, and set the parameters to increase the temperature from 125℃ by 20℃ in each step to 265℃. Repeat the above steps 6 times to observe whether the IC substrate has delamination, fracture, or explosion. If not, the test result is qualified, otherwise it is unqualified.

[0151] The IC substrate performance test results of the above embodiments and comparative examples are shown in Table 1.

[0152] Table 1 Performance test results

[0153]

[0154] From the test results of Examples 1-8 in Table 1, it can be seen that the surface roughness Ra value of the IC carrier obtained by using the browning additive of the present invention is stable at about 0.15. The low roughness indicates that the surface after browning is uniform, which is conducive to reducing the insertion loss. The insertion loss of the board surface is only about 0.61 db / inch, which has good signal integrity performance; at the same time, the peel strength of the board after browning is about 1.2 kg / cm, and the adhesion of the copper surface meets the production requirements; in the thermal stress test and reflow test, the test sample has no delamination, fracture, or explosion phenomenon, showing good heat resistance, suitable for application in the production of IC carrier browning process.

[0155] The differences between Comparative Examples 1-5 and Example 1 are that the brownification additives in Comparative Examples 1-5 respectively lack a single component among the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer or the oxidizing agent of the brownification additive of the present invention. The test results show that the brownification effect on the IC substrate is related to the functions of each additive component. The lack of any component will affect the roughness, peel strength, insertion loss, thermal stress and reflow soldering test effect of brownification. Among them, the first corrosion inhibitor and the second corrosion inhibitor have a synergistic effect. By utilizing the synergistic effect between corrosion inhibitors with different polarities, when the ratio range of the two is appropriate, a multi-molecular layer anti-corrosion film with high coverage, good compactness and stability can be formed on the metal surface, effectively improving the adsorption speed. The crosslinking agent has a strong adsorption force with the copper surface, can promote crosslinking and coupling, is beneficial to forming a multi-layer composite film on the copper foil surface, and improving the quality of the organic metal film. The plasticizer is easy to form a coordination bond with metallic copper and strongly adsorbs on the copper foil surface. It can also have a strong polymerization effect with the semi-cured resin, enhancing the bonding force between the metal and the resin, and can also form a hydrophobic protective film on the metal surface to inhibit the erosion of corrosive media. The oxidizing agent can make the surface of the copper foil form a rough surface with moderate depth and uniform consistency, providing favorable conditions for the formation of the organic metal film on the copper foil surface of the copper surface, and also being beneficial to increasing the contact area between the copper foil surface and the resin. When any one of the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer and the oxidizing agent is lacking in the component, the roughness, peel strength, insertion loss, thermal stress and reflow soldering test effect of brownification all decrease significantly.

[0156] The differences between Comparative Examples 6-10 and Example 1 are that the contents of the first corrosion inhibitor, the second corrosion inhibitor, the crosslinking agent, the plasticizer and the oxidizing agent in their brownification additives are respectively lower than the mass lower limits defined in the present invention. The test results show that the decrease in the content of each component will cause the brownification effect to decline, and the roughness, peel strength, insertion loss, thermal stress and reflow soldering test effect all decrease significantly, unable to meet the requirements for brownification of the IC substrate. Therefore, the concentration of each component must be controlled within the range of the present invention.

[0157] The differences between Comparative Example 11, Comparative Example 12 and Example 1 are that the mass ratios of the first corrosion inhibitor and the second corrosion inhibitor are respectively higher and lower than the range defined in the present invention. The test results show that when the mass ratio of the first corrosion inhibitor and the second corrosion inhibitor exceeds the range defined in the present invention, the roughness, peel strength, insertion loss, thermal stress and reflow soldering test effect of brownification all decrease significantly. It shows that the first corrosion inhibitor and the second corrosion inhibitor have a synergistic effect within the defined range. By utilizing the synergistic effect between corrosion inhibitors with different polarities, when the ratio range of the two is appropriate, a multi-molecular layer anti-corrosion film with high coverage, good compactness and stability can be formed on the metal surface, effectively improving the adsorption speed. Therefore, the mass ratio of the first corrosion inhibitor and the second corrosion inhibitor must be controlled within the range of the present invention.

[0158] Comparative Example 13 used a chemical brownification solution of the prior art. The comparison of its test results with those of Examples 1-5 showed that the brownification additive of the present invention has lower roughness, higher peel strength, and lower insertion loss.

[0159] The SEM image of the IC substrate after the brownification process of Example 1 is as Figure 2 shown; the SEM image of the IC substrate after the brownification process of Comparative Example 13 is as Figure 3 shown.

[0160] In summary, the brownification additive of the present invention is applicable to the brownification process of IC substrates. This brownification additive contains a first corrosion inhibitor, a second corrosion inhibitor, a crosslinking agent, a plasticizer, and an oxidizing agent, and can form an organic metal film on the uneven active micro-rough copper surface, effectively improving the uniformity and bonding strength of the copper surface after brownification, making it have low roughness, high peel strength, low insertion loss, and good heat resistance, meeting the production requirements of the IC substrate brownification process.

[0161] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A browning additive, characterized in that: The composition is composed of the following ingredients per 100 parts by weight: 1.0-3.0 parts of the first corrosion inhibitor, 1.0-3.0 parts of the second corrosion inhibitor, 0.5-2.0 parts of the crosslinking agent, 0.5-2.0 parts of the plasticizer, 0.2-1.0 parts of the oxidant, and the balance is water; The structural formula of the first corrosion inhibitor is as follows: wherein R is F, Cl, Br or I; The second corrosion inhibitor is selected from at least one of guar gum, locust bean gum and alginate; The mass ratio of the first corrosion inhibitor to the second corrosion inhibitor is 1:(0.5-2.0); The plasticizer is selected from at least one of oxazole-2-carboxylic acid amide, oxazole-4-carboxylic acid amide, and oxazole-5-carboxylic acid amide; The oxidant is selected from at least one of N-allylbenzylamine, 4-vinylbenzylamine and N-benzylbutylamine.

2. The browning additive according to claim 1, characterized in that The crosslinking agent is selected from at least one of bis(bipyridine)-4'-methyl-4-carbonylpyridinium ruthenium-N-succinimide ester bishexafluorophosphate, 4-(azidosulfonyl)benzoic acid N-succinimide ester, and 3-maleimidopropionic acid N-hydroxysuccinimide ester.

3. A method for browning an IC substrate, characterized in that: The following steps are included in sequence: Activation: Activating the IC substrate with an activation solution; the activation solution is an aqueous solution of the browning additive as claimed in claim 1 or 2 with a mass concentration of 3-4%; Browning: The IC substrate is browned using a browning solution; the browning solution is composed of the following components in mass fractions: 3-5% of the browning additive as described in claim 1 or 2, 4-6% of sulfuric acid, 2-3% of hydrogen peroxide, and the balance is water.

4. The method for browning an IC substrate according to claim 3, characterized in that: The activation solution is used to activate the IC substrate, specifically: the activation solution is sprayed on the IC substrate at a spray pressure of 1.5±0.5kg / cm 2 , time 35-50S.

5. The method for browning an IC substrate according to claim 3, characterized in that: The browning treatment of the IC substrate with the browning solution is specifically as follows: the IC substrate is sprayed with the browning solution at a spraying pressure of 1.5±0.5kg / cm 2 , time 35-50S.

6. The method for browning an IC substrate according to claim 3, characterized in that: Before the activation step, it also includes pickling, degreasing and water washing.

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