Method of manufacturing an ic carrier and ic carrier

Abstract

The application relates to the technical field of IC (Integrated Circuit) carrier plates, in particular to an IC carrier plate manufacturing method and an IC carrier plate. The IC carrier plate manufacturing method provided by the application comprises the following steps: obtaining a semi-finished IC plate with a gold finger; performing copper surface modification on the semi-finished IC plate, so that the copper surface of the semi-finished IC plate satisfies a first roughness; performing micro-etching on the semi-finished IC plate with the copper surface satisfying the first roughness; and performing soft gold electroplating on the copper surface of the semi-finished IC plate after the micro-etching is completed, so as to form an IC carrier plate with a copper surface satisfying a second roughness and having a gold finger. Through the copper surface modification on the semi-finished IC plate, the roughness of the copper surface of the semi-finished IC plate is improved, the roughness of the gold surface formed after the soft gold electroplating is improved, the gold surface of the IC carrier plate becomes rougher, the packaging and wire bonding of the IC carrier plate are facilitated, and the problem of jumper wire of the gold finger of the IC carrier plate in the packaging and wire bonding process is avoided.

Description

[Technical Field]

[0002] This invention relates to the field of IC substrate technology, and in particular to a method for manufacturing an IC substrate and an IC substrate. [Background Technology]

[0004] IC substrates can be packaged in two ways: wire bonding substrates and flip chip substrates. Traditional wire bonding involves connecting the connection points on the IC chip to the gold fingers on the IC substrate.

[0005] However, the gold fingers of IC substrates manufactured using existing technology are prone to skipping issues during the packaging and wire bonding process, resulting in a low yield rate and increased production costs. [Summary of the Invention]

[0007] To address the issue of jumpers that easily occur on the gold fingers of IC substrates manufactured using existing technologies during the packaging and wire bonding process, this invention provides a method for manufacturing an IC carrier and an IC carrier.

[0008] The solution to the technical problem of this invention is to provide a method for manufacturing an IC carrier board, comprising the following steps:

[0009] Obtain a semi-finished IC board with gold fingers;

[0010] The copper surface of the semi-finished IC board is modified to make the copper surface of the semi-finished IC board meet the first roughness.

[0011] Micro-etching is performed on the semi-finished IC board whose copper surface meets the first roughness.

[0012] Electroplating soft gold is performed on the copper surface of the semi-finished IC board after micro-etching, so that the copper surface with the gold fingers forms a gold surface, and an IC substrate with the gold surface meeting the second roughness is obtained.

[0013] Preferably, before modifying the copper surface of the semi-finished IC board to meet the first roughness requirement, the method further includes:

[0014] The semi-finished IC board is subjected to solder resist curing to form a solder resist layer on the semi-finished IC board;

[0015] The semi-finished IC board that forms the solder resist layer is subjected to pretreatment, lamination, exposure and development in sequence to form a circuit pattern on the semi-finished IC board.

[0016] Preferably, the copper surface of the semi-finished IC board is modified to ensure that the copper surface of the semi-finished IC board meets a first roughness, specifically including:

[0017] The semi-finished IC board is moved at a preset linear speed for a preset first time in the first solution in the degreasing tank to perform degreasing treatment;

[0018] The degreased semi-finished IC board is moved at a preset linear speed for a preset second time in a second solution in an ultra-roughening tank to perform ultra-roughening treatment.

[0019] The semi-finished IC board, after undergoing ultra-roughening treatment, is moved at a preset linear speed for a preset third time in a third solution in a hydrochloric acid washing tank to perform acid washing treatment, thereby completing the copper surface modification of the semi-finished IC board and making the copper surface of the semi-finished IC board meet the first roughness.

[0020] Preferably, the degreasing treatment uses a first solution with a copper ion concentration of less than 18 g / L, a hydrogen peroxide concentration of 15 g / L-25 g / L, and a sulfuric acid concentration of 60 g / L-80 g / L; the ultra-roughening treatment uses a second solution with a copper ion concentration of 16.5 g / L-27 g / L and a concentration of -9%-9%; and the acid washing treatment uses a third solution with a copper ion concentration of less than 1.8 g / L and a hydrochloric acid concentration of 1.1 mol / L-1.35 mol / L.

[0021] Preferably, the preset second time for the ultra-roughening treatment is 35s-40s, and the first micro-etching amount of the ultra-roughening treatment on the semi-finished IC board is 0.4um-0.5um.

[0022] Preferably, the copper surface of the semi-finished IC board has a first roughness Ra of 0.55um-0.65um.

[0023] Preferably, the second micro-etching amount on the semi-finished IC board is 0.4um-0.5um.

[0024] Preferably, after micro-etching the semi-finished IC board that meets the first roughness, the method further includes:

[0025] The semi-finished IC board, after micro-etching, is then subjected to sandblasting and degreasing to clean it.

[0026] To solve the above-mentioned technical problems, the present invention also provides an IC carrier board, which is manufactured using the IC carrier board manufacturing method described in any of the preceding claims.

[0027] Preferably, the second roughness Ra of the gold surface of the IC substrate is 0.28um-0.35um.

[0028] Compared with the prior art, the IC substrate fabrication method and IC substrate provided by the present invention have the following advantages:

[0029] 1. A method for manufacturing an IC substrate according to the present invention includes the following steps: obtaining a semi-finished IC board with gold fingers; modifying the copper surface of the semi-finished IC board to make the copper surface of the semi-finished IC board meet a first roughness; micro-etching the semi-finished IC board with the copper surface meeting the first roughness; electroplating soft gold on the copper surface of the micro-etched semi-finished IC board to form an IC substrate with gold fingers and a copper surface meeting a second roughness. By modifying the copper surface of the semi-finished IC board, the roughness of the copper surface of the semi-finished IC board is improved, so that the roughness of the copper surface of the semi-finished IC board can meet the first roughness. Therefore, the roughness of the gold surface formed after electroplating soft gold on the copper surface meeting the first roughness is improved, so that the roughness of the gold surface can reach the second roughness. This makes the gold surface of the IC substrate rougher, better meeting the requirements of wire bonding and packaging, and more conducive to the wire bonding of the IC substrate. This avoids the problem of skipped wires on the gold fingers of the IC substrate during the wire bonding process, thereby improving the pass rate and speed of wire bonding, achieving fast and efficient wire bonding, and reducing production costs.

[0030] 2. Before modifying the copper surface of a semi-finished IC board to meet a first roughness requirement, the method of the present invention further includes: performing solder resist curing on the semi-finished IC board to form a solder resist layer. The semi-finished IC board with the solder resist layer is then subjected to pretreatment, lamination, exposure, and development sequentially to form a circuit pattern on the semi-finished IC board. By performing solder resist curing on the semi-finished IC board to form a solder resist layer, the IC carrier board is protected from short circuits, leakage, and other problems during subsequent manufacturing and use. By performing pretreatment, lamination, exposure, and development sequentially on the semi-finished IC board with the solder resist layer, a preset circuit pattern is transferred to the semi-finished IC board, forming a circuit pattern on the semi-finished IC board, thereby completing the circuit fabrication.

[0031] 3. The present invention modifies the copper surface of a semi-finished IC board to achieve a first roughness. Specifically, this includes: moving the semi-finished IC board at a preset linear speed for a preset first time in a first solution in a degreasing tank for degreasing; moving the degreased semi-finished IC board at a preset linear speed for a preset second time in a second solution in an ultra-roughening tank for ultra-roughening; and moving the ultra-roughened semi-finished IC board at a preset linear speed for a preset third time in a third solution in a hydrochloric acid washing tank for acid washing, thereby completing the copper surface modification of the semi-finished IC board and achieving the first roughness. By controlling the semi-finished IC board to sequentially undergo degreasing, ultra-roughening, and acid washing, the copper surface modification of the semi-finished IC board is completed, thereby improving the roughness of the copper surface and enabling the semi-finished IC board to achieve the first roughness.

[0032] 4. The preset second time for the ultra-roughening treatment of the present invention is 35s-40s, and the first micro-etching amount of the ultra-roughening treatment on the semi-finished IC board is 0.4um-0.5um. By controlling the ultra-roughening treatment, the first micro-etching amount of the ultra-roughening treatment on the semi-finished IC board can reach 0.4um-0.5um, thereby improving the roughness of the copper surface of the semi-finished IC board.

[0033] 5. The copper surface of the semi-finished IC board of the present invention satisfies a first roughness Ra of 0.55um-0.65um. By modifying the copper surface of the semi-finished IC board to satisfy 0.55um-0.65um, the roughness of the gold surface of the final IC can reach a second roughness. When the first roughness Ra is 0.55um-0.65um, the gold surface of the final IC achieves the optimal roughness effect.

[0034] 6. The second micro-etching depth of the semi-finished IC board in this invention is 0.4um-0.5um. By controlling the second micro-etching depth to 0.4um-0.5um, the copper surface after copper surface modification is micro-etched again, thereby preserving the roughness of the modified copper surface as much as possible, avoiding excessively deep micro-etching that would affect the circuit, and insufficient micro-etching that would not achieve the desired effect, and making the roughening of the copper surface more uniform.

[0035] 7. After micro-etching the semi-finished IC board that meets the first roughness, the method of the present invention further includes: sequentially sandblasting and degreasing the micro-etched semi-finished IC board to clean it. By sequentially sandblasting and degreasing the micro-etched semi-finished IC board, dirt, impurities, and residues on the surface of the semi-finished IC board are removed.

[0036] 8. The present invention also provides an IC substrate, which is manufactured using the IC substrate manufacturing method described in any of the preceding claims. The IC substrate with gold fingers manufactured using the above method has a second roughness Ra of 0.28um-0.35um, which is greater than the roughness of the gold surface of IC substrates manufactured by prior art, and better meets the requirements of packaging wire bonding. [Attached Image Description]

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is an example image of the gold surface of an IC board manufactured using existing technology.

[0040] Figure 2 This is a flowchart of the IC carrier board fabrication method provided in the first embodiment of the present invention. Figure 1 .

[0041] Figure 3 This is an example diagram of the gold surface of an IC substrate manufactured by the IC substrate manufacturing method provided in the first embodiment of the present invention.

[0042] Figure 4 This is a flowchart of the IC carrier board fabrication method provided in the first embodiment of the present invention. Figure 2 .

[0043] Figure 5 This is a flowchart illustrating the specific steps of step S20 in the IC carrier board fabrication method provided in the first embodiment of the present invention.

Detailed Implementation Methods

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0046] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0047] Please see Figure 1 Based on existing IC board manufacturing methods, the roughness of the copper surface after micro-etching can only reach 0.3um-0.4um. Therefore, after the final electroplating of soft gold, the roughness of the gold surface can only reach 0.1um-0.2um. This results in insufficient final roughness and a smooth gold surface, which can easily lead to skipped wires during the packaging and wire bonding process, resulting in a decrease in yield and an increase in production time and production costs.

[0048] Based on this, please refer to Figure 2 and Figure 3 The first embodiment of the present invention provides a method for manufacturing an IC carrier board, comprising the following steps:

[0049] S10: Obtain a semi-finished IC board with gold fingers;

[0050] S20: Modify the copper surface of the semi-finished IC board to make the copper surface of the semi-finished IC board meet the first roughness.

[0051] S30: Micro-etch the semi-finished IC board whose copper surface meets the first roughness.

[0052] S40: Electroplating soft gold onto the copper surface of the semi-finished IC board after micro-etching, so that the copper surface with the gold fingers forms a gold surface, and obtaining an IC substrate with the gold surface satisfying the second roughness.

[0053] Understandably, in this embodiment, the gold fingers are conductive contacts on a semi-finished IC board, shaped like fingers, used to connect external chips or components. The first roughness is the surface roughness Ra of the copper surface of the semi-finished IC board, which is the copper surface where the gold fingers are located. The second roughness is the surface roughness Ra of the gold surface formed after electroplating soft gold onto the plane containing the gold fingers of the semi-finished IC board. The smaller the surface roughness Ra, the smoother the copper surface of the semi-finished IC board; conversely, the smaller the surface roughness Ra, the rougher the copper surface of the semi-finished IC board.

[0054] Understandably, in this embodiment, step S10 allows for the direct acquisition of a semi-finished IC board with pre-prepared gold fingers. Step S20 modifies the copper surface of the semi-finished IC board, specifically the copper surface where the gold fingers are located, to improve the surface roughness, achieving a first roughness. Step S30 then micro-etches the copper surface meeting the first roughness, preserving as much of the modified surface roughness as possible and achieving a more uniform surface roughness. Step S40 further allows for the electroplating of soft gold onto the copper surface of the micro-etched semi-finished IC board. This involves first electroplating a layer of nickel as a barrier layer on the copper surface meeting the first roughness, followed by electroplating a gold layer on top of the barrier layer to form a gold surface. This gold layer enhances the solderability, oxidation resistance, corrosion resistance, and contact resistance of the final IC substrate. In this embodiment, after electroplating soft gold, the surface roughness of the gold surface still reaches a second roughness Ra of 0.3um-0.35um. Compared to the 0.1um-0.2um in the prior art, the surface roughness of the gold surface is improved. Therefore, the gold surface with gold fingers is rougher, which better meets the requirements of wire bonding and is more conducive to the wire bonding of IC substrates. This avoids the problem of skipped wires on the gold fingers of IC substrates during the wire bonding process, thereby improving the yield and production speed of wire bonding, achieving fast and efficient wire bonding, and reducing production costs. As shown in Table 1 below, Table 1 is a comparison chart of the effects of the prior art and this embodiment:

[0055] Table 1

[0056]

[0057] Please see Figure 4Furthermore, prior to step S20, the method further includes:

[0058] S11: Solder resist curing is performed on the semi-finished IC board to form a solder resist layer on the semi-finished IC board;

[0059] S12: The semi-finished IC board that forms the solder resist layer is subjected to pretreatment, lamination, exposure and development in sequence to form a circuit pattern on the semi-finished IC board.

[0060] Understandably, before modifying the copper surface of the semi-finished IC board, step S11 is required to cure the solder resist, forming a solder resist layer on the board. Solder resist curing involves applying a layer of solder resist to the unsoldered circuitry and substrate of the semi-finished IC board, setting the baking temperature to 150°C and the baking time to 120 minutes. This cures the solder resist, forming a solder resist layer that provides insulation, prevents oxidation, and enhances the appearance, thus protecting the IC substrate from short circuits and leakage during subsequent manufacturing and use. It should be noted that the surface roughness of the copper surface of the semi-finished IC board after solder resist curing is 0.28µm-0.3µm.

[0061] Understandably, after the solder resist is cured, step S12 is required to perform pretreatment, lamination, exposure and development on the semi-finished IC board in which the solder resist layer is formed, thereby transferring the preset circuit pattern to the semi-finished IC board and forming a circuit diagram on the semi-finished IC board.

[0062] Specifically, the pretreatment involves controlling the semi-finished IC board to move at a linear speed of 3-4 m / min in a liquid with an H2O2 concentration of 6-12 g / L and an H2SO4 content of 3%-7% for 40-45 seconds. This pretreatment completes the process, achieving a micro-etching depth of 0.4-0.5 μm on the copper surface to remove contaminants and increase its roughness, facilitating subsequent lamination. It should be noted that the surface roughness of the copper surface of the semi-finished IC board after pretreatment is 0.35-0.39 μm.

[0063] Specifically, lamination involves applying a layer of photosensitive dry film to the copper surface of the pre-treated semi-finished IC board using a hot-pressing method. The hot-pressing conditions are a temperature of 80℃ and a pressure of 5 kg / cm². 2The vacuum time is 30 seconds. After lamination, exposure is required, specifically by irradiation with a light source. The light passing through the mask hardens the irradiated photosensitive dry film, forming the circuit pattern of the semi-finished IC board. Finally, the circuit pattern on the mask is transferred to the semi-finished IC board. The exposure conditions are a temperature of 21℃-25℃ and a light source irradiation time of 3 minutes. After exposure, the semi-finished IC board needs to be developed. Specifically, the semi-finished IC board is moved at a linear speed of 1.5m / min-2.5m / min in a liquid with a Na2CO3 content of 0.85%-1.15% for 2.5 minutes, thereby washing away the unexposed photosensitive dry film and leaving the circuit pattern of the exposed dry film. It should be noted that during the lamination, exposure, and development processes, since the copper surface of the semi-finished IC board is not manipulated, its surface roughness remains unchanged after the pretreatment process.

[0064] Please see Figure 5 Furthermore, step S20 specifically includes:

[0065] S201: The semi-finished IC board is moved at a preset linear speed in the first solution in the degreasing tank for a preset first time to perform degreasing treatment;

[0066] S202: The semi-finished IC board that has completed the degreasing process is moved at a preset linear speed for a preset second time in the second solution in the ultra-roughening tank to perform ultra-roughening treatment;

[0067] S203: The semi-finished IC board after the ultra-roughening treatment is moved at a preset linear speed for a preset third time in the third solution in the hydrochloric acid washing tank to perform acid washing treatment, thereby completing the copper surface modification of the semi-finished IC board and making the copper surface of the semi-finished IC board meet the first roughness.

[0068] Understandably, through step S201, the semi-finished IC board can be moved in the degreasing tank at a preset linear speed for a preset first time to perform degreasing treatment, thereby removing dirt and foreign matter from the copper surface of the semi-finished IC board. In this embodiment, preferably, the preset linear speed is 4m / min-5m / min, and the preset first time is 13s-15s, so as to remove dirt and foreign matter from the copper surface of the semi-finished IC board and avoid the dirt and foreign matter on the copper surface affecting the subsequent processing of the copper surface. After the degreasing treatment is completed, the semi-finished IC board can be subjected to ultra-roughening treatment through step S202. Specifically, the semi-finished IC board after degreasing treatment can be moved in the second solution in the ultra-roughening tank at a preset linear speed for a preset second time to make the copper surface of the semi-finished IC board rougher, so that the roughness of the semi-finished IC board can reach the first roughness, achieving the effect of copper surface modification. After the ultra-roughening treatment is completed, in step S203, the semi-finished IC board that has undergone ultra-roughening treatment is moved at a preset linear speed for a preset third time in the third solution of the hydrochloric acid washing tank for acid washing treatment, thereby removing copper surface oxides. This preserves and enhances the surface roughness of the copper surface after ultra-roughening treatment, thus completing the entire copper surface modification process and enabling the roughness of the semi-finished IC board to reach and stabilize at the first roughness. In this embodiment, preferably, by controlling the preset third time to 13s-15s, copper surface oxides can be removed more effectively.

[0069] Understandably, by sequentially performing degreasing, ultra-roughening, and pickling treatments on the semi-finished IC board, the copper surface of the semi-finished IC board is modified, and the roughness of the copper surface of the semi-finished IC board is improved, so that the roughness of the semi-finished IC board can reach the first roughness.

[0070] Furthermore, the degreasing treatment uses a first solution with a copper ion concentration of less than 18 g / L, a hydrogen peroxide concentration of 15 g / L-25 g / L, and a sulfuric acid concentration of 60 g / L-80 g / L; the ultra-roughening treatment uses a second solution with a copper ion concentration of 16.5 g / L-27 g / L and a concentration of -9%-9%; and the acid washing treatment uses a third solution with a copper ion concentration of less than 1.8 g / L and a hydrochloric acid concentration of 1.1 mol / L-1.35 mol / L.

[0071] Understandably, the degreasing treatment uses a first solution with a copper ion concentration of less than 18 g / L, a hydrogen peroxide concentration of 15 g / L-25 g / L, and a sulfuric acid concentration of 60 g / L-80 g / L. The strong oxidizing properties of this first solution are used to remove dirt and foreign matter from the copper surface. The ultra-roughening treatment uses a second solution with a copper ion concentration of 16.5 g / L-27 g / L and a concentration of -9%-9%. This second solution further roughens the copper surface, achieving a surface modification effect. The pickling treatment uses a third solution with a copper ion concentration of less than 1.8 g / L and a hydrochloric acid concentration of 1.1 mol / L-1.35 mol / L. This third solution is used for pickling, removing oxides from the copper surface and preserving and enhancing the surface roughness of the copper surface after ultra-roughening.

[0072] Furthermore, the preset second time for the ultra-roughening treatment is 35s-40s, and the first micro-etching amount of the ultra-roughening treatment on the semi-finished IC board is 0.4um-0.5um.

[0073] Understandably, in this embodiment, preferably, the second time is preset to 35s-40s. By controlling the semi-finished IC board to move at a preset linear speed of 4m / min-5m / min in the second solution in the ultra-roughening tank for 35s-40s, the ultra-roughening treatment is completed, so that the micro-etching amount of the semi-finished IC board can reach 0.4um-0.5um, thereby making the copper surface of the semi-finished IC board rougher, so that the roughness of the semi-finished IC board can reach the first roughness, and achieve the effect of copper surface modification.

[0074] Furthermore, the copper surface of the semi-finished IC board meets a first roughness Ra of 0.55um-0.65um.

[0075] Understandably, by controlling the semi-finished IC board to move at a preset linear speed of 4m / min-5m / min in the second solution of the ultra-roughening tank for 35s-40s, the ultra-roughening treatment is completed, so that the micro-etching amount of the semi-finished IC board can reach 0.4um-0.5um. This allows the surface roughness of the copper surface after the entire copper surface modification process to reach a first roughness Ra of 0.55um-0.65um, which is 0.15um-0.25um higher than the surface roughness of the copper surface after development. As a result, the surface roughness of the gold surface after electroplating soft gold is also improved, reaching a second roughness Ra of 0.3um-0.35um. This is more conducive to the IC substrate packaging wire bonding and avoids the problem of skipped wires on the gold fingers of the IC substrate during the packaging wire bonding process.

[0076] Furthermore, the second micro-etching amount on the semi-finished IC board is 0.4um-0.5um.

[0077] Understandably, after the copper surface modification is completed, step S30 is required to perform micro-etching on the copper surface of the semi-finished IC board, which means that the copper surface after copper surface modification is micro-etched again.

[0078] Specifically, the micro-etching process involves controlling the movement of the semi-finished IC board in a micro-etching tank at a linear velocity of 3.5 m / min in a liquid with an SPS concentration of 60 g / L-100 g / L, a sulfuric acid content of 3%-5%, and a copper ion concentration of less than or equal to 9 g / L. This results in a final micro-etching depth of 0.4 μm-0.5 μm, preserving as much of the roughness of the copper surface as possible after modification. This avoids excessively deep micro-etching that could affect the circuitry, while insufficient micro-etching would be ineffective, and also ensures more uniform roughening of the copper surface. In this embodiment, the surface roughness Ra of the copper surface after modification and subsequent micro-etching is 0.40 μm-0.45 μm.

[0079] Please see Figure 4 Furthermore, after step S30, the method further includes:

[0080] S31: The semi-finished IC board after micro-etching is sequentially sandblasted and degreased to clean the semi-finished IC board.

[0081] Understandably, after micro-etching is completed and before electroplating soft gold, the semi-finished IC board needs to be sandblasted and degreased in sequence to clean the semi-finished IC board and prevent dirt or debris from affecting the electroplating soft gold and causing uneven roughness of the final gold surface.

[0082] Specifically, sandblasting involves spraying a 16%-20% slurry of abrasive water onto the copper surface of the semi-finished IC board at a linear velocity of 3.5 m / min for 60-65 seconds. This high-speed impact removes surface contaminants, oxides, and residues. Sandblasting makes the copper surface of the semi-finished IC board smoother, removes the oxide layer, and improves the adhesion for soldering and electroplating. Additionally, sandblasting removes surface scratches and uneven coloring, resulting in a more aesthetically pleasing appearance for the semi-finished IC board. In this embodiment, after sandblasting, the surface roughness Ra of the copper surface of the semi-finished IC board is 0.36 μm-0.4 μm.

[0083] Specifically, after sandblasting, degreasing is required. Degreasing is performed using a degreasing agent with a concentration of 90ml / L-110ml / L at a temperature of 30℃-40℃ for 40s-45s. This allows the micro-etching depth to reach 0.4um-0.5um, thereby cleaning the copper surface of the semi-finished IC board, removing oil and dirt, and improving the quality and reliability of the final IC substrate.

[0084] Specifically, after degreasing, soft gold plating can be performed. Soft gold plating must be carried out at a temperature of 75℃-85℃, using a plating solution with a nickel ion concentration of less than or equal to 500ppm and a copper ion concentration of less than or equal to 20ppm. When plating nickel and gold on the copper surface, the pH must be maintained at a weakly acidic environment of 5.8-6.2. The entire plating process should last 10-11 minutes. After completing the gold plating operation on the copper surface of the semi-finished IC board, the IC substrate is formed, and the surface roughness of the gold surface of the IC substrate can reach a second roughness Ra of 0.3um-0.35um. After the soft gold plating is completed, the gold-plated IC substrate can be washed with water. Specifically, pure water with a conductivity of less than 10µs / cm is used to wash the IC substrate at a linear speed of 1.5m / min-2.5m / min for 40-45 seconds to remove contaminants from the soft gold plating. Water washing does not affect the surface roughness of the gold surface of the IC substrate. Therefore, the surface roughness of the gold surface of the IC substrate after water washing is still 0.3um-0.35um.

[0085] The second embodiment of the present invention provides an IC carrier board, which is manufactured using the IC carrier board manufacturing method of the first embodiment.

[0086] Understandably, the surface roughness of the gold surface of the IC substrate fabricated using the IC substrate fabrication method in the first embodiment can reach a second roughness Ra of 0.28-0.35, which is higher than the 0.1um-0.2um in the prior art. Therefore, the gold surface with gold fingers is rougher, which better meets the requirements of packaging and wire bonding, and is more conducive to the packaging and wire bonding of IC substrates. This avoids the problem of skipped wires on the gold fingers of IC substrates during the packaging and wire bonding process, thereby improving the yield and production speed of packaging and wire bonding, achieving fast and efficient wire bonding, and reducing production costs.

[0087] Compared with the prior art, the IC substrate fabrication method and IC substrate provided by the present invention have the following advantages:

[0088] 1. A method for manufacturing an IC substrate according to the present invention includes the following steps: obtaining a semi-finished IC board with gold fingers; modifying the copper surface of the semi-finished IC board to make the copper surface of the semi-finished IC board meet a first roughness; micro-etching the semi-finished IC board with the copper surface meeting the first roughness; electroplating soft gold on the copper surface of the micro-etched semi-finished IC board to form an IC substrate with gold fingers and a copper surface meeting a second roughness. By modifying the copper surface of the semi-finished IC board, the roughness of the copper surface of the semi-finished IC board is improved, so that the roughness of the copper surface of the semi-finished IC board can meet the first roughness. Therefore, the roughness of the gold surface formed after electroplating soft gold on the copper surface meeting the first roughness is improved, so that the roughness of the gold surface can reach the second roughness. This makes the gold surface of the IC substrate rougher, better meeting the requirements of wire bonding and packaging, and more conducive to the wire bonding of the IC substrate. This avoids the problem of skipped wires on the gold fingers of the IC substrate during the wire bonding process, thereby improving the pass rate and speed of wire bonding, achieving fast and efficient wire bonding, and reducing production costs.

[0089] 2. Before modifying the copper surface of a semi-finished IC board to meet a first roughness requirement, the method of the present invention further includes: performing solder resist curing on the semi-finished IC board to form a solder resist layer. The semi-finished IC board with the solder resist layer is then subjected to pretreatment, lamination, exposure, and development sequentially to form a circuit pattern on the semi-finished IC board. By performing solder resist curing on the semi-finished IC board to form a solder resist layer, the IC carrier board is protected from short circuits, leakage, and other problems during subsequent manufacturing and use. By performing pretreatment, lamination, exposure, and development sequentially on the semi-finished IC board with the solder resist layer, a preset circuit pattern is transferred to the semi-finished IC board, forming a circuit pattern on the semi-finished IC board, thereby completing the circuit fabrication.

[0090] 3. The present invention modifies the copper surface of a semi-finished IC board to achieve a first roughness. Specifically, this includes: moving the semi-finished IC board at a preset linear speed for a preset first time in a first solution in a degreasing tank for degreasing; moving the degreased semi-finished IC board at a preset linear speed for a preset second time in a second solution in an ultra-roughening tank for ultra-roughening; and moving the ultra-roughened semi-finished IC board at a preset linear speed for a preset third time in a third solution in a hydrochloric acid washing tank for acid washing, thereby completing the copper surface modification of the semi-finished IC board and achieving the first roughness. By controlling the semi-finished IC board to sequentially undergo degreasing, ultra-roughening, and acid washing, the copper surface modification of the semi-finished IC board is completed, thereby improving the roughness of the copper surface and enabling the semi-finished IC board to achieve the first roughness.

[0091] 4. The preset second time for the ultra-roughening treatment of the present invention is 35s-40s, and the first micro-etching amount of the ultra-roughening treatment on the semi-finished IC board is 0.4um-0.5um. By controlling the ultra-roughening treatment, the first micro-etching amount of the ultra-roughening treatment on the semi-finished IC board can reach 0.4um-0.5um, thereby improving the roughness of the copper surface of the semi-finished IC board.

[0092] 5. The copper surface of the semi-finished IC board of the present invention satisfies a first roughness Ra of 0.55um-0.65um. By modifying the copper surface of the semi-finished IC board to satisfy 0.55um-0.65um, the roughness of the gold surface of the final IC can reach a second roughness. When the first roughness Ra is 0.55um-0.65um, the gold surface of the final IC achieves the optimal roughness effect.

[0093] 6. The second micro-etching depth of the semi-finished IC board in this invention is 0.4um-0.5um. By controlling the second micro-etching depth to 0.4um-0.5um, the copper surface after copper surface modification is micro-etched again, thereby preserving the roughness of the modified copper surface as much as possible, avoiding excessively deep micro-etching that would affect the circuit, and insufficient micro-etching that would not achieve the desired effect, and making the roughening of the copper surface more uniform.

[0094] 7. After micro-etching the semi-finished IC board that meets the first roughness, the method of the present invention further includes: sequentially sandblasting and degreasing the micro-etched semi-finished IC board to clean it. By sequentially sandblasting and degreasing the micro-etched semi-finished IC board, dirt, impurities, and residues on the surface of the semi-finished IC board are removed.

[0095] 8. The present invention also provides an IC substrate, which is manufactured using the IC substrate manufacturing method described in any of the preceding claims. The IC substrate with gold fingers manufactured using the above method has a second roughness Ra of 0.28um-0.35um, which is greater than the roughness of the gold surface of IC substrates manufactured by prior art, and better meets the requirements of packaging wire bonding.

[0096] The foregoing has provided a detailed description of a method for fabricating an IC substrate and the IC substrate disclosed in the embodiments of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention. Any modifications, equivalent substitutions, and improvements made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing an IC substrate, characterized in that: Includes the following steps: Obtain a semi-finished IC board with gold fingers; The copper surface of the semi-finished IC board is modified to make the copper surface of the semi-finished IC board meet the first roughness. Specifically, modifying the copper surface of the semi-finished IC board to ensure that the copper surface meets a first roughness requirement includes: The semi-finished IC board is moved at a preset linear speed for a preset first time in the first solution in the degreasing tank to perform degreasing treatment; The degreased semi-finished IC board is moved at a preset linear speed for a preset second time in a second solution in an ultra-roughening tank to perform ultra-roughening treatment. The semi-finished IC board, after undergoing ultra-roughening treatment, is moved at a preset linear speed for a preset third time in a third solution in a hydrochloric acid washing tank to perform acid washing treatment, thereby completing the copper surface modification of the semi-finished IC board and making the copper surface of the semi-finished IC board meet the first roughness. Micro-etching is performed on the semi-finished IC board whose copper surface meets the first roughness. Electroplating soft gold is performed on the copper surface of the semi-finished IC board after micro-etching, so that the copper surface with the gold fingers forms a gold surface, and an IC substrate with the gold surface meeting the second roughness is obtained.

2. The method for manufacturing an IC substrate as described in claim 1, characterized in that: Before modifying the copper surface of the semi-finished IC board to meet the first roughness requirement, the method further includes: The semi-finished IC board is subjected to solder resist curing to form a solder resist layer on the semi-finished IC board; The semi-finished IC board that forms the solder resist layer is subjected to pretreatment, lamination, exposure and development in sequence to form a circuit pattern on the semi-finished IC board.

3. The method for manufacturing an IC substrate as described in claim 1, characterized in that: The degreasing treatment uses a first solution with a copper ion concentration of less than 18 g / L, a hydrogen peroxide concentration of 15 g / L-25 g / L, and a sulfuric acid concentration of 60 g / L-80 g / L; the ultra-roughening treatment uses a second solution with a copper ion concentration of 16.5 g / L-27 g / L and a concentration of -9%-9%; the acid washing treatment uses a third solution with a copper ion concentration of less than 1.8 g / L and a hydrochloric acid concentration of 1.1 mol / L-1.35 mol / L.

4. The method for manufacturing an IC substrate as described in claim 3, characterized in that: The preset second time for the ultra-roughening treatment is 35s-40s, and the first micro-etching amount of the ultra-roughening treatment on the semi-finished IC board is 0.4um-0.5um.

5. The method for manufacturing an IC substrate as described in claim 1, characterized in that: The copper surface of the semi-finished IC board has a first roughness Ra of 0.55um-0.65um.

6. The method for manufacturing an IC substrate as described in claim 1, characterized in that: The second micro-etching amount for the semi-finished IC board is 0.4um-0.5um.

7. The method for manufacturing an IC substrate as described in claim 1, characterized in that: After micro-etching the semi-finished IC board that meets the first roughness, the method further includes: The semi-finished IC board, after micro-etching, is then subjected to sandblasting and degreasing to clean it.

8. An IC carrier board, characterized in that: It is manufactured using the method for manufacturing an IC substrate as described in any one of claims 1-7.

9. The IC carrier board as described in claim 8, characterized in that: The gold surface of the IC substrate satisfies a second roughness Ra of 0.28µm-0.35µm.

Images