TWI708537B - Method for producing circuit patterns - Google Patents

Abstract

A method for producing circuit patterns is provided. The method includes pre-processing, film laminating, exposure, development, etching and film removing. The method uses dry film processing and Directing Imaging laser exposure machine. Due to no need negative film, the cost is decreased significantly and also to decrease variation which is caused from dry film resolution capability reducing. After optimizing parameters of pre-processing, film laminating, exposure, development, dry film resolution capability is increased up to 40 micrometer and able to produce circuit which has width in 50 micrometer and spacing between two circuits is smaller than 50 micrometer. The method is an ideal producing processing for current circuit board producing.

Description

Line pattern production method

The invention discloses a line pattern production method, in particular in the technical field of printed circuit boards.

Due to the rapid improvement of electronic technology, Printed Circuit Board (PCB) DDR3 memory has been in the mainstream of the market for a long time. Advances in technology have made DDR3 memory unable to meet the needs of customers. With the central processing unit , The performance of graphics cards has gradually increased, and the performance of DDR3 memory has become the performance bottleneck of the computer, and the brand-new DDR4 memory has the advantages of higher frequency, lower energy consumption, and stronger performance, so DDR4 memory has sufficient reasons. Usher in the dawn of popularization.

However, DDR4 memory has higher requirements for circuit levels and smaller line width spacing, which increases the difficulty of production and processing, and must have higher requirements for dry film resolution.

The purpose of the present invention is to provide a circuit pattern production method that uses a dry film process with a direct imaging (DI) laser exposure machine to directly image, so as to solve the problems of difficult production and processing of conventional DDR4 memory circuits and low dry film resolution capabilities. .

In order to achieve the above objectives, the present invention provides the following technical solutions: a method for producing circuit patterns, the method includes the following steps: (a) pretreatment: baking and medium roughening pretreatment on a substrate with a conductive layer; (b) pressing Film: A dry film is applied to the conductive layer in step (a) by heating and pressing; (c) exposure: laser exposure is performed on the dry film in step (b), in the resist in the exposed area The photosensitive initiator absorbs photons and decomposes into free radicals, and the free radicals initiate cross-linking reaction of monomers to form a spatial network macromolecular structure that is insoluble in dilute alkali; (d) development: the exposure of step (c) The dry film undergoes a development process. The active groups in the unexposed part of the dry film react with the dilute alkali solution to form soluble substances and dissolve, thereby dissolving the unexposed part, and the spatial network in the exposed area The macromolecular structure is not dissolved; (e) etching: the conductive layer exposed after the substrate is developed in step (d) is etched away by a chemical solution to form a circuit pattern; (f) film removal: an alkaline solution is used to protect In step (e), the spatial network macromolecular structure of the conductive layer of the substrate is peeled off to expose the circuit pattern.

The medium roughening treatment method in the step (a) adopts one of sandblasting grinding method, chemical treatment method or mechanical grinding method.

The chemical treatment method uses chemicals to bite the conductive layer of the substrate.

The chemical substance is sodium persulfate (SPS).

The energy of the laser exposure in the step (c) is in the range of 16 to 18 steps.

The linear velocity of the imaging in the step (d) is in the range of 3.9 to 4.5 meters per minute (m/min).

The pressure of the imaging in the step (d) is in the range of 0.5 to 1.5 kilograms per square centimeter (kg/cm2).

The etching operation in this step (e) is a vacuum etching operation.

The alkaline solution in this step (f) is a sodium hydroxide solution with a concentration of 8 to 12%.

In this step (b), the dry film is applied to the conductive layer by heating and pressing with a hot pressing wheel.

Compared with the prior art, the beneficial effects of the present invention are: the method adopts a dry film process, and is matched with a direct imaging (DI) laser exposure machine, direct imaging, no negative film is required, and the exposure cost is greatly reduced, and at the same time, it can reduce the variation of The dry film resolution ability of the film is reduced. After optimizing the pre-processing, lamination, exposure, and development parameters, the dry film resolution ability can reach 40 microns (um), and mass production of lines with a width of 50 microns (um) and line spacing less than 50 microns , Is the ideal production process for fine circuits in the production of printed circuit boards.

100: Process of line graphics production method

102~112: Steps of the process of the production method of circuit graphics

1: substrate

2: conductive layer

3: dry film

4: Space network macromolecular structure

Figure 1 is a flow chart of the method for producing circuit patterns of the present invention.

Fig. 2 is a schematic diagram of structural preparation changes of an embodiment of the present invention.

Hereinafter, each embodiment of the content of the present invention will be described in detail, and the drawings will be used as examples. In addition to these detailed descriptions, this case can also be widely implemented in other embodiments. Easy substitution, modification, and equivalent changes of the embodiments are all included in the scope of this case, and the scope of subsequent patents shall prevail. In the description of the specification, in order to enable the reader to have a more complete understanding of the case, many specific details are provided; however, the case may still be implemented under the premise of omitting some or all of these specific details. In addition, well-known steps or elements are not described in the details to avoid unnecessary limitation of the case. The same or similar elements in the drawings will be represented by the same or similar symbols. It should be noted that the drawings are for illustration purposes only, and do not represent the actual size or quantity of the components, unless otherwise specified.

Please refer to FIG. 1, the present invention provides a line pattern production method. The method flow 100 includes the following steps: Step 102: pre-processing; Step 104: lamination; Step 106: Exposure; Step 108: Development; Step 110: Etching; and step 112: removing the film.

Please refer to FIG. 2 to specifically describe the structure preparation changes in the various steps of the circuit pattern production method of the present invention: Step (a): Pre-treatment: For the substrate 1 with the conductive layer 2 (for example, copper) Carry out baking sheet and pretreatment for medium roughening; remove moisture and organic volatiles by baking, release internal stress, promote crosslinking reaction, and increase the dimensional stability, chemical stability and mechanical strength of the substrate 1 sheet; and medium roughening The pre-treatment can be carried out by sandblasting, chemical treatment or mechanical polishing. For example, a chemical treatment method is used to uniformly bite the conductive layer 2 of the substrate 1 with a chemical substance (such as an acidic substance such as sodium persulfate (SPS)). Roughening pre-treatment to remove impurities such as grease and oxides of the conductive layer 2, increase the roughness of the conductive layer 2, and increase the adhesion of the dry film; step (b): film pressing: the dry film 3 is heated and pressurized Paste the conductive layer 2 in step (a); first peel off the polyethylene protective film (not shown in the figure) from the dry film 3, and then under the condition of heating and pressing, for example, by a hot pressing wheel, the dry The film 3 has one side of the resist layer adhered to the conductive layer 2. The resist layer in the dry film 3 becomes softened by heat, and the fluidity increases, and then with the help of the pressure of the hot pressing wheel and the role of the adhesive in the resist The dry film 3 is pasted on the conductive layer 2 in step (a). The pressure, temperature and hot pressing line speed of the hot pressing roller are set according to actual needs. For example, the pressure of the hot pressing roller is in the range of 0.35 to 0.45 million Pascals (MPa), and the temperature of the hot pressing roller is between 105 and 125. ℃ (Celsius), the hot pressing line speed is in the range of 1.8 to 2.2 m/min (m/min); Step (c): Exposure: Direct imaging (DI) on the dry film 3 in step (b) The laser exposure machine performs laser exposure. The photosensitive initiator in the resist in the exposed area absorbs photons and decomposes into free radicals. The free radicals initiate cross-linking reaction of monomers to form a spatial network macromolecular structure that is insoluble in dilute alkali 4 ; Exposure energy is set according to actual needs, for example, the energy of laser exposure is in the range of 16 to 18 steps (step); step (d): development: the dry film 3 after exposure in step (c) During the development process, the active groups in the unexposed part of the dry film 3 react with the dilute alkali solution to form soluble substances and dissolve, thereby dissolving the unexposed part, and the spatial network macromolecular structure in the exposed area 4 Does not dissolve; the development line speed and pressure can be set in the range of 3.9 to 4.5 meters per minute (m/min) and 0.5 to 1.5 kilograms/square centimeter (kg/cm ² ) to increase The developing line speed reduces the developing pressure and increases the adhesion of the dry film 3.

Step (e): Etching: Use a chemical solution to etch away the conductive layer 2 exposed after the substrate 1 is developed in step (d) to form a circuit pattern; the type of chemical solution depends on the material of the conductive layer 2, if the conductive layer 2 For copper, copper ammonium chloride can be used as the chemical solution, and the conductive layer 2 exposed after the substrate 1 is developed in step (d) is etched away by the copper ammonium chloride solution, and the conductive layer 2 is ionized by the ammonia copper ion complex. Form the inner layer circuit pattern. The etching pressure is determined according to actual needs, for example, in the range of 1.2 to 2.5 kilograms per square meter (kg/m ² ); step (f): film removal: use an alkaline solution to protect the substrate 1 in step (e) The spatial network macromolecular structure 4 of the conductive layer 2 is peeled off to expose the circuit pattern. The type of alkaline solution is not limited. For example, it can be a sodium hydroxide solution with a concentration ranging from 8 to 12%.

Example 1

Step (a): Carry out baking and medium roughening pretreatment on the substrate 1 with the conductive layer 2 (for example, copper); remove water vapor and organic volatiles by baking, release internal stress, promote cross-linking reaction, and increase substrate 1 The dimensional stability, chemical stability and mechanical strength of the sheet; and the pre-treatment for medium roughening can be done by sandblasting, chemical treatment or mechanical polishing. For example, chemical treatment can be used with chemical substances (such as sodium persulfate). (SPS) and other acidic substances) uniformly bite the conductive layer 2 of the substrate 1 and perform medium roughening pretreatment to remove grease and oxides and other impurities in the conductive layer 2, increase the roughness of the conductive layer 2, and increase the adhesion of the dry film; step (b): Film pressing: the dry film 3 is attached to the conductive layer 2 in step (a) by heating and pressing; the polyethylene protective film (not shown in the figure) is first peeled off from the dry film 3, Then, under heating and pressing conditions, for example, by using a hot pressing wheel, one side of the dry film 3 with the resist layer is adhered to the conductive layer 2, and the resist layer in the dry film 3 becomes soft by the heat, and the fluidity increases Then, the dry film 3 is attached to the conductive layer 2 in step (a) by means of the pressure of the hot pressing wheel and the action of the adhesive in the resist. The pressure of the hot pressing wheel is 0.35 million Pascals (MPa), the temperature of the hot pressing wheel is 105°C (degrees Celsius), and the hot pressing line speed is 1.8 m/min (m/min); step (c): exposure: right step The dry film 3 in (b) is laser exposed with a direct imaging (DI) laser exposure machine. The photosensitive initiator in the resist in the exposed area absorbs photons and decomposes into radicals, and the radicals initiate cross-linking of monomers The reaction generates a spatial network macromolecular structure 4 that is insoluble in dilute alkali; the energy of the laser exposure is 16 steps (step); step (d): development: display the dry film 3 after exposure in step (c) For image processing, the active groups in the unexposed part of the dry film 3 react with the dilute alkali solution to form soluble substances and dissolve, thereby dissolving the unexposed part, while the spatial network macromolecular structure 4 in the exposed area is not Dissolve; the development line speed and pressure are 3.9 m/min (m/min) and 0.5 kg/cm ² (kg/cm ² ) respectively, increase the development line speed, reduce the development pressure, and increase the adhesion of the dry film 3 Step (e): Etching: Use a chemical solution to etch away the conductive layer 2 exposed after the substrate 1 is developed in step (d) to form a circuit pattern; the type of chemical solution depends on the material of the conductive layer 2, if the conductive layer 2 is copper, the chemical solution can be copper ammonium chloride, and the conductive layer 2 exposed after the substrate 1 is developed in step (d) is etched away by the copper ammonium chloride solution, and the conductive layer 2 is ionized by the copper ammonia ion complex , Form the inner layer circuit pattern. The etching pressure is 1.2 kg/m ² (kg/m ² ); step (f): remove the film: use 8% sodium hydroxide to protect the spatial network macromolecules of the conductive layer 2 of the substrate 1 in step (e) Structure 4 is peeled off to expose the circuit pattern.

Example 2

Step (a): Carry out baking and medium roughening pretreatment on the substrate 1 with the conductive layer 2 (for example, copper); remove water vapor and organic volatiles by baking, release internal stress, promote cross-linking reaction, and increase substrate 1 The dimensional stability, chemical stability and mechanical strength of the sheet; and the pre-treatment for medium roughening can be done by sandblasting, chemical treatment or mechanical polishing. For example, chemical treatment can be used with chemical substances (such as sodium persulfate). (SPS) and other acidic substances) uniformly bite the conductive layer 2 of the substrate 1 and perform medium roughening pretreatment to remove grease and oxides and other impurities in the conductive layer 2, increase the roughness of the conductive layer 2, and increase the adhesion of the dry film; step (b): Film pressing: the dry film 3 is attached to the conductive layer 2 in step (a) by heating and pressing; the polyethylene protective film (not shown in the figure) is first peeled off from the dry film 3, Then, under heating and pressing conditions, for example, by using a hot pressing wheel, one side of the dry film 3 with the resist layer is adhered to the conductive layer 2, and the resist layer in the dry film 3 becomes soft by the heat, and the fluidity increases Then, the dry film 3 is attached to the conductive layer 2 in step (a) by means of the pressure of the hot pressing wheel and the action of the adhesive in the resist. The pressure of the hot pressing wheel is 0.4 million Pascals (MPa), the temperature of the hot pressing wheel is 115°C (degrees Celsius), and the hot pressing line speed is 2 meters/minute (m/min); step (c): exposure: to step The dry film 3 in (b) is laser exposed with a direct imaging (DI) laser exposure machine. The photosensitive initiator in the resist in the exposed area absorbs photons and decomposes into radicals, and the radicals initiate cross-linking of monomers The reaction generates a spatial network macromolecular structure 4 that is insoluble in dilute alkali; the energy of the laser exposure is 17 steps (step); Step (d): Visualization: Visualize the dry film 3 after exposure in step (c) For image processing, the active groups in the unexposed part of the dry film 3 react with the dilute alkali solution to form soluble substances and dissolve, thereby dissolving the unexposed part, while the spatial network macromolecular structure 4 in the exposed area is not Dissolve; the development line speed and pressure are 4.2 m/min (m/min) and 1 kilogram/square centimeter (kg/cm ² ) respectively, increase the development line speed, reduce the development pressure, and increase the adhesion of the dry film 3 Step (e): Etching: Use a chemical solution to etch away the conductive layer 2 exposed after the substrate 1 is developed in step (d) to form a circuit pattern; the type of chemical solution depends on the material of the conductive layer 2, if the conductive layer 2 is copper, the chemical solution can be copper ammonium chloride, and the conductive layer 2 exposed after the substrate 1 is developed in step (d) is etched away by the copper ammonium chloride solution, and the conductive layer 2 is ionized by the copper ammonia ion complex , Form the inner layer circuit pattern. The etching pressure is 1.8 kg/m ² (kg/m ² ); step (f): remove the film: use 10% sodium hydroxide to protect the spatial network macromolecules of the conductive layer 2 of the substrate 1 in step (e) Structure 4 is peeled off to expose the circuit pattern.

Example 3

Step (a): Carry out baking and medium roughening pretreatment on the substrate 1 with the conductive layer 2 (for example, copper); remove water vapor and organic volatiles by baking, release internal stress, promote cross-linking reaction, and increase substrate 1 The dimensional stability, chemical stability and mechanical strength of the sheet; and the pre-treatment for medium roughening can be done by sandblasting, chemical treatment or mechanical polishing. For example, chemical treatment can be used with chemical substances (such as sodium persulfate). (SPS) and other acidic substances) uniformly bite the conductive layer 2 of the substrate 1 and perform medium roughening pretreatment to remove grease and oxides and other impurities in the conductive layer 2, increase the roughness of the conductive layer 2, and increase the adhesion of the dry film; step (b): Film pressing: the dry film 3 is attached to the conductive layer 2 in step (a) by heating and pressing; the polyethylene protective film (not shown in the figure) is first peeled off from the dry film 3, Then, under heating and pressing conditions, for example, by using a hot pressing wheel, one side of the dry film 3 with the resist layer is adhered to the conductive layer 2, and the resist layer in the dry film 3 becomes soft by the heat, and the fluidity increases Then, the dry film 3 is attached to the conductive layer 2 in step (a) by means of the pressure of the hot pressing wheel and the action of the adhesive in the resist. The pressure of the hot pressing wheel is 0.45 million Pascals (MPa), the temperature of the hot pressing wheel is 125°C (degrees Celsius), and the hot pressing line speed is 2.2 m/min (m/min); Step (c): Exposure: Right step The dry film 3 in (b) is laser exposed with a direct imaging (DI) laser exposure machine. The photosensitive initiator in the resist in the exposed area absorbs photons and decomposes into radicals, and the radicals initiate cross-linking of monomers The reaction generates a spatial network macromolecular structure 4 that is insoluble in dilute alkali; the energy of laser exposure is 18 steps (step); step (d): imaging: display the dry film 3 after exposure in step (c) For image processing, the active groups in the unexposed part of the dry film 3 react with the dilute alkali solution to form soluble substances and dissolve, thereby dissolving the unexposed part, while the spatial network macromolecular structure 4 in the exposed area is not Dissolve; the development line speed and pressure are 4.5 m/min (m/min) and 1.5 kg/cm ² (kg/cm ² ) respectively, increase the development line speed, reduce the development pressure, and increase the adhesion of the dry film 3 Step (e): Etching: Use a chemical solution to etch away the conductive layer 2 exposed after the substrate 1 is developed in step (d) to form a circuit pattern; the type of chemical solution depends on the material of the conductive layer 2, if the conductive layer 2 is copper, the chemical solution can be copper ammonium chloride, and the conductive layer 2 exposed after the substrate 1 is developed in step (d) is etched away by the copper ammonium chloride solution, and the conductive layer 2 is ionized by the copper ammonia ion complex , Form the inner layer circuit pattern. The etching pressure is 2.5 kg/m ² (kg/m ² ); step (f): remove the film: use 12% sodium hydroxide to protect the spatial network macromolecules of the conductive layer 2 of the substrate 1 in step (e) Structure 4 is peeled off to expose the circuit pattern.

Although the present invention has been described above with reference to some embodiments, without departing from the scope of the present invention, various modifications can be made to it and the components therein can be replaced with equivalents. In particular, as long as there is no structural conflict, the various features in the various embodiments disclosed in the present invention can be combined with each other in any way. The description of these combinations is not exhaustive in this specification, but only Omit space and save resources consider. Therefore, the present invention is not limited to the specific embodiments disclosed in the text, and includes all technical solutions falling within the scope of the claims.

100: Process of line graphics production method

102~112: Steps of the process of the production method of circuit graphics

Claims (10)

A line pattern production method, the method includes the following steps: (a) pre-treatment: baking and medium roughening pre-treatment on a substrate with a conductive layer; (b) lamination: drying the film by heating and pressing Paste the conductive layer in step (a); (c) exposure: perform laser exposure on the dry film in step (b), the photosensitive initiator in the resist in the exposed area absorbs photons and decomposes into radicals, The free radicals initiate the cross-linking reaction of the monomers to form a spatial network macromolecular structure that is insoluble in dilute alkali; (d) development: the dry film after exposure in step (c) is developed, and the dry film is not The active groups in the exposed part react with the dilute alkali solution to form soluble substances and dissolve, thereby dissolving the unexposed part, while the spatial network macromolecular structure in the exposed area is not dissolved; (e) etching: Use a chemical solution to etch away the conductive layer exposed after the substrate in step (d) is developed to form a circuit pattern; and (f) remove the film: use an alkaline solution to protect the conductive layer of the substrate in step (e) The spatial network macromolecular structure is stripped off to expose the circuit pattern. According to the method for producing a circuit pattern as described in item 1 of the scope of patent application, the intermediate roughening pretreatment in the step (a) adopts one of sandblasting, chemical treatment or mechanical polishing. According to the method for producing the circuit pattern described in item 2 of the scope of patent application, the chemical treatment method uses chemicals to bite the conductive layer of the substrate. As described in item 3 of the scope of patent application, the method for producing circuit patterns, wherein the chemical substance is sodium persulfate (SPS). The circuit pattern production method described in item 1 of the scope of patent application, wherein the energy of the laser exposure in the step (c) is in the range of 16 to 18 steps. The line pattern production method described in item 1 of the scope of patent application, wherein the line speed of the display in the step (d) is in the range of 3.9 to 4.5 meters per minute (m/min). The circuit pattern production method as described in item 1 of the scope of patent application, wherein the developing pressure in the step (d) is in the range of 0.5 to 1.5 kilograms per square centimeter (kg/cm ² ). According to the line pattern production method described in claim 1, wherein the etching operation in the step (e) is a vacuum etching operation. The circuit pattern production method as described in the first item of the scope of patent application, wherein the alkaline solution in the step (f) is a sodium hydroxide solution with a concentration range of 8 to 12%. The circuit pattern production method as described in item 1 of the scope of patent application, wherein the step (b) is to apply the dry film to the conductive layer by heating and pressing with a hot pressing wheel.

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