阅读说明：本技术 一种碳膜印制板高导电浆料阻值调控方法 (Carbon film printed board high-conductivity paste resistance value regulation and control method ) 是由 詹红有 邱炳潮 詹诚杰 贾文明 柯延春 刘兴 于 2019-10-25 设计创作，主要内容包括：本发明涉及一种碳膜印制板高导电浆料阻值调控方法,包括以下步骤：一,高导值碳油制作；将石墨烯、导电炭黑、连接料、混合溶剂和助剂混合均匀分散,制得高导值碳油；二,印制板加工预前处理；三,阻焊制作；对步骤四得到的电路板进行阻焊印刷,阻焊印刷完成后固化,四,碳膜印制板加工；根据预设的电阻值确定线路板丝印的碳油长宽比,在线路板上调整刮刀根据电路图形对线路板进行丝印；五,碳膜固化处理；以在电路板上形成导电碳油电阻。本发明形成的导电碳油电阻具有导电性能好,内阻小的特点,能实现对电阻厚膜厚度的精确控制,利于后期碳膜印制板阻值的控制。(The invention relates to a method for regulating and controlling the resistance of high-conductivity paste of a carbon film printed board, which comprises the following steps of: firstly, preparing high-conductivity carbon oil; uniformly mixing and dispersing graphene, conductive carbon black, a connecting material, a mixed solvent and an auxiliary agent to prepare high-conductivity carbon oil; secondly, preprocessing the printed board; thirdly, solder resist manufacturing; c, performing solder resist printing on the circuit board obtained in the step four, and curing after the solder resist printing is finished; determining the length-width ratio of carbon oil for silk-screen printing of the circuit board according to a preset resistance value, and adjusting a scraper on the circuit board to perform silk-screen printing on the circuit board according to a circuit pattern; fifthly, curing the carbon film; to form a conductive carbon oil resistor on the circuit board. The conductive carbon oil resistor formed by the invention has the characteristics of good conductivity and small internal resistance, can realize accurate control of the thickness of a resistor thick film, and is beneficial to control of the resistance value of a carbon film printed board in the later period.)

1. A method for regulating and controlling the resistance of high-conductivity paste of a carbon film printed board is characterized by comprising the following steps of:

step one, preparing high-conductivity carbon oil; uniformly mixing and dispersing graphene, conductive carbon black, a connecting material, a mixed solvent and an auxiliary agent to prepare high-conductivity carbon oil;

step two, preprocessing printed board processing; manufacturing a circuit pattern on a circuit board, and cutting the circuit board into a circuit board with a target size;

step three, solder mask manufacturing; performing solder resist printing on the circuit board obtained in the step two, and drying after the solder resist printing is finished;

step four, processing a carbon film printed board; determining the length-width ratio of carbon oil for silk-screen printing of the circuit board according to a preset resistance value, and adjusting a scraper on the circuit board to perform silk-screen printing on the circuit board according to a circuit pattern; starting to lower high-conductivity carbon oil from a preset distance outside the circuit board, simultaneously lowering a scraper, and adjusting the stroke of the scraper so as to start silk-screen printing when the scraper moves to the circuit board;

step five, curing treatment; placing the circuit board obtained in the step four in a tunnel baking furnace for curing treatment until the fluctuation range of the resistance value of the carbon oil area of the circuit board is less than 5%, and finishing reflow soldering treatment;

to form a conductive carbon oil resistor on the circuit board.

2. The method for regulating the resistance of the carbon film printed board high-conductivity paste according to claim 1, wherein the high-conductivity carbon oil comprises the following components in parts by weight: 10-40 parts of graphene, 3-10 parts of conductive carbon black, 0.5-5 parts of a connecting material, 40-80 parts of a mixed solvent and 0.5-5 parts of an auxiliary agent.

3. The method for regulating the resistance of the carbon film printed board high-conductivity paste according to claim 2, wherein the first step specifically comprises the following steps:

adding the connecting material and the auxiliary agent into the mixed solvent, and stirring until the connecting material and the auxiliary agent are completely dissolved in the mixed solvent to form a carrier;

adding graphene and conductive carbon black into a carrier, and stirring to form a mixed material;

and (3) carrying out ultrasonic treatment on the mixed material until all components in the mixed material are uniformly dispersed to obtain the high-conductivity carbon oil.

4. The method for regulating the resistance of the carbon film printed board high-conductivity paste according to claim 3, wherein: the ultrasonic treatment time is 10-20 h.

5. The method for regulating the resistance of the carbon film printed board high-conductivity paste according to claim 2, wherein the mixed solvent is a mixture of water and an organic solvent, and the mass ratio of water to the organic solvent in the mixed solvent is 6: 1, the organic solvent is an alcohol solvent.

6. The method for regulating the resistance of the carbon film printed board high-conductivity paste according to claim 2, wherein: the auxiliary agent is one or more of a flatting agent, a defoaming agent and an adhesion promoter.

7. The method for regulating the resistance of the carbon film printed board high-conductivity paste according to claim 2, wherein: the graphene is mechanically stripped graphene, and the particle size of the conductive carbon black is 15-100 nm.

8. The method for regulating the resistance of the carbon film printed board high-conductivity paste according to claim 1, wherein the second step further comprises the steps of:

the circuit board is arranged on the silk-screen workbench surface, a backing plate is arranged between the circuit board and the workbench surface, and the thickness of the backing plate is equal to that of the circuit board.

9. The method for regulating the resistance of the carbon film printed board high-conductivity paste according to claim 1, wherein: in the fourth step, the preset resistance range is 300-450 omega, and the length-width ratio of the carbon oil of the silk screen of the circuit board is 5: 4.5.

10. the method for regulating the resistance of the carbon film printed board high-conductivity paste according to claim 1, wherein: in the third step, the drying temperature is 140-170 ℃, and the drying time is 15-60 min.

Technical Field

The invention relates to the technical field of PCB (printed circuit board) carbon paste, in particular to a method for regulating and controlling the resistance of high-conductivity paste of a carbon film printed board.

Background

With the rapid development of the electronic industry, the carbon film printed board is gradually adopted in the trend of multi-functionalization and miniaturization of the common electrical appliance and instrument industry, such as: television, telephone, electronic organ, game machine, video recorder, etc. New technologies and new functions are continuously developed and adopted, and the electronic fields of computer keyboards, card-type computing machines, mini-recorders, electronic measuring instruments and SMT are also selected, so that the demand is expanded; the carbon film printed board is a circuit board with a resistance thick film formed by coating carbonaceous conductive oil (carbon oil for short) on a circuit board substrate and curing; at present, carbon oil is mainly printed on a circuit board through a screen printing (also called silk screen printing) mode, but the requirements of the circuit board are higher and higher, so that the requirements of the carbon film printed board on electrical property are high, the requirements of the resistance value are higher and higher, but the carbon oil in the market cannot meet the requirements of high-resistance equipment, cannot meet the requirements of various high-conductivity pastes, cannot realize the regulation and control of the resistance value of the high-conductivity paste of the carbon film printed board, influences the use of the carbon film printed board in the later period, is not perfect in the carbon oil printing method on the carbon film printed board in the market, is difficult to accurately control the thickness of a resistor thick film, and has the problem of uneven thickness, so that the resistance value of; affecting the quality of the finished carbon film printed board.

Disclosure of Invention

The invention aims to provide a method for regulating and controlling the resistance of high-conductivity paste of a carbon film printed board, so as to solve the problems in the background technology.

In order to solve the technical problems, the invention provides the following technical scheme:

a method for regulating and controlling the resistance of high-conductivity paste of a carbon film printed board is characterized by comprising the following steps of:

step one, preparing high-conductivity carbon oil; uniformly mixing and dispersing graphene, conductive carbon black, a connecting material, a mixed solvent and an auxiliary agent to prepare high-conductivity carbon oil;

step two, preprocessing printed board processing; manufacturing a circuit pattern on a circuit board, and cutting the circuit board into a circuit board with a target size;

step three, solder mask manufacturing; and C, performing solder mask printing on the circuit board obtained in the step II, and drying after the solder mask printing is finished.

Step four, processing a carbon film printed board; determining the length-width ratio of carbon oil for silk-screen printing of the circuit board according to a preset resistance value, and adjusting a scraper on the circuit board to perform silk-screen printing on the circuit board according to a circuit pattern; starting to lower high-conductivity carbon oil from a preset distance outside the circuit board, simultaneously lowering a scraper, and adjusting the stroke of the scraper so as to start silk-screen printing when the scraper moves to the circuit board;

step five, curing treatment; placing the circuit board obtained in the step four in a tunnel baking furnace for curing treatment until the fluctuation range of the resistance value of the carbon oil area of the circuit board is less than 5%, and finishing reflow soldering treatment;

to form a conductive carbon oil resistor on the circuit board.

Preferably, the high-conductivity carbon oil comprises the following components in parts by weight: 10-40 parts of graphene, 3-10 parts of conductive carbon black, 0.5-5 parts of a connecting material, 40-80 parts of a mixed solvent and 0.5-5 parts of an auxiliary agent.

As a preferred scheme, the first step specifically comprises:

adding the connecting material and the auxiliary agent into the mixed solvent, and stirring until the connecting material and the auxiliary agent are completely dissolved in the mixed solvent to form a carrier;

adding graphene and conductive carbon black into a carrier, and stirring to form a mixed material;

and (3) carrying out ultrasonic treatment on the mixed material until all components in the mixed material are uniformly dispersed to obtain the high-conductivity carbon oil.

Preferably, the ultrasonic treatment time is 10-20 h.

Preferably, the mixed solvent is a mixture of water and an organic solvent, and the mass ratio of water to the organic solvent in the mixed solvent is 6: 1, the organic solvent is an alcohol solvent.

Preferably, the auxiliary agent is one or more of a leveling agent, a defoaming agent and an adhesion promoter.

Preferably, the graphene is mechanically stripped graphene, and the particle size of the conductive carbon black is 15-100 nm.

Preferably, the second step further comprises:

the circuit board is arranged on the silk-screen workbench surface, a backing plate is arranged between the circuit board and the workbench surface, and the thickness of the backing plate is equal to that of the circuit board.

Preferably, in the fourth step, the preset resistance range is 300-450 Ω, and the length-width ratio of the carbon oil of the silk screen of the circuit board is 5: 4.5.

preferably, in the third step, the drying temperature is 140-170 ℃, and the drying time is 15-60 min.

Compared with the prior art, the invention has the following beneficial effects:

the formula of the existing carbon oil is improved, the finished carbon oil has the characteristics of good conductivity and small internal resistance, and the materials of the formula of the carbon oil are fully dispersed and mixed, so that the integral particle size distribution is uniform, the later-stage uniform coating and printing are facilitated, the use requirement of high-resistance equipment can be met, the regulation and control of the high-conductivity paste resistance of the carbon film printed board in the later stage can be realized, the carbon oil printing method on the carbon film printed board is perfected, the accurate control of the thickness of the thick film of the resistor can be realized, the uniformity of the thickness is ensured, and the control of the resistance of the carbon film printed board in the later stage is facilitated; the quality of the finished carbon film printed board is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a flow chart of the method of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the present invention provides a technical solution:

a method for regulating and controlling the resistance of high-conductivity paste of a carbon film printed board comprises the following steps:

step one, preparing high-conductivity carbon oil;

step two, preprocessing printed board processing;

step three, solder mask manufacturing;

step four, processing a carbon film printed board;

and step five, curing treatment.

In the first step, the preparation of the high-conductivity carbon oil comprises the following steps:

1) the formula of the high-conductivity carbon oil comprises: the graphene-based conductive carbon black composite material comprises graphene, conductive carbon black, a connecting material, a mixed solvent and an auxiliary agent, wherein the graphene-based conductive carbon black composite material comprises the following components in parts by mass: 10-40 parts of graphene, 3-10 parts of conductive carbon black, 0.5-5 parts of a connecting material, 40-80 parts of a mixed solvent and 0.5-5 parts of an auxiliary agent;

in the first step, the mixed solvent in the formula of the high conductivity carbon oil is a mixture of water and an organic solvent, and the mass ratio of water to the organic solvent in the mixed solvent is 6: 1, water is deionized water, and an organic solvent is an alcohol solvent; in the first step, the auxiliary agent in the formula of the medium-high conductivity carbon oil is one or more of a flatting agent, a defoaming agent and an adhesion promoter; in the first step, graphene in the formula of the medium-high conductivity carbon oil is mechanically stripped graphene, and the particle size of the conductive carbon black is 15-100 nm;

2) weighing the following materials: the composition comprises the following components in parts by mass: weighing 10-40 parts of graphene, 3-10 parts of conductive carbon black, 0.5-5 parts of a binder, 40-80 parts of a mixed solvent and 0.5-5 parts of an auxiliary agent;

3) mixing carbon oil: adding the connecting material and the auxiliary agent in the step into a mixed solvent, stirring until the connecting material and the auxiliary agent are completely dissolved in the mixed solvent to form a carrier, mixing the graphene and the conductive carbon black in the step, adding the mixture into the carrier, stirring to form a mixed material, and performing ultrasonic treatment on the mixed material until all components in the mixed material are completely and uniformly dispersed to obtain the high-conductivity carbon oil; in the first step, the ultrasonic treatment time in the mixed preparation of the medium carbon oil is 10-20 hours;

in the second step, the pretreatment of the printed board processing comprises the following steps:

1) manufacturing a circuit pattern on a circuit board, and cutting the circuit board into a circuit board with a required size;

2) moving the cut circuit board to a silk-screen workbench surface, and arranging a backing plate between the circuit board and the workbench surface, wherein the thickness of the backing plate is the same as that of the circuit board;

in the third step, solder resist ink without diluent is used for solder resist printing of the circuit board, and the circuit board is transferred to an oven for drying after the solder resist printing is finished.

In the fourth step, the processing of the carbon film printed board comprises the following steps:

1) on the working table, starting to discharge carbon oil from a position 50mm outside the circuit board, simultaneously discharging a scraper, adjusting the stroke of the scraper, ensuring that the thickness of the carbon oil on the circuit board is uniform when the scraper is moved to the circuit board to start silk-screen printing, baking the circuit board after coating, and solidifying the carbon oil; the drying temperature in the third step is 140-170 ℃, and the drying time is 15-60 min;

2) according to a preset resistance value, after the length-width ratio of carbon oil during silk-screen printing on the circuit board is determined, adjusting a scraper on the circuit board to perform silk-screen printing on the circuit board according to a circuit pattern;

the preset resistance value range in the fourth step is 300-450 omega; according to the formula carbon-oil resistance ═ carbon-oil resistivity × resistance length/cross-sectional resistance area, the carbon-oil length-to-width ratio was set to 5: 4.5.

in the fifth step, the circuit board printed with the carbon oil is placed into a tunnel furnace for rapid heating treatment, the resistance value of the carbon oil area is measured after the rapid heating treatment is finished, the circuit board is repeatedly placed into the tunnel furnace for rapid heating treatment again, the resistance value of the carbon oil area is measured, and the curing treatment is finished until the fluctuation range of the resistance value of the carbon oil area is less than 5%; thus, the conductive carbon oil resistor with high resistance precision is formed on the circuit board.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.