阅读说明：本技术 半密闭非真空氮气保护电路模块烧结系统 (Semi-closed non-vacuum nitrogen protection circuit module sintering system ) 是由 郭全民 范文明 李振华 田英侠 杨建华 马超 于 2019-08-30 设计创作，主要内容包括：本发明涉及到电路模块烧结技术领域,具体涉及一种半密闭非真空氮气保护电路模块烧结系统。本发明一种半密闭非真空氮气保护电路模块烧结系统,包括计算机、控制台和烧结台三大部分,所述的控制台是整个系统的核心控制装置,一方面控制台通过电缆线连接烧结台,控制烧结台的烧结温度和氮气浓度；另一方面控制台通过串行通信线连接计算机,配合计算机实现多台烧结的控制功能。在保证烧结品质的前提下,具有系统结构简单、小型便携、成本低廉的优点,以克服现有技术存在的系统结构复杂、体积大、造价高的问题。(The invention relates to the technical field of circuit module sintering, in particular to a semi-closed non-vacuum nitrogen protection circuit module sintering system. The invention relates to a semi-closed non-vacuum nitrogen protection circuit module sintering system which comprises a computer, a console and a sintering table, wherein the console is a core control device of the whole system, and on one hand, the console is connected with the sintering table through a cable to control the sintering temperature and the nitrogen concentration of the sintering table; on the other hand, the console is connected with the computer through a serial communication line, and is matched with the computer to realize the control function of a plurality of sintering devices. On the premise of ensuring the sintering quality, the sintering device has the advantages of simple system structure, small size, portability and low cost, and solves the problems of complex system structure, large volume and high manufacturing cost in the prior art.)

1. The semi-closed non-vacuum nitrogen protection circuit module sintering system comprises a computer (1), a console (2) and a sintering table (3), wherein the console (2) is connected with the computer (1) through a serial communication line and is connected with the sintering table (3) through a cable;

the sintering table (3) comprises a nitrogen sensor (11), a nitrogen protective cover (12), a heating table (13), an electric regulating valve (14) and a heating table wiring port (15), the heating table (13) uses a heating plate formed by one-time casting as a heating element, and a platinum resistor for measuring temperature is placed inside the heating table; the nitrogen protection cover (12) can be covered on the heating table (13) in an opening and closing manner, a nitrogen sensor (11) is arranged on the nitrogen protection cover (12), and an electric regulating valve (14) is arranged on the nitrogen protection cover (12);

a display screen (18), a key (19), a power switch (16) and a status indicator lamp (17) are arranged on the front panel outside the console (2); the rear panel is provided with a serial communication port (4), a temperature detection and control port (5), a nitrogen concentration detection and control port (6), an AC220V power port (7), a grounding terminal (8), a buzzer (9) and a safety seat (10), the serial communication port (4) is connected with the computer (1), the temperature detection and control port (5) is connected with a wiring port (15) on the heating table (13), and the nitrogen concentration detection and control port (6) is connected with a nitrogen sensor (11) and an electric regulating valve (14);

the control circuit in the console (2) takes a microprocessor as a core control device and consists of a solid-state relay, a key circuit, a display circuit, a serial port communication interface circuit and a power supply circuit, and a control program in the microprocessor is provided with a decoupling control algorithm:

circuit module sintering systemThe system is a bivariate (sintering temperature and nitrogen concentration) coupling system, and the system is coupled with a transfer function G_P(s) is:

in the formula (2), G_N(s)、G_T(s) is a nitrogen concentration transfer function and a temperature transfer function under a single control variable; g_NT(s) is the transfer function of temperature on nitrogen concentration, G_TN(s) is the transfer function of nitrogen concentration to influence temperature.

Calculating a decoupling matrix G_F(s)：

The decoupled system transfer function g(s) is:

Technical Field

The invention relates to the technical field of circuit module sintering, mainly relates to the technical field of accurate control of nitrogen concentration and sintering temperature of a semi-closed non-vacuum nitrogen protection sintering table, and particularly relates to a semi-closed non-vacuum nitrogen protection circuit module sintering system.

Background

The welding of large-area substrates and shells, devices and shells is an important link for realizing the mechanical and electrical connection of modules, and is also an important link for grounding and heat dissipation of electronic components. Aiming at large-area welding of a printed board and a metal base in a circuit module, soft soldering is mainly used, a soldering tin sheet is placed on the metal base, the printed board is heated to a certain temperature, and a brazing filler metal is melted and wetted to form an alloy with a welded base metal. The void ratio of the welding layer can be increased due to poor control of the co-sintering crystal process, various impedances can be formed due to the voids, the electrical conductivity and the thermal conductivity of the welding layer are greatly reduced, the heat dissipation of the module is greatly influenced, poor grounding can be caused, circuit crosstalk and insertion loss are caused, additional capacitance and vibration are brought, and the reliability and the durability cannot meet the requirements. The sintering quality of the circuit module is mainly related to two factors, namely the sintering atmosphere and the sintering heating mode, so that the sintering quality can be effectively improved by changing the sintering atmosphere and the heating mode.

At present, common sintering systems at home and abroad generally comprise a computer, a control console and a sintering console in terms of functions. The sintering table mainly comprises a sealed vacuum cavity and a heating table arranged in the vacuum cavity, when the sintering table is used, reductive hydrogen and inert nitrogen are further filled in the vacuum cavity to serve as sintering protective gas, so that the sintering quality is prevented from being influenced by oxidation of a sintering surface in the high-temperature sintering process, and meanwhile, the heating table is heated by adopting different heating modes such as a hot air blower, induction heating or microwave heating. The problems of the existing system are as follows: 1. because a closed vacuum environment is formed, the heating table needs to bear large negative pressure, so that the system has a complex structure and a large volume, and the system cost is high; 2. the hot blowing heating mode is applied to the large-area welding of the circuit module metal base and the printed board, the required sintering time is long, the efficiency is low, and the sintering object is heated unevenly; the induction heating equipment is complex, the cost required for one-time investment is relatively high, the interchangeability and the adaptability of an induction part are poor, and the induction heating equipment is not suitable for sintering a large-area substrate and a circuit module of a shell, a device and a shell; although the microwave heating method has high heating efficiency and high heating speed, the heating temperature is not uniform, and the microwave heating method is not suitable for heating metal workpieces.

At present, the sintering table can be used for welding a circuit module metal base and a printed board in a large area abroad, a vacuum closed environment and a heat conduction heating mode are adopted, and the existing problems are that: the price is high, one set of system is converted into RMB one two million yuan, and the RMB is hard to bear for most small and medium-sized enterprises, so that the application of the RMB is severely restricted.

Disclosure of Invention

The invention provides a semi-closed non-vacuum nitrogen protection circuit module sintering system, which has the advantages of simple system structure, small size, portability and low cost on the premise of ensuring the sintering quality, and solves the problems of complex system structure, large volume and high manufacturing cost in the prior art.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a semi-closed non-vacuum nitrogen protection circuit module sintering system comprises a computer, a console and a sintering table, wherein the console is connected with the computer through a serial communication line and is connected with the sintering table through a cable;

the sintering table comprises a nitrogen sensor, a nitrogen protection cover, a heating table, an electric regulating valve and a heating table wiring port, the heating table uses a heating plate formed by one-time casting as a heating element, and a platinum resistor for measuring temperature is placed in the heating table; the nitrogen protection cover can be covered on the heating table in an opening and closing manner, a nitrogen sensor is arranged on the nitrogen protection cover, and an electric regulating valve is arranged on the nitrogen protection cover;

the external front panel of the console is provided with a display screen, keys, a power switch and a status indicator lamp; the rear panel is provided with a serial communication port, a temperature detection and control port, a nitrogen concentration detection and control port, an AC220V power supply port, a grounding terminal, a buzzer and a safety seat. The serial communication port is connected with a computer, the temperature detection and control port is connected with a wiring port on the heating table, and the nitrogen concentration detection and control port is connected with a nitrogen sensor and an electric regulating valve;

the control circuit in the console takes a microprocessor as a core control device and consists of a solid-state relay, a key circuit, a display circuit, a serial port communication interface circuit and a power circuit. The control program in the microprocessor is provided with a decoupling control algorithm:

the circuit module sintering system is a bivariate (sintering temperature and nitrogen concentration) coupling system, and the system is coupled with a transfer function G_P(s) is:

in the formula (2), G_N(s)、G_T(s) is a nitrogen concentration transfer function and a temperature transfer function under a single control variable; g_NT(s) is the transfer function of temperature on nitrogen concentration, G_TN(s) is the transfer function of nitrogen concentration to influence temperature.

Calculating a decoupling matrix G_F(s)：

The decoupled system transfer function g(s) is:

compared with the prior art, the invention has the advantages that:

1. the invention creatively replaces the prior common vacuum sintering environment with a semi-closed non-vacuum non-pressure environment, achieves the control of nitrogen concentration by controlling the opening of an electric regulating valve, adopts a heating plate for heating, adopts a platinum resistor for temperature measurement, and combines a decoupling control algorithm to carry out decoupling control on the sintering temperature and the nitrogen concentration, thereby solving the problem that the input change of nitrogen affects the sintering temperature, improving the control precision of the system, and simplifying the system structure while ensuring the sintering quality of a circuit module. More importantly, the semi-closed non-vacuum system provided by the invention greatly reduces the manufacturing cost of the system and controls the manufacturing cost of the whole system within ten thousand yuan.

2. The system has small volume, is convenient to carry, has simple structure and is convenient to disassemble and maintain; the invention adopts a sintering mode of heating by a heating plate and soldering by soft soldering, has uniform heating, can effectively reduce the deformation of a circuit module and ensures the welding precision. For medium and small enterprises, the problems of complex structure, large volume, high investment cost and the like of sintering equipment can be solved.

Drawings

FIG. 1 is a schematic diagram of a circuit module sintering system;

FIG. 2 is a schematic diagram of a circuit module sintering system connection;

FIG. 3 is a schematic view of a front panel of a circuit module sintering system console;

FIG. 4 is a schematic block diagram of the internal control circuitry of the circuit module sintering system console.

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.

The semi-closed non-vacuum nitrogen protection circuit module sintering system provided by the invention comprises a computer 1, a control console 2 and a sintering table 3.

The control console 2 is a core control device of the whole system, on one hand, the control console 2 is connected with the sintering table 3 through a cable, and the sintering temperature and the nitrogen concentration of the sintering table 3 are controlled; on the other hand, the console 2 is connected to the computer 1 through a serial communication line, and realizes a control function of a plurality of sintering in cooperation with the computer 1.

The sintering station 3 includes a heating station 13, a platinum resistor, a nitrogen protection cover 12, a nitrogen sensor 11, an electric control valve 14, and a heating station wiring port 15. The heating table 13 uses a heating disc formed by one-time casting as a heating element, a platinum resistor for measuring temperature is placed in the heating table, and when the heating table is used, a sintered object is placed on the table top of the heating table 13, and the platinum resistor is used for detecting the temperature of the sintering table; a nitrogen protective cover 12 can be covered on the heating table 13 in an openable and closable manner to provide nitrogen protectionAtmosphere(s)The nitrogen sensor 11 is installed on the nitrogen protective cover 12 for detecting the nitrogen concentration, the electric control valve 14 is installed on the side surface of the protective cover 13, and the nitrogen concentration is controlled by adjusting the opening of the electric control valve 14.

The front panel outside the console 2 is provided with a display screen 18, a key 19, a power switch 16 and a status indicator lamp 17. The key 19 is used for setting built-in parameters and sintering process flow parameters of the console 2; the display screen 18 is used for displaying real-time detection and control data of the key operation process and the sintering process; the power switch 16 controls the on-off of the power of the whole system; the status indicator light 17 is on when energized and off when de-energized.

The back panel of the console 2 is provided with a serial communication port 4, a temperature detection and control port 5, a nitrogen concentration detection and control port 6, an AC220V power port 7, a grounding terminal 8, a buzzer 9 and a safety seat 10. The serial communication port 4 is connected with the upper computer 1, the temperature detection and control port 5 is connected with the wiring port 15 on the heating table 13, and the nitrogen concentration detection and control port 6 is connected with the nitrogen sensor 11 and the electric control valve 13.

The control circuit in the console 2 takes a microprocessor as a core control device and is composed of a solid-state relay, a key circuit, a display circuit, a serial port communication interface circuit, a power circuit and the like. The microprocessor controls the on-off of the power supply of the sintering table 3 by controlling the on-off of the solid-state relay so as to realize the control of the sintering temperature; the microprocessor controls the nitrogen concentration in the nitrogen protective cover 12 by controlling the opening of the electric control valve 13; the microprocessor detects the nitrogen concentration and the sintering temperature in real time through a platinum resistor arranged in the nitrogen sensor 11 and the heating table 13 as feedback quantity of a control algorithm. The key circuit sends the input of the key 19 to the microprocessor for corresponding processing; the display circuit transmits the data to be displayed to the display screen 18 for display. The serial communication interface circuit is connected with the upper computer 1 through the serial communication port 4 to realize communication with the upper computer. The power supply circuit realizes alternating current-direct current voltage conversion and conversion between different direct current voltages, and supplies power for different components and equipment.

A program in a microprocessor of the control console 2 is provided with a feedback compensation decoupling control algorithm to perform decoupling control on the sintering temperature and the nitrogen concentration in the nitrogen protection cover of the sintering console, so that the sintering temperature and the nitrogen concentration are independently controlled, and the control precision of the system is improved.