Four wave soldering daily maintenance and maintenance knowledge

Last Update Time: 2018-10-30 11:01:43

Four wave soldering daily maintenance and maintenance knowledge 1 regularly check the heating pipe voltage is normal,too high voltage will damage the heating pipe. 

When the preheater temperature is too high due to abnormal,the control circuit will automatically cut off the power supply,and alarm instructions to protect the temperature control and heating components,if the operating temperature control table indicates that the temperature fluctuation is too large to be stable,it may be that the alarm temperature limit is set too low,should be appropriately increased;or the contactless switch has been broken down,or the heating pipe has been burned,should be replaced. The temperature of the bottom of the PCB substrate is often tested to ensure the best solder effect.

Check the high temperature area of the wire is aging,to prevent the current interruption. 

Four wave soldering daily maintenance and maintenance knowledge 

regularly check the heating pipe voltage is normal,too high voltage will damage the heating pipe.

When the preheater temperature is too high due to abnormal,the control circuit will automatically cut off the power supply,and alarm instructions to protect the temperature control and heating components,if the operating temperature control table indicates that the temperature fluctuation is too large to be stable,it may be that the alarm temperature limit is set too low,should be appropriately increased;or the contactless switch has been broken down,or the heating pipe has been burned,should be replaced. The temperature of the bottom of the PCB substrate is often tested to ensure the best solder effect.

Check the high temperature area of the wire is aging, to prevent the current interruption. 

Diode Diode can be divided into glass and plastic, luminous and non-luminous, etc. The negative electrode of the ordinary diode is calibrated by color, which is divided into white, red or black. LEDs are marked with pins, short for negative. 

For LEDs,the DS * is marked on the PCB as a light-emitting chip diode.

For ordinary diodes,the thicker end of the PCB board corresponds to the negative electrode 

The triode can be divided into NPN, PNP and MOS transistors according to the processing technology of the triode ( Figure 2-24 ).1SOT-like SOT23,SOT89 and SOT143.SOT23 is a general purpose surface assembly triode.SOT89 is suitable for higher power.SOT143 is generally used as a RF transistor.The 2SOT package can be used both as a transistor and as a diode.The welding conditions of 3SOT are wave soldering / reflow soldering,230 ~ 260C,5-10 s,and SOT as small outline package transistors.4 according to the shape of the chip,the structure is divided into roughly:DIP,SIP,ZIP,S-DIP,SK a DIP,PGA,is a pin plug-in type; sOP, MSP, QFP, SVP, LCCC, PLCC, SOJ, BGA, CSP are surface mount type ( Figure 2-2-5 ).

The common mounting IC is SOJ ( double-row inner J-shaped ), PLCC ( square J-pin ), QFP ( square ), BGA ( bottom spherical shape ) four forms.

SOP ( Small Outline Package ) chip width is less than 0.15in, the electrode pin is less ( usually between 8 to 40 feet ).

SOL chip width is above 0.25in, and the number of electrode pins is above 44.

the width of the sOW chip is above 0.6in, and the number of the electrode pins is above

The SOJ pin is shaped as a J-shaped pin ( Figure 2-2, 6 ).SOJ package IC ( double row inline J shape inside ):SOJ package IC ( double row inline ),IC silk screen mask with model screen printing,direction indication gap,first foot indicator ( Figure 227 ).