Soldering training

• Soldering equipment.
• Types of thermal air soldering stations.
• Thermocouple calibration and setting of soldering stations.
• Principal differences of soldering stations.
• The applicability of the nozzles for the dryer, depending on the repair that you perform.
• Correct temperatures when removing the chip from the motherboard mounted on lead-free solder.
• Types of soldering irons: ceramic and induction. Manufacturers of soldering equipment.
• Types and applicability of tips when using soldering irons.
• Induction soldering systems (METCAL PS-900, Quick-202d and others).
• Maintenance of hot-air and induction soldering stations.
• Heaters printed circuit boards, types and manufacturers (Thermopro and ppd 120). Their applicability in the repair.
• Microscope for soldering. Manufacturers of optics for repairing circuit boards for phones and tablets. The main characteristics of microscopes. Recommendations for selection. Service maintenance of microscopes.
• Laboratory power supply (LBP).
• IPower Pro diagnostic cable and test cable for iPhone (iBridge).
• Measuring equipment for diagnostics and troubleshooting on a printed circuit board.
  Which multimeter to choose.
• Oscilloscope for electronics repair, selection recommendations.
• SMD tester.
  Programmer for iPhone ip box, flash programmer WL-PCIE NAND, multifunctional programmer JC Pro1000S.
• Soldering tools.
• Holders for boards.
• Mechanical tool: tweezers, pullers, shovels, probes, knives to remove the compound.
• Consumables for soldering.
• Copper braid for removing solder.
• Types of soldering flux (washing and non-washing).
• Types of bga paste and what are the differences. Types of solders.
• 0.2 mm bga balls.
• Stencils for bga soldering. 3d stencils. Manufacturers of high quality stencils. Choice of stencils for mounting BGA chips.
• Cleaner flux and other solder waste from printed circuit boards.
• Rose alloy to lower the melting point of solder.
• Proven suppliers of equipment, tools and consumables for the repair of electronic devices.

Equipment, tools and supplies for diagnostics and bga soldering

A thermal imaging camera Seek Thermal Compact PRO

iPower Pro

Zillion x Work diagnostic SOFTWARE

A mandatory section of the training program is the basics of radio engineering.

The basics of radio engineering is the a mandatory part of the training program. People with different initial levels of knowledge in electronics are enrolled in soldering courses at Bgacenter.

Therefore, we begin training from the very basics:

• We recall Ohm’s Law for a section of a chain and for a complete chain. We will learn in practice the applicability of Kirchhoff’s laws for the repair of electronics.
• Conventional graphic and letter designations of radio components on the circuit board of electronic devices.
• Purpose and principle of operation of radio components: capacitor, filter, resistor, transistor, inductor, diode.
• The structure of the motherboard of the phone and tablet. Arrangement of microchips and radio components on the board.
• Designation of connectors and their purpose.
• We will learn how to read electronic circuits, abbreviations and designation of parts on the board.
• We will learn how to work with Zillion X Work and wu xin ji.
• Work with single-line circuit diagrams in PDF and Pads Router, and BlackFish.
  Determination of the relationship between microcircuits and radio components on the board, and their location.
• We will study what components the charge circuit consists of. The principle of operation of the charge circuit of the phone. Charge circuit diagnostics using a multimeter and / or laboratory power supply.
• Primary and secondary iPhone power circuit. Faulty power supply circuits. Interface bus I2C.

We will study circuitry using an example:

• charge circuit;
• Tigris;
• short circuit in the primary and secondary power circuits;
• backlight unit;
• flashlight flash driver;
• power controller display and touch panel;
• touchscreen controllers;
• average contact;
• power supply of the main and front cameras;
• NAND Flash and PCIE Express;
• audio codec and sound amplifier;
• Wi-Fi and Bluetooth;
• modem and modem power controller;
• central processing unit CPU.

Circuitry and reading circuits

iPhone X components on the system

iPhone XR motherboard

iPhone XS Max motherboard

• Visual inspection of the motherboard for damaged or missing elements, oxides, “overheated” chips.Connecting the motherboard to an external power supply-LBP.
• Briefly turn on the motherboard by applying iPower Pro.
• Determination of the presence of a short circuit in the Board using a laboratory power supply and a multimeter.
• Measurements of voltages in the primary and secondary power supply circuits at TestPoint.
• Measurements of resistance and voltage drop, diode ringing. Comparison of indications with “donor” payment.
• Diagnostics of the charge circuit by connecting to the laboratory power supply. Short-term start of the phone from LBP. Check for low voltage in the charge circuit.
• Set a jumper to diagnose iPhone board faults.

We will study the possible phone malfunctions and the sequence of diagnostics in the following cases:

• does not turn on or “apple reboot”;
• not charging or a false charge;
• not determined by the PC;
• search and elimination of short circuits, by various methods;
• there is no backlight;
• no image;
• the touchscreen does not work fully or partially;
• one or both cameras, including a flashlight, do not work;
• the Home button does not work;
• no sounds;
• the flashlight does not work;
• there is no standby voltage on the power button;
• could not find the SIM card;
• “gray” Wi – Fi or weak Wi – Fi signal;
• does not catch a network or network search;
• LTE does not work;
• activation failure, memory increase iPhone and iPad;
• iTunes errors 4013, 9, 4014, -1;
• “overheated” central processor.

iSocKet for iPhone x Board diagnostics

Pomona professional feelers

IPhone x diagnostics

Diagnosis of faults on circuit Board

• Setting up the microscope to perform a visual inspection of the motherboard.
• Inspection of the board and determine the presence of the compound under and around the perimeter of the chip.
  Installation of the phone motherboard in a specialized holder.
• Use of heat sinks when removing chips from the Board.
• Selection of temperature and air flow for pairing radio components. Calibration of thermal air soldering station using thermocouple.
• Selection and preparation of hand tools (tweezers, puller) to remove the chip.
• The difference between lead of the soldering and lead-free solders.
• Dismantling NAND Flash, Baseband, Wi-Fi, CPU using PCB heater. Compliance with the correct PCB heating technology.
• Dismantling of the chip induction soldering iron. Application soldering iron for soldering bga chips.

Method for removing the microcircuit from the board with a drop of solder:

• charge control chip – Tristar (U2),
• sensor control chip,
• audio codec,
• main power controller,
• display power controller,
• display backlight driver,
• modem power controller,
• Connectors for display, touchscreen, main and front cameras, Home button.

How to avoid damage to the contact area, tearing off nickels, with bga soldering.
Restoring bga chipset.
How to properly prepare the contact pad for subsequent soldering.
Checking the contact area using a multimeter for the presence of a short circuit or breaks in the tracks or the “dump” of microcircuits.

Soldering bga chips

Soldering iPhone

• Preparation of the contact area. Collecting solder with copper braid and soldering iron.
• Repair damaged contacts and conductive tracks on the Board of the smartphone and tablet.
• Preparation of the chip for reballing (rolling). Cleaning the chip surface from solder and compound.
  What to do with gray contacts “nickels”.
• Choice of stencil for bga soldering.
• Final contact formation when reballing bga paste.
• Determining the key on the chip body
• Applying the required amount of non-washing flux to the contact area.
• Correct positioning on the contact area.
• Method of restoring or replacing (after getting wet) chip binding
• Required air flow and temperature when soldering a bga chip
• Diagnostics of the phone Board, after soldering using a laboratory power supply.

Soldering bga chips on the Board

Soldering of BGA

• Types of compound and its purpose.
• How to determine the “overheated” chip on the compound by conducting a visual inspection of the board.
• Proper preparation of the bga chip for soldering from the board.
• Use of a circuit board heater when dismantling microchips on a compound.
• Learn how to prevent overheating of adjacent elements.
• The use of heat-removing elements for safe soldering.
  How to remove a compound from the contact pad and microcircuit without damaging the mask.
• Determination of the moment of removing the microcircuit from the board, in order to avoid damage to the contact area (tearing off nickels, damage to the factory mask).
• Ways to repair a damaged mask.

Working with compound