BGA means a chip packaged with a BGA packaging process.

There are four basic types of BGA: PBGA, CBGA, CCGA and TBGA, which are generally connected to the bottom of the package body as an I/O lead-out solder ball array. The typical pitches of the solder ball arrays of these packages are 1.0mm, 1.27mm, 1.5mm. The lead-tin components of the solder balls are mainly 63Sn/37Pb and 90Pb/10Sn. The diameter of the solder balls is currently not corresponding in this respect. The standards vary from company to company. From the perspective of BGA assembly technology, BGA has more superior characteristics than QFP devices, which is mainly reflected in the less stringent requirements of BGA devices for placement accuracy.

 

 

Theoretically speaking, in the soldering reflow process, even if the solder balls are relative to The offset of the pad is as much as 50%, and the position of the device can be automatically corrected due to the surface tension of the solder. This situation has been proved to be quite obvious through experiments. Secondly, BGA no longer has the problem of pin deformation of devices like QFP, and BGA also has better coplanarity than QFP and other devices. Its lead-out distance is much larger than that of QFP, which can significantly reduce soldering Paste printing defects lead to the problem of solder joints "bridging"; in addition, BGA has good electrical and thermal properties, as well as higher interconnect density. The main disadvantage of BGA is that it is difficult to detect and repair the solder joints, and the reliability of the solder joints is relatively strict, which limits the application of BGA devices in many fields.

 

BGA soldering station

BGA soldering station is generally called BGA rework station. It is a special equipment used when BGA chips have soldering problems or need to be replaced with new BGA chips. Because the temperature requirements for BGA chip soldering are relatively high, heating tools (such as Hot air gun) cannot meet its needs.

 

When the BGA soldering station is working, it uses the standard reflow soldering curve (for details of the curve, please refer to the article "BGA rework station temperature curve" on the encyclopedia). Therefore, the effect of using it for BGA rework is very good. If you use a better BGA soldering station, the success rate can reach more than 98%.

With function

1. Whether it is 3 temperature zones

Including upper heating head, lower heating head, infrared preheating zone. Three temperature zones are the standard configuration. At present, products with two temperature zones appear on the market, including only the upper heating head and the infrared preheating zone. The welding success rate is very low. Please pay attention to it when buying.

2. Whether the lower heating head can move up and down

The lower heating head can move up and down, which is one of the necessary functions of the bga rework station. Because when welding a relatively large circuit board, the tuyere of the lower heating head is structurally designed to play an auxiliary support role. If it can't move up and down, it can't play the role of auxiliary support, and the success rate of welding is greatly reduced.

3. Whether it has the function of intelligent curve setting

When applying the bga rework station, the temperature profile setting is the most important aspect. If the temperature curve of the bga rework station is not set correctly, the welding success rate is very low, and the welding or disassembly is impossible.

 

4. Whether it has welding function

If the temperature curve setting is not accurate, using this function can greatly improve the success rate of welding. The welding temperature can be adjusted during the heating process.

5. Whether it has cooling function

Generally, a cross-flow fan is used for cooling.

6. Whether there is a built-in vacuum pump

When it is convenient to disassemble the bga chip, absorb the bga chip.

7. If it is a bga rework station controlled by a temperature instrument, you are firmly opposed to your purchase

The bga rework station controlled by the temperature instrument has many problems. The main problem is the high failure rate.

The current temperature control instruments on the market are basically fakes. Taiwan’s genuine temperature control instruments support temperature curves, and the price is 1200-2000 yuan/unit. The temperature control of the bga rework station is the core function. Inferior temperature control instruments cannot guarantee the accuracy of temperature control and the quality of welding.

The temperature meter data setting is cumbersome, you need to switch from number to number. After entering a temperature curve, you don't want to enter the second one, that is, the man-machine interface is very unfriendly.

Excellent performance

1. What is the temperature control accuracy of the bga rework station?

Generally, the soldering temperature accuracy requirement of reflow soldering is ±1℃, and the bga rework station with temperature control accuracy greater than ±1℃ is recommended not to buy, because the temperature control accuracy is low, there is no way to reach the precise temperature set by your temperature curve. Especially in the small pitch bga welding, it is extremely easy to produce bridging. Some company's products cannot achieve this accuracy because the control technology of temperature control accuracy is not good enough.

2. Is the actual temperature curve displayed on the screen?

When the temperature curve is displayed on the screen, some manufacturers only display the set curve instead of the actual temperature curve. This is very problematic. If he dare not open the actual temperature curve to the customer, it proves that his temperature control accuracy is very low.

 

Equipment nature

1. The equipment must have safety protection functions, such as failure of thermocouples, fans, and heating devices, no safety accidents can occur.

2. The selection of the components of the equipment must be good, and the wiring must be standardized.

3. The equipment has a self-test function, which is convenient for users to locate faults.

4. The interface settings are reasonable, the operation is convenient, and the function buttons are easy to find.