How to solve the problem of poor tin creep in QFN? -SMT solder paste

QFNPackaged chipICSoldering the side pins is a big problem. We often encounter some customer feedback:qfnHow to solve the problem of poor tin climbing?qfnHow is the standard soldering height for chip pins determined?qfnIs there no tin crawling on the side? Now, let Shenzhen JJY Solder Paste Manufacturer explain it to you:

1.QFNThe flow direction of the molten solder after the solder paste melts

During the reflow soldering process of solder paste, the flow direction of the molten solder solution is mainly affected by the interaction of gravity and the attraction between molecules after wetting the base material. To achieve the requirement of high solder climbing height and reaching the top, the solder paste needs to have sufficient wetting performance. Only when the attraction between the molten solder solution and the base material is greater than gravity can the solder paste climb to the top.

Ii.QFNWhy don't the packaged chips be tinned

Generally, for solder paste to climb, it is required to have an anti-gravity climbing force. The solder paste should be sufficient to moisten the base material. The ordinary type of solder paste has insufficient solder climbing ability, mainly due to its insufficient ability to moisten the base material and insufficient affinity for the base material. As a result, after the solder paste melts, it does not climb under the action of gravityQFNThe reverse solder climbing ability is insufficient during the surface mount soldering process.

Iii. How to ChooseQFNSolder paste

"Choose"QFNSolder pasteWhen choosing, it is necessary to select solder paste with good activity and wetting performance. The solder paste needs to be heated at high temperature through surface mount reflow soldering and the base material should be sufficiently wetted to achieve a good solder climbing effect.

Iv.QFNThe operation of climbing tin to the top

Produced by JJYQFNSpecial lead-containing solder pasteTLP-JJY9RX-62836804T4andQFNSpecial lead-free high-temperature solder pasteLFP-JJY5RQ-305T4orLFP-JJY5RQ-0307T4,All can be satisfied.QFNThe climbing tin85%~99%The high requirements. It has strong wetting performance and has no effect on the impedance performance of the circuit board.

Shenzhen JJY Industrial Technology Co., Ltd. is a professional manufacturer of various types of solder paste. We offer:QFNHigh solder climbing rate solder paste, zero halogen solder pasteVOIDLow-porosity solder paste, laser solder paste, water-washed solder paste, and high-reliability ones used in military, aerospace, power, photovoltaic and other industriesSn62Pb36Ag2Solder pasteSn62.8Pb36.8Ag0.4Solder paste6337Solder paste, transparent and colorlessLEDHigh-brightness anti-monument solder pastemini-LED/micro-LEDDie bonding solder paste, high-reliability lead-free low-temperature solder paste, low-temperature solder paste for heat sinks, lead-free low-temperature solder paste for heat sinks washed with water, professional solder paste for hardware soldering, lead-free medium-temperature solder paste, lead-free high-temperature solder paste0307/105/305Manufacturers of solder paste and other soldering materials. Our products are of excellent quality, reasonable price and considerate service. We welcome inquiries and orders from all customers.