Nov28
Understanding Melt Flow Index (MFI) for Quality Control in Plastic Injection Molding

post on November 28, 2024

MFI/MI/MFR tester

The “Melt Flow Index” (MFI) of plastic refers to the weight (in grams) of molten plastic that flows through a standardized tube with a specific diameter under a defined load (in kilograms) and temperature (in °C) within a set period of time (typically 10 minutes). A higher MI value indicates better plastic flowability, while a lower MI value suggests poorer flowability. This concept is similar to comparing clear broth and thick soup in the same type of container: when you open the valve, the amount of liquid flowing out within the same period will differ, as clear broth flows more easily than thick soup. Essentially, the thicker the liquid, the less it will flow out.

MFI: Melt Flow Index
MI: Melt Index
MFR: Melt Flow Rate

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Plastic     WorkingBear    Views (2,000)     comment (0)

Nov21
What Are PCB Cross-out Boards (X-out Boards)?

post on November 21, 2024

What Are PCB Cross-out Boards (X-out Boards)? | Definition and Explanation of Defective PCBs

In the PCB industry, there is a specific term called “Cross-out boards” or “X-out boards” to indicate that a panel of PCBs contains defective boards. The term “Cross” refers to marking these defective boards with an “X” symbol.

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PCB/FPC/PTF     WorkingBear    Views (1,179)     comment (0)
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Nov07
The Benefits of Using “Mirrored Panelization” for PCBs

post on November 7, 2024

The Benefits of Using

In the electronics assembly manufacturing industry, what we commonly refer to as a “Mirrored Panel Board” or “Flipped Panel Board” actually comes in two types. The first type is a different-side mirrored panel board, where one board’s top side and another board’s bottom side appear on the same panel. The second type is a same-side mirrored panel board, where all boards are oriented on the same side but are mirrored left to right, such as in a “pdpd” layout pattern.

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PCB/FPC/PTF, Process, SMT     WorkingBear    Views (683)     comment (0)

Oct31
The Limitations of Using “Mirrored Panels” or “Flipped Panels” in SMT

post on October 31, 2024

The Limitations of Using "Mirrored Panels" or "Flipped Panels" in SMT

We all know that when producing PCBs and PCBAs, multiple individual PCBs are usually combined into one larger panel, a process called panelization, to improve production efficiency. Typically, these individual boards are arranged in a neat and consistent manner with the same orientation. However, when the PCB has an irregular shape or special requirements, a mirrored panel or flipped panel design might be used. While this design can improve efficiency in the SMT production line and reduce material costs, it may also come with certain design and production challenges. In this article, we will explore these issues and consider potential solutions.

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PCB/FPC/PTF, Process, SMT     WorkingBear    Views (1,341)     comment (0)

Oct24
Causes and Prevention of PCB Warping and Bending After Reflow

post on October 24, 2024

Causes and Prevention of PCB Warping and Bending After Reflow

A reader recently asked: “In surface mount assembly, PCBs often warp or bend after going through the reflow process, which can cause issues like open solder joints or tombstoning. How can we overcome this?”

To be honest, the reasons behind PCB warping or bending may vary, but they can generally be traced back to the stress applied to the PCB exceeding what the material can handle. When stress is uneven across the PCB or when different areas of the PCB resist stress unevenly, warping or bending occurs.

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PCB/FPC/PTF, Quality, SMT     WorkingBear    Views (2,231)     comment (0)