Key Points in the Production of SMT Temperature Measurement Boards

Reflow soldering temperature measurement boards are indispensable tools in the electronICs manufacturing industry. By setting multiple temperature measurement points on the board and installing temperature sensors, they enable real-time monitoring of the temperature at various points within the reflow oven, providing data support for process adjustment and optimization.

1. Materials and Tools Required for Temperature Measurement Board Production

   1. Thermal-tracker: Temperature measuring instrument

   2. Thermal-couple: (K type, Φ0.4 mm)

   3. Drill: Φ 0.5 mm

   4. Nipper: Metal

   5. Scissors: Metal

   6. SCRewdriver: Metal

   7. UV glue

2. Definition of Temperature Measurement Points on the Temperature Measurement Board

   1. Responsibility for Selecting Temperature Measurement Points: During product trial production, process engineers select the measurement points (at least 8 points for Server models) for reference by technicians in making the temperature measurement board.

   2. Principles for Selecting Temperature Measurement Points

      1. Divide the Pcb Board roughly into 9 equal areas, and select points based on the principle of even distribution of temperature measurement points. The priority order for selecting different types of components is as follows: BGA, large-size ICs, ICs, chip components.

      2. Based on the distribution of components on the product and the temperature resistance specifications of the components, prioritize selecting CPU Socket, BGA, CSP, Connector, QFP & QFN, PCB, Chip (special components should be prioritized, and plastic components need to measure the component body).

      3. If there are multiple types and sizes of BGAs in each area, select all; if there are no BGAs, select QFP type components; if there are no QFP type IC components, select Chip components. When selecting Chip components, prioritize 0603 type components on the diagonal of the PCB.

   3. The number of temperature measurement points for each type of component is selected according to the following rules

      1. CPU SKT requires 3 measurement points distributed at the center, corner, and side.

      2. BGA Body size >38*38mm requires 2 measurement points (Center & Corner)

      3. BGA Body size <38*38mm requires 1 measurement point (Center)

      4. Requirements for measurement points on QFP & SOP type components

3. Requirements for Soldering Points and Contact Points of Temperature Measurement Points (Follow customer requirements if there are special requirements):

   1. The soldering points for temperature measurement must be soldered with high-temperature solder to the component pins or solder balls and the temperature measurement wires must be fixed with red glue (no adhesive tape should be used to fix the temperature measurement wires). The temperature measurement points on the component body must be fixed with solid thermal conductive glue to the component body.

   2. Temperature measurement metal wires must be separated and not crossed (as shown in the figure)

   3. BGA measurement point requirements:                         

   4. Use HIROX microscope and X-ray to check if the temperature measurement point contacts are good.

   5. Example of temperature measurement point distribution on a Profile board

   6. Method for making a Profile board: The temperature measurement board must first be drilled, have temperature measurement wires attached, then apply solder paste, and pass through the oven to fix the measurement points. Refer to the Profile board production SOP for details.