Installation design data for the 500SFK series fuse
1. Recommended mounting hole pitch

More than 2
Reference value

LandHole

2. Temperature rise
Fuse temperature changes according to the width of the pattern and the conduction current. The
temperature rise characteristics, as shown below, follow a pattern that becomes 1A/mm (copperfoil thickness:35μm) at the time of conducting a current that is 50% of the fuse’s rated current.
Please refer to the data when designing a pattern.
 Conditions
Board size: 150mm X 100mm
Board material: FR-4
Copper foil thickness: 35μmUnit: mm

Data No. 06-10-26 (1/5)

 Temperature rise characteristics
500SFK06

Terminal

Temperature rise value (℃)

Center of the cylinder

Center of the cylinder

Terminal

Conduction current (A) rms

Conduction current (A) rms

500SFK10500SFK16

Center of the cylinder

Terminal

Conduction current (A) rms

Temperature rise value (℃)

Temperature rise value (℃)

Temperature rise value (℃)

500SFK04

Center of the cylinder
Terminal

Conduction current (A) rms

Temperature rise value (℃)

500SFK20

Center of the cylinder

Terminal

Conduction current (A) rmsData No. 06-10-26 (2/5)

3. Temperature rise value of the board
Due to the heating of the fuse and/or from the pattern, the board temperature around the fuseincreases.

Please consider this when designing the placement of devices.

The curves below

show the relationship of the surrounding temperature distribution on the board at each amperage.
Please refer to the data when designing.

Temperature rise ratio (％)

Terminal-Copper foil
Relationship between distance and temperature riseStandard value
Temperature rise valueof the terminalDistance (mm)Temperature rise ratio (％)

Terminal-Copper foil
Relationship between distance and temperature riseStandard value
Temperature rise value
on a copper foil line※Distance (mm)※ “ON COPPER FOIL LINE” means a centerline that connects the copper foilat the both ends. This includes the fuse on the same line.
※ If the conduction current value is lower than the fuse rated value (lowerthan 25%), temperature rise ratio may decrease by about 20%.

Data No. 06-10-26 (3/5)

 Calculation of the temperature rise value at a random point
Unit: mmFuse

21.5

Copper foilCopper foil line
Terminal location※ Terminal location is about 8.5mm apart from the center of the fuse.
From the 500SFK20 Temperature Rise Characteristics graph, when 15A current is conducted tothe fuse, the temperature rise value of the fuse and fuse terminal are read as follows;・Temperature rise value at the center of the cylinder: About 73℃
・Temperature rise value at the terminal: About 69℃a) Plot point A:
From the graph, Terminal-Copper foil Relationship between distance and temperature rise, thetemperature rise ratio at the distance of 21.5mm is about 50%.
69℃ (the terminal temperature rise) X 50% (temperature rise ratio) = 35℃
The temperature rise value at plot point A is around 35℃.
b) Plot point B:
From the graph, Terminal-Copper foil Relationship between distance and temperature rise, thetemperature rise ratio at the distance of 51.5mm is about 33%.
69℃ (the terminal temperature rise) X 33% (temperature rise ratio) = 23℃
The temperature rise value at plot point B is around 23℃.
c) Plot point ①:
From the graph, Copper foil line-board Relationship between distance and temperature rise, thetemperature rise ratio at the distance of 20mm is about 35%.
73℃ (the temperature rise at the center of the cylinder) X 35% (temperature rise ratio) = 26℃
The temperature rise value at plot point ① is around 26℃.

Data No. 06-10-26 (4/5)

d) Plot point ②:
From the graph, Copper foil line-board Relationship between distance and temperature rise, thetemperature rise ratio at the distance of 20mm is about 35%.
35℃ (the temperature rise value at plot point A) X 35% (temperature rise ratio) = 13℃
The temperature rise value at plot point ② is around 13℃.
e) Plot point ③:
From the graph, Copper foil line-board Relationship between distance and temperature rise, thetemperature rise ratio at the distance of 40mm is about 22%.
23℃ (the temperature rise value at plot point B) X 22% (temperature rise ratio) = 5℃
The temperature rise value at plot point ③ is around 5℃.
※ To calculate the temperature rise value at a random point, it is necessary at first tomeasure the temperature rise value on the copper foil line that is vertical to therandom point.

Data No. 06-10-26 (5/5)