The types of solder pads for Viking resistors are diverse, mainly designed based on the packaging form, application scenarios, and process requirements of the resistors. The following are common types of solder pads and their characteristics for Guangjie resistors:
1、 MELF (Metal Electrode Bare Foot Surface) Resistance Solder Pad
Packaging features:
The MELF resistor is designed as a cylindrical pinless device, with pad pattern dimensions identical to standard SMD chip resistors.
Typical series: CSRV series (metal thin film precision MELF resistor), CSRF series (metal thin film high-frequency MELF resistor).
Pad design:
The solder pads are circular or rectangular, symmetrically distributed to ensure welding stability.
The pad spacing and size are compatible with SMD resistors, making it easy for automated mounting.
Application scenarios:
Suitable for circuits with high reliability requirements, such as automotive electronics (BMS, motor control), industrial control (precision current detection), and communication equipment (high-frequency modules).
2、 SMD resistor pads
Common packaging:
0402, 0603, 0805, 1206, 2512, etc., with dimensions corresponding to length x width (e.g. 0402 is 1.0mm x 0.5mm).
Pad design:
Symmetry: The two end solder pads must be strictly symmetrical to ensure balanced surface tension of the molten solder during soldering.
Pad spacing: Adjust according to the component size to avoid "monument" defects (such as the recommended pad spacing of 0.52mm for 0402 components).
Pad width: Match with the width of the component end (e.g. 0402 component pad width 0.7-0.71mm).
Application scenarios:
Consumer electronics (smartphones, tablets), communication devices (5G modules), medical equipment (precision instruments).
3、 Through Hole resistor pad
Common types:
Axial lead resistance (such as RT series carbon film resistance), radial lead resistance (such as high-power wire wound resistance).
Pad design:
Aperture: Designed according to the lead diameter (e.g. aperture=lead diameter+0.1~0.3mm).
Solder pad shape: circular or elliptical, with hole ring width meeting welding strength requirements.
Spacing: Follow standard hole spacing (such as 7.5mm, 10mm) and adapt to wave soldering technology.
Application scenarios:
High power circuits (power supplies), scenarios that require mechanical fixation (industrial equipment), and situations that require high maintenance convenience.
4、 TO package planar power resistor pads
Common packaging:
TO-220, TO-247, etc., used with heat sinks.
Pad design:
Large area solder pads: Match with package pins to ensure electrical connection and heat dissipation performance.
Heat dissipation holes: Design through holes near the solder pads to enhance heat dissipation (such as when TO-220 package is paired with 25W power, heat dissipation design is required).
Insulation spacing: In high-voltage applications, the spacing between solder pads must meet safety regulations (such as 2500V withstand voltage requirements).
Application scenarios:
Switching power supply, motor drive, RF power amplifier, industrial automation controller.
5、 Special application pads
High voltage resistor pad:
Design points: widen the pad spacing and increase the insulation layer (such as HMR series high-voltage thick film resistors).
Application: Power monitoring equipment, ESD electrostatic protection module.
High precision resistance pad:
Design key points: strict symmetry, low TCR materials (such as PR series thin film resistors, TCR ± 15ppm/℃).
Application: Medical equipment, testing instruments, analog signal processing circuits.
Alloy resistance pad:
Design points: Low inductance design (such as LR series alloy resistors, with almost zero inductance).
Application: High current detection (battery management system, charging station), overcurrent protection.
6、 General principles for pad design
Symmetry: Ensure surface tension balance of molten solder during welding to avoid "monument" defects.
Spacing control: Excessive spacing between solder pads can lead to virtual soldering, while insufficient spacing may cause short circuits.
Pad size: Match the width of the component end or pin to ensure that the solder joint forms a curved surface.
Thermal isolation: High power resistor pads should be kept at an appropriate distance from the surrounding copper foil to prevent thermal stress damage.
The types of solder pads for Guangjie resistors cover a diverse range of requirements, from micro mount to high-power plugs. When designing, it is necessary to comprehensively consider the type of resistor, packaging size, application scenarios, and process requirements. By optimizing the symmetry, spacing, size, and heat dissipation performance of solder pads, the welding quality and circuit reliability can be ensured, meeting the needs of high-end fields such as automotive electronics, industrial control, and communication equipment.