本规范规定了如图1所示的超声波焊接接线端子的试验方法和性能标准。本规范使零件暴露在环境中，以模拟道路车辆的现场暴露寿命。本规范中引用的暴露包括热冲击、温湿度循环和机械应力。本规范旨在评估电线和电气端子焊盘之间接口的强度和性能。 所使用的图形是特定于线性焊接类型的工艺设备。端子的验证是一项单独的任务（参考SAE/UCAR-2等部件验证测试）。适用于使用本规范的车辆和产品条件为:适用用途:当电线和端子是环境温度为-40至+150°C的道路车辆中使用的电气连接系统的一部分时，本规范适用。施加的电压可以是低（0到60VDC）或高（到1000VAC或VDC）。 USCAR-38适用于所有长度的电线，包括对短于500 mm的电线进行的特殊测试，其中焊接是在另一个部件组装后进行的，以评估电线另一端端子的潜在工艺损坏。线束制造商通常有责任根据适用工程工作说明书中的声明跟踪短电线应用。适用设计:所述程序适用于总线、端子或设备连接，包括孔眼和电池终端，包括单线或多线终端。 有或没有压接绝缘翼的设计都适用。适用的多线配置:对于多线焊接，12根或更少的线是优选的，因为超过12根线会增加焊接的成本和复杂性。建议对超过12根焊丝的焊缝进行设计审查，以确定将接头拆分成更小的部分是否是更好的选择。≥20根焊丝的焊缝不适用（因为这种复杂性的焊缝需要超出USCAR-38范围的设备能力评估）。 建议最小电线尺寸与总焊缝横截面积的比例至少为1:10（即，最小电缆必须至少占焊缝总横截面积10%）。适用电线:本规范是使用清洁、裸露、未涂覆的多股汽车电线制定的。已知带有锡涂层、涂有润滑剂或污染的电线会影响超声波焊接电缆终端的机械和电气性能，不适用于根据本规范进行评估。 USCAR-38不适用于线对线拼接焊接（USCAR-45适用）。适用的电线尺寸和类型:根据ISO 6722-1或ISO 19642-3，铜线尺寸在0.22至150 mm2之间，根据ISO 6722-2或ISO 19642.4，铝尺寸在0.5至150 mm2范围内适用。其他电线类型可以进行测试，但不能声称符合要求。“其他”电线类型的示例包括压缩芯、压实芯、实心电线芯和除铜、铜合金、铝或铝合金以外的中心股材料。 不同中心股材料的例子是镀铜或钢制中心芯线。所描述的验证过程仅适用于线性超声波焊接，通常将压力、能量和振幅设置为输入，并通过基于过程监控传感器的“反馈”限制能量来控制焊接时间。使用过程反馈可以确保每次焊接的能量得到保持。如果用于制作USCAR-38测试样品的设备与本说明书不同，则本说明书可能需要修改或不适用。

This specification defines test methods and performance criteria for ultrasonically welded wire-to-terminal bonds as shown in Figure 1. This specification subjects parts to environmental exposures to simulate a lifetime of field exposure for a road vehicle. Exposures referenced in this specification include thermal shock, temperature humidity cycling, and mechanical stress. This specification is intended to evaluate the strength and performance of the interface between wires and the electrical terminal pad. The graphics used are specific to the linear weld type of process equipment. Validation of the terminal is a separate task (refer to a component validation test such as SAE/USCAR-2).Vehicle and product conditions applicable to use of this specification are:Applicable use: This specification is applicable where the wire and terminal are part of an electrical connection system used in road vehicles at ambient temperatures from -40 to +150 °C. Applied voltage may be either low (0 to 60 VDC) or high (to 1000 VAC or VDC). USCAR-38 applies to all wire lengths and includes a special test for wires shorter than 500 mm where a weld is done after another component has been assembled to assess potential process damage to the terminal at the other end of the wire. Wire harness makers typically will be given the responsibility to track short wire applications per a statement in the applicable engineering statement of work.Applicable designs: The procedures described are applicable to buss, terminal, or device connections, including eyelet and battery terminations comprising either single or multiple wire terminations. Designs with and without crimped insulation wings are applicable.Applicable multiple wire configurations: For multi-wire welds, 12 or fewer wires is preferred since having over 12 wires increases the cost and complexity of the weld. A design review is recommended for welds having over 12 wires to see if splitting the splice into smaller pieces is a better choice. Welds of ≥20 wires are not applicable (because welds of that complexity require equipment capability assessments beyond the scope of USCAR-38). The ratio of the smallest wire size to the total weld cross-sectional area is recommended to be at least 1:10 (i.e., the smallest cable must be at least 10% of the total cross-sectional area of the weld).Applicable wire: This specification was developed using clean, bare, uncoated, stranded automotive wire. Wire with tin coatings, applied lubricants, or contamination is known to affect the mechanical and electrical performance of ultra-sonically welded cable terminations, and are not applicable to be evaluated per this specification. USCAR-38 is not applicable for wire-to-wire splice welding (USCAR-45 is applicable).Applicable wire sizes and types: Copper wire sizes between 0.22 to 150 mm2 per ISO 6722-1 or ISO 19642-3 and aluminum sizes between 0.5 to 150 mm2 per ISO 6722-2 or ISO 19642-4 are applicable. Other wire types may be tested but cannot claim compliance. Examples of “other” wire types are compressed core, compacted core, solid wire core, and center strand materials other than copper, copper alloy, aluminum, or aluminum alloy. Examples of different center strand materials are copper-clad or steel-center-core wires.The validation process described applies only to linear ultrasonic welding, typically with pressure, energy, and amplitude set as inputs and weld time controlled by limiting energy based on “feedback” from process monitoring sensors. Using process feedback assures the energy-per-weld is maintained. If the equipment used to make samples for USCAR-38 testing is different from this description, this specification may need to be modified or may not be applicable.