借鉴热电分离式设计理念, 利用图形转移和蚀刻技术将铜合金板材加工成带有导热柱的底座, 然后通过压合工艺将金属底座与FR4复合制备成热电分离式金属基板。利用冷热冲击试验箱对基板进行了热冲击试验, 并借助SEM对历经1000个高低温突变冷热循环后的铜基材与FR4界面形貌进行了观察与研究。利用结温测试仪、功率计、积分球系统、半导体制冷温控台等仪器和设备, 通过结温及热阻测试对比研究了普通铜基板与热电分离式铜基板在铜基、绝缘层及线路层厚度相同的情况下, 对大功率LED模组散热效果的影响。结果表明, 基板在经低温-55℃、高温125℃、1000次冷热循环后, 铜基材与FR4界面处既无裂纹萌生, 也无气泡产生, FR4与铜基材结合完好。对于驱动功率为13W的LED灯珠, 在模组辐射功率与热功率大致相同的情况下, 热电分离式铜基板与普通铜基板所对应的芯片结温分别为49.72和73.14℃, 所对应模组的热阻则分别为2.21和4.37℃/W, 这意味着热电分离式铜基板较之普通铜基板在大功率LED散热管理方面更具优势。

Based on electricity-and-thermal-go-separately concept, the copper substrate with electrically neutral thermal path was prepared using copper base with heat dissipation pillar made by pattern transfer and etching techniques, followed by lamination process which complete the integration of the copper base and FR4 material. The microscopic morphology of interface between FR4 and copper base experiencing sudden temperature change 1000 times was studied by temperature cycle test using scanning electron microscope (SEM). A comparison of heat dissipation effect between copper substrate with electrically neutral thermal path and regular MCPCB of copper base in LEDs’ application was done through junction temperature and thermal resistance test using junction temperature tester, Power meter, integrating sphere system and semiconductor refrigeration temperature control platform, etc. on the same thickness of copper base, insulation layer and circuit layer condition. As a result, it is shown that when the temperature goes from -55℃ up to 125℃, no crack and bubble happens at the interface between FR4 and copper base, which takes on a sound combination after 1000 cycles’ drastic temperature change. Meanwhile, as for the LED with 13W driving power, the junction temperatures are 49.72 and 73.14℃, with the thermal resistances being 2.21 and 4.37℃/W when the copper substrate with electrically neutral thermal path and the regular MCPCB with copper base are used respectively.