Anti-skew mounting pads and processing method for electronic surface
mount components
    1.
    发明授权
    Anti-skew mounting pads and processing method for electronic surface mount components 失效
    防倾斜安装垫和电子表面贴装元件的加工方法

    公开(公告)号:US5663529A

    公开(公告)日:1997-09-02

    申请号:US528369

    申请日:1995-09-14

    IPC分类号: H05K1/02 H05K1/11 H05K3/34

    摘要: A footprint, and method for forming the footprint, of the type for mounting a surface mount component having a heatsink which defines a first registration edge thereon. The substrate pad is positioned on the substrate for registrated engagement with the heatsink. The substrate pad has an area substantially larger than the area of the heatsink to improve the dissipation of thermal energy. The substrate pad includes notches for defining registration edges which are juxtaposed with corresponding registration edges on the heatsink when the electronic component is in proper alignment with the substrate pad. Surface tension forces produced by melting solder interposed between the heatsink and the substrate pad act upon the registration edges to maintain proper alignment of the component with the substrate pad.

    摘要翻译: 用于形成用于安装具有限定其上的第一对准边缘的散热器的表面安装部件的类型的覆盖区和方法。 衬底垫定位在衬底上以与散热器配准接合。 衬底焊盘的面积明显大于散热器的面积,以改善热能耗散。 衬底焊盘包括用于定义配准边缘的凹口,当电子部件与衬底焊盘正确对准时,它们与散热器上的对应配准边缘并置。 通过熔化置于散热器和基板焊盘之间的焊料产生的表面张力作用在对准边缘上,以保持部件与基板焊盘的适当对准。

    Anti-tombstoning solder joints
    2.
    发明授权
    Anti-tombstoning solder joints 失效
    防抱死焊点

    公开(公告)号:US06303872B1

    公开(公告)日:2001-10-16

    申请号:US08882482

    申请日:1997-06-25

    IPC分类号: H01R909

    摘要: An electronic circuit assembly having anti-tombstoning solder joints, including: a substrate 10 having at least one mounting pad 20 thereon; an SMD 30 having at least one termination 40; and at least one solder joint 50 connecting each termination 40 to its respective mounting pad 20. Each solder joint 50 is convex in shape, having a continuous and substantially circular arcuate outer profile 60 and covering substantially all of the mounting pad 20 and substantially all of a top portion 42 of each termination 40. Each mounting pad 20 has a predetermined length lp and each solder joint has a predetermined volume of solder selected such that a positive net anti-tombstoning moment is exerted upon the SMD 30 when at least one solder joint 50 is in a molten state.

    摘要翻译: 一种具有防抱死焊点的电子电路组件,包括:衬底10,其上具有至少一个安装垫20; 具有至少一个终端40的SMD 30; 以及至少一个将每个终端40连接到其相应的安装垫20的焊接接头50.每个焊接接头50的形状是凸的,具有连续且大致圆弧形的外轮廓60,并且基本上覆盖所有的安装垫20, 每个端子40的顶部42.每个安装垫20具有预定的长度lp,并且每个焊点具有预定体积的焊料选择,使得当至少一个焊点 50处于熔融状态。

    Optimized solder joints and lifter pads for improving the solder joint
life of surface mount chips
    4.
    发明授权
    Optimized solder joints and lifter pads for improving the solder joint life of surface mount chips 失效
    优化的焊点和升降垫,以提高表面贴装芯片的焊接寿命

    公开(公告)号:US5936846A

    公开(公告)日:1999-08-10

    申请号:US786389

    申请日:1997-01-16

    摘要: There is disclosed herein a surface mount printed circuit board having a substrate, at least one surface mount device, at least two mounting pads per device, solder joints connecting the terminations of the device to their respective mounting pads, at least one rectangular lifter pad on the substrate amid the mounting pads, and a solder mass on each lifter pad in contact with the bottom surface of the device. The inner and outer extensions of the mounting pads, the size, number, and shape of the lifter pads, and the amounts of solder deposited on the mounting and lifter pads are designed such that the solder joint has preferably convex outer fillets, the device is maintained at a predetermined height above the mounting pads, the inner fillet angle is maintained above a predetermined minimum angle to increase solder joint crack initiation time, and the overall solder joint crack propagation length is increased. An alternate embodiment also includes plugged vias under the lifter pads and/or mounting pads, with gas pockets trapped between the solder masses/solder joints and the plugged vias. This trapped gas pocket provides additional buoyant force upon the SMD during reflow.

    摘要翻译: 这里公开了一种表面贴装印刷电路板,其具有衬底,至少一个表面贴装器件,每个器件至少两个安装焊盘,将器件的端子连接到其相应的安装焊盘的焊点,至少一个矩形升降器垫 在安装焊盘之间的衬底,以及每个升降器衬垫上与接触器件的底表面的焊料质量。 安装垫的内部和外部延伸部分,升降器垫的尺寸,数量和形状以及沉积在安装和升降器垫上的焊料的量被设计成使得焊接接头具有优选的凸形外圆角,该装置是 保持在安装焊盘上方的预定高度处,内圆角保持在预定的最小角度以上以增加焊点裂纹的起始时间,并且总的焊点裂纹扩展长度增加。 替代实施例还包括在升降器垫和/或安装垫之下的插入通孔,其中气囊被捕获在焊料块/焊接接头和堵塞的通孔之间。 这种被捕获的气体袋在回流焊时在SMD上提供额外的浮力。

    Optimally shaped solder joints for improved reliability and space savings
    6.
    发明授权
    Optimally shaped solder joints for improved reliability and space savings 失效
    最佳形状的焊点,可提高可靠性和节省空间

    公开(公告)号:US5639013A

    公开(公告)日:1997-06-17

    申请号:US363768

    申请日:1994-12-23

    IPC分类号: H05K3/34

    摘要: A method for improving the reliability of solder joints is disclosed for use in reflow soldering. In the method, a predetermined amount of solder is applied to at least two solder pads on a circuit board and a component having at least two terminals is fixed in relation to the solder pads. The solder is melted so that the component floats to a predetermined height above the solder pads and, when solidified, the solder fillet formed at each terminal holds the component a predetermined height above the circuit board and forms a convex shape.

    摘要翻译: 公开了一种用于提高焊点可靠性的方法,用于回流焊接。 在该方法中,将预定量的焊料施加到电路板上的至少两个焊盘,并且具有至少两个端子的部件相对于焊盘固定。 焊料熔化,使得部件浮动到焊盘上方的预定高度,并且当固化时,形成在每个端子处的焊接圆角将部件保持在电路板上方的预定高度并形成凸形。