A solder bump forming member including: a base substrate having a plurality of recesses; and solder particles in the recesses, in which the solder particle has an average particle diameter of 1 to 35 μm and a C.V. value of 20% or less, and a part of the solder particle projects from the recess, or in cross-sectional view, when a depth of the recess is designated as H.sub.1, and a height of the solder particle is designated as H.sub.2, H.sub.1<H.sub.2 is established.

A lead-free solder ball is provided which suppresses interfacial peeling in a bonding interface of a solder ball, fusion defects which develop between the solder ball and solder paste, and which can be used both with Ni electrodes plated with Au or the like and Cu electrodes having a water-soluble preflux applied atop Cu. The lead-free solder ball for electrodes of BGAs or CSPs consists of 1.6-2.9 mass % of Ag, 0.7-0.8 mass % of Cu, 0.05-0.08 mass % of Ni, and a remainder of Sn. It has excellent resistance to thermal fatigue and to drop impacts regardless of the type of electrodes of a printed circuit board to which it is bonded, which are Cu electrodes or Ni electrodes having Au plating or Au/Pd plating as surface treatment.

A method for step-soldering includes applying a first solder alloy having a melting point in a temperature range from 160 to 210° C. to a jointed portion of a first electronic component and a substrate, and heating them in the temperature range from 160 to 210° C., and applying a second solder alloy having the melting point in a temperature range lower than 160° C. to a joint portion of a second electronic component and the substrate, and heating them in the temperature range lower than 160° C. The first solder alloy consists of 13-22 mass % of In, 0.5-2.8 mass % of Ag, 0.5-5.0 mass % of Bi, 0.002-0.05 mass % of Ni and a balance Sn.

According to an aspect of the disclosure, an example microelectronic device assembly includes a substrate, a microelectronic element electrically connected to the substrate, a stiffener element overlying the substrate, and a heat distribution device overlying the rear surface of the microelectronic element. The stiffener element may extend around the microelectronic element. The stiffener element may include a first material that has a first coefficient of thermal expansion (“CTE”). A surface of the stiffener element may face toward the heat distribution device. The heat distribution device may include a second material that has a second CTE. The first material may be different than the second material. The first CTE of the first material of the stiffener element may be greater than the second CTE of the second material of the heat distribution device.

Apparatus and methods are disclosed for transferring solder to a substrate. A substrate belt moves one or more substrates in a belt direction. A decal has one or more through holes in a hole pattern that hold solder. Each of the solder holes can align with respective locations on one of the substrates. An ultrasonic head produces an ultrasonic vibration in the solder in a longitudinal direction perpendicular to the belt direction. The ultrasonic head and substrate can be moved together in the longitudinal direction to maintain the ultrasonic head in contact with the solder while the ultrasonic head applies the ultrasonic vibration. Various methods are disclosed including methods of transferring the solder with or without external heating.

A BGA structure having larger solder balls in high stress regions of the array is disclosed. The larger solder balls have higher solder joint reliability (SJR) and as such may be designated critical to function (CTF), whereby the larger solder balls in high stress regions carry input/output signals between a circuit board and a package mounted thereon. The larger solder balls are accommodated by recessing each ball in the package substrate, the circuit board, or both the package substrate and the circuit board. Additionally, a ball attach method for mounting a plurality of solder balls having different average diameters is disclosed.

Disclosed are a printed circuit board connector according to an embodiment and a module device including same. The printed circuit board connector comprises: a substrate; holes formed in the substrate at predetermined intervals and coated with a metal material on the inner circumferential surface thereof so as to form a metal layer; a first metal pad formed at one end of the holes and connected to the metal layer; and a second metal pad formed at the other end of the holes and connected to the metal layer.

The present disclosure relates to an electronic device comprising a wafer comprising a first upper surface having at least one first contact arranged thereon; and at least one die comprising a second upper surface having at least one second contact arranged thereon, and at least one first lateral surface orthogonal to the second upper surface, said first contact being coupled to said second contact by a connector comprising one first conductive pillar formed on said first contact of said wafer; one second conductive pillar formed on said second contact of said die; and at least one conductive ball positioned in contact with at least a first upper portion of said first pillar(s) and in contact with at least one second upper portion of said second pillar(s).

A method for soldering an electronic component to a circuit board involves jetting liquefied solder. A laser beam melts a solid solder ball to produce a liquefied solder ball before the ball is jetted. The liquefied solder ball is jetted towards a through hole in the circuit board such that a portion of the liquefied solder ball flows into an annular gap between a pin and sides of the through hole. The pin is attached to the electronic component and passes through the through hole. As the liquefied solder ball is jetted towards the through hole, the laser beam is directed at the ball so as to keep it liquefied. How much of the solder ball remains outside the through hole after liquefied solder has flowed into the annular gap is determined. The filling degree of the annular gap is determined based on how much solder remains outside the hole.

Methods and apparatus relating to processor and chipset continuity testing of package interconnect for functional safety applications are described. In an embodiment, voltage divider logic circuitry divides a reference voltage. Controller logic circuitry compares a divided voltage value from a node of the voltage divider logic circuitry and a threshold voltage value. A first end of the voltage divider logic circuitry is coupled to receive the reference voltage and a second end of the voltage divider logic circuitry is coupled to a Non-Critical-To-Function (NCTF) solder ball. The controller logic circuitry generates an error signal in response to a mismatch between the divided voltage value and the threshold voltage value. Other embodiments are also disclosed and claimed.