Abstract: Some implementations of the disclosure are directed to a method, comprising: receiving a sheet of graphite comprising a first surface and a second surface opposite the first surface; and perforating the sheet in a first plurality of locations from the first surface through the second surface to form a first plurality of perforations through the sheet and a first plurality of protrusions of the graphite oriented outward from the second surface, the first plurality of protrusions configured to conduct heat away from a plane of the sheet. Further implementations comprise perforating the sheet in a second plurality of locations from the second surface through the first surface to form a second plurality of perforations through the sheet and a second plurality of protrusions of graphite material oriented outward from the first surface, wherein the second plurality of protrusions are configured to conduct heat away from the plane of the sheet.

Abstract: High reliability leadfree solder alloys for harsh service conditions are disclosed. In some embodiments, a solder alloy comprises 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn. In some embodiments, an apparatus comprises: a component comprising: a main ceramic body, and a side surface having disposed thereon an electrode and a thermal pad; a copper substrate; and a solder alloy electrically coupling the component and the copper substrate, wherein the solder alloy comprises: 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn. In some embodiments, an apparatus comprises: a light-emitting diode (LED) component; a Metal Core Printed Circuit Board (MCPCB); and a solder alloy electrically coupling the LED component and the MCPCB, wherein the solder alloy comprises: 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn.

Abstract: Some implementations of the disclosure relate to a lead-free solder paste with mixed solder powders that is particularly suitable for high temperature soldering applications involving multiple board-level reflow operations. In one implementation, the solder paste consists of 10 wt % to 90 wt % of a first solder alloy powder, the first solder alloy powder consisting of an SnSbCuAg solder alloy that has a wt % ratio of Sn:Sb of 0.75 to 1.1; 10 wt % to 90 wt % of a second solder alloy powder, the second solder alloy powder consisting of an Sn solder alloy including at least 80 wt % of Sn; and a remainder of flux.

Abstract: Solder pastes comprise a high temperature solder powder, a low temperature solder powder and flux. The melting temperature of the low temperature solder powder is lower than that of the high temperature solder powder. The high temperature solder powder and the low temperature solder powder are both capable of wetting upon heating.

Abstract: Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.

Abstract: Some implementations of the disclosure are directed to a thermal interface material. In some implementations, a method comprises: applying a solder paste between a surface of a heat generating device and a surface of a heat transferring device to form an assembly; and reflow soldering the assembly to form a solder composite, wherein the solder composite provides a thermal interface between the heat generating device and the heat transferring device, wherein the solder paste comprises: a solder powder; particles having a higher melting temperature than a soldering temperature of the solder paste, wherein the solder paste has a volume ratio of solder powder to high melting temperature particles between 5:1 and 1:1.5; and flux.

Abstract: Some implementations of the disclosure are directed to a method, comprising: receiving a sheet of graphite comprising a first surface and a second surface opposite the first surface; and perforating the sheet in a first plurality of locations from the first surface through the second surface to form a first plurality of perforations through the sheet and a first plurality of protrusions of the graphite oriented outward from the second surface, the first plurality of protrusions configured to conduct heat away from a plane of the sheet. Further implementations comprise perforating the sheet in a second plurality of locations from the second surface through the first surface to form a second plurality of perforations through the sheet and a second plurality of protrusions of graphite material oriented outward from the first surface, wherein the second plurality of protrusions are configured to conduct heat away from the plane of the sheet.

Abstract: Some implementations of the disclosure are directed to low melting temperature (e.g., liquidus temperature below 210° C.) SnIn solder alloys. A SnIn solder alloy may consist of: 8 to 20 wt % In; greater than 0 wt % to 4 wt % Ag; optionally, one or more of greater than 0 wt % to 5 wt % Sb, greater than 0 wt % to 3 wt % Cu, greater than 0 wt % to 2.5 wt % Zn, greater than 0 wt % to 1.5 wt % Ni, greater than 0 wt % to 1.5 wt % Co, greater than 0 wt % to 1.5 wt % Ge, greater than 0 wt % to 1.5 wt % P, and greater than 0 wt % to 1.5 wt % Mn; and a remainder of Sn.

Abstract: A SnAgCuSbBi-based Pb-free solder alloy is disclosed. The disclosed solder alloy is particularly suitable for, but not limited to, producing solder joints, in the form of solder preforms, solder balls, solder powder, or solder paste (a mixture of solder powder and flux), for harsh environment electronics.

Abstract: A SnAgCuSb-based Pb-free solder alloy is disclosed. The disclosed solder alloy is particularly suitable for, but not limited to, producing solder joints, in the form of solder preforms, solder balls, solder powder, or solder paste (a mixture of solder powder and flux), for harsh environment electronics.

Abstract: Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.

Abstract: Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.

Abstract: A SnAgCuSb-based Pb-free solder alloy is disclosed. The disclosed solder alloy is particularly suitable for, but not limited to, producing solder joints, in the form of solder preforms, solder balls, solder powder, or solder paste (a mixture of solder powder and flux), for harsh environment electronics. An additive selected from 0.1-2.5 wt. % of Bi and/or 0.1-4.5 wt. % of In may be included in the solder alloy.

Abstract: Some implementations of the disclosure relate to a lead-free solder paste with mixed solder powders that is particularly suitable for high temperature soldering applications involving multiple board-level reflow operations. In one implementation, the solder paste consists of 10 wt % to 90 wt % of a first solder alloy powder, the first solder alloy powder consisting of an SnSbCuAg solder alloy that has a wt % ratio of Sn:Sb of 0.75 to 1.1; 10 wt % to 90 wt % of a second solder alloy powder, the second solder alloy powder consisting of an Sn solder alloy including at least 80 wt % of Sn; and a remainder of flux.

Abstract: A lead-free solder preform includes a core layer and adhesion layer coated over surfaces of the core layer, where the preform delivers the combined merits from constituent solder alloys of the core and adhesion layers to provide both high temperature performance and improved wetting in high-temperature solder applications such as die attach. The core layer may be formed of a Bi Alloy having a solidus temperature above 260° C., and the adhesion layer may be formed of Sn, a Sn alloy, a Bi alloy, In, or an In alloy having a solidus temperature below 245° C. The solder preform may be formed using techniques such as: (1) electroplating a core ribbon with an adhesion material, (2) cladding an adhesion material foil onto a core ribbon, and/or (3) dipping a core ribbon in a molten adhesion alloy bath to allow thin layers of adhesion material to adhere to a core ribbon.

Abstract: Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.

Abstract: Implementations of the disclosure describe techniques for eliminating or reducing hot tearing in via-in-pad plated over (VIPPO) solder joints by incorporating an adhesive into a printed circuit board assembly (PCBA). In an embodiment, the adhesive is an adhesive containing fluxing agent that prevents tearing by reducing a differential in thermal expansion caused by a coefficient of thermal expansion (CTE) mismatch between a plated metal of the VIPPO pads and the PCB substrate.

Abstract: High reliability leadfree solder alloys for harsh service conditions are disclosed. In some embodiments, a solder alloy comprises 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn. In some embodiments, an apparatus comprises: a component comprising: a main ceramic body, and a side surface having disposed thereon an electrode and a thermal pad; a copper substrate; and a solder alloy electrically coupling the component and the copper substrate, wherein the solder alloy comprises: 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn. In some embodiments, an apparatus comprises: a light-emitting diode (LED) component; a Metal Core Printed Circuit Board (MCPCB); and a solder alloy electrically coupling the LED component and the MCPCB, wherein the solder alloy comprises: 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn.

Abstract: The disclosure describes techniques for eliminating or reducing non-wet open (NWO) defect formation by using a low activity flux to prevent a solder paste from sticking to ball grid array (BGA) solder balls during reflow soldering. The low activity flux may be configured such that: i) it creates a barrier that prevents the solder paste from sticking to the solder balls of the BGA; and ii) it does not impede the formation of solder joints during reflow. In implementations, a solid coating of the low activity flux may be formed over balls of the BGA, and the BGA may then be bonded to a PCB during reflow. In implementations, the balls of a BGA may be dipped in a low-activity creamy or liquid flux prior to reflow. In some implementations, the flux may applied on a solder paste printed on pads of the PCB, followed by placement of a BGA.

Abstract: Some implementations of the disclosure are directed to a thermal interface material. In some implementations, a method comprises: applying a solder paste between a surface of a heat generating device and a surface of a heat transferring device to form an assembly; and reflow soldering the assembly to form a solder composite, wherein the solder composite provides a thermal interface between the heat generating device and the heat transferring device, wherein the solder paste comprises: a solder powder; particles having a higher melting temperature than a soldering temperature of the solder paste, wherein the solder paste has a volume ratio of solder powder to high melting temperature particles between 5:1 and 1:1.5; and flux.