Skip to main content

Custom Designed Printed Circuit Boards

A surface-mount technology line provides Packet Digital the opportunity to take years of experience designing printed circuit boards and put it to wider use by assembling custom designs at its manufacturing facility in Fargo, North Dakota.

Surface Mount Technology Line

Surface Mount Technology (SMT) is a key process in the electronics manufacturing industry, used for the assembly of electronic components onto printed circuit boards (PCBs). Packet Digital’s SMT line offers considerable advantages for PCB assembly including smaller component sizes, higher component density and increased automation.

Contact us today to learn more about how our professional SMT line operators can be the solution for your PCB production.

High Accuracy Screen Printer

The solder paste screen printer prepares the PCB for the placement of surface-mount components. The paste — a mixture of solder alloy particles and flux — serves as the medium for creating solder joints during the subsequent reflow soldering process.

The printer uses a stencil with openings corresponding to the locations where the solder paste needs to be placed on the PCB. A squeegee is used to spread the solder paste over the stencil and is controlled in terms of pressure, speed and angle to achieve precise and consistent application. The printing process is completely automated and programmable, allowing for quick setup and changeover between different PCB designs.

Solder Paste Inspection Machine (SPI)

The solder paste inspection machine verifies the solder paste deposit volumes on the PCB. This includes checking for solder bridges, insufficient solder, excessive solder and any other anomalies that may affect the integrity of the joint.

Pick and Place Machine

A pick-and-place machine precisely places electronic components onto PCBs during the assembly process. Using a conveyor system, the machine moves the PCB to the designated component placement position. The machine then lowers the component, placing it on the PCB with high precision.

Before placement, a vision system is used to verify the correct alignment of components. The pick-and-place machine is capable of placing up to 25,000 components per hour.

Equipped with feeders that hold reels and a tray tower to hold trays of components, the feeders can easily be changed to accommodate different component types and sizes. The machine is also programmed with specific coordinates, orientations and other parameters for each component on the PCB, allowing it to be programmed for different PCB designs and component placements.

Automated Optical Inspection Machine (AOI)

An optical inspection machine inspects and verifies the quality of the PCBA placements and the solder joints of surface-mounted components. The machine ensures components are accurately positioned according to the design specifications and examines the solder joints formed during the reflow soldering process.

Optical inspection machines verify the correct orientation of polarized components to prevent assembly errors that could lead to circuit failures. The system identifies various defects, anomalies and irregularities on the PCBA surface such as scratches, stains or foreign materials. The automated nature of the inspection reduces the need for manual inspection and increases the speed of production.

Reflow Oven

A reflow oven is responsible for melting the solder particles within the solder paste that was applied to the PCB during the solder paste printing process. The reflow soldering process involves the controlled heating and cooling of the PCB to melt and solidify solder paste, forming reliable electrical/mechanical connections between the components and the PCB.

The reflow soldering process is characterized by a specific temperature profile — preheating, soaking, reflow and cooling.

In the preheat zone, the temperature is gradually increased to remove solvents from the solder paste and to prevent thermal shock to the components. The assembly then moves through a soak zone where it is held at a specific temperature for a set duration. This allows the solder paste to reach a fully liquid state in reflow, promoting proper wetting and bonding. The reflow zone is where the temperature is raised to the peak reflow temperature. At this point, the solder paste reaches its melting point, and the liquid solder forms reliable connections between the components and the PCB pads. After reflow, the assembly enters a cooling zone where the temperature is gradually reduced. Controlled cooling is crucial to avoid thermal stress on the components and the PCB.

Selective Soldering Machine

A selective soldering machine is designed to solder through-hole components and other areas of a PCB selectively. While the reflow oven is typically used for surface-mount components, the selective solder machine is employed for components that are not suitable for reflow soldering or for specific areas that require selective soldering.