Frequently Asked
Questions

Solder paste printing transfers a controlled volume of paste onto PCB pads through a stencil. Print quality directly affects downstream solder joint quality.

The stencil is the metal template used for solder paste printing; its apertures determine where paste is transferred and the approximate volume. Aperture design affects paste release and joint formation. Fine-pitch, QFN/BGA, and thermal-pad areas require optimization against pad design, paste, and process.

SPI (Solder Paste Inspection) measures paste position, area, volume, and height to catch printing defects before components are placed.

Pick-and-place is the automated SMT placement process: machines pick components from feeders or trays and place them at programmed pad positions on the PCB.

Reflow uses a controlled temperature profile to melt the solder in the paste, form joints, then cool and solidify. The actual profile must be validated against the solder alloy, PCB, components, and equipment.

The reflow profile controls preheat, soak, peak temperature, and cooling. An unsuitable profile can cause insufficient wetting, thermal damage to components, joint defects, or reliability risks.

Inserting through-hole component leads into PCB holes; manual, semi-automatic, or automatic depending on the product and volume.

Wave soldering forms large numbers of through-hole joints by flowing a wave of molten solder across the bottom of the PCB, suitable for products meeting the relevant process conditions.

Selective soldering uses a localized solder nozzle to solder specific through-hole joints — suited to mixed-technology boards that cannot or should not be wave-soldered as a whole.

An operator soldering with an iron or similar tool; commonly used for prototypes, small batches, rework, or certain special components. Volume products require controlled personnel, tools, and process.

Removing residues or contaminants from the PCB surface. Whether to clean, and by which method, depends on flux type, reliability requirements, customer specification, and downstream processes.

Applying a protective coating (e.g., acrylic or polyurethane) to the PCBA surface to improve protection against moisture, contaminants, and corrosion.

Encasing electronic components in resin or similar material for mechanical protection, environmental protection, insulation, or other product requirements.

Rework restores a nonconforming solder joint, component, or assembly to specification — it requires a controlled process and must avoid additional damage to the PCB. Repair restores a damaged PCB or PCBA to its specified function and typically involves more complex issues such as conductors, pads, components, or laminate structure.

Before production, an engineering data and manufacturability review: BOM, Gerber, pick-and-place coordinates, assembly drawing, revision, and special process requirements.

DFM (Design for Manufacturability) finds design issues that could cause manufacturing difficulty, yield loss, or higher cost before production. Many problems can be reduced early through design rules, component spacing, pads, testability, and placement orientation. The later a problem is found, the more expensive the correction or rework.

DFT (Design for Testability) improves test coverage and efficiency through test points, interfaces, and boundary scan. DFX (Design for Excellence) is the umbrella term covering DFM, DFA, DFT, DFR, etc. — optimizing the design for manufacturing, assembly, test, reliability, and cost.

ICT leans toward structure, electrical connectivity, and some component parameters; FCT focuses on whether the product actually works as required. The two are complementary.

Flying probe testing uses movable probes contacting test points for electrical checks, without necessarily requiring a dedicated ICT fixture. It suits some low- to mid-volume products or products that change frequently.

A device that holds the PCBA and provides electrical, mechanical, or interface connections for testing, improving repeatability and efficiency.

A systematic check of the first unit(s) after production starts or after a change, confirming the manufacturing result meets design and process requirements. The specific definition follows the customer’s quality system.

Yield is the ratio of good units to units input; it can be tracked per process (first-pass rate, final yield). FPY (First Pass Yield) is the share of products passing a process on the first attempt with no rework — a key indicator of process stability.

DPMO (Defects Per Million Opportunities) standardizes quality performance for comparing processes of different complexity.

The ability to trace a product’s production history through serial numbers, batches, materials, equipment, programs, process parameters, and test data.

ESD (Electrostatic Discharge) control reduces static risk to sensitive components and PCBAs through grounding, anti-static workstations, anti-static packaging, personnel protection, and environment management.

• IPC-A-610: acceptability standard for electronic assemblies — how to judge the appearance and acceptability of assembled products.
• J-STD-001: requirements for the soldering process, materials, and related work; it is typically used together with IPC-A-610.
• In short: J-STD-001 leans toward the soldering process and materials; IPC-A-610 leans toward assembly acceptability and inspection judgment. Projects follow the contract and applicable standard versions.

IPC product classes distinguish different product environments, performance, and reliability needs. Class 3 represents the stricter requirements for continuous high-performance, mission-critical, or demanding environments. Acceptance criteria follow the project documents and the applicable IPC revision.

Tracing a defect to its true cause instead of only treating symptoms. Common methods: 5 Whys, fishbone/Ishikawa diagram, data stratification, and experimental verification.

CAPA (Corrective and Preventive Action) is the system for handling an occurred issue and reducing the probability of similar issues recurring.

DNI marks a BOM item that is not installed in the current production revision. To avoid procurement and assembly misunderstanding, it should be clearly marked in the BOM, assembly drawing, or manufacturing file.

Common factors: PCB cost, component cost, component count and types, placement count (CPL), THT process, stencils/fixtures, testing, labor, loss/waste, order quantity, lead time, logistics, plus PCB size, layer count, component packages, SMT/THT ratio, and component sourcing. There is no single fixed price.

Small batches cannot sufficiently absorb the fixed or semi-fixed costs of engineering preparation, stencils, programs, changeovers, procurement, and test fixtures.

Main drivers: BOM availability, PCB lead time, order quantity, board complexity, component count, process types, test requirements, fixtures, and line scheduling. To shorten lead time: provide complete data early, lock long-lead items early, confirm alternates, minimize unnecessary engineering changes, confirm the quote and samples promptly, and plan production to the project timeline.

A component whose procurement cycle is significantly longer than normal and can become the bottleneck of the whole project. Identify them as early as possible during NPI.

Component procurement and supplier management: quotation, stock confirmation, lead time, authorized channels, alternates, and risk control.

Discontinued or soon-to-be-discontinued parts can cause procurement difficulty, price fluctuation, and product lifecycle risk. Before mass production, confirm lifecycle and establish a substitution strategy.

MOQ (Minimum Order Quantity) — the smallest order size, which may come from the component supplier, the PCB fab, or the manufacturer’s production policy.

Organizing multiple PCB units in a panel on one production board to improve SMT, test, or downstream processing efficiency. Panel design must consider mechanical strength, V-cut, mouse bites, process edges, and safe distance for components.

One or more materials needed for production not arriving on schedule — a major risk to PCBA lead time and scheduling.

Concentrating, checking, and preparing the materials required by the BOM and work order at the production line, reducing wrong-part and missing-part issues.

Kitting is a single step (preparing the line). A supply-chain service additionally covers sourcing, stock management, lifecycle monitoring, and risk control.

Yes. Mainstream modules and BGA packages can be placed, with AOI inspection and reflow temperature control as safeguards. The specific case is assessed against the PCB design.

Conformal coating (acrylic or polyurethane), with moisture-resistant PCB material and component selection; the solution can be customized to the required IP rating.

Key devices are all industrial grade, the PCB uses high-Tg material, and the power design is wide-temperature. High/low temperature testing can be run during the sample stage for validation.

WiFi is the primary path; Bluetooth is also available. Firmware is delivered from the cloud, with a bootloader partition designed in so a failed upgrade can roll back.

Yes. We can evaluate adding WiFi and APP control based on your existing product solution. We will need to confirm the existing PCBA, communication method, and APP functional requirements.

Yes. We design the control solution around the whole-product functional requirements, integrate these functions into a single PCBA control system, and configure function interlocks per your requirements.

Yes. We can do custom PCBA design based on your display specifications, interface definition, structural dimensions, and mounting position.

Yes. All of these functions can be designed and integrated around the product requirements; we would then confirm your operation logic and functional details.

We can evaluate a specific solution based on your display model, resolution, interfaces, and display content. Three different screens requires design around MCU performance, display drivers, and interface resources.

Yes. ESP32-S3 supports WiFi and Bluetooth, and the touch panel, SD card, and audio can be configured through the specific interfaces; resource allocation is confirmed against the project requirements.

Yes. You provide the functional requirements, target market, size/enclosure constraints, and target cost; we handle electronic solution design, PCB development, prototyping and testing, and push the project through to mass production.

We can design temperature sensing, heating control, overheat protection, and fault indication around your product requirements; details are confirmed together with the whole-product structure and control logic.

Yes. We develop the PCBA against your communication protocol and functional requirements, and support hardware-software co-debugging throughout.

Yes. Based on your PCBA, the physical product, the specific abnormal behavior, and test data, we analyze and determine whether the problem is hardware, software, or other — then optimize further.