Case Overview

This project provides a complete one-stop solution for mid-to-high-end desktop computer cases, covering from sheet metal processing to final assembly. The solution is made of anti-fingerprint SECC electro-galvanized steel plates. It integrates a series of sheet metal processing (laser cutting, precise bending, riveting, spot welding) and surface treatment (powder coating and other processes) into a smooth production process, and finally delivers fully assembled and ready-to-ship case units.

Case Details

The complete chassis assembly is composed of several matching metal parts (chassis frame, motherboard, side panel and top cover, front panel frame and I/O back panel, internal mounting brackets), designed specifically for structural rigidity, thermal ventilation, and user installation without tools.

Processing Details

• Large thin-panel flatness control: At 1.0mm thickness, the large-area side panels and top cover undergo extensive piercing for ventilation holes. Unbalanced internal stress after punching easily causes warping and waviness, which would create uneven assembly gaps, panel rattling and degraded appearance quality.
• Standardized hole position interchangeability: Each chassis includes over 80 functional mounting holes for motherboards, power supplies, expansion cards and storage drives. Cross-batch dimensional deviation would break compatibility with standard PC hardware, leading to assembly failures and end-user complaints.
• Uniform assembly gap accuracy: The chassis is assembled from multiple bent sheet metal parts. Cumulative tolerance errors from separate bending processes would cause uneven gaps between mating panels, affecting both visual quality and EMI shielding performance.
• Press-rivet fastener reliability: Hundreds of press-riveted studs and nuts are used for internal component mounting. Insufficient riveting force or poor verticality would cause fastener loosening or misalignment, directly impacting assembly efficiency and long-term structural durability.

Project Background

Consumer electronic cases (PC case shells) usually require coatings that are scratch-resistant, do not peel off, and also ensure a smooth and even finish.

Our cooperating client previously adopted a decentralized purchasing model from multiple suppliers: the sheet metal parts, surface treatment, and final assembly were provided by different suppliers. This model often led to color differences and thin coatings, or even exposed base layers, in the surface treatment of different production batches of the shell products. This also resulted in a high rework rate, causing the total delivery cycle of the product to exceed the originally scheduled 30 days.

Therefore, the client hopes to find a single strategic manufacturing partner who can provide a one-stop service including sheet metal processing, surface treatment and final assembly, ensuring stable quality, scalable production capacity, shorter delivery cycle, and fully meeting global EMC and environmental compliance requirements.

Longwang Solution

Optimization of powder spraying details: The areas where the sheet metal chassis shell is bent, has holes or grooves are the main trouble spots causing uneven powder spraying. Therefore, at the beginning of the design, we will add small holes on the inner side wall to guide the electric field and improve the powder deposition on the inner wall. During the processing, the coating is applied in sections: first, all the internal cavities and the areas with bends are sprayed, and finally, the entire outer surface is subjected to normal high-pressure spraying.

Automated powder coating line: Another point worth mentioning is that before manufacturing, to prevent any contact or scratching of the shell surface, we apply a protective film to the raw steel coils. This ensures that all components are conveyed using custom soft fixtures. Additionally, thanks to our own spraying production line, each batch of products undergoes fully automatic electrostatic powder spraying processing under the same specifications (optimized parameters and details), guaranteeing uniform coating thickness, consistent color, and no collapse or pimple defects on the shell surfaces.

Results Achieved

• Overall dimensional pass rate reached 99.7%, with 100% interchangeability for standard motherboard and hardware mounting positions.
• Large panel flatness pass rate reached 99.5%, and assembly gap uniformity was controlled within 0.15mm, eliminating appearance gap complaints.
• Previous customer pain point: Defect rate of powder coating appearance. It has been reduced from 8% of the previous supplied model to below 0.6%, with consistent color and no scratch defects.
• Previous customer pain point: Defect rate of powder coating appearance. It has been reduced from 8% of the previous supplied model to below 0.6%, with consistent color and no scratch defects.
• Average order lead time was reduced from 32 days to 14 days, cutting the client’s product launch cycle by more than 56%.
• The client’s total procurement and in-house assembly cost decreased by 16% through consolidated one-stop fabrication and assembly.
• Zero critical quality complaints were recorded over the first 12 months of mass production.

Why This Project Matters

This case once again demonstrates the maturity of Longwang's one-stop processing service. At the same time, it strengthens our determination to further improve the process and customize services for this purpose, with the aim of providing customers with a better cooperation experience.

As the global PC market continues to evolve towards high-end gaming hardware, electronic enclosures, and faster product iterations, this solution provides hardware brands with a proven approach to optimize the supply chain, reduce total cost of ownership, and more quickly bring Longwan's high-quality processing experience and capabilities in related industries and fields to the market.