Name: 8L HDI PCB 2+N+2 Mobile Phone Board PCB
Brand: PCB Printed Circuit Board and PCBA manufacturing
Rating: 5 (1 reviews)

Description
Data Sheet

1. Corporate Overview

Maxipcb Circuits Limited (Maxipcb®) is a national high-tech enterprise specialized in the R&D and intelligent manufacturing of high-precision PCB samples and mass-production boards. The company independently developed the industry-leading PCB Automatic Quotation System (PAQS), which realizes data interconnection between engineering, production and factory terminals. Through digital intelligent scheduling, it shortens the overall cycle from design verification to rapid prototyping.

Taking “Internet + Industry 4.0” intelligent manufacturing as the core layout, Maxipcb is committed to building a standardized intelligent PCB factory cluster, and providing one-stop professional technical support and customized fabrication services for global customers in high-density and high-precision circuit board fields.

2. Product Layout & Process Capacity

Maxipcb features a diversified product matrix, covering microwave RF high-frequency boards, hybrid high-speed composite PCB, 1–70 layer ultra-multilayer boards, HDI high-density interconnection boards, rigid-flex combined circuits, metal substrate PCB and ceramic substrate PCB.

In response to complex customized demands, the company has long-term technical accumulation and mature mass-production capability for special process boards, including blind & buried via structure, controlled depth back-drilling, step groove routing, IC carrier board and ultra-thick copper circuit boards.

3. Introduction to Mobile Phone Motherboard Hardware

The mainboard is the core hardware carrier of smart phones, undertaking overall operation control, signal interaction and power management. The core functional modules are divided into three categories: baseband and power management chip group for signal encoding and power distribution; RF processing units and power amplifiers for wireless signal transceiving; as well as main control CPU, memory, touch control, Bluetooth, Wi-Fi and various sensor chips.

Peripheral functional components such as microphones, audio modules, camera components, display screens and external interface components are all mounted and integrated on the mainboard to realize centralized scheduling of the whole machine. In addition, flexible flat cables are adopted for internal interconnection between modules to meet the structural assembly and bending resistance requirements of mobile terminals.

Common failure factors of mobile phone mainboards include liquid corrosion, extreme temperature working environment, static breakdown, mechanical drop impact, abnormal transient current caused by battery failure, and mismatched power adapter charging, all of which will affect the long-term reliability of circuit boards.

4. Design Specification for Mobile Phone PCB Routing

4.1 Power Circuit Width Specification

For VBAT battery power traces connected to RF power amplifier pins, the line width shall be formulated according to wiring length:

Trace length＜60mm：minimum line width ≥ 1.5mm
60mm ≤ trace length＜90mm：minimum line width ≥ 2.0mm

To ensure stable operating performance of RF devices, the total wiring distance from battery connector to power amplifier shall not exceed 90mm. All high-current circuits shall follow the same width standard; conventional power lines shall adopt 0.2mm–0.4mm width matching actual current load.

4.2 Signal Crosstalk Suppression

For mutually susceptible signal lines, the trace spacing shall be more than twice the line width. Direct overlapping routing of upper and lower layers without ground isolation is strictly prohibited, so as to restrain coupling interference and guarantee signal transmission quality.

4.3 High‑Speed Signal Design Criteria

High-frequency high-speed signals shall adopt arc transition routing preferentially; 135° chamfer turning is allowed under layout constraints, while right-angle and acute-angle routing are forbidden.

Component grounding pins shall be directly connected to complete ground planes. Local short-distance grounding is recommended, with grounding line width maintained above 0.5mm to avoid long-distance grounding wiring impedance deviation.

4.4 Reinforced Design for Large Components

For high-load and large-size devices such as tantalum capacitors and battery connectors, pad teardrop transition and local copper cladding reinforcement are adopted. Adding distributed interlayer vias effectively improves pad bonding strength and anti-stripping performance.

4.5 Board Edge Safety Margin

All internal circuits shall maintain a safe distance from the board outline, with the minimum routing edge clearance ≥ 0.4mm, preventing mechanical damage and circuit abnormality during CNC forming and SMT processing.

5. HDI PCB Technical Standard for Mobile Terminals

5.1 Core Professional Definition

Blind Via: Micro interconnection hole connecting outer layer and inner layer without penetrating the whole board, with conventional aperture of 0.05mm–0.15mm, mainly manufactured by CO₂ laser, UV laser and precision micro-etching processes.
Buried Via: Inner-layer hidden conduction hole independent of outer layers, applied to multi-layer internal interconnection, with larger aperture than blind vias and stable conduction performance.

5.2 HDI Classification & 6-Layer Structural Process

HDI products are classified by lamination cycles and laser drilling times. 6-layer HDI, widely used in mobile terminal mainboards, is mainly divided into first-order and second-order structures.

6-layer First-Order HDI
Standard blind hole combination: 1-2 / 2-5 / 5-6. Outer layer blind holes adopt laser drilling, and middle layer holes adopt conventional mechanical drilling. With mature process, stable yield and cost advantages, it is suitable for cost-effective consumer terminal products.
6-layer Second-Order HDI
Covering multi-group cross-layer blind holes, two times of lamination and two rounds of laser drilling are required. The process flow includes inner buried hole processing, primary lamination, first laser blind hole fabrication, secondary lamination, secondary laser drilling and final finished hole forming.

Second-order HDI is divided into staggered via and stacked via structures. Staggered blind holes feature low process difficulty and stable production; stacked blind holes realize higher wiring density, applicable for high-end high-integration mainboards. Higher-order HDI products achieve further density improvement through multiple lamination and laser processes.

6. Maxipcb Core HDI Product & Technical Advantages

Aiming at the miniaturization and high-density development trend of smart terminals, Maxipcb independently develops dedicated AnyLayer HDI mainboard boards for Android devices. With advanced sequential lamination, laser micro-hole processing and via filling technology, the product optimizes circuit layout density and high-speed signal integrity, and meets comprehensive requirements such as compact structural design, low power consumption and stable wireless transmission.

Core advantages are summarized as follows：

Cost optimization: HDI structure reduces comprehensive manufacturing cost for high-layer multilayer boards compared with traditional lamination schemes;
High integration: Micro blind hole interconnection greatly improves space utilization, adapting to terminal miniaturization;
Process compatibility: Support stacked vias, laser direct imaging and other advanced processes;
Excellent high-speed performance: Effectively reduce high-frequency loss and ensure stable signal transmission;
High environmental reliability: Adapt to high temperature, humidity and complex electromagnetic working conditions;
Balanced thermal design: Optimized copper laying and via distribution to improve heat dissipation efficiency;
Standard EMC design: Suppress EMI/RFI interference and enhance overall electromagnetic compatibility.

7. Quality Control System & Industrial Standards

Maxipcb implements full-process standardized quality management, with clear quality and service indicators. Strict engineering DFM review is carried out for customer design files to identify manufacturability risks in advance.

The whole process covers incoming material inspection, tooling verification, in-process patrol inspection and finished product full inspection. All products are manufactured and inspected in accordance with international industrial standards including IPC‑A‑600G, IPC‑6018A and military specifications, to ensure stable and consistent product quality.

8. Cooperation Suggestions

It is recommended to conduct pre-production technical communication with our engineering team for HDI stacking design, high-speed impedance requirements and mobile board layout schemes, so as to comply with DFM design specifications, reduce process risks, control comprehensive cost and ensure delivery stability.

As a reliable high-precision PCB manufacturer, Maxipcb relies on complete production lines and rich industry experience to provide stable, high-quality and cost-effective circuit board overall solutions for global customers.

Model：8L 2+N+2 Mobile Main Board
Material ： FR4
Construction：8L 2+N+2 HDI
Finished Thickness：1.0mm
Copper Thickness：1OZ
Color ：Green /White
Surface Treatment：Immersion Gold
Min Trace / Space：3.5mil/3.5mil
Min Hole：Mechanical Hole0.2mm，Laser Hole0.1mm
Application： Mobile Main Board

8L HDI PCB 2+N+2 Mobile Phone Board PCB

Description

Data Sheet