Double-sided through-hole PCB boards

ฉัน. ภาพรวมผลิตภัณฑ์

UGPCB Double-Sided Through-Hole PCB Board is a high-performance 2-layer rigid แผงวงจรพิมพ์ built on an FR-4 glass-epoxy substrate using plated through-hole (พท) เทคโนโลยี. The board measures 86.9 × 73.58 mm with a thickness of 1.0 มม, copper foil thickness of 1/1 ออนซ์ (35 μm on both outer and inner layers), and a lead-free hot air solder leveling (เลือดออก) พื้นผิวเสร็จสิ้น. The solder mask is green, and the silkscreen legend is white.

A double-sided through-hole PCB (double-sided printed circuit board) features conductive circuitry on both sides of the insulating substrate, with plated through-holes enabling electrical interconnection between the two layers. Compared to single-sided PCBs, double-sided PCBs offer 60%–80% higher routing density and support more complex circuit designs. UGPCB, backed by ISO-certified quality systems and IPC-compliant manufacturing processes, delivers high-quality double-sided through-hole PCBs and turnkey พีซีบี services to electronics manufacturers worldwide.

ครั้งที่สอง. Product Definition and Technical Specifications

Per IPC-6012F Qualification and Performance Specification for Rigid Printed Boards (published September 2023), the double-sided through-hole PCB is classified as a rigid printed board with plated through-holes (พิมพ์ 2). Its core feature is the electrical connection between conductors on both sides through copper-plated hole walls. UGPCB manufactures this product in full compliance with IPC-6012F and meets Class 2 performance requirements (dedicated service electronic equipment).

ข้อกำหนดที่สำคัญ:

ที่สาม. แนวทางการออกแบบ

3.1 Substrate Material Selection — Engineering Value of FR-4

FR-4 is a flame-retardant grade designation established by the National Electrical Manufacturers Association (NEMA). The letters “FR” stand for flame-retardant, and the number “4” denotes an epoxy resin system reinforced with woven glass fabric. Per IPC-4101 Specification for Base Materials for Rigid and Multilayer Printed Boards, FR-4 Grade A1 represents the core performance tier with optimal mechanical strength, electrical properties, and long-term reliability.

Key Performance Indicators of FR-4 (แหล่งที่มา: IPC-4101 and industry standards):

• อุณหภูมิการเปลี่ยนแก้ว (ทีจี): 130–140°C (มาตรฐาน FR-4)

• ค่าคงที่ไดอิเล็กตริก (ดีเค) @ 1 กิกะเฮิรตซ์: 4.2–4.5

• ปัจจัยการกระจาย (ฟ) @ 1 กิกะเฮิรตซ์: ≤ 0.020

• คะแนนความไวไฟ: อล 94 วี-0

• การดูดซึมน้ำ (24 ชั่วโมง): ≤ 0.10%

FR-4 remains the predominant substrate material in the PCB industry because it offers an outstanding balance of mechanical strength, ฉนวนไฟฟ้า, เสถียรภาพมิติ, and processability.

3.2 Circuit Design Standards per IPC-2221

Per IPC-2221 มาตรฐานทั่วไปเกี่ยวกับการออกแบบแผ่นพิมพ์, conductor width design must account for current-carrying capacity, temperature rise, and copper thickness. The IPC-2221 current-carrying capacity formula is:

I = k · ΔT^0.44 · A^0.725

ที่ไหน:

• I = Maximum current-carrying capacity (อัน)

• k = Empirical constant (0.048 for external layers, 0.024 for internal layers)

• ΔT = Allowable temperature rise (องศาเซลเซียส)

• A = Conductor cross-sectional area (ล้าน²), where A = W × T

UGPCB’s product features a line width of 0.32 มม (ประมาณ. 12.6 MIL), line spacing of 0.37 มม (ประมาณ. 14.6 MIL), and copper thickness of 1 ออนซ์ (35 μm). For an external layer trace with a 10°C temperature rise:

A = 0.32 มม. × 0.035 mm = 0.0112 mm² ≈ 17.36 ล้าน²

I = 0.048 × 10^0.44 × 17.36^0.725 ≈ 0.048 × 2.75 × 7.82 ≈ 1.03 อัน

This conductor width supports approximately 1 A of current, meeting the power and signal transmission needs of most consumer electronics and industrial control equipment. IPC-2221 recommends limiting the maximum temperature rise to 10°C or 20°C to preserve PCB service life.

3.3 Hole Diameter and Aspect Ratio Design

The aspect ratio of a through-hole is a critical metric for evaluating drilling and hole metallization difficulty. The formula is:

Aspect Ratio = Board Thickness / Drilled Hole Diameter

For UGPCB’s product with 1.0 mm board thickness and 0.236 mm minimum hole diameter:

Aspect Ratio = 1.0 / 0.236 ≈ 4.24:1

This aspect ratio is well below the industry-recommended upper limit of 10:1 and the conservative design threshold of 8:1. It indicates low difficulty in drilling and metallization, high yield rates, controlled costs, and assured through-hole reliability.

3.4 Land Pattern Design Reference

Per IPC-7351 Generic Requirements for Surface Mount Design and Land Pattern Standard, land pattern design must ensure adequate solder fillet formation and meet solderability, inspectability, and reworkability requirements. สำหรับส่วนประกอบของรูทะลุ, land diameter is typically recommended at 1.8–2.2 times the hole diameter to ensure sufficient annular ring width.

IV. หลักการทำงาน

The double-sided through-hole PCB operates on three core technologies:

1. Double-Sided Routing — Conductive circuit patterns are etched on both the top and bottom surfaces of the FR-4 insulating substrate, allowing component placement on both sides. This significantly increases circuit density and design flexibility.

2. Plated Through-Hole (พท) Interconnection — After drilling, electroless copper deposition and electrolytic copper plating build up a conductive layer on the hole walls. This creates low-resistance, highly reliable electrical connections between the top and bottom layers. Per IPC-6012F Class 2, the minimum average plated copper thickness on hole walls must be ≥ 20 μm.

3. Component Assembly and Soldering — Components are mounted through hole (tht) or surface mount (SMT) techniques and electrically connected via reflow or wave soldering, producing a fully functional PCBA (ชุดประกอบแผงวงจรพิมพ์) โมดูล.

วี. การจำแนกประเภทผลิตภัณฑ์

Per the IPC-6012F classification system for rigid printed boards, UGPCB’s product is classified as follows:

By application domain, this product falls into the General Industrial Grade Double-Sided PCB category, suitable for consumer electronics, การควบคุมทางอุตสาหกรรม, อุปกรณ์สื่อสาร, power adapters, and other medium-reliability applications.

วี. องค์ประกอบของวัสดุ

6.1 Substrate — FR-4 Copper-Clad Laminate

FR-4 is a glass-reinforced epoxy laminate composed of electronic-grade woven glass fabric as reinforcement and epoxy resin as the binder, consolidated under high temperature and pressure. Its UL 94 วี-0 flammability rating means that in the vertical burn test, the material self-extinguishes within 10 seconds after each of two 10-second flame applications, with no flaming drips that ignite cotton.

6.2 Copper Foil — 1/1 ออนซ์

One ounce (1 ออนซ์) of copper foil has a thickness of 35 μm (1.37 MIL). UGPCB uses 1 OZ copper on both outer layers (designated 1/1 ออนซ์), ensuring equal current-carrying capacity and conductivity on both sides.

6.3 Surface Finish — Lead-Free HASL

Lead-Free HASL involves immersing the PCB in molten lead-free solder (typically Sn-Cu, Sn-Cu-Ni, or Sn-Ag-Cu alloys), then using high-pressure hot air knives to level and remove excess solder. This produces a uniform, solderable protective coating on the copper surfaces. The process complies with IPC-6012F requirements and RoHS environmental directives.

6.4 หน้ากากประสานและตำนาน

• Green Solder Mask — Covers all circuit areas except pads, providing insulation, oxidation protection, and short-circuit prevention.

• White Silkscreen Legend — Identifies component reference designators, polarity markers, board part numbers, and revision levels to facilitate assembly and debugging.

VII. Product Performance

7.1 ประสิทธิภาพไฟฟ้า

7.2 สมรรถนะทางกล

7.3 ความน่าเชื่อถือ

Per IPC-6012F Class 2 ความต้องการ, the product must pass the following reliability verifications:

• Thermal Stress Test (288องศาเซลเซียส, 10 ไม่กี่วินาที, no delamination or blistering)

• Plated Through-Hole Copper Adhesion Test (minimum average hole-wall copper thickness ≥ 20 μm)

• Solderability Test

• Electrical Continuity and Insulation Resistance Test

VIII. Product Structure

UGPCB’s double-sided through-hole PCB features a symmetrical 2-layer construction. From top to bottom:

1. Top Legend Layer (White Silkscreen)

2. Top Solder Mask Layer (Green Ink)

3. Top Copper Foil Layer (1 ออนซ์, 35 μm)

4. FR-4 Insulating Substrate (1.0 ความหนา มม)

5. Bottom Copper Foil Layer (1 ออนซ์, 35 μm)

6. Bottom Solder Mask Layer (Green Ink)

7. Bottom Legend Layer (White Silkscreen)

8. Plated Through-Holes (พท) — Span the full board thickness with copper-plated hole walls enabling interlayer interconnection

IX. Product Features

1. High Routing Density — Double-sided routing delivers 60%–80% higher density than single-sided boards, supporting more complex circuit designs.

2. Highly Reliable Through-Hole Interconnection — Plated through-hole (พท) technology ensures long-term electrical reliability between layers, with hole-wall copper thickness meeting IPC-6012F Class 2 ความต้องการ (≥ 20 μm average).

3. Excellent Flame Retardancy — FR-4 substrate meets UL 94 วี-0 flammability rating, ensuring safety under abnormal operating conditions.

4. Lead-Free and Environmentally Friendly — Lead-free HASL surface finish complies with RoHS environmental directives.

5. Fine-Pitch Circuit Capability — Minimum line width of 0.32 mm and minimum spacing of 0.37 mm accommodate medium- to high-density circuit designs.

6. Superior Dimensional Stability — FR-4’s low water absorption (≤ 0.10%) ensures minimal dimensional change in humid environments, preserving assembly accuracy.

7. Mature Manufacturing Process — With 1.0 mm board thickness and 0.236 mm minimum hole diameter, the aspect ratio of only 4.24:1 enables mature processes, high yields, and short lead times.

เอ็กซ์. ผังกระบวนการผลิต

UGPCB’s standard double-sided through-hole PCB manufacturing process:

1. การตรวจสอบวัสดุที่เข้ามา → Verify FR-4 copper-clad laminate thickness, copper foil quality, and visual defects.

2. การตัด → Cut large-format copper-clad laminate to working panel size (86.9 × 73.58 มม).

3. การขุดเจาะ → Use high-precision CNC drilling machines to drill all through-holes per the Gerber drill file (minimum diameter 0.236 มม).

4. Plated Through-Hole (พท) → Deposit a thin copper seed layer on hole walls via electroless copper deposition.

5. Panel Plating → Electrolytically plate copper to build up hole-wall and surface copper to target thickness (1 ออนซ์).

6. การถ่ายโอนรูปแบบ → Laminate dry film, expose, and develop to form the circuit pattern resist.

7. การแกะสลัก → Etch away unprotected copper to form the final circuit pattern.

8. Stripping → Remove the resist dry film from circuit traces.

9. แอปพลิเคชันมาสก์ประสาน → Apply green solder mask ink, expose, and develop to expose pads.

10. พื้นผิวเสร็จสิ้น → Lead-Free HASL.

11. Legend Printing → Screen-print white silkscreen legend.

12. การกำหนดเส้นทาง / V-Cut → CNC routing to final board outline.

13. การทดสอบไฟฟ้า → Flying probe or fixture testing to verify open/short integrity.

14. การควบคุมคุณภาพขั้นสุดท้าย (ฟค) → Visual inspection, dimensional sampling, and packaging for shipment.

XI. สถานการณ์การใช้งาน

UGPCB Double-Sided Through-Hole FR-4 PCB Boards, with their balanced performance and mature processes, are widely used in:

11.1 อุปกรณ์อิเล็กทรอนิกส์สำหรับผู้บริโภค

• Power adapters and chargers

• Home appliance control boards

• อุปกรณ์สมาร์ทโฮม

11.2 การควบคุมทางอุตสาหกรรม

• PLC programmable logic controllers

• Industrial power modules

• Instrumentation and meters

11.3 อุปกรณ์สื่อสาร

• Routers and switches

• Communication modules

• Signal conversion devices

11.4 อุปกรณ์อิเล็กทรอนิกส์ยานยนต์

• On-board chargers

• Body control modules (non-safety-critical)

• ระบบสาระบันเทิง

11.5 อุปกรณ์การแพทย์

• Patient monitor auxiliary boards

• อุปกรณ์การแพทย์แบบพกพา (ระดับ 2 applicable)

XII. Product Advantages and Selection Guide

12.1 Why Choose UGPCB Double-Sided Through-Hole PCBs?

• IPC-Compliant Process Control — From material selection to finished goods, full compliance with IPC-6012F, IPC-4101, and other international standards.

• High-Precision Manufacturing — Minimum hole diameter of 0.236 mm and minimum line width of 0.32 mm meet medium- to high-density design requirements.

• Environmental Compliance — Lead-free HASL surface finish complies with RoHS 2.0 directives.

• ความน่าเชื่อถือที่พิสูจน์แล้ว — FR-4 substrate has been market-validated for decades with consistent performance.

• จัดส่งที่รวดเร็ว — Standard specifications are stocked with ample raw materials, ensuring reliable lead times.

12.2 Selection Reference

UGPCB Double-Sided Through-Hole PCBs are the ideal choice when your project meets these criteria:

• Moderate circuit complexity that 2 layers can accommodate

• Operating frequency below 1 กิกะเฮิรตซ์ (FR-4 performs excellently in this range)

• Long-term operating environment not exceeding 120°C

• Cost-sensitive applications demanding high value

XIII. Request a Quote

UGPCB is committed to delivering high-quality PCB manufacturing and turnkey PCBA services to customers worldwide. Whether you need standard-specification double-sided through-hole PCBs or custom requirements (special board thickness, copper weight, พื้นผิวเสร็จสิ้น, การควบคุมความต้านทาน, ฯลฯ), UGPCB’s expert team provides full support from engineering design to volume production.

Get a Quote Today:

• Submit Gerber files + specifications — receive a quote within 24 ชั่วโมง

• Support from prototype to high-volume production

• Free Design for Manufacturing (DFM) ทบทวน

ติดต่อ UGPCB:
📧 Sales Inquiries: [sales@ugpcb.com]
🌐 Website: [www.ugpcb.com]

XIV. Data Source Declaration

The standards and data cited in this document are sourced from the following authoritative organizations:

1. IPC (สมาคมเชื่อมต่ออุตสาหกรรมอิเล็กทรอนิกส์): IPC-6012F Qualification and Performance Specification for Rigid Printed Boards (September 2023); IPC-4101 Specification for Base Materials for Rigid and Multilayer Printed Boards; ไอพีซี-2221 มาตรฐานทั่วไปเกี่ยวกับการออกแบบแผ่นพิมพ์; ไอพีซี-7351 Generic Requirements for Surface Mount Design and Land Pattern Standard

2. อล (Underwriters Laboratories): อล 94 Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances

3. NEMA (National Electrical Manufacturers Association): FR-4 material grade definition

4. Industry Standard Technical Data: FR-4 dielectric constant, ปัจจัยการกระจาย, and other material property parameters