Por que a placa PCB deforma?

Postado em 21/11/2019

O empenamento da placa PCBpode causar mau contato entre os componentes eletrônicos e as almofadas da placa de circuito durante o patch SMT posterior, e os componentes podem não ser completamente fixados às almofadas, o que pode causar produtos defeituosos ou afetar as propriedades elétricas de a placa de circuito. O que causa o empenamento da placa pcb?

PCB board

1. The circuit diagram of the PCB board is not properly designed. The circuit of the pcb circuit board is obviously asymmetrical, and the copper area of one side of the substrate is large, which causes a large stress, which causes the pcb board to warp. The baking of the board in front of the printed circuit board can relax the stress of the substrate and reduce the warpage of the substrate during the printing process.

2. The PCB circuit board may have slight warpage before printing. In the process of circuit board printing and processing, it is affected by external factors such as heat and chemicals, which increases the warpage of the pcb board.

3. The placa PCB is not properly stored. The humidity of the pcb board storage space is too high, and the moisture absorption of the board will be deepened after the circuit board absorbs moisture; in particular, the single-panel has a larger moisture absorption area. Therefore, the pcb board without moisture-proof packaging should be stored in a dry space as much as possible, and try to avoid the bare copper plate.

4. The placa PCB layout method is incorrect. Heavy object extrusion, improper placement, and incorrect packaging will deepen the warpage of the pcb board.

Pbc Allegro manufacturers should take appropriate measures to reduce warpage. Jiedubang pcb adheres to the “quality-centered” business philosophy, checks the substrate before production, screens out the bad substrate, and then bakes the board to relax the stress of the substrate and further reduce the warpage. The substrate with relatively large warpage is flattened by the machine in time, and then the next step is produced, which can effectively reduce the defect rate of the warpage plate. 6pcba is committed to becoming the world’s leading manufacturer of circuit board and sample cards, and continues to provide quality services for the innovation of China’s information electronics industry.

Project project name Process Capability
Overall process capability Number of layers 1-30 Floor
High frequency mixing HDI Ceramic materials, PTFE materials can only be used for mechanical drilling blind buried holes or controlled deep drilling, back drilling, etc. (cannot be laser drilled, can not directly press copper foil)
high speed HDI Made by conventional HDI
Laser order 1-5Order(≥6Level needs review)
Plate thickness range 0.1-5.0mm (less than 0.2mm, more than 6.5mm need to be reviewed,)
Minimum finished size Veneer 5*5mm (less than 3mm to be reviewed)
Maximum finished size 2-20 layers 21*33inch; Remarks: The short side of the board exceeds 21inch for review.
Maximum copper thickness Outer layer 8OZ (more than 8OZ for review), inner layer 6OZ (more than 6OZ for review)
Minimum copper thickness 1/2oz
Inter-layer alignment ≤3mil
Through hole filling range Plate thickness ≤0.6mm, hole diameter ≤0.2mm
Resin plug thickness range 0.254-6.0mm, PTFE plate resin plug hole needs to be reviewed
Plate thickness tolerance Plate thickness ≤1.0mm; ±0.1mm
Plate thickness >1.0mm; ±10%
Impedance tolerance ±5Ω (<50Ω), ±10% (≥50Ω); ±8% (≥50Ω, review required)
Warpage Regular: 0.75%, limit 0.5% (requires review) Max. 2.0%
Number of presses The same core plate is pressed ≤ 5 times (more than 3 times to be evaluated)
material type Ordinary Tg FR4 Shengyi S1141, Jianye KB6160A, Guoji GF212
Medium Tg FR4 Shengyi S1150G (medium Tg sheet), Jianye KB6165F, Jianye KB6165G (halogen-free)
High Tg FR4 Shengyi S1165 (halogen-free), Jianye KB6167G (halogen-free), Jianye KB6167F
Aluminum plate Guoji GL12, clear CS-AL-88/89 AD2, Ju Qin JQ-143 1-8 layer mixed FR-4
HDI board material type LDPP (IT-180A 1037 and 1086), normal 106 and 1080
High CTI Shengyi S1600
High Tg FR4 Isola: FR408, FR408HR, IS410, FR406, GETEK, PCL-370HR; Lianmao: IT-180A,
IT-150DA; Nelco: N4000-13, N4000-13EP, N4000-13SI, N4000-13EP
SI; Panasonic: R-5775K (Megtron6), R-5725 (Megtron4); Jianye: KB6167F;
Taiwan: EM-827; Hongren: GA-170; South Asia: NP-180; Tai Yao: TU-752, TU-662;
Hitachi: MCL-BE-67G (H), MCL-E-679 (W), MCL-E-679F (J); Tenghui: VT-47;
Ceramic powder filled with high frequency material Rogers:Rogers4350、Rogers4003;Arlon:25FR、25N;
PTFE high frequency material Rogers, Taconic, Arlon, Nelco, TP
PTFE prepreg Taconic: TP series, TPN series, HT1.5 (1.5mil), Fastrise series
Material mixing Rogers, Taconic, Arlon, Nelco and FR-4
Metal substrate Number of layers Aluminum substrate, copper substrate: 1-8 layers; cold plate, sintered plate, buried metal plate: 2-24 layers; ceramic plate: 1-2 layers;
Finished product size (aluminum substrate, copper substrate, cold plate, sintered plate, buried metal plate) MAX:610*610mm、MIN:5*5mm
Largest production size (ceramic plate) 100*100mm
Finished board thickness 0.5-5.0mm
Copper thickness 0.5-10 OZ
Metal base thickness 0.5-4.5mm
Metal base material AL:1100/1050/2124/5052/6061;Copper:Copper pure iron
Minimum finished aperture and tolerance NPTH: 0.5±0.05mm; PTH (aluminum substrate, copper substrate): 0.3±0.1mm; PTH (cold plate, sintered plate, buried metal plate): 0.2±0.10mm;
Shape processing accuracy ±0.2mm
PCB part surface treatment process With/without lead spray tin; OSP; nickel (palladium) gold; electric (nickel) soft/hard gold; electroplated tin; nickel-free electroplated soft and hard gold;
Metal surface treatment Copper: nickel-plated gold; aluminum: anodizing, hard oxidation, chemical passivation; mechanical treatment: dry sandblasting, drawing
Metal based material Quanbao aluminum substrate (T-110, T-111); Tenghui aluminum substrate (VT-4A1, VT-4A2, VT-4A3); Laird aluminum substrate (1KA04, 1KA06); Berges metal substrate (MP06503 , HT04503); TACONIC metal substrate (TLY-5, TLY-5F);
Thermal paste thickness (medium layer) 75-150um
Buried copper block size 3*3mm—70*80mm
Buried copper block flatness (difference accuracy) ±40um
Buried copper block to hole wall distance ≥12mil
Thermal Conductivity 0.3-3W/m.k (aluminum substrate, copper substrate, cold plate); 8.33 W/m.k (sintered plate); 0.35-30 W/m.k (buried metal plate); 24-180 W/m.k (ceramic plate);
product type Rigid plate Backplane, HDI, multi-layer buried blind hole, thick copper plate, power thick copper, semiconductor test board
Lamination method Multiple compression blind buried plate The same surface is pressed ≤3
HDI board type 1+n+1, 1+1+n+1+1, 2+n+2, 3+n+3 (buried hole ≤0.3mm in n), laser blind hole can be plated and filled
Local mixed pressure Minimum distance of mechanical drilling to conductor in local mixed zone ≤10 layers: 14mil; 12 layers: 15mil; >12 layers: 18mil
Minimum distance from the local mixed pressure junction to the borehole ≤12 layers: 12mil;>12 layers: 15mil
Surface treatment Lead-free Electroplated copper nickel gold, immersion gold, hard gold plating (with/without nickel), gold-plated fingers, lead-free tin, OSP, chemical nickel palladium gold, soft gold plating (with/without nickel), immersion silver, sink tin, ENIG +OSP, ENIG+G/F, full plate gold plating + G/F, sinking silver + G/F, sinking tin + G / F
Leaded Lead spray tin
Thickness to diameter ratio 10:1 (lead/lead-free spray tin, chemical nickel-plated gold, immersion silver, immersion tin, chemical nickel-palladium); 8:1 (OSP)
Processing size (MAX) Shen Jin: 520*800mm, vertical sinking tin: 500*600mm, horizontal tin: less than 500mm on one side; horizontal sinking silver: less than 500mm on one side; lead/lead-free spray tin: 520*650mm; OSP: less than one side 500mm; electroplated hard gold: 450*500mm; no more than 520mm on one side
Processing size (MIN) Shen tin: 60*80mm; immersion silver: 60*80mm; lead/lead-free spray tin: 150*230mm; OSP: 60*80mm; smaller than the above size
Processing plate thickness Shen Jin: 0.2-7.0mm, Shenyang Tin: 0.3-7.0mm (vertical sinking tin wire), 0.3-3.0mm (horizontal wire); immersion silver: 0.3-3.0mm; lead/lead-free spray tin: 0.6-3.5mm ; 0.4mm below the tin plate needs to be reviewed; OSP: 0.3-3.0mm; electroplated hard gold: 0.3-5.0mm (thickness ratio 10:1)
Immersed gold plate IC minimum spacing or PAD to line minimum spacing 3mil
Gold finger height is the largest 1.5inch
Minimum spacing between gold fingers 6mil
Segmented gold finger minimum segment spacing 7.5mil
Surface treatment Spray tin 2-40um (the thinnest thickness of lead-spray tin tin is 0.4um, the thinnest thickness of lead-free tin-plated tin is 1.5um)
OSP Film thickness: 0.2-0.4um
Chemical nickel-plated gold Espessura do níquel: 3-5um; espessura do ouro: 1-3uinch, ≥3uinch precisam ser revisados
Prata de imersão química 6-12uinch
Estanho químico Espessura de estanho ≥1um
Ouro duro galvanizado 2-50uinch
Chapeamento de ouro macio Espessura de ouro 0,10-1,5um (processo de revestimento de filme seco), espessura de ouro 0,10-4,0um (processo de revestimento de filme não seco)
Níquel paládio químico NI: 3-5um , Pd : 1-6uinch , Au : 1-4uinch
Níquel paládio químico Espessura do ouro 0,025-0,10um, espessura do níquel ≥3um, espessura da base do cobre máximo 1OZ
Dedo de ouro banhado a níquel Espessura do ouro 1-50uinch (o valor necessário se refere ao ponto mais fino), espessura do níquel ≥ 3um
Óleo de carbono 10-50μm
óleo verde Óleo de cobertura de cobre (10-18um), óleo de cobertura sobre o orifício (5-8um), canto da linha ≥5um (uma impressão, espessura de cobre 48um ou menos)
Cola azul 0,20-0,80mm
perfuração Espessura máxima de perfuração mecânica de 0,1 / 0,15 / 0,2 mm 0,8 mm / 1,5 mm / 2,5 mm
A abertura de perfuração a laser é a menor 0,1 mm
Laser drilling aperture is the largest 0,15 mm
Mechanical hole diameter (finished product) 0.10-6.2mm (corresponding to the drill 0.15-6.3mm)
PTFE material (including mixed pressure) board minimum finished hole diameter 0.25mm (corresponding to drill 0.35mm)
Mechanical buried blind hole diameter ≤0.3mm (corresponding to drill 0.4mm)
The hole diameter of the green hole plug hole in the disk is ≤0.45mm (corresponding to the drill 0.55mm)
The minimum aperture of the hole is 0.35mm (corresponding to the drill 0.45mm)
Metallized half hole aperture minimum 0.30mm (corresponding to drill 0.4mm)
Through hole plate thickness to diameter ratio maximum 20:1 (excluding ≤0.2mm tool diameter; >12:1 to be evaluated)
Laser drilling depth aperture ratio maximum 1:1
Mechanically controlled deep drilling blind hole depth aperture ratio maximum 1.3:1 (aperture ≤0.20mm), 1.15:1 (pore diameter ≥0.25mm)
Mechanically controlled deep drilling (back drilling) with minimal depth 0,2 mm
Drilling – mechanical drilling to conductor minimum distance (non-buried blind hole plate and first-order laser blind hole) 5.5mil (≤8 layers); 6.5mil (10-14); 7mil (>14 layers)
Drilling – mechanical drilling to conductor minimum distance (mechanical buried blind plate and second-order laser buried blind hole) 7 mil (primary press); 8 mil (secondary press); 9 mil (three press)
Drilling – mechanical drilling to the minimum distance of the conductor (laser blind buried hole) 7mil(1+N+1);8mil(1+1+N+1+1或2+N+2)
Drilling – laser drilling to conductor minimum body distance (1, 2nd order HDI board) 5mil
Drilling – the smallest distance between different network hole walls (after compensation) 10mil
Perfuração - a menor distância entre as mesmas paredes do furo da rede (após a compensação) 6mil (através do orifício; orifício cego para laser); 10mil (buraco enterrado cego mecânico)
Perfuração - a distância mínima entre as paredes não metálicas do furo (após compensação) 8mil
Perfuração - tolerância do furo (em comparação com os dados CAD) ± 2mil
Perfuração - A tolerância do diâmetro do furo NPTH é mínima ± 2mil
Perfuração - precisão da abertura do orifício do dispositivo sem solda ± 2mil
Perfuração - Tolerância à profundidade do furo cônico ± 0,15 mm
Tolerância de diâmetro de orifício de furo cônico de perfuração ± 0,15 mm
Pad (anel) As almofadas internas e externas do orifício do laser são as menores 10mil (furo do laser de 4mil), 11mil (furo do laser 5mil)
Tamanho mínimo das almofadas internas e externas nas vias mecânicas 16mil (abertura de 8mil)
O diâmetro da almofada BGA é o menor Processo de spray de chumbo de 10mil, processo de spray de estanho sem chumbo 12mil, outros processos de 7mil
Tolerância de almofada (BGA) +/-1.2mil (pad <12mil); +/-10% (pad ≥12mil)
Line width/pitch Limit line width corresponding to copper thickness
1/2OZ:3/3mil
1OZ: 3/4mil
2OZ: 5/5mil
3OZ: 7/7mil
4OZ: 12/12mil
5OZ: 16/16mil
6OZ: 20/20mil
7OZ: 24/24mil
8OZ: 28/28mil
9OZ: 30/30mil
10OZ: 32/30mil
Line width tolerance ≤10mil:+/-1.0mil
>10mil:+/-1.5mil
Solder mask character Soldering plug hole maximum drilling diameter (two sides cover oil 0.5mm
Solder mask ink color  yellow, black, blue, red, white, purple, matte green, dumb oil black, high refractive white oil
Character ink color White, yellow, black
Blue rubber aluminum plate plug hole diameter 5mm
Resin plug hole drilling aperture range 0.1-1.0mm
Resin plug hole thickness to diameter ratio 12:1
Solder solder bridge minimum width Green oil 4mil, variegated 6mil control soldering bridge requires special requirements
Minimum character line width White character 3mil high 24mil; black character 5mil high 32mil
Minimum spacing of hollow words Hollow width 8mil high 40mil
Solder mask Hollow width 8mil high 40mil
shape V-CUT does not leak copper centerline to graphic distance H ≤ 1.0 mm: 0.3 mm (20° means V-CUT angle), 0.33 mm (30°), 0.37 mm (45°);
1.0<H≤1.6mm:0.36mm(20°)、0.4mm(30°)、0.5mm(45°);
1.6<H≤2.4mm:0.42mm(20°)、0.51mm(30°)、0.64mm(45°);
2.4<H≤3.2mm:0.47mm(20°)、0.59mm(30°)、0.77mm(45°);
V-CUT symmetry tolerance ±4mil
The largest number of V-CUT lines 100
V-CUT angular tolerance ±5degree
V-CUT angle specification 20, 30, 45 degrees
Gold finger chamfer angle 20、30、45degrees
Gold finger chamfer angle tolerance ±5度
The minimum distance from the TAB to the gold finger 6mm
Minimum distance between the side of the gold finger and the edge of the profile 8mil
Control deep groove (edge) depth accuracy(NPTH) ±0.10mm
Dimensional accuracy (edge to edge) ±8mil
Milling slot slot tolerance(PTH) Groove width and groove length are ±0.15mm
Milling slot slot tolerance(NPTH) Groove width and groove length are ±0.10mm
Drill slot slot minimum tolerance(PTH) Groove width direction ±0.075mm; slot length/slot width <2: slot length direction +/-0.1mm; slot length/slot width ≥2: slot length direction +/-0.075mm
Drill slot slot minimum tolerance(NPTH) ±0.05mm in the groove width direction; groove length/slot width <2: groove length direction +/-0.075mm; groove length/slot width ≥2: groove length direction +/-0.05mm