tn-12-25: nor land pad design - micron technology...table 5: so8w suggested land pattern dimensions...

Technical NoteLand Pad Design for NOR Flash Memories

IntroductionThis document provides high-level information on Micron's NOR Flash memory pack-ages and their suggested PCB land patterns. For additional information and assistancefor any manufacturability issues, contact your Micron representative or log on towww.micron.com.

Package Outlines and Suggested Land Pattern Designs

The following sections contain detailed mechanical descriptions of Micron's NOR Flashpackages and the related suggested PCB land pattern designs. The suggested land pat-tern (mm) designs were developed using Mentor's PCB Matrix Calculator software,which is based on the IPC-7351B standard. For additional information refer to the NORFlash section of Micron's website.

Figure 1: Key Land Pattern Sizes Definitions (from IPC-7351B)

L

T

L

G

Z

S

S = L - 2 T

0.05“N” places

Manufacturer's dimensions andtolerances converted to profiledimensions, with S at maximummaterial condition.

If S is not provided by the componentmanufacturer, it may be determined bysubtracting T terminal dimensionsfrom the length.

Manufacturing dimensions of SOICs.

MMC

MMC MMC LMC

Fabrication toleranceequals 0.1mm.

There are many options available to determine the tolerances for each component. TheIPC-7351B formulas for calculating the ZMAX distance are shown below (based on theRMS method).

TN-12-25: NOR Land Pad DesignIntroduction

PDF: 09005aef8503ed82tn1225_land_pad_design.pdf - Rev. A 10/13 EN 1 Micron Technology, Inc. reserves the right to change products or specifications without notice.

© 2012 Micron Technology, Inc. All rights reserved.

Products and specifications discussed herein are for evaluation and reference purposes only and are subject to change byMicron without notice. Products are only warranted by Micron to meet Micron's production data sheet specifications. All

information discussed herein is provided on an "as is" basis, without warranties of any kind.

ZMAX = LMIN + 2JT + CL2 + F2 + P2

GMIN = SMAX - 2JH - CS2 + F2 + P2

XMAX = WMIN + 2JS + CW2 + F2 + P2

Where:

ZMAX = overall length of land patternGMIN = minimum distance between land of the patternXMAX = maximum width of the patternSMAX = maximum distance among component terminationWMIN = minimum width of the leadLMIN = minimum distance of the component lengthJT = toe joint dimensionCL = tolerance for component lengthF = fabrication toleranceP = positioning toleranceJH = solder fillet or land protrusion at heelCS = tolerance on distance between component terminationsCW = tolerance on the lead width

Table 1: Tolerance Definitions (from IPC-7351b)

Tolerance Element Description

Compound tolerance The difference of maximum material condition (MMC) and least material condition (LMC) ofeach component dimension length, width, and distance between terminations or leads. Thisnumber is the "C" tolerance in the equations.

Printed board tolerance The difference of MMC and LMC of each land pattern dimension length. This number is the"F" tolerance in the equations.

Positional accuracy The diameter of true position (DTP). This is the variation of the part centroid related to theland pattern theoretical center (includes feature location tolerance from Table 2.

All tolerances for lands are intended to provide a projected land pattern with individuallands at maximum size, while unilateral tolerance will result in a smaller area for solderjoint formation. Land patterns are within these outer and inner extremities.

The LPW tool uses the distance between pin centers ("C" as shown in the land patternfigures) instead of the distance between the pin ends (Z). This is the way most of toolsused in the industry manage that dimension.

Some rounding off of values occurs, which is controlled by the calculator settings tab.These settings should be reviewed and set to meet the user's fabrication and assemblybest practices for their industry and their fabrication/assembly technology. The toleran-ces shown below have been used in all of the land pattern calculations that follow inthis document.

Table 2: Applied Tolerances

Tolerance Element Tolerance (mm)

Land-to-land MIN 0.20




Table 2: Applied Tolerances (Continued)

Tolerance Element Tolerance (mm)

Silkscreen to Land MIN 0.25

Solder mask web MIN 0.075

Fabrication 0.05

Placement 0.05

Land place round-off (C) 0.10

Land size round-off 0.05

Definitions of the areas and dimensions provided in this document:

• Land pattern: The combinations of lands used for the mounting of a particular com-ponent.

• Courtyard: The smallest rectangular area that provides a minimum electrical and me-chanical clearance around the combined component body and land pattern bounda-ries.

• Silkscreen: The printed area of the position where the component body will beplaced, in relation to the orientation indicator.

• Assembly area: Maximum area allowed for component body mounting on the PCB.




SO Packages

Figure 2: Calculated SO Parameters

Silkscreen

R1

Land pattern

C

Y

1

2

3

4

8

7

6

5

X

R2

Courtyard

V1

Assembly

V2

ANOM

BNOM

Table 3: SO Packages and Parameter Values

Package Type Pins Width (mm) Length (mm)

MaxThickness

(mm) Pitch (mm)

SOP2-8 150 mils body width (SO8N) 8 4.9 6 1.75 1.27

SOP2-8 208 mils body width (SO8W) 8 5.28 7.9 2.5 1.27

SOP2-16 300 mils body width (SO16W) 16 10.3 10.3 2.65 1.27

TN-12-25: NOR Land Pad DesignSO Packages



SO8N

Figure 3: SO8N Package Outline

8

1

0.25 mmGAUGE PLANE

0.10 MIN/0.25 MAX

0.40 MIN/1.27 MAX

0o MIN/8o MAX

0.28 MIN/0.48 MAX

0.17 MIN/0.23 MAX

x 45°0.25 MIN/0.50 MAX

0.10 MAX

1.75 MAX/

1.27 TYP

1.04 TYP

1.25 MIN

3.90 ±0.10

6.00 ±0.20

4.90 ±0.10

Note: 1. All dimensions are in millimeters.

Table 4: SO8N Suggested Land Pattern Dimensions

Reference

Land Pattern (mm) Silkscreen (mm) Assembly (mm) Courtyard (mm)

C Y X R1 R2 ANOM BNOM V1 V2

Typical dimension 5.2 1.35 0.55 4.9 3.9 3.9 4.9 6.8 5.2

Note: 1. See Figure 2 (page 4) for suggested land pattern.




SO8W

Figure 4: SO8W Package Outline

8

1 0.00 MIN/0.25 MAX

1.51 MIN/2.00 MAX

5.02 MIN/6.22 MAX

7.62 MIN/8.89 MAX

0º MIN/10° MAX

0.10 MIN/0.35 MAX

0.50 MIN/0.80 MAX

2.50 MAX

6.05 MAX

1.27 TYP

0.40 -0.05+0.11 0.10 MAX


Table 5: SO8W Suggested Land Pattern Dimensions

Reference


C Y X R1 R2 ANOM BNOM V1 V2

Typical dimension 7.5 1.7 0.6 5.15 6 5.62 5.95 9.4 6.3





SO16W

Figure 5: SO16W Package Outline

16

0.23 MIN/0.32 MAX

1 8

9

0.40 MIN/1.27 MAX

0.20 ±0.12.5 ±0.15

10.30 ±0.20

7.50 ±0.10

10.00 MIN/10.65 MAX

0.33 MIN/0.51 MAX

0.1 Z

0° MIN/8° MAX

1.27 TYP

h x 45°

Z


Table 6: SO16W Suggested Land Pattern Dimensions

Reference

Land Pattern (mm) Silkscreen (mm) Assembly (mm)Courtyard

(mm)

C Y X R1 R2 ANOM BNOM V1

Typical dimension 9.2 1.75 0.6 6.8 10.3 7.5 10.3 10.7





DFN Packages

Figure 6: Calculated DFN Parameters

Silkscreen

R1

R2 Y2

Land pattern

C

Y1 X2

2

3

4

X1 1

79

6

5

8

Courtyard

V1

Assembly

V2

ANOM

BNOM

Table 7: DFN Packages and Parameter Values


MaxThickness

(mm) Pitch (mm)

U-PDFN-8 2 x 3mm (MLPA8) 8 2 3 0.6 0.5

U-PDFN-8 4 x 3mm (MLPA8) 8 4 3 0.6 0.8

V-PDFN-8 6 x 5mm (MLP8) 8 5 6 1 1.27

V-PDFN-8 6 x 5mm Sawn (MLP8) 8 5 6 0.9 1.27

VPDFN-8 8 x 6mm (MLP8) 8 6 8 1 1.27

TN-12-25: NOR Land Pad DesignDFN Packages



DFN-8 2mm x 3mm

Figure 7: DFN-8 2mm x 3mm Package Outline

0.55 -0.10+0.05

0.25 -0.05+0.05

0.02 -0.02+0.03

0.50 TYP

0.15 MAX0.30 MIN

0.08 MAX

2.00 -0.10+0.10

1.60 -0.10+0.10

3.00 -0.10+0.10 0.20 -0.10

+0.10

0.45 -0.05+0.05


Table 8: DFN-8 2mm x 3mm Suggested Land Pattern Dimensions

Reference


C X1 Y1 X2 Y2 R1 R2 ANOM BNOM V1 V2

Typical dimension 2.8 0.3 0.75 0.3 1.7 1.3 2 3 2 3.8 2.3





DFN-8 4mm x 3mm


Top View

B

A

0.10 C

0.10 C

2X

2X

Bottom View

Side View

C

0.05 C

0.10 C

Seating Plane

0.20 DIA TYP

0.10 C A B

0.05 C

M

M

Datum A

Datum B

See detail A

Even Terminal/Side

Datum A or B

Detail A

Terminal Tip

1 2

0.127 MIN/0.15 MAX

0.80 TYP

0.80 TYP

0.40 TYP

0.02 -0.02+0.03

0.55 -0.10+0.05

//

0.60 ±0.05

8 x (0.30 ±0.05)

0.20 ±0.10

4.00 ±0.10

0.80 ±0.10

8 x (0.60 ±0.05)

3.00 ±0.10

2 3 41

5678

(See note 1)



Reference

Land Pattern (mm)2 Silkscreen (mm) Assembly (mm) Courtyard (mm)

C X1 Y1 X 2 Y2 R1 R2 ANOM BNOM V1 V2

Typical dimension 2.6 0.35 0.95 0.3 2.4 3 4 3 4 3.8 4.3

Notes: 1. See Figure 6 (page 8) for suggested land pattern.2. The software used to generate the land pattern dimensions, does not have the capabili-

ty to split the thermal tab in two as shown in the drawing above. Please consider doingone of the following:1) Screen print such that the part is not lifted excessively by the solder, or2) Break the thermal tab in two with .05mm clearance around the pad, similar to dimen-sion X2.




DFN-8 6mm x 5mm


0.20 TYP

Seating planeLeads coplanarity

Pin 1 IDlaser marking

1.27TYP

3.00 ±0.20

0.6 +0.15

-0.1

0.02 +0.03-0.02

0.40 +0.08-0.053.00 ±0.20

0.90 ±0.10

C

6 TYP

Pin 1 IDPin 1 IDoption

5 TYP

0.08 C

0.1 C



Reference








DFN 5mm x 6mm (Not Sawn)

Figure 10: DFN 5mm x 6mm (Not Sawn) Package Outline

12°

0.20 TYP0 MIN/

0.05 MAX

5.75 TYP

Pin oneindicator 1.27

TYP4 +0.30-0.20

0.60 +0.15-0.10

0.85 +0.15-0.05

0.40 +0.08-0.053.40 ±0.20

θ

0.10 MAX/0 MIN

C

A

B

M

2x

6 TYP

4.75 TYP

0.05

5 TYP

0.65 TYP

0.10 C B

0.10 C A

0.15

CB

0.10

CA

B

0.15 C A


Table 11: DFN 5mm x 6mm (Not Sawn) Suggested Land Pattern Dimensions

Reference








DFN-8 8mm x 6mm


8.00 TYP

6.00 TYP 4.80 TYP

5.16 TYP0.2MIN

0.50 -0.05+0.10

(NE

- 1)

× 1

.27

TYP

Pin 1 IDØ0.3

1.27TYP

8

7

6

5

1

2

3

4

0.05 MAX

0.40 +0.08-0.05

0.85 TYP/1 MAX

Pin 1 ID R 0.20

ddd C

bbb C

Mee

eC

AB

aaa CA

B

aaa

C

Mff

fC



Reference



Typical dimension 7.7 0.45 0.9 5.15 4.8 8 6 8 6 8.8 6.4





TSOP Packages

Figure 12: Calculated TSOP Parameters

Land pattern

Assembly

ANOM

BNOM

R2

Y

X

V2

C

123456789101112131415161718192021222324

484746454443424140393837363534333231302928272625

Silkscreen

Courtyard

V1

R1

Table 13: TSOP Packages and Parameter Values


MaxThickness

(mm) Pitch (mm)

TSOP48: 12mm x 20mm 48 12 20 1.2 0.5

TSOP56: 14mm x 20mm 56 14 20 1.2 0.5

TN-12-25: NOR Land Pad DesignTSOP Packages



TSOP-I 48 12mm x 20mm

Figure 13: TSOP-I 48 12mm x 20mm Package Outline

DIE

1

24

48

25

0.50 TYP

0.10 MAX

0.10 MIN/0.21 MAX

0.60 +0.10

+3o 2o

3o

0.22 +0.05

0.10 +0.05

1.20 MAX1.00 +0.05

0.80 TYP

20.00+0.20

18.40+0.10

12.00+0.10


Table 14: TSOP-I 48 12mm x 20mm Suggested Land Pattern Dimensions

Reference


C X Y R1 R2 ANOM BNOM V1 V2

Typical dimension 19.5 0.25 1.1 17.75 12 18.4 12 20.7 12.3





TSOP-I 56 14mm x 20mm

Figure 14: TSOP-I 56 14mm x 20mm Package Outline

DIE

28

1 56

29

0.50 TYP

0.10 MAX

0.10 MIN/0.21 MAX

0.60 +0.10

0.22 +0.05

0.10 +0.05 +3o 2o

3o

1.20 MAX1.00 +0.05

20.00+0.20

18.40+0.10

14.00+0.10

0.80 TYP


Table 15: TSOP-I 56 14mm x 20mm Suggested Land Pattern Dimensions

Reference


C X Y R1 R2 ANOM BNOM V1 V2

Typical dimension 19.4 0.25 1.1 17.65 14 18.4 14 20.7 14.3





QFP Packages

Figure 15: Calculated QFP Parameters

Land pattern

R2

Y

X

C1

123456789101112131415161718192021222324

25 27 29 31 33 35 37 39

80 78 76 74 72 70 68 66

26 28 30 32 34 36 38 40

79 77 75 73 71 69 67 65

646362616059585756555453525150494847464544434241

Silkscreen

R1

BNOM

Assembly

ANOM

C2 V2

Courtyard

V1

QFP 48 12mm x 20mm

QFP assumptions:

• Toe (outside) goal = 0.15• Toe MIN = 0.17• Toe MAX goal = 0.43• Heal (in side) goal = 0.25• Heal MIN = 0.23• Heal MAX = 0.57• Side goal = 0.25• Side MIN = 0.23• Side MAX = 0.57

TN-12-25: NOR Land Pad DesignQFP Packages



Figure 16: PQFP80 Package Outline

801

+ 0.2517.20

+ 0.1014.00

+ 0.252.80

+ 0.150.800.25 MIN

3.40 MAX

0.10 MAX

12.00 TYP

0.80 TYP

1.60 TYP

0.30 MIN/0.45 MAX

0.13 MIN/0.23 MAX

+0.25

23.20

+0.10

20.00

16

24

18.40 TYP

MIN0oMAX7

o


Table 16: PQFP80 Suggested Land Pattern Dimensions

Reference


C X Y C2 R1 R2 ANOM BNOM V1 V2

Typical dimension 16.3 0.55 1.5 14.1 14.1 20.1 14 20 18 27


TN-12-25: NOR Land Pad DesignQFP Packages



BGA PackagesBGA land pattern calculations are mainly based on ball size, but other features are alsoconsidered. Variations that affect BGA land patterns include pitch, ball diameter, thepositional accuracy of the balls vs. the true position of the component on the PCB, andthe manufacturing allowance that can be held for the land on the substrate that mountsthe ball. Basically, the land pattern of the component (where the ball is attached) andthe land pattern of the substrate mounting structure (PCB) should be as close in size aspossible. Reducing the PCB land size by some percentage of the ball diameter is accept-able as well. The IPC-7351 table below show the parameters that may cause variationsof land pattern needed to describe variations in the system. This data is usually descri-bed at the MMC for NSMD lands.

Table 17: BGA Tolerances (Reproduced from the IPC-7351B Standard)

Tolerance values are in millimetersLand Size

LocationAllowance

BallVariation

PCBFabricationAllowance Nominal

Ball Size% Reduction

from NominalVariation

AllowanceMMC LMC MMC LMC

0.60 0.50 0.10 0.25 0.10 0.75 0.90 0.65 25% 0.29

0.50 0.40 0.10 0.20 0.10 0.60 0.70 0.50 25% 0.24

0.45 0.35 0.10 0.15 0.10 0.55 0.65 0.45 25% 0.20

0.45 0.35 0.10 0.10 0.10 0.50 0.55 0.45 20% 0.17

0.40 0.30 0.10 0.10 0.10 0.45 0.50 0.40 20% 0.17

0.35 0.25 0.10 0.10 0.10 0.40 0.45 0.35 20% 0.17

0.25 0.20 0.05 0.10 0.05 0.30 0.35 0.25 20% 0.15

0.20 0.17 0.05 0.06 0.03 0.25 0.28 0.22 20% 0.08

0.20 0.14 0.05 0.04 0.03 0.20 0.22 0.18 15% 0.07

0.20 0.14 0.05 0.04 0.02 0.17 0.17 0.13 15% 0.07

0.18 0.12 0.05 0.04 0.02 0.15 0.15 0.10 15% 0.07

TN-12-25: NOR Land Pad DesignBGA Packages



BGA Calculated Land Pattern Parameters

Figure 17: BGA Calculated Land Pattern Parameters

24-Ball TBGA land pattern

C2

X

C1

A1

B1

C1

D1

E1

A2

B2

C2

D2

E2

A3

B3

C3

D3

E3

A4

B4

C4

D4

E4

A5

B5

C5

D5

E5

Easy BGA64 land pattern

C2

X

C1

A1

B1

C1

D1

E1

F1

G1

H1

A2

B2

C2

D2

E2

F2

G2

H2

A3

B3

C3

D3

E3

F3

G3

H3

A4

B4

C4

D4

E4

F4

G4

H4

A5

B5

C5

D5

E5

F5

G5

H5

A6

B6

C6

D6

E6

F6

G6

H6

A7

B7

C7

D7

E7

F7

G7

H7

A8

B8

C8

D8

E8

F8

G8

H8

VFBGA56 land pattern

C2

X

C1

A1

B1

C1

D1

E1

F1

G1

A2

B2

C2

D2

E2

F2

G2

A3

B3

C3

D3

E3

F3

G3

A4

B4

C4

D4

E4

F4

G4

A5

B5

C5

D5

E5

F5

G5

A6

B6

C6

D6

E6

F6

G6

A7

B7

C7

D7

E7

F7

G7

A8

B8

C8

D8

E8

F8

G8

TFBGA88 land pattern

C2

X

C1

A1

B1

C1

D1

E1

F1

G1

J1

K1

L1

M1

A2

B2

C2

D2

E2

F2

G2

J2

K2

L2

M2

A3

B3

C3

D3

E3

F3

G3

J3

K3

L3

M3

A4

B4

C4

D4

E4

F4

G4

J4

K4

L4

M4

A5

B5

C5

D5

E5

F5

G5

J5

K5

L5

M5

A6

B6

C6

D6

E6

F6

G6

J6

K6

L6

M6

A7

B7

C7

D7

E7

F7

G7

J7

K7

L7

M7

A8

B8

C8

D8

E8

F8

G8

J8

K8

L8

M8

lBGA80 land pattern

C2

X

C1

A1

B1

C1

D1

E1

F1

G1

J1

K1

A2

B2

C2

D2

E2

F2

G2

J2

K2

A3

B3

C3

D3

E3

F3

G3

J3

K3

A4

B4

C4

D4

E4

F4

G4

J4

K4

A5

B5

C5

D5

E5

F5

G5

J5

K5

A6

B6

C6

D6

E6

F6

G6

J6

K6

A7

B7

C7

D7

E7

F7

G7

J7

K7

A8

B8

C8

D8

E8

F8

G8

J8

K8

TFBGA48 land pattern

C2

X

C1

A1

B1

C1

D1

E1

F1

G1

H1

A2

B2

C2

D2

E2

F2

G2

H2

A3

B3

C3

D3

E3

F3

G3

H3

A4

B4

C4

D4

E4

F4

G4

H4

A5

B5

C5

D5

E5

F5

G5

H5

A6

B6

C6

D6

E6

F6

G6

H6

Table 18: BGA Packages and Parameter Values

Package Type Balls Width (mm) Length (mm)

MaxThickness

(mm) Pitch (mm)

Easy BGA64 10 x 13 x 1.2mm 64 10 13 1.2 1

TBGA24 6 x 8 x 1mm 24 6 8 1 1

LBGA80 10 x 12 x 1.4mm 80 10 12 1.4 0.6

TFBGA88 8 x 10 x 1.2mm 88 8 10 1.2 0.8

TFBGA48 6 x 9 x 1.2mm 48 6 9 1.2 0.8

VFBGA56 7.7 x 9 x 1mm 56 7.7 9 1 0.75




24-Ball TBGA

Figure 18: 24-Ball TBGA Package Outline

Ball A1 ID

1.20 MAX

6 ±0.10

0.20 MIN

1.00 TYP

1.00 TYP

8 ±0.104.00

Ball A1 ID

4.00

0.79 TYP

Seatingplane

0.1 A

A

24X Ø0.40 ±0.055 4 3 2 1

A

B

C

D

E


Table 19: 24-Ball TBGA Suggested Land Pattern Dimensions

Reference

Land Pattern (mm)

C1 C2 X

Typical dimension 4 4 0.35





Easy BGA64

Figure 19: Easy BGA64 Package Outline

Ball A1 ID

0.78 TYP

Seatingplane

0.1

1.20 MAX

1.00 TYP

A

B

C

D

E

F

G

H

8 7 6 5 4 3 2 1

0.5 ±0.1

10 ±0.1

64X Ø0.43 ±0.1

1.00 TYP

8 ±0.1

1.5 ±0.1 Ball A1 ID


Table 20: Easy BGA64 Suggested Land Pattern Dimensions

Reference

Land Pattern (mm)

C1 C2 X






TFBGA48

Figure 20: TFBGA48 Package Outline

Ball A1

5.60 TYP

1.20 MAX

1.00 MAX

0.10 MAX

0.20 MIN

1.00 TYP0.40 TYP

4.00 TYP

0.40 TYP

1.70 TYP

0.80 TYP

0.80 TYP

9.00 + 0.10

0.40 + 0.05

6.00 + 0.10


Table 21: TFBGA48 Suggested Land Pattern Dimensions

Reference

Land Pattern (mm)

C1 C2 X

Typical dimension 4 5.6 0.35





VFBGA56

Figure 21: VFBGA56 Package Outline

A

B

C

D

E

F

G

13572468

Ball A1 IDBall A1 ID

1 MAX

0.2 MIN

56X Ø0.35 ±0.05

7.7 ±0.1

0.75TYP

0.75 TYP

4.5 CTR

9 ±0.1

Seating plane

0.08 A

5.25 CTR

A


Table 22: VFBGA56 Suggested Land Pattern Dimensions

Reference

Land Pattern (mm)

C1 C2 X

Typical dimension 5.3 4.5 0.35





TFBGA88

Figure 22: TFBGA88 Package Outline

13572468

A

B

C

D

E

F

G

H

J

K

L

M

Ball A1 ID88X Ø0.35 ±0.05 Ball A1 ID

1.2 MAX

0.2 MIN8 ±0.1

0.8 TYP

5.6 CTR

0.8 TYP

8.8 CTR

10 ±0.1

Seating plane

0.1 AA


Table 23: TFBGA88 Suggested Land Pattern Dimensions

Reference

Land Pattern (mm)

C1 C2 X

Typical dimension 5.6 8.8 0.35





LBGA80

Figure 23: LBGA80 Package Outline

BALL A1

1.60 MAX

0.40 MIN

0.15 MAX

1.05 MAX

10.00 TYP

12.00 TYP

7.00 TYP

9.00 TYP

0.60 TYP

1.50 TYP

1.50 TYP

1.00 TYP

1.00 TYP

0.50 TYP

0.50 TYP


Table 24: LBGA80 Suggested Land Pattern Dimensions

Reference

Land Pattern (mm)

C1 C2 X






Land Pattern CompatibilitySome small outline (SO) and dual flat no-lead (DFn) packages can use the same landpattern on a PCB. SO8W and DFN8L 6 x 8mm packages have a very similar overall foot-print; both packages fit the same area on the PCB. The shaded areas in the picture be-low indicate the areas that match between the DFN8L 6 x 8mm and the SO8W packages.All of the dimensions for the DFN 6 x 8mm, particularly pads, are smaller than the cor-responding maximum dimensions for the SO8W packages.

Figure 24: SO8W and DFN 6 x 8mm Land Pattern Compatibility

SO8W DFN 6 x 8

Another difference between the packages is the DFN's central conductive pad, whichdoes not require a solder connection. Micron recommends that no PCB traces run be-low the DFN package, because they could short-circuit to the central pad. A recommen-ded trace routing in the PCB specifically for DFN packages is shown in the figure below.

TN-12-25: NOR Land Pad DesignLand Pattern Compatibility



Figure 25: Recommended Trace Routing for DFN and SO Packages

Land pads

Traces

No Yes

The same recommendations apply for SO8N and DFN 8L 5 x 6mm package compatibili-ty. A complete analysis and verification of the design and requirements regarding thevariations between the packages should be made before attempting to match the PCBland pad.

TN-12-25: NOR Land Pad DesignLand Pattern Compatibility



Revision History

Rev. A – 10/13

• Initial release

8000 S. Federal Way, P.O. Box 6, Boise, ID 83707-0006, Tel: 208-368-3900www.micron.com/productsupport Customer Comment Line: 800-932-4992

Micron and the Micron logo are trademarks of Micron Technology, Inc.All other trademarks are the property of their respective owners.

TN-12-25: NOR Land Pad DesignRevision History



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