Wave Soldering Solder Quantity Estimation Program

- Polliwog Solder Checker

Needs

Increasing needs for calculation for solder quanties depening on increasing oursourcing of PCB Assembly companies.

Needs for solder quantity calcuation for one model depending on various/small quantity product.

Increasing Soldering Cost by "Lead Free".

img1.gifPrevious Soldering Caculation Methods.

1. Weight calculation before/after Soldering + (Loss).

2. Lot model weight calculation and multiplying quantities (in case of mass production).

3. Partially applying simple calcuation method.

img1.gifProblems in Previous Soldering Calculation Methods

1. Mass Weighting Accuracy.

(hundred)s errors in gram(s) in assembly weight variation.

(hundred)s g ->1.0 g(unit)

small g -> 0.1 g(unit) (minimize)

2. A Lot of Product Models.

same application in main model for mass production.

ignore small error aberration.

3. No evidency for proper Quantity.

differenent production line result in different quantities.(require proper quantity estimation)

soldering variables and loss management for companies.

4. Difficulties for prediction.

can find out after assembly.

soldering schedule?

cost for changing solder paste material?

Solder Quantity Prediction Software Development Concept.

- Accuracy Quantity extraction from ECAD data by extacting shape of solder paste shape.

Design Factor

Process Factor

Circular

- Land Type

  Lead / Bare

- Land Diameter

- Hole Diameter

- Lead Type

  Clinch / Straight

Machine

- Fluxing Type

  Spray / Bubble

- Speed

- Temerature

- Oxidation

Irreqular

- S/R Open

Mainteance

- Solder Pot Change

- Solder Surface Remove

Developing Ways.

1. Extract weight calculation function for each design.

img1.gif Target : Change design factor area depending function through mass weighting laboatory work.

                 We define process factor as constant.

"Solder Amount in Wave Soldering  = F(design, process) = f(area) + C"

Lead Type

  

After Increasing Area

  

Lead

Clinch

YLC = fLC(area)

Straight

YLS = fLS(area)

Bare

Circular

YBC = fBC(area)

Inregular

YBI = fBI(area)

SMD

Gull Wing

YSG = fSG(area)

Chip

YSC = fSC(area)

2. Dimension Calculation Software for Design.

img1.gif Target : Using ECAD data, classify solder joint depening on design case and calculate solder quantities by using f(area) function after calculating each pads dimension.

img1.gif Software requirements

1. Major ECAD Interface.

Cadene, Mentor, Zuken, PADS, PCAD

2. Design Case recognition.

Calculation dimension after calssifying Lead, Bare and Irregular shape.

3. Irregular shape accuracy.

Calculation dimension for dummy land and various solder open shapes.

4. Various Soder shapes.

All alloyed solder metal quantity calculation.

3. Weight Calculation Function

img1.gif Laboratory Work for Bare - Circle / Irregular

img1.gif Laboratory Work for Lead - Clinch / Straight

straight

Clinch

img1.gif Laboratory Work for bare SMD

- Chip (1608R/C, 2125R/C, 3216R/C)

- IC (0.65Pitch)

img1.gif Laboratory Work for Component Mounted SMD

4. Weight Extraction Function Completion

X axis - dimension(mm^2), Y axis - Weight (gram)

5. Experimental Results

Solder Quantity Prediction Program

Logic for Wetting dimension extraction

1. Land area calculation in S/R (except Hole area)

2. Copper area calculation in S/R (except Land area)

Solder Quantity Prediction Program Feature.

- Solder wetting dimension extracting feature for all design type, shape and routing and solder resisit.

Final UI for Solder Quantity Prediction Program.

 Metal Mask & Solder Paste Amount Analyzing Program

- Polliwog Metal Mask Checker

Needs

Manufacturing Engineers need to check board file.

Needs to calculate accurate solder paste quantities.

Check Meatl Mask Dimension related to soldering quality.

Solder Paste Quantity Calculation

Individual Land / Component Solder Paste Quantity Calculation  - Process/Quality Control.

Calculation for Solder Paste for one Board  - Cost.

Calculation for Various Alloyed Metal / Flux - Extract Cost for Materials.

Metal Mask Analyzing

Check Pads not having Metal Mask.

Check Changed Specification.

Verify Dimension for individual Pad.

Devlopment Guide

"Solder Past Weight = Volume * Dimension"

img1.gifVolume - Calculate in PollEx Solder/Metal Mask.

Using CAD data, automatically calculate solder/paste volume after getting metal mask dimension.

img1.gifDesity - Extract from experimentation(laboratory work).

Software Requirement

1. ECAD Interface for major ventor / major EDA format.

Cadence, Mentor, Zuken, PADS, PCAD, Gencad, Gerber...

2. Solder Paste quantity calculation

Accurate quantity calculation for single Pad and all Pads in whole board.

Accurate quantity calculation for all Alloyed-Metal.

3. Mask Dimension verification feature.

Comparing feature for PCB Pads and metal mask holes.

4. Missing Mask comparing feature.

Comparing feature for PCB Pads and metal mask holes.

Way of extracting Density.

Type

Solder Paste Metal

Flux(%)

Manufacturer

Model

A

63Sn/37Pb

11

Alpha-Metal

RMA2007

B

62.8Sn/36.8Pb/0.4Ag

10

TAMURA

RMA-012FP

C

96.5Sn/3.0Ag/0.5Cu

12

KOKI

S3X58-M310-3

img1.gifPrint.

Printing Dimension : 6.63661448mm3

img1.gifWeight Calculation.

Electronic digial balance : 0.0000 Digit

img1.gifDensity of Alloyed-Metal Solder

gr. for Solder Alloyed-Metal calculation Table

Metal

Density

composition(wt %)

Vx

[g/ml]

[g/mm^3]

Sn

7.3

0.0073

96.5

13.21918

Pb

11.4

0.0114

0

0

Ag

10.5

0.0105

3.0

0.285714

Cu

8.96

0.00896

0

0

Zn

7.14

0.00714

0

0

Bi

9.8

0.0098

0

0

Al

2.7

0.0027

0

0

In

7.31

0.00731

0

0

Sb

6.62

0.00662

0.5

0.075529

Sum

    

100.0

13.58042

Density

      

7.36354[g/ml]

0.007364[g/mm^3]

img1.gifPads Volume Calculation SoftwareDensity of Alloyed-Metal Solder

Metal Mask / Solder Paste analyzing program after accurate ECAD interface(reading).

 img1.gifPads Volume Calculation Software

After Solder Paste Volume calculation, extract weight by mutiplying Paste density.

You would..