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Asse mb ly In st ruct i on s 0100 5- Pac ket E di tio n 1 2 /20 07 72 4. 1. 2. 1 Err or : Bad Er r o r Ra te Compon ents are placed flipped, uprig ht or tilted at the nozz le when viewing the vision life image; Compon en…

Assembly Instructions 01005-Packet

Edition 12/2007

4.1.2 (Error Detection (Fine tuning)

The following actions serve as a check list for improvement of the pickup rate and the DPM rate.4

Various tests showed that a bad pickup rate affects the quality of the placement. If the components

rest highly excentric, flipped, tilted or reversed on the nozzle after pickup, the components might

shift out of place or may be inserted inaccurately when impinging onto the soldering paste storage.

That is primarely the case, when the vision system allows for this due to wrong component mea-

surements or too large tolerance entries in the component shape description. Hence it is important

to ensure that real component dimensions are used and that the entries for tolerance strike a sen-

sible balance between too many vision errors and a secure pickup. The values for component di-

mensions or pickup tolerances entered into the default component shapes should serve as

reference values. These might vary depending on the component manufacturer, the component

type or the quality criteria. Therefore it is possible that a component type produced by different

manufacturers requires the construction of different component shapes. 4

Vision errors can be analyzed subsequently in the "View" => "Vision Measurements" menu. This

allows for a quick assessment whether a damaged component, inferior component shape descrip-

tions or a flawed pickup process are the error cause. Distorted or partially fractured components

are a sign of defective components. Tolerance discrepancies in frame measurements are far more

frequent though. 4

Additionally, differences in brightness at the passivation layer with terminators can lead to face

down recognition errors. 4

The quality of the soldering paste print further determines the placement quality. The use of too

much soldering paste or lthe build up of lobe structure during the print process will influence the

placement accuracy. The use of dried-up or too little soldering paste corrupts the component grip

onto the PCB. This increases the danger of components being pulled-up by the nozzle after place-

ment. 4

Assembly Instructions 01005-Packet

Edition 12/2007

4.1.2.1 Error: Bad Error Rate

Components are placed flipped, upright or tilted at the nozzle when viewing the vision life image;

Components jump out of the component pocket or stick to the extracted tape foil during feeder

synchronizing. 4

– Causes at the feeder:

– Does the feeder synchronize with delay? > Remove extracted tape foil from feeder > Tape

must unroll smooth-running from tape reel!

– Is the pickup position or the pitch set correctly?

– Is the feeder cover cap closed properly?

– Is the discharged spacer available?

– Is the foil extraction clean?

– Is the correct feeder 00176100.xx in use?

– Is the tape placed onto the spacer or does it bounce?

– Does the feeder stay in pickup position during synchronizing?

(Verification suggestion: via LP camera in the ("Display setup" => "Correct position") menu.

Pickup position will be started up. If the feeder is synchronized repeatedly, the pickup posi-

tion must not move around).

– Causes at the machine:

– Is the feeder position recognition active?

– Has the component pocket not been recognized properly during feeder position recogni-

tion? (Verification suggestion: via LP camera in the (Display setup > Correct position menu).

If necessary, repeat the feeder position recognition with the component in the tape slot (Dis-

play setup > Feeder position recognition).

– Is the automatic compressed air switch off active? Reduce switch off time, if necessary.

– Are the nozzles soiled, worn out or put on the wrong way? Verification possibility through

individual functions (Gantry > <Nozzle offsets revolver head > new measurement).

– Replace all nozzles displayed as soiled or worn out with clean ones.

– For SIPLACE D4 only: Has the changeover table height been adjusted so that the feeder

position recognition will function reliably?

Assembly Instructions 01005-Packet

Edition 12/2007

– Causes at the components:

– Is the tape cover foil sticky?

– Do the components slip easily out of the component pockets when the tape cover foil is

stripped off?

– Have the components been stored in an area too dry? After opening the component tape

packaging, wait a few moments until a humidity exchange between the environment and

the component tape has taken place. (approx. 30min depending on the difference in humid-

ity).

4.1.2.2 Error: Face-Down Error, GF Out of Tolerance (Vision Error)

Wrong face-down error at resistors; Component shape measurements out of tolerance 4

– Causes at the machine:

When dealing with the 01005 resistors, we recommend to activate the face-down recognition in

the component shape description. This will set the default value for a grey zone limit of 127 for

flipped components. In order to determine the exact value, during pickup you can wait until a com-

ponent actually sits flipped at the nozzle and this is displayed as face-down in the vision errors.

Go to View => "Vision measurement context" to activate this vision dump and use the cursor to

define the grey tone for the component upper side. In addition, you need the grey tone for the com-

ponent lower side. You can determine the grey tone for example in the => "Measure component

and edit component shape data" => "Test component" menu. Use the pointer and move to the

component lower side. The mean value of both grey tones yields the threshold value for the face-

down recognition. Enter this threshold value at the station in the "Measure component and edit

component shape data" => "Manipulate allgorithm parameter" => "Face Down" menu. 4

A mean value around 80 for Rohm and Kamaya resistors proved to be useful. 4

If too many vision errors for component shape measurements out of tolerance are displayed, we

recommend to enter the real component measurements into the component shape. In order to do

so, pick up a component in the "Measure component and edit component shape data" => "Test

component" => menu and read out the measured value in component length and component

width in the "Dimension results" option. Repeat this action and compute the mean value. When

you are finished, enter the real component length and component width into the component shape

description. 4

– Causes at the components:

The dimension values for 01005 components are usually specified with a length of 0,4mm and a

width of 0,2mm at a tolerance of +- 20µm. In our experience the condenser dimensions are more

likely to lie in the lower tolerance limits. They are therefore a little smaller than the resistor dimen-

sions. This should be taken into account with the dimensions in the component shape descrip-

tion. 4