IPC9850_Surface Mount Equipment Characterization.pdf - 第8页

IPC-9850 Official Proposal May 2001 8 SEMI E10-0699E Standard for Definition and Measurement of Equipment Reliability (Semiconductor Equipment and Materials International 805 East Middlefield Road Mountain View, CA 94043…

IPC-9850

Official Proposal

May 2001

dev

refers to the placement error in the Y-direction direction (perpendicular to the “9850 Verification” label found

on the Placement Verification Panel).

θθ

dev

refers to the rotational placement error (about the component’s X-Y area centroid location).

Overhang refers to the portion of the lead’s width, at the lead’s tip, that extends off of the land’s edge. Overhang I

is due to placement error jointly caused by the X, Y, and θ deviations.

Assist is defined as an unplanned interruption that occurs during an equipment cycle where all three of the following

conditions apply:

• The interrupted equipment cycle is resumed through external intervention (e.g., by an operator or user, either

human or host computer).

• There is no replacement of a machine part (defined specifically to distinguish from component parts being

placed by the machine), other than vendor specified machine consumable parts.

• There is no further variation from specifications of equipment operations.

Build Time - The amount of time it takes the machine to pick and place all the components. This time period

includes fiducial read time and nozzle change time if any.

Failure is defined as any unplanned interruption or variance from the specifications of equipment operation other

than assists. Specifically, some part of the placement machine has to be replaced or the machine had to be turned off

and then back on in order to continue production.

Net Throughput - The number of Components Per Hour (CPH) the machine can place on the verification PVP.

Preventive Maintenance (PM) is a machine stop required by the supplier's published PM schedule.

Repeatability is defined as one standard deviation of the placement error when placing multiple components upon

multiple boards.

Tact Time - The average time required to place a single component while maintaining the specified placement

process capability. Excludes transfer time, fiducial time and nozzle change time.

Total Tact Time - The time required to place all components on verification glass verification panel while

maintaining the specified placement process capability. Excludes Transfer Time, Fiducial Time and Nozzle Change

Time.

Transfer time – The total transport time in and out of the machine, excluding the time the panel spends in the work-

area.

• Movement in and out of work area

• Time to clamp/release the board in the work area

Land The termination areas on the PWB referred to by the IPC-T-50 Terms and Definitions as a portion of a

conductive pattern usually, but not exclusively, used for the connection and/or attachment of components, also

commonly referred to as pads.

1.8 Units of Measurement All dimensions in this document are provided in hard metric (SI) followed by soft

English/Imperial in brackets. All components are referenced as a metric definition, i.e. 1608C is equivalent to the

0603 (60milx30mil) component type.

2. Referenced Documents

IPC-A-610 Acceptability of Electronic Assemblies

IPC-SM-782 Surface Mount Design and Land Pattern Standard

IPC-T-50 Terms and Definitions for Interconnecting and Packaging Electronic Circuits

IPC-9850

Official Proposal

May 2001

SEMI E10-0699E Standard for Definition and Measurement of Equipment Reliability (Semiconductor Equipment

and Materials International 805 East Middlefield Road Mountain View, CA 94043-4080)

MSA-2 Measurement Systems Analysis Second Edition February 1995 published by AIAG (Automotive Industry

Action Group, 26200 Lahser Road Suite 200, Southfield MI 48034

IPC/EIA J-STD-001 Soldered Electrical and Electronic Assemblies standard (sometimes called the National

Soldering Standard)

3 Placement Performance Metric

3.1 Machine Performance Form IPC-9850-F1

This form (see 7 Forms) serves two distinct functions. One is to report the general performance by machine model

type. The second is to validate the performance of each machine shipped, as identified by serial number.

The top of the form is divided into two sections. At the top left is a region for identifying the vendor and machine

model. At the top right there is a region for use only when the form is utilized for performance validation:

• Serial Number

• Build Date and Time

The following information is reported in the body of the form, which is divided into four sections.

Section I informs of the Test Conditions during the build that generated the data reported in form Sections II, III and

IV. The conditions are:

• Number of Heads/Spindles

• Type of Heads/Spindles

• Type of Camera

• Number of Feeders/Trays

• Type of Nozzles

• Number of Nozzles

• Number of Panels Built

• Number of Parts Per Panel

and describe the hardware and software setup of the equipment for the reported results.

Section II presents the time-based parameters measured during the build cycle as components are placed. The

parameters are

• Build Time, seconds

• Transfer Time, seconds

• Tact Time, seconds

The Net Throughput (in CPH) also is attained from the time-based parameters.

Section III and IV present CMM measured and analyzed performance parameters attained for the panels populated

during the data collection for Section II while under the equipment setup of Section I:

• Repeatability (one standard deviation)

• Accuracy Spec. Limits for Cpk=1.33 for

• Accuracy Spec. Spec. Limits for Cpk=2.0

• Cpk for Termination-to-Land 50% Coverage

• Cpk for Termination-to-Land 75% Coverage

The Repeatability and Accuracy parameters are individually calculated for the X-axis, Y-axis, and θ rotation, while

the Termination-to-Land calculations integrate the X-axis, Y-axis, and θ rotation placement errors. See Section

3.4.3.2.2 (Cpk for Termination-to-Land Coverage) for details.

Appendix D provides a guide for two possible methods of measuring the center locations of the components to attain

the measurement error.

IPC-9850

Official Proposal

May 2001

3.1.1 General Performance When IPC-9850 is used, Form IPC-9850-F1 shall be used to present the placement

capability of a specific machine model when the metric is derived using the methodologies of this standard.

Completed copies of this form shall be used as part of a placement machine model’s documentation and

performance package (i.e. it applies to all machines of the model type listed).

3.1.2 Performance Validation Form IPC-9850-F1 shall be used to validate the performance of a specific individual

machine prior to customer delivery. The vendor shall provide the customer form IPC-9850-F1 with data for at least

one component type placed by that specific machine and derived using the methodologies of this standard. The

vendor shall provide data for the most representative component placed by that machine, or as otherwise agreed

upon between the customer and the supplier. When form IPC-9850-F1 is used to validate a specific machine, the

serial number of the machine and the date of the build shall be provided.

A specific exception is provided for the performance verification using the 1608C component type only. The

exception is that the supplier may choose to measure only rows 1, 5, 9, 13, 17, and 20 (where row 1 is defined to be

the first horizontal line of components above the ‘IPC 9850 Verification Panel’ text) per panel when verifying the

performance of the shipping machine. This exception is granted in order to reduce the time suppliers spend in

preparation to ship a machine, specifically to reduce the CMM measurement time and to reduce the amount of tape

stretch the components on the panels waiting to be measured are exposed to after placement but prior to

measurement. However, the panel must still be populated with all 400 components in according to the procedures of

this standard.

Supplier commitments regarding all component types shown in IPC-9850-F1 that are within the capability claims of

the equipment must be included in the Machine Model type evaluation. Additionally, columns for other component

types may be added at vendor discretion. If this is done, these guidelines shall be followed:

1) at least 30 components/ slugs, or as many as will fit on the 8” x 8” Placement Verification Panel.

2) All 4 orientations must be utilized equally (unless the placement machine is not capable of placing at multiple

orientations).

3) The entire width and length of the area inside the Placement Verification Panel’s fiducials should be used.

4) The placement pattern should be reasonably balanced, density-wise, from left-to-right and top-to-bottom.

5) For boards shall be run.

6) If the pattern contains less than 100 parts, all parts shall be measured.

7) If the pattern contains at least 100 parts, then if orientation is identical throughout a row, a systematic sample of

columns must be measured for accuracy, while if orientation is identical throughout a column, then a systematic

sample of rows must be measured for accuracy.

3.2 Characterization Methodology

3.2.1 Background Many methods for evaluating the performance capabilities of placement equipment have been

employed in the past. The preferred method for this standard utilizes a non-contact optical CMM for measuring the

location of components with respect to panel fiducials. This method was selected because many vendors and users

have extensive knowledge of the method and have already developed evaluation and diagnostic tools utilizing

optical CMM equipment.

The characterization methodology for obtaining numeric values for the specified parameters was designed to be

repeatable and reproducible, and independent of a specific user product. To meet this goal, a standard PVP is

specified as a common test substrate for all procedures (see Section 6.1). This test vehicle is laminated with a layer

of adhesive that is used to capture and hold the mounted components.

The characterization procedure yields a set of performance parameters. These parameters are evaluated through the

population of four PVPs. The four panels must be populated consecutively by the machine, as though they were four

adjacent PWBs in a production environment. Machines that buffer PWBs pre and post population may utilize

additional panels to obtain the appropriate pulse rate, however only four consecutive panels are used for the analysis.

PVP carriers may be used at vendor’s discretion, as long as the carrier supports exactly one PVP. See Appendix I for

a PVP carrier designed by committee members.

3.2.1.1 Component-to-Component Variability Variability due to component-to-component physical differences is

reduced through the use of glass slugs to represent the QFP-100, QFP-208 and BGA-256 fine-pitch components.