PC Board Design Checklist

 

For Through Hole Components

This document should be used as a supplement to existing machine General Specifications and IM Design Guidelines.  This document is designed as a checklist rather than a reference for use when examining an existing or new product.  For detailed specifications refer to the appropriate General Specification.

 

PC board considerations

For Axial or Radial auto insertion:

 

  • Is the overall size of the board within specification?  (max/min size varies by machine and board handling type)
  • Is the board thickness within specification?

Possible challenges:

Radial can accept boards from 0.032” to 0.093” thick with no set up change, axial machines require mechanical adjustment to handle thickness variations.

  • If using automatic board handling, is the board shape acceptable?  (i.e. contiguous edges.)

Possible challenges:

Non-contiguous edges, may work but requires testing.  Example, instrument cluster.

  • Is the board a good candidate for panelization?  (i.e. creating multiple images of the same board on one panel for ease of assembly and increased throughput.)
  • Is the board warpage within specification?

Possible challenges:

Warpage can cause issues with insertion as well as clinch angle/length, especially on radial machine.

  • Does the PC board contain location reference holes to allow proper fixturing?

Possible challenges:

If product was previously hand assembled it may not have locating holes.

  • Are the components positioned at 0º and/or 90º with respect to the X axis?

Possible challenges:

Sometimes components are arranged at odd angles because of space constraints or because designer wanted to keep component body straight.  (example: ECCO board.)

  • Are the component hole diameters within specification for each component type (lead diameter) being inserted?

Possible challenges:

Boards currently hand assembled are most likely to have undersize holes.

  • Is there sufficient clearance below the board for the clinched component leads?  Consider the following:
    • Solder bridging to other component leads
    • Solder bridging to via holes or adjacent pads

Note: Universal does not specify required clearance to prevent solder bridging, this should be determined by the customer.  However, obvious cases of conflict should be noted.

  • Is there sufficient clearance for the insertion and clinch tooling?  Take into consideration:
    • Previously inserted IM components
    • Previously placed SM components
    • Workboard holder locating and support fixtures
    • Obstructions on the bottom of the board that could interfere with the clinch or board transfer.

 

Component and tooling considerations

 

Axial

  • Are components packaged properly for automatic insertion?  (Tape and reel/ammo pack)

Possible challenges:

Customer may have “sample” components in bulk, are these components readily available in a taped format?

  • Is the component input tape width (i.e. 26mm or “standard”) compatible with the component hole span?

Possible challenges:

Universal does not offer a machine that can accept 26mm input.  Virtually all components are available in 52mm format, however, a subcontractor may have to deal with “kits” from an OEM that contain 26mm components.

  • Is the insertion tooling (i.e. 5mm, 5.5mm or standard) compatible with the component hole span?

Possible challenges:

Does the product include both very wide and very narrow span components?  Use tooling selection matrix to evaluate best tooling fit.

  • Is the component hole span compatible with the component body length?

Possible challenges:

Be especially careful when moving product from hand assembly to automatic assembly.

  • Is the component body diameter compatible with the board thickness and insertion tooling requirements?

Possible challenges:

Watch out for very thick boards and/or large diameter components.

  • Is the component lead diameter compatible with the insertion tooling?  (i.e. standard vs. large lead)

Possible challenges:

May have to sacrifice (to hand assembly) some insertions at either the large end or the small end of the spectrum.

  • Does the component require a stand off between the body and the PC board?  Components requiring a stand off cannot be inserted with an axial inserter, but may be auto insertable with a radial inserter if packaged in the proper format.

Possible challenges:

“Stand-off” type resistors are more common where high power handling is required, power supplies, monitors, etc.

 

Radial

  • Are components packaged properly for automatic insertion?  (Tape and reel/ammo pack)

Possible challenges:

Customer may have “sample” components in bulk, are these components readily available in a taped format?

  • If components are packaged on tape, use the following “quick check” list to get a general idea of which components may be automatically inserted:  (See note 1 below)
    • Body diameter 13.0mm or less
    • “H” dimension (distance from centerline of feed hole to bottom of component) within acceptable limits
    • Lead diameter within acceptable limits

Possible challenges:

Radial taping specifications are quite involved, use “quick check” list as a sanity check, forward component samples to applications group for detailed evaluation.

  • Are the lead spans of the components compatible with standard automatic radial insertion?  (i.e. 2.5mm, 5.0mm, 7.5mm or 10.0mm)  (See note 2 below)

Possible challenges:

1)    May have to “sacrifice” some components to hand assembly because of tooling footprint issues or span requirements.

2)    Some PCB’s contain components are non-standard span’s, i.e. 2.0mm, 4.0mm.

  • Are transistor leads in line? (i.e. not in a “triangle” configuration)
  • If the component is required to stand off the PC board, are features built into the component lead to accomplish this?

Possible challenges:

Board designer may “require” a certain type of standoff without checking to see if the package is readily available, common with LED applications.

 

Notes:

1)  The simplified guidelines were created to draw attention to the most common areas where components fall outside the limits for auto insertion.  These simplified guidelines should only be used as a general guide.  Component input must meet all criteria called out in the Radial General Specification.

2)         Tooling selection will depend upon insertion span requirements as well as board density considerations.     Muniak98-052B  Revised 01-00

DEK Horizon

Screen Frames  
External (w x l x t) Internal (w x l) Type

Standard

736 x 736 x 38/40mm

(29” x 29”)660 x 660mm

(26” x 26”)DEK 265

Options*

585 x 585mm

 

(23” x 23”)508 x 508mm

(20” x 20”)DEK 260 All common stencil sizes available:

Sanyo, Ekra, Fuji, Panasonic MPM etc.

Image to Stencil position

Centre, Front, Custom  Board Handling

Minimum size

50 x 70 mm

Maximum size

510 x 508 mm *(610 x 508mm)

Thickness

0.2 – 6 mm

Warpage

Up to 8mm including PCB thickness

Underside component

clearance

 

 

Programmable 3- 42mm

Transport conveyors

Programmable motorized

Transport Direction

Left to Right

 

Right to Left

Left to Left

Right to Right

Interface Protocols

All popular interfaces available

Board Location

Patented Over the Top clamps

 

Edge clamping*

Vacuum*

Registration

Fully automatic Vision.  Process Parameters

Print Speed

2 – 150 mm/sec

Print pressure

0 – 20 kg  Software programmable (*closed loop feed back)

Print Gap

0 – 6 mm

Stencil separation

Speed:      0.1 – 20 mm/sec

 

Distance:  0 – 3 mm

Print Modes

ProFlowTM*

 

Print Print

Print Flood

Flood Print

Adhesive

Paste Knead

Programmable: Number, Period, On demand  Vision

Vision System

Cognex 8100 vision system

Camera lighting

Software controlled programmable lighting

Fiducials

2 or 3

Fiducial Types

Synthetic fiducial library or unique pattern recognition

Fiducial size

0.5 – 3 mm

Fiducial position

Anywhere on PCB

Fiducial error recovery

Auto lighting adjustment.

 

Auto fiducial search.

Smart fiducial.

Comparison: Radial II vs. Radial 5 versus Radial 8 and Radial 8xt

Comparison: Radial II vs. Radial 5 versus Radial 8 and Radial 8xt

Updated 11-2004

 

Feature

6346A/6348A

Radial II

6360D

Radial 5

6380A

Radial 8

6380B

Radial 8xt

Benefit

Machine Speed

7,200/Hour

9,200/Hour

16,0000/Hour

21,0000/Hour

Higher throughput.
Main Drive System

Pneumatic

Pneumatic

DC Brushless Servo

DC Brushless Servo

Significant reliability increase.  Lower noise level and higher machine uptime.
Component transfer/CTA

Loader

CTA pneumatic

CTA pneumatic

CTA servo drive

Less maintenance, fewer adjustments, higher speed and reliability
“Off axis” insertion

No

No

No

Yes

Radial 8xt can insert at one degree increments.
Machine Controller

DEC J11

DEC J11

VME 68000

VME 68000

Higher speed, capable of supporting more features than the DEC J11.  Modern architecture, support available.
User interface

UICS

UICS

IM-UPS (Like GSM) USOS

IM-UPS (Like GSM) USOS

Powerful graphical interface with CRT, keyboard, trackball, consistent with GSM products.
Soft Touch Pusher (STP)

No

Yes, pneumatic.

Yes, servo controlled.

Yes, servo controlled.

Stabilizes components during insertion for higher reliability  Servo control means less maintenance, higher performance.
Management Data

Non-user friendly binary format

Non-user friendly binary format

Easily accessible management data

Easily accessible management data.

Displays management data in graph form at the click of a button.  Further improvements on latest Radial 8xt.
Diagnostics

Non-user friendly binary format

Non-user friendly binary format

Menu Driven

Menu Driven

Powerful IM diagnostics allow for easy troubleshooting.
Triple Span Radial available

No

Yes, non standard.

Yes

Yes

Optional tooling available to insert 2.5/5.0/7.5 mm span components
On Line Documentation

No

No

Yes

Yes

Supports quick on-line retrieval of machine operating and maintenance information.
Chain Clip Locating

No

Yes

Yes

Yes

Reliability, fewer adjustments.
100 Station Sequencer available

No

Yes

Yes

Yes

More components/input.
Auto Recovery

No

No

Yes

Yes

Higher PCB quality.
Clinch Scrap Lead Enhancement

No

No

Yes

Yes

Increased uptime.
Odd Form Capability

No

No

Yes

Yes

Smooth servo drive leads to increased component insertion capabilities.
In-Line or Straight back  Sequencer Available

No

Yes

Yes

Yes

Manufacturing floor space.
Single Pivot Clinch

No

Yes

Yes

Yes

Increased uptime/longer tooling life, fewer adjustments.
13mm Body Diameter Component Capability

No

No

Yes

Yes

Increased component insertion capabilities.
Low Part Warning visible to operator.

No

No

Yes

Yes

Audible as well as visual notification to operator on CRT.
Uninterruptable Power Supply

No

No

Standard

Standard

Allow for proper machine shut down and uninterrupted operation during power fluctuation.
Product Trainer

No

No

Yes

Yes

Available CD Rom Software provides on-line training for machine operation.
CE Mark European Code compliance.

No

Yes

Yes, only with auto board handling.

Yes, with OR without auto board handling.

Compliant with European Community safety standards.
4 Tier Light

No

Yes, not configurable.

Yes, user configurable.

Yes, user configurable.

Improved machine status information for more efficient machine operation.
CD-ROM for software loading

No

No

Standard

Standard

Allows for fast loading of software updates and on-line documentation.

 

Global Semiconductor Report

Global Semiconductor Report

New Trends Impacting Electronics Assembly

 

Not only are the ubiquitous “smaller, cheaper, faster” drivers forever reshaping electronics, but the demand for multi-functionality and mobility is also fueling the convergence of the computer, telecommunications, and consumer markets.  Computer games can now be linked to the Internet. Cellular phones can be used to purchase soft drinks and send e-mail.  Bluetooth technology is making wireless data transfer possible for computer and consumer products.  With all of these changes in the products themselves, we can expect to see modifications in their manufacturing requirements.

 

The increasing sophistication of electronics products is driving advances in a number of aspects of electronics assembly, from components and substrates to the materials and processes used in production. We can start to see new trends at the component level.  The explosion of the wireless market and increasing demands for advanced functionality in cellular phones have led to a steady rise in the number of components per phone within the same small space.  Due to the throughput and yield constraints these requirements place on cellular phone manufacturers, we are experiencing a resurgence of multi-chip modules.

 

Because multi-chip modules can be pre-assembled and tested, performance issues affecting yield are typically resolved prior to production of the final product. Additionally, if a performance issue does arise with a multi-chip module, the module can be removed from the circuit and replaced without sacrificing the other components on the circuit board.

 

In turn, the growing volumes of multi-chip modules are driving the need for much smaller (less than 1 mm) and thinner (less than 0.1 mm) dies as well as smaller capacitors (0201).  At the other end of the spectrum, microprocessors and high-end Asics are pushing die sizes above 400 square millimeters and pin counts above 2000 I/O’s. Wafer sizes are scheduled to migrate to 300mm, which will significantly impact all semiconductor-related equipment.

 

On the substrate side of the package, new challenges arise as the demand for advanced packaging and high density rigid and flex substrates increases. Challenges associated with manipulating and imaging these novel carriers and ensuring accurate placement of fine pitch components, which can be compromised by solder mask registrations, are driving changes in equipment handling, illumination (see figure 1) and vision systems.

 

Regarding process, flip chip and wafer level packaging present requirements for new fluxes, new underfills, and flux and underfill combinations with some level of particle fillers and new conductive adhesives. This translates into dispensing, vision and placement challenges for the assembly equipment.  Additionally, the regulatory push in Asia and Europe to eliminate lead will force the use of more lead free solders, whose higher reflow temperatures place more pressure on substrate materials and component reliability.  The drive to eliminate lead will also increase the use of conductive adhesives that require higher pressure and temperature during placement, greatly impacting machine throughput.

 

In light of these challenges, what is the ultimate package?  Unfortunately, there is no ultimate package or silver bullet.  Everyone has a favorite BGA, CSP, and WLCSP “du jour” from different suppliers.  Today’s applications require different permutations of materials and processes, leading to a multiplicity of packages and form factors. The traditional boundaries between component (first level packaging) and card assembly (second-level packaging) have all but disappeared.

 

To handle a myriad of different substrates and new process materials, placement equipment is facing new requirements for increased flexibility and more sophisticated vision systems and lighting schemes. To keep up with the volatility of the market, electronics manufacturers are looking to partner with suppliers that provide both placement equipment and process solutions for state-of-art assemblies, global supply capabilities and best-of-breed cost of ownership.

 

Biography:

Richard Boulanger is Vice President of the Advanced Semiconductor Assembly Division of Universal Instruments Corporation.  This business unit focuses on bare die and flip chip applications such as plastic and ceramic ball grid arrays, flip chip on flexible circuits and hybrid assemblies.

 

 

 

 

[CAPTION, for figure 1, attached “BlueLight.jpg”]: New approaches to illumination are improving vision clarity and increasing placement accuracy on advanced substrates such as flexible circuits.

IM Applications Analysis

IM Applications Analysis Request Matrix For Sales Engineers

 

 

Request

When should you use this?

What we need

What you will receive from us

Throughput analysis Get customer interested in Generation 8 machines by showing them throughput advantage of new equipment. Pattern program (UIC, competitor, or text component location file)orQuantity of components per panel

 

Analysis showing how many boards of the sample product type will be produced per hour/day/month using Gen 8 equipment.
PCB evaluation Determine how many components currently being hand inserted or inserted by old UIC or competitor equipment can be inserted with Gen 8 equipment. Fully populated PCBBare PCBPattern program (UIC, competitor, or text component location file) Report listing which components can be inserted “as is”, which can be inserted with minor modifications to the board and which cannot be inserted.
Machine demonstration Customer is not familiar with Universal or is not familiar with Gen 8 equipment.  Introduce customer to Universal’s support infrastructure, help establish UIC as a partner rather than merely a vendor. Demo with UIC boards – call to discuss timing of visit and machine availabilityDemo with customer boards – Same as above as well as customer boards (one fully assembled, several bare) and any “unusual” components along with pattern program (if available) at least 2 weeks prior to visit. Upon request, we can give a Gen 8 equipment presentation tailored to the customer, a plant tour and/or demonstrate the Gen 8 machine(s) using the customer’s product.
Machine replacement proposal Show customer we can replace old (UIC or competitor) http://ambienbuy.net machines with fewer Gen 8 machines. Average” number of components per panel or actual number on a representative panel.Hours per day and days per week machine(s) are in production.Qty of panels required per day. Report showing the number of machines required to meet the requested production quantity as well as the total capacity of the machine(s).
Machine financial justification Show how Gen 8 equipment can pay for itself by saving operator and maintenance labor as well as reducing replacement parts cost. Same information as for machine replacement study and:Current spare parts cost (preferably in $/M insertions).Operator and technician fully burdened labor rate. Report showing number of machines required to meet production quantity as well as projected savings in labor and spare parts compared to old equipment.
Cost per insertion report(competitive comparison) Show how UIC Gen 8 equipment compares with competitors equipment. Same information as required for machine financial justification and:Any information you can provide about the competitor’s proposed solution.  Include competitor price quotes and machine mix if possible, otherwise we will use our estimates which may be different than your customer’s situation. Report showing number of UIC and competitor machines required to meet production quantity.  “Cost per insertion” calculation for UIC and competitor equipment.  This type of calculation helps us show that the cost of operation can be lower with UIC even though our equipment price may be higher than the competition.