Fundamentals Flashcards
What type of connectors are these?
Female Card Edge Connectors
A mechanical/electrical interface to the edge of a PCB or male Card Edge connector.
What type of connectors are these?
Male Card Edge Connectors
Mate with female card edge connectors. Good for hi-cycle applications as they increase the lifespan of the female connector.
What type of connector is this?
Dual Female Card Edge Connector
Provides a solderless mechanical/electrical interface between two PCBs on the same plane.
What gender options do we have in the Card Edge category?
Dual Female, Female, Male, and Male-Female
What type of connector is this?
Bi-level Card Edge Connector
Contains two levels of contacts, enabling the use of larger contacts in hi-density for a 3 Amps rating, as well as reliable contact/pad alignment.
What type of connectors are these?
Test Sockets
Used in test and burn-in applications. Typically, test sockets are soldered to a PCB in a test chamber, the device under test (DUT) is plugged into the test socket, and high temperatures, high cycles, and/or high voltages are applied. The purpose is to detect early failures and reduce the potential for defects and failures in the field.
What type of connectors are these?
Headers
Male/female electrical connector interface.
What type of connectors are these?
Box Headers
Also known as: Shrouded Headers
Basically, Pin Headers with shroud and key for better blind mating.
What type of connectors are these?
Jumpers
Used to connect two header contacts.
What type of connectors are these?
Wafers
Wafers are similar to standard Pin Headers, but the female is crimped to a wire cable for a wire-to-board connection. Sold as 3 pieces: Wafer, Wafer Housing, Crimp Terminal
What type of Card Edge Connector is this?
PCI Express (PCI-E)
Industry standard hi-speed card edge connector for graphics cards, memory cards, and storage cards.
What type of Connector is this?
Axial Test Socket
Used for testing axial lead resistors/diodes.
What type of connectors are these?
TO Test Sockets
Used for testing Transistor Outline (TO) packages, which typically have 3 or more leads protruding from the bottom.
What type of connector is this?
SIP Test Socket
Used for testing the Single-in-Line (SIP) Package, which is an IC package that has a single row of leads protruding from the bottom.
What are are these connector accessories called?
Card Guides
Guides the mating PCB and protects the connector from damage.
Dust Cover
Prevents dust/FOD accumulation in unused connectors.
Hood
Provides insulation and strain relief for wire solder joints (e.g. eyelet).
What is another word for “Contacts”?
Pins
What do you call the point at which the pin touches the mating PCB?
Contact Point
What do you call the area at which the pin touches the mating PCB?
Contact Area, Contact Surface, or Wiping Area
Name this contact bellows type
Loop Bellows
Name this contact bellows type
Hairpin Bellows
Name this contact bellows type
Full Bellows
Name this contact bellows type
Cantilever
Name these two (different) contact bellows types.
Double Point
Two (2) contact points per contact for higher normal force/board stabilization for a more “rugged” or “ruggedized” connector solution to operate in harsh environments, such as strong vibrations.
Make-Before-Break (MBB)
Two (2) contact points per contact with the lower contact points shorted by design such that the mating PCB makes contact with the upper contact point before the lower contact short is broken. Used for “hot swap” applications where the mating PCB is swapped without shutting down.
What is the plastic connector housing called?
Insulator or Body
What is this feature called?
Molded Key or Molded-in Polarizing Key
Available in-position or between positions. Ensures the mating PCB is inserted in the correct orientation. Offers more strength and durability than loose piece Polarizing Keys, which are sold seperately.
What are these plastic features called, protruding through the PCB?
Guide Posts
Sometimes refered to as pegs
What is dimensioned here?
Standoff
Creates clearance between the connector and solder-side PCB for cleaning.
What is this excess plastic called?
Flash
Excess plastic attached to an insulator after molding, caused by unintended leakage of plastic between two mold surfaces. This is different than a “burr”, which is uncut material remaining on a workpiece after a machining, cutting, or shearing operation.
What is dimensioned here?
Profile
Also known as: Insulator Height or Body Height
What do you call the PCB that is inserted into the female side of the connector?
Mating PCB or Mating side PCB
What do you call the PCB that is soldered to the tail side of the connector?
Solder Side PCB
What is dimensioned here?
Card Slot (Width)
Sized to have clearance with the specified mating PCB thickness.
What is dimensioned here?
Insertion Depth or Card Slot Depth
The distance the mating PCB can be inserted into card slot. Determines the contact point and recommended plated PCB pad length.
What do you call the amount of force it takes to push the mating PCB into the connector?
Insertion Force
Typically specified at 16 oz max per contact pair. Provides “wiping action” to clean the plated PCB pads. Generally, lower insertion force = less plating wear.
What do you call the amount of force it takes to pull the mating PCB out of the connector?
Withdrawal Force
Typically specified at 1 oz min oz per contact pair (0.5 oz min for hi-density)
What do you call the amount of perpendicular force that a contact applies to a mating PCB after it is fully inserted?
Normal Force
Necessary to ensure a good electrical connection.
What is the specification for the number of times a mating PCB can be inserted and withdrawn (aka “cycles”)?
Durability
Impacted significantly by insertion/withdrawal force, plating thickness, plating type, and mating PCB characteristics (thickness, plating, chamfer, etc.). Utilizing a male card edge significantly increases durability with a smooth gold-on-gold connection, in place of the edge of a PCB, which can be abrasive.
What is “Termination Method”
The method by which a connection is made to a PCB, ribbon cable, or wires.
What is this termination method?
Thru Hole or Dip Solder
What is this termination method?
Surface Mount
Connector is soldered to the surface of the PCB, usually via reflow soldering. Can be straight or right angle orientation.
What is this Termination Method?
Card Extender
The contact tails straddle the PCB edge, placing both PCBs on the same plane. Sometimes referred to as Straddle Mount.
What is this Termination method?
Eyelet
Used for a wire-to-board connection.
What is this Termination method?
Wire Wrap
For a wire-to-board connection. Tails are typically long and square, ideal for wrapping wire around
What is this Termination method?
Press Fit
This contact tail has a “compliant” design that provides an interference fit with the plated thru holes in a PCB, eliminating the need to solder the connection.
What type of termination is this?
IDC (Insulation-Displacement Connector)
For ribbon-cable-to-board applications. Contacts pierce through the insualtion to make contact. Both Header and Card Edge version available. Optional “Strain Relief Clip” to secure the ribbon cable and prevent strain on the connection point.
What is the “mounting”?
The feature utilized to hold the connector in place.
Sometimes refered to as “mounting ears”
What do we call a card slot without ends?
Open Card Slot
May be used to place connectors end-to-end.
What is this mounting option?
No Mounting
What is this mounting option?
Clearance Hole
Allows a screw or bolt to pass through the mounting flange.
What is this mounting option?
Side Mount
Commonly used with right angle orientation.
What is this mounting option?
Straddle Mount
Mounting flanges straddle the PCB.
Commonly used with Card Extender Bend.
What is this mounting option?
Threaded Insert
Connector can be mounted with a bolt only (no nut needed)
What do we call this mounting option?
Floating Bobbin
Allows the connector to float slightly.
What is this optional mounting feature?
Metal Board Lock
For precise positioning and retention.
What do you call the process by which contacts are punched out of wire or strip metal?
Stamping
Generally, contacts stamped from wire are then held by a bandolier while contacts stamped from strip remain attached to the metal strip. Alternatively, contacts can be “loose piece”.
What is the contact plating type that features different plating metals or thicknesses on the contact area and termination?
Selective Plating
Commonly gold on the contact point
and tin on the tail for lower cost.
Contacts are typically plated with gold or tin on top of nickel.
What are our three (3) standard plating methods?
Reel-to-Reel Plating
Reeled contacts pass thru plating baths and can be selectively plated.
Barrel Plating
Loose contacts are tumbled for uniform “overall” plating.
Rack Plating
Strips of contacts are dipped for uniform “overall” plating
What is a “High Density” connector?
Contact pitch of .050” or less.
Typically rated at 1 Amp per contact.
What do we consider a “High Temperature” connector?
Max operating temperature of 150C or more.
Typical colors:
Tan (Natural Peek), Brown (PPS), Green (PPS), Black (PPS), Black (PA9T)
What do you call the rated temperature and time at which the connector is specified for soldering?
Processing Temperature
What do you call the solder process in which a PCB passes over a pan of flowing molten solder?
Wave Solder
Typically used with thru-hole connectors.
What do you call the solder process in which the PCB passes through a heat tunnel causing the solder pads and/or solder paste to melt and form solder joints?
Reflow Oven Soldering
Typically used with surface mount connectors. Sometimes used with thru-hole connectors with solder paste-in-hole. Reflow ovens may be infrared (IR) or convection.
What do you call the solder process in which a connector is soldered to a PCB using a hand soldering iron.
Manual Soldering
Note: if the soldering iron makes contact for too long, the contact can heat up and melt the surrounding plastic causing the contact to “float” out of position.
Which do we call a position?
What do we call a contact?
Note: Other connector manufacturers may use these words interchangebly.
What is dimensioned here?
Mating PCB Thickness
Most common is .062”
Generally increments by ~.031”
(.031”, .062”, .093”, .125”, .156”)
What do we call this orientation?
Straight
Can be thru hole or surface mount.
PCBs are typically perpendicular.
What do we call this orientation?
Straddle
PCBs are on the same plane.
What do we call this orientation?
Right Angle
Can be thru hole or surface mount
PCBs are typically parallel.
What is dimensioned here?
Tail Length
Thru hole: Typically, the tail length is the thickness of the solder-side PCB + .031”
Surface mount: Typically, the minimum solder-side PCB plated pad dimensions are greater than the maximum tail length/width + 25%.
What is dimensioned here?
Row Spacing
What is dimensioned here?
Contact Centers or Pitch
What is dimensioned here?
Contact Point
Typically measured from the top of the insulator to the contact point.
What do we call the distance between two PCBs in a “Board Stacking” application?
Stack Height or Board-to-Board Distance
Generally, the customer will specify this dimension, which must be met by the total mated-height of a male and female connector.
What type of card edge connector is specified when the mating PCB only has contact pads (or “gold fingers” on one side?
Half Loaded
Only one row of contacts make electrical connection. Sometimes the oposing row of contacts are still loaded to serve only as “back-up springs” to apply opposing force to the PCB. The contact tails of the back-up springs are trimmed or bent out of the way so they make no electrical connection.
What is called when contacts are not fully populated by design?
Omitted Contacts
(Special Load or Selective Load)
What specifies the allowable electrical current which can flow continuously through a contact.
Current Rating
Generally specified in amps per contact with more information found on a current carrying capacity chart. Current carrying capacity is identified by a temperature rise test (pictured here) and is generally limited by 30°C temperature rise.
In which operation are the traveler and insulators released to production?
Kitting
What are our 4 packaging types?
Tube, Tray, Bulk (bag), Tape & Reel
What is RoHS?
Restriction of Hazardous Substances
Adopted by the Eurpopean Union in 2003, this directive restricts the use of hazardous materials (e.g. lead) in the manufacture of various types of electronics.
What is Contact Resistance?
What is Contact Retention?
Contact Resistance
The resistance to electrical current flow due to contact material, contact geometry, contact area, normal force, plating, etc. Measured by applying test current to the mated PCB and measuring current at the contact tail.
Contact Retention
The force required to remove a contact from an insulator due to a crimp, dimple, or tab. Measured by pushing the contact out of the insulator with a force gauge.
