id stringlengths 24 24 | title stringlengths 3 59 | context stringlengths 151 3.71k | question stringlengths 12 217 | answers dict |
|---|---|---|---|---|
572f8d4da23a5019007fc72b | Printed_circuit_board | When the board has no embedded components it is more correctly called a printed wiring board (PWB) or etched wiring board. However, the term printed wiring board has fallen into disuse. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB assembly ... | What's the more appropriate, but mostly unused, name for a printed circuit board when it doesn't have embedded components? | {
"text": [
"printed wiring board"
],
"answer_start": [
72
]
} |
572f8d4da23a5019007fc72c | Printed_circuit_board | When the board has no embedded components it is more correctly called a printed wiring board (PWB) or etched wiring board. However, the term printed wiring board has fallen into disuse. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB assembly ... | What's the abbreviation for a printed wiring board? | {
"text": [
"PWB"
],
"answer_start": [
94
]
} |
572f8d4da23a5019007fc72d | Printed_circuit_board | When the board has no embedded components it is more correctly called a printed wiring board (PWB) or etched wiring board. However, the term printed wiring board has fallen into disuse. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB assembly ... | What would we call a printed circuit board with embedded electronics, abbreviated PCA? | {
"text": [
"printed circuit assembly"
],
"answer_start": [
241
]
} |
572f8d4da23a5019007fc72e | Printed_circuit_board | When the board has no embedded components it is more correctly called a printed wiring board (PWB) or etched wiring board. However, the term printed wiring board has fallen into disuse. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB assembly ... | What organization likes the term "circuit card assembly" for boards that have already been assembled? | {
"text": [
"IPC"
],
"answer_start": [
332
]
} |
572f8d4da23a5019007fc72f | Printed_circuit_board | When the board has no embedded components it is more correctly called a printed wiring board (PWB) or etched wiring board. However, the term printed wiring board has fallen into disuse. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB assembly ... | What abbreviation would the IPC use for an assembled circuit board? | {
"text": [
"CCA"
],
"answer_start": [
398
]
} |
572f8ec5947a6a140053ca5e | Printed_circuit_board | Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints inc... | What did PCB designers used to employ on a mylar sheet? | {
"text": [
"photomask"
],
"answer_start": [
52
]
} |
572f8ec5947a6a140053ca5f | Printed_circuit_board | Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints inc... | In the old PCB design method, what was used to connect component pin pads? | {
"text": [
"traces"
],
"answer_start": [
225
]
} |
572f8ec5947a6a140053ca60 | Printed_circuit_board | Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints inc... | What were traces originally made out of? | {
"text": [
"self-adhesive tape"
],
"answer_start": [
361
]
} |
572f8ec5947a6a140053ca61 | Printed_circuit_board | Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints inc... | Designers would rub on a dry transfer of what to make the process of laying out components simpler? | {
"text": [
"common component footprints"
],
"answer_start": [
289
]
} |
572f8ec5947a6a140053ca62 | Printed_circuit_board | Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints inc... | What kind of metal coated the blank boards used to make PCBs? | {
"text": [
"copper"
],
"answer_start": [
572
]
} |
572f9268a23a5019007fc785 | Printed_circuit_board | Panelization is a procedure whereby a number of PCBs are grouped for manufacturing onto a larger board - the panel. Usually a panel consists of a single design but sometimes multiple designs are mixed on a single panel. There are two types of panels: assembly panels - often called arrays - and bare board manufacturing ... | What process groups PCBs before transfer to a panel? | {
"text": [
"Panelization"
],
"answer_start": [
0
]
} |
572f9268a23a5019007fc786 | Printed_circuit_board | Panelization is a procedure whereby a number of PCBs are grouped for manufacturing onto a larger board - the panel. Usually a panel consists of a single design but sometimes multiple designs are mixed on a single panel. There are two types of panels: assembly panels - often called arrays - and bare board manufacturing ... | Is it more common for panels to have a single design or many designs? | {
"text": [
"a single design"
],
"answer_start": [
144
]
} |
572f9268a23a5019007fc787 | Printed_circuit_board | Panelization is a procedure whereby a number of PCBs are grouped for manufacturing onto a larger board - the panel. Usually a panel consists of a single design but sometimes multiple designs are mixed on a single panel. There are two types of panels: assembly panels - often called arrays - and bare board manufacturing ... | What type of panels can also be referred to as an "array?' | {
"text": [
"assembly panels"
],
"answer_start": [
251
]
} |
572f9268a23a5019007fc788 | Printed_circuit_board | Panelization is a procedure whereby a number of PCBs are grouped for manufacturing onto a larger board - the panel. Usually a panel consists of a single design but sometimes multiple designs are mixed on a single panel. There are two types of panels: assembly panels - often called arrays - and bare board manufacturing ... | Besides assembly panels, what's the other type of panel? | {
"text": [
"bare board manufacturing panels"
],
"answer_start": [
295
]
} |
572f9268a23a5019007fc789 | Printed_circuit_board | Panelization is a procedure whereby a number of PCBs are grouped for manufacturing onto a larger board - the panel. Usually a panel consists of a single design but sometimes multiple designs are mixed on a single panel. There are two types of panels: assembly panels - often called arrays - and bare board manufacturing ... | What step of the bare board manufacture would be impossible if panels weren't always used? | {
"text": [
"the plating process"
],
"answer_start": [
532
]
} |
572f94e7b2c2fd140056821b | Printed_circuit_board | The panel is eventually broken apart into individual PCBs; this is called depaneling. Separating the individual PCBs is frequently aided by drilling or routing perforations along the boundaries of the individual circuits, much like a sheet of postage stamps. Another method, which takes less space, is to cut V-shaped gr... | What is the process called whereby the individual PCBs are separated? | {
"text": [
"depaneling"
],
"answer_start": [
74
]
} |
572f94e7b2c2fd140056821c | Printed_circuit_board | The panel is eventually broken apart into individual PCBs; this is called depaneling. Separating the individual PCBs is frequently aided by drilling or routing perforations along the boundaries of the individual circuits, much like a sheet of postage stamps. Another method, which takes less space, is to cut V-shaped gr... | What boundaries would you follow to separate PCBs on a panel? | {
"text": [
"individual circuits"
],
"answer_start": [
201
]
} |
572f94e7b2c2fd140056821d | Printed_circuit_board | The panel is eventually broken apart into individual PCBs; this is called depaneling. Separating the individual PCBs is frequently aided by drilling or routing perforations along the boundaries of the individual circuits, much like a sheet of postage stamps. Another method, which takes less space, is to cut V-shaped gr... | What technology has made depaneling possible without needing to physically interact with the board? | {
"text": [
"lasers"
],
"answer_start": [
474
]
} |
572f94e7b2c2fd140056821e | Printed_circuit_board | The panel is eventually broken apart into individual PCBs; this is called depaneling. Separating the individual PCBs is frequently aided by drilling or routing perforations along the boundaries of the individual circuits, much like a sheet of postage stamps. Another method, which takes less space, is to cut V-shaped gr... | What does the V-shaped groove method save? | {
"text": [
"space"
],
"answer_start": [
292
]
} |
572f94e7b2c2fd140056821f | Printed_circuit_board | The panel is eventually broken apart into individual PCBs; this is called depaneling. Separating the individual PCBs is frequently aided by drilling or routing perforations along the boundaries of the individual circuits, much like a sheet of postage stamps. Another method, which takes less space, is to cut V-shaped gr... | What delicate component is less likely to be damaged if laser depanelization is used? | {
"text": [
"circuits"
],
"answer_start": [
567
]
} |
572f97ee947a6a140053caac | Printed_circuit_board | Subtractive methods remove copper from an entirely copper-coated board to leave only the desired copper pattern. In additive methods the pattern is electroplated onto a bare substrate using a complex process. The advantage of the additive method is that less material is needed and less waste is produced. In the full ad... | Do additive or subtractive methods use less raw materials? | {
"text": [
"additive"
],
"answer_start": [
230
]
} |
572f97ee947a6a140053caad | Printed_circuit_board | Subtractive methods remove copper from an entirely copper-coated board to leave only the desired copper pattern. In additive methods the pattern is electroplated onto a bare substrate using a complex process. The advantage of the additive method is that less material is needed and less waste is produced. In the full ad... | What chemical element is often present in the bath used to sensitive exposed film after it's been imaged? | {
"text": [
"palladium"
],
"answer_start": [
566
]
} |
572f97ee947a6a140053caae | Printed_circuit_board | Subtractive methods remove copper from an entirely copper-coated board to leave only the desired copper pattern. In additive methods the pattern is electroplated onto a bare substrate using a complex process. The advantage of the additive method is that less material is needed and less waste is produced. In the full ad... | What object is used to expose selected parts of the photosensitive film to light? | {
"text": [
"mask"
],
"answer_start": [
435
]
} |
572f97ee947a6a140053caaf | Printed_circuit_board | Subtractive methods remove copper from an entirely copper-coated board to leave only the desired copper pattern. In additive methods the pattern is electroplated onto a bare substrate using a complex process. The advantage of the additive method is that less material is needed and less waste is produced. In the full ad... | In subtractive methods, what metal covers the board and is then partially removed? | {
"text": [
"copper"
],
"answer_start": [
27
]
} |
572f97ee947a6a140053cab0 | Printed_circuit_board | Subtractive methods remove copper from an entirely copper-coated board to leave only the desired copper pattern. In additive methods the pattern is electroplated onto a bare substrate using a complex process. The advantage of the additive method is that less material is needed and less waste is produced. In the full ad... | In the additive method, which parts of the laminate are plated with copper? | {
"text": [
"sensitized areas"
],
"answer_start": [
733
]
} |
572f9d1db2c2fd140056825f | Printed_circuit_board | Semi-additive is the most common process: The unpatterned board has a thin layer of copper already on it. A reverse mask is then applied. (Unlike a subtractive process mask, this mask exposes those parts of the substrate that will eventually become the traces.) Additional copper is then plated onto the board in the unm... | In the semi-additive process, what do the areas exposed by the mask become at the end? | {
"text": [
"traces"
],
"answer_start": [
253
]
} |
572f9d1db2c2fd1400568260 | Printed_circuit_board | Semi-additive is the most common process: The unpatterned board has a thin layer of copper already on it. A reverse mask is then applied. (Unlike a subtractive process mask, this mask exposes those parts of the substrate that will eventually become the traces.) Additional copper is then plated onto the board in the unm... | What metal is used to plate the unmasked parts of the board in the semi-additive method? | {
"text": [
"copper"
],
"answer_start": [
273
]
} |
572f9d1db2c2fd1400568261 | Printed_circuit_board | Semi-additive is the most common process: The unpatterned board has a thin layer of copper already on it. A reverse mask is then applied. (Unlike a subtractive process mask, this mask exposes those parts of the substrate that will eventually become the traces.) Additional copper is then plated onto the board in the unm... | After the mask comes off of the board, what step takes off the original plating? | {
"text": [
"etching"
],
"answer_start": [
468
]
} |
572f9d1db2c2fd1400568262 | Printed_circuit_board | Semi-additive is the most common process: The unpatterned board has a thin layer of copper already on it. A reverse mask is then applied. (Unlike a subtractive process mask, this mask exposes those parts of the substrate that will eventually become the traces.) Additional copper is then plated onto the board in the unm... | What company used to make radios with additive boards in the mid-20th century? | {
"text": [
"General Electric"
],
"answer_start": [
663
]
} |
572f9d1db2c2fd1400568263 | Printed_circuit_board | Semi-additive is the most common process: The unpatterned board has a thin layer of copper already on it. A reverse mask is then applied. (Unlike a subtractive process mask, this mask exposes those parts of the substrate that will eventually become the traces.) Additional copper is then plated onto the board in the unm... | What weight of plating is possible with copper? | {
"text": [
"any"
],
"answer_start": [
357
]
} |
572f9fd104bcaa1900d76aff | Printed_circuit_board | The simplest method, used for small-scale production and often by hobbyists, is immersion etching, in which the board is submerged in etching solution such as ferric chloride. Compared with methods used for mass production, the etching time is long. Heat and agitation can be applied to the bath to speed the etching rat... | What non-professionals might use immersion etching, since it's the easiest way to make a PCB? | {
"text": [
"hobbyists"
],
"answer_start": [
66
]
} |
572f9fd104bcaa1900d76b00 | Printed_circuit_board | The simplest method, used for small-scale production and often by hobbyists, is immersion etching, in which the board is submerged in etching solution such as ferric chloride. Compared with methods used for mass production, the etching time is long. Heat and agitation can be applied to the bath to speed the etching rat... | Is the immersion etching process long or short compared to other production methods? | {
"text": [
"long"
],
"answer_start": [
244
]
} |
572f9fd104bcaa1900d76b01 | Printed_circuit_board | The simplest method, used for small-scale production and often by hobbyists, is immersion etching, in which the board is submerged in etching solution such as ferric chloride. Compared with methods used for mass production, the etching time is long. Heat and agitation can be applied to the bath to speed the etching rat... | If you wanted to speed up the etching process, you could agitate the bath up or add what to it? | {
"text": [
"Heat"
],
"answer_start": [
250
]
} |
572f9fd104bcaa1900d76b02 | Printed_circuit_board | The simplest method, used for small-scale production and often by hobbyists, is immersion etching, in which the board is submerged in etching solution such as ferric chloride. Compared with methods used for mass production, the etching time is long. Heat and agitation can be applied to the bath to speed the etching rat... | What funny name is used for the etching process where air is blown through the etching solution to get it moving around? | {
"text": [
"bubble etching"
],
"answer_start": [
326
]
} |
572f9fd104bcaa1900d76b03 | Printed_circuit_board | The simplest method, used for small-scale production and often by hobbyists, is immersion etching, in which the board is submerged in etching solution such as ferric chloride. Compared with methods used for mass production, the etching time is long. Heat and agitation can be applied to the bath to speed the etching rat... | What's the fastest and most easily controlled process for etching? | {
"text": [
"spray etching"
],
"answer_start": [
590
]
} |
572fa22c04bcaa1900d76b1e | Printed_circuit_board | Multi-layer printed circuit boards have trace layers inside the board. This is achieved by laminating a stack of materials in a press by applying pressure and heat for a period of time. This results in an inseparable one piece product. For example, a four-layer PCB can be fabricated by starting from a two-sided copper-... | What makes up the inside of a multi-layer PCB? | {
"text": [
"trace layers"
],
"answer_start": [
40
]
} |
572fa22c04bcaa1900d76b1f | Printed_circuit_board | Multi-layer printed circuit boards have trace layers inside the board. This is achieved by laminating a stack of materials in a press by applying pressure and heat for a period of time. This results in an inseparable one piece product. For example, a four-layer PCB can be fabricated by starting from a two-sided copper-... | Pressure is one thing you need to apply to make a multi-layer PCB; what's the other thing? | {
"text": [
"heat"
],
"answer_start": [
159
]
} |
572fa22c04bcaa1900d76b20 | Printed_circuit_board | Multi-layer printed circuit boards have trace layers inside the board. This is achieved by laminating a stack of materials in a press by applying pressure and heat for a period of time. This results in an inseparable one piece product. For example, a four-layer PCB can be fabricated by starting from a two-sided copper-... | What tool is used to push the trace layers in a multi-layer PCB together? | {
"text": [
"press"
],
"answer_start": [
128
]
} |
572fa37304bcaa1900d76b25 | Printed_circuit_board | Holes through a PCB are typically drilled with small-diameter drill bits made of solid coated tungsten carbide. Coated tungsten carbide is recommended since many board materials are very abrasive and drilling must be high RPM and high feed to be cost effective. Drill bits must also remain sharp so as not to mar or tear... | What kind of drill bit do you need to drill holes in a PCB? | {
"text": [
"coated tungsten carbide"
],
"answer_start": [
87
]
} |
572fa37304bcaa1900d76b26 | Printed_circuit_board | Holes through a PCB are typically drilled with small-diameter drill bits made of solid coated tungsten carbide. Coated tungsten carbide is recommended since many board materials are very abrasive and drilling must be high RPM and high feed to be cost effective. Drill bits must also remain sharp so as not to mar or tear... | What kind of material sometimes used for drilling will lose sharpness quickly if used for PCBs? | {
"text": [
"high-speed-steel"
],
"answer_start": [
347
]
} |
572fa37304bcaa1900d76b27 | Printed_circuit_board | Holes through a PCB are typically drilled with small-diameter drill bits made of solid coated tungsten carbide. Coated tungsten carbide is recommended since many board materials are very abrasive and drilling must be high RPM and high feed to be cost effective. Drill bits must also remain sharp so as not to mar or tear... | What property do PCBs have that makes them tough to drill through? | {
"text": [
"abrasive"
],
"answer_start": [
187
]
} |
572fa37304bcaa1900d76b28 | Printed_circuit_board | Holes through a PCB are typically drilled with small-diameter drill bits made of solid coated tungsten carbide. Coated tungsten carbide is recommended since many board materials are very abrasive and drilling must be high RPM and high feed to be cost effective. Drill bits must also remain sharp so as not to mar or tear... | What does the "NCD" in "NCD files" mean? | {
"text": [
"numerically controlled drill"
],
"answer_start": [
633
]
} |
572fa37304bcaa1900d76b29 | Printed_circuit_board | Holes through a PCB are typically drilled with small-diameter drill bits made of solid coated tungsten carbide. Coated tungsten carbide is recommended since many board materials are very abrasive and drilling must be high RPM and high feed to be cost effective. Drill bits must also remain sharp so as not to mar or tear... | What's another name for NCD files that has an "x" in it? | {
"text": [
"Excellon files"
],
"answer_start": [
678
]
} |
572fa92fb2c2fd14005682d3 | Printed_circuit_board | The hole walls for boards with two or more layers can be made conductive and then electroplated with copper to form plated-through holes. These holes electrically connect the conducting layers of the PCB. For multi-layer boards, those with three layers or more, drilling typically produces a smear of the high temperatur... | What do the hole walls in two-layer PCBs have to be before they can be electroplated? | {
"text": [
"conductive"
],
"answer_start": [
62
]
} |
572fa92fb2c2fd14005682d4 | Printed_circuit_board | The hole walls for boards with two or more layers can be made conductive and then electroplated with copper to form plated-through holes. These holes electrically connect the conducting layers of the PCB. For multi-layer boards, those with three layers or more, drilling typically produces a smear of the high temperatur... | What's the minimum number of layers a PCB can have to be considered "multi-layer"? | {
"text": [
"three"
],
"answer_start": [
241
]
} |
572fa92fb2c2fd14005682d5 | Printed_circuit_board | The hole walls for boards with two or more layers can be made conductive and then electroplated with copper to form plated-through holes. These holes electrically connect the conducting layers of the PCB. For multi-layer boards, those with three layers or more, drilling typically produces a smear of the high temperatur... | What process does a multi-layer PCB usually undergo before plating to make sure the layers have good connectivity with each other? | {
"text": [
"de-smear"
],
"answer_start": [
509
]
} |
572fa92fb2c2fd14005682d6 | Printed_circuit_board | The hole walls for boards with two or more layers can be made conductive and then electroplated with copper to form plated-through holes. These holes electrically connect the conducting layers of the PCB. For multi-layer boards, those with three layers or more, drilling typically produces a smear of the high temperatur... | What type of boards undergo the etch-back process? | {
"text": [
"high reliability"
],
"answer_start": [
622
]
} |
572fa92fb2c2fd14005682d7 | Printed_circuit_board | The hole walls for boards with two or more layers can be made conductive and then electroplated with copper to form plated-through holes. These holes electrically connect the conducting layers of the PCB. For multi-layer boards, those with three layers or more, drilling typically produces a smear of the high temperatur... | Etch-back removes glass fibers and what other material? | {
"text": [
"resin"
],
"answer_start": [
774
]
} |
572fb2d4b2c2fd140056836d | Printed_circuit_board | Matte solder is usually fused to provide a better bonding surface or stripped to bare copper. Treatments, such as benzimidazolethiol, prevent surface oxidation of bare copper. The places to which components will be mounted are typically plated, because untreated bare copper oxidizes quickly, and therefore is not readil... | What happens to untreated copper that makes it difficult to solder? | {
"text": [
"oxidizes"
],
"answer_start": [
275
]
} |
572fb2d4b2c2fd140056836e | Printed_circuit_board | Matte solder is usually fused to provide a better bonding surface or stripped to bare copper. Treatments, such as benzimidazolethiol, prevent surface oxidation of bare copper. The places to which components will be mounted are typically plated, because untreated bare copper oxidizes quickly, and therefore is not readil... | What chemical treatment will prevent bare copper from oxidizing? | {
"text": [
"benzimidazolethiol"
],
"answer_start": [
114
]
} |
572fb2d4b2c2fd140056836f | Printed_circuit_board | Matte solder is usually fused to provide a better bonding surface or stripped to bare copper. Treatments, such as benzimidazolethiol, prevent surface oxidation of bare copper. The places to which components will be mounted are typically plated, because untreated bare copper oxidizes quickly, and therefore is not readil... | What's the process by which bare copper gets covered in solder? | {
"text": [
"hot air solder levelling"
],
"answer_start": [
394
]
} |
572fb2d4b2c2fd1400568370 | Printed_circuit_board | Matte solder is usually fused to provide a better bonding surface or stripped to bare copper. Treatments, such as benzimidazolethiol, prevent surface oxidation of bare copper. The places to which components will be mounted are typically plated, because untreated bare copper oxidizes quickly, and therefore is not readil... | What does hot air solder leveling ensure the coated copper will have? | {
"text": [
"solderable surface"
],
"answer_start": [
513
]
} |
572fb2d4b2c2fd1400568371 | Printed_circuit_board | Matte solder is usually fused to provide a better bonding surface or stripped to bare copper. Treatments, such as benzimidazolethiol, prevent surface oxidation of bare copper. The places to which components will be mounted are typically plated, because untreated bare copper oxidizes quickly, and therefore is not readil... | What alloy can no longer be used in HASL because of restrictions on the use of one of its metal components? | {
"text": [
"tin-lead"
],
"answer_start": [
551
]
} |
572fb4cfb2c2fd1400568381 | Printed_circuit_board | Other platings used are OSP (organic surface protectant), immersion silver (IAg), immersion tin, electroless nickel with immersion gold coating (ENIG), electroless nickel electroless palladium immersion gold (ENEPIG) and direct gold plating (over nickel). Edge connectors, placed along one edge of some boards, are often... | What does OSP stand for? | {
"text": [
"organic surface protectant"
],
"answer_start": [
29
]
} |
572fb4cfb2c2fd1400568382 | Printed_circuit_board | Other platings used are OSP (organic surface protectant), immersion silver (IAg), immersion tin, electroless nickel with immersion gold coating (ENIG), electroless nickel electroless palladium immersion gold (ENEPIG) and direct gold plating (over nickel). Edge connectors, placed along one edge of some boards, are often... | What metal is often under the gold plating on edge connectors? | {
"text": [
"nickel"
],
"answer_start": [
321
]
} |
572fb4cfb2c2fd1400568383 | Printed_circuit_board | Other platings used are OSP (organic surface protectant), immersion silver (IAg), immersion tin, electroless nickel with immersion gold coating (ENIG), electroless nickel electroless palladium immersion gold (ENEPIG) and direct gold plating (over nickel). Edge connectors, placed along one edge of some boards, are often... | What's the abbreviation for immersion silver plating? | {
"text": [
"IAg"
],
"answer_start": [
76
]
} |
572fb4cfb2c2fd1400568384 | Printed_circuit_board | Other platings used are OSP (organic surface protectant), immersion silver (IAg), immersion tin, electroless nickel with immersion gold coating (ENIG), electroless nickel electroless palladium immersion gold (ENEPIG) and direct gold plating (over nickel). Edge connectors, placed along one edge of some boards, are often... | Ag3Cu is one intermetallic that tin forms; what's the other one? | {
"text": [
"Cu5Sn6"
],
"answer_start": [
469
]
} |
572fb4cfb2c2fd1400568385 | Printed_circuit_board | Other platings used are OSP (organic surface protectant), immersion silver (IAg), immersion tin, electroless nickel with immersion gold coating (ENIG), electroless nickel electroless palladium immersion gold (ENEPIG) and direct gold plating (over nickel). Edge connectors, placed along one edge of some boards, are often... | What might the rapid diffusion of coating metal into tin solder leave in the surface coating? | {
"text": [
"voids"
],
"answer_start": [
577
]
} |
572fb648b2c2fd140056839d | Printed_circuit_board | Electrochemical migration (ECM) is the growth of conductive metal filaments on or in a printed circuit board (PCB) under the influence of a DC voltage bias. Silver, zinc, and aluminum are known to grow whiskers under the influence of an electric field. Silver also grows conducting surface paths in the presence of halid... | What's the process whereby metal filaments are grown on or in a PCB via DC voltage? | {
"text": [
"Electrochemical migration"
],
"answer_start": [
0
]
} |
572fb648b2c2fd140056839e | Printed_circuit_board | Electrochemical migration (ECM) is the growth of conductive metal filaments on or in a printed circuit board (PCB) under the influence of a DC voltage bias. Silver, zinc, and aluminum are known to grow whiskers under the influence of an electric field. Silver also grows conducting surface paths in the presence of halid... | Along with silver and aluminum, what metal grows metal filaments when exposed to an electric field? | {
"text": [
"zinc"
],
"answer_start": [
165
]
} |
572fb648b2c2fd140056839f | Printed_circuit_board | Electrochemical migration (ECM) is the growth of conductive metal filaments on or in a printed circuit board (PCB) under the influence of a DC voltage bias. Silver, zinc, and aluminum are known to grow whiskers under the influence of an electric field. Silver also grows conducting surface paths in the presence of halid... | In addition to "whiskers," what does silver sprout around ions like halide? | {
"text": [
"conducting surface paths"
],
"answer_start": [
271
]
} |
572fb648b2c2fd14005683a0 | Printed_circuit_board | Electrochemical migration (ECM) is the growth of conductive metal filaments on or in a printed circuit board (PCB) under the influence of a DC voltage bias. Silver, zinc, and aluminum are known to grow whiskers under the influence of an electric field. Silver also grows conducting surface paths in the presence of halid... | What do scientist call the function whereby tin changes when it's very cold? | {
"text": [
"tin pest"
],
"answer_start": [
651
]
} |
572fb648b2c2fd14005683a1 | Printed_circuit_board | Electrochemical migration (ECM) is the growth of conductive metal filaments on or in a printed circuit board (PCB) under the influence of a DC voltage bias. Silver, zinc, and aluminum are known to grow whiskers under the influence of an electric field. Silver also grows conducting surface paths in the presence of halid... | What's present in plated surfaces that causes tin to grow metal filaments? | {
"text": [
"tension"
],
"answer_start": [
415
]
} |
572fd395b2c2fd14005684bd | Printed_circuit_board | Areas that should not be soldered may be covered with solder resist (solder mask). One of the most common solder resists used today is called "LPI" (liquid photoimageable solder mask). A photo-sensitive coating is applied to the surface of the PWB, then exposed to light through the solder mask image film, and finally d... | If part of a PCB isn't solderable, what can be used instead? | {
"text": [
"solder resist"
],
"answer_start": [
54
]
} |
572fd395b2c2fd14005684be | Printed_circuit_board | Areas that should not be soldered may be covered with solder resist (solder mask). One of the most common solder resists used today is called "LPI" (liquid photoimageable solder mask). A photo-sensitive coating is applied to the surface of the PWB, then exposed to light through the solder mask image film, and finally d... | What's another term used for "solder resist"? | {
"text": [
"solder mask"
],
"answer_start": [
69
]
} |
572fd395b2c2fd14005684bf | Printed_circuit_board | Areas that should not be soldered may be covered with solder resist (solder mask). One of the most common solder resists used today is called "LPI" (liquid photoimageable solder mask). A photo-sensitive coating is applied to the surface of the PWB, then exposed to light through the solder mask image film, and finally d... | What solder resist with a four-word name is a popular choice in the industry? | {
"text": [
"liquid photoimageable solder mask"
],
"answer_start": [
149
]
} |
572fd395b2c2fd14005684c0 | Printed_circuit_board | Areas that should not be soldered may be covered with solder resist (solder mask). One of the most common solder resists used today is called "LPI" (liquid photoimageable solder mask). A photo-sensitive coating is applied to the surface of the PWB, then exposed to light through the solder mask image film, and finally d... | What kind of coating gets applied to the PWB before light exposure? | {
"text": [
"photo-sensitive"
],
"answer_start": [
188
]
} |
572fd395b2c2fd14005684c1 | Printed_circuit_board | Areas that should not be soldered may be covered with solder resist (solder mask). One of the most common solder resists used today is called "LPI" (liquid photoimageable solder mask). A photo-sensitive coating is applied to the surface of the PWB, then exposed to light through the solder mask image film, and finally d... | What solder resist is so inaccurate that few choose it anymore? | {
"text": [
"screen print epoxy ink"
],
"answer_start": [
630
]
} |
572fd62fb2c2fd14005684e9 | Printed_circuit_board | Unpopulated boards are usually bare-board tested for "shorts" and "opens". A short is a connection between two points that should not be connected. An open is a missing connection between points that should be connected. For high-volume production a fixture or a rigid needle adapter is used to make contact with copper ... | What are bare-board tests looking for besides "opens"? | {
"text": [
"\"shorts\""
],
"answer_start": [
53
]
} |
572fd62fb2c2fd14005684ea | Printed_circuit_board | Unpopulated boards are usually bare-board tested for "shorts" and "opens". A short is a connection between two points that should not be connected. An open is a missing connection between points that should be connected. For high-volume production a fixture or a rigid needle adapter is used to make contact with copper ... | What's an absent connection that needs to be linked up on an unpopulated board called? | {
"text": [
"An open"
],
"answer_start": [
148
]
} |
572fd62fb2c2fd14005684eb | Printed_circuit_board | Unpopulated boards are usually bare-board tested for "shorts" and "opens". A short is a connection between two points that should not be connected. An open is a missing connection between points that should be connected. For high-volume production a fixture or a rigid needle adapter is used to make contact with copper ... | What conductive metal are the lands on a circuit board made out of? | {
"text": [
"copper"
],
"answer_start": [
605
]
} |
572fd62fb2c2fd14005684ec | Printed_circuit_board | Unpopulated boards are usually bare-board tested for "shorts" and "opens". A short is a connection between two points that should not be connected. An open is a missing connection between points that should be connected. For high-volume production a fixture or a rigid needle adapter is used to make contact with copper ... | What does a flying probe tester deliver to the contact points during testing? | {
"text": [
"voltage"
],
"answer_start": [
677
]
} |
572fd62fb2c2fd14005684ed | Printed_circuit_board | Unpopulated boards are usually bare-board tested for "shorts" and "opens". A short is a connection between two points that should not be connected. An open is a missing connection between points that should be connected. For high-volume production a fixture or a rigid needle adapter is used to make contact with copper ... | What system tells the flying probe where to go and what to do? | {
"text": [
"CAM system"
],
"answer_start": [
623
]
} |
572fdf4104bcaa1900d76e27 | Printed_circuit_board | Often, through-hole and surface-mount construction must be combined in a single assembly because some required components are available only in surface-mount packages, while others are available only in through-hole packages. Another reason to use both methods is that through-hole mounting can provide needed strength f... | Surface-mount is one type of construction used in PCB assembly; what's the other one? | {
"text": [
"through-hole"
],
"answer_start": [
7
]
} |
572fdf4104bcaa1900d76e28 | Printed_circuit_board | Often, through-hole and surface-mount construction must be combined in a single assembly because some required components are available only in surface-mount packages, while others are available only in through-hole packages. Another reason to use both methods is that through-hole mounting can provide needed strength f... | Which type of construction makes components that use more space? | {
"text": [
"through-hole"
],
"answer_start": [
269
]
} |
572fdf4104bcaa1900d76e29 | Printed_circuit_board | Often, through-hole and surface-mount construction must be combined in a single assembly because some required components are available only in surface-mount packages, while others are available only in through-hole packages. Another reason to use both methods is that through-hole mounting can provide needed strength f... | Which of the two kinds of construction is weaker under strain? | {
"text": [
"surface-mount"
],
"answer_start": [
449
]
} |
572fdf4104bcaa1900d76e2a | Printed_circuit_board | Often, through-hole and surface-mount construction must be combined in a single assembly because some required components are available only in surface-mount packages, while others are available only in through-hole packages. Another reason to use both methods is that through-hole mounting can provide needed strength f... | If you're building a circuit board that has a lot of components that won't be used, which construction would be better? | {
"text": [
"surface-mount"
],
"answer_start": [
449
]
} |
572fe0d1947a6a140053cd9c | Printed_circuit_board | In boundary scan testing, test circuits integrated into various ICs on the board form temporary connections between the PCB traces to test that the ICs are mounted correctly. Boundary scan testing requires that all the ICs to be tested use a standard test configuration procedure, the most common one being the Joint Tes... | Do test circuits create permanent or temporary connections between traces? | {
"text": [
"temporary"
],
"answer_start": [
86
]
} |
572fe0d1947a6a140053cd9d | Printed_circuit_board | In boundary scan testing, test circuits integrated into various ICs on the board form temporary connections between the PCB traces to test that the ICs are mounted correctly. Boundary scan testing requires that all the ICs to be tested use a standard test configuration procedure, the most common one being the Joint Tes... | What's the most frequently used test configuration procedure for ICs? | {
"text": [
"Joint Test Action Group"
],
"answer_start": [
311
]
} |
572fe0d1947a6a140053cd9e | Printed_circuit_board | In boundary scan testing, test circuits integrated into various ICs on the board form temporary connections between the PCB traces to test that the ICs are mounted correctly. Boundary scan testing requires that all the ICs to be tested use a standard test configuration procedure, the most common one being the Joint Tes... | What would you avoid by using the Joint Test Action Group standard? | {
"text": [
"physical test probes"
],
"answer_start": [
471
]
} |
572fe0d1947a6a140053cd9f | Printed_circuit_board | In boundary scan testing, test circuits integrated into various ICs on the board form temporary connections between the PCB traces to test that the ICs are mounted correctly. Boundary scan testing requires that all the ICs to be tested use a standard test configuration procedure, the most common one being the Joint Tes... | What component of the printed circuit board is appraised with boundary scan testing? | {
"text": [
"ICs"
],
"answer_start": [
148
]
} |
572fe0d1947a6a140053cda0 | Printed_circuit_board | In boundary scan testing, test circuits integrated into various ICs on the board form temporary connections between the PCB traces to test that the ICs are mounted correctly. Boundary scan testing requires that all the ICs to be tested use a standard test configuration procedure, the most common one being the Joint Tes... | To whom would you go to acquire the algorithms you'd use for the Joint Test Action Group procedures? | {
"text": [
"JTAG tool vendors"
],
"answer_start": [
493
]
} |
572fe1edb2c2fd1400568553 | Printed_circuit_board | PCBs intended for extreme environments often have a conformal coating, which is applied by dipping or spraying after the components have been soldered. The coat prevents corrosion and leakage currents or shorting due to condensation. The earliest conformal coats were wax; modern conformal coats are usually dips of dilu... | If a PCB is intended for use in an setting with extreme conditions, what would probably be applied? | {
"text": [
"conformal coating"
],
"answer_start": [
52
]
} |
572fe1edb2c2fd1400568554 | Printed_circuit_board | PCBs intended for extreme environments often have a conformal coating, which is applied by dipping or spraying after the components have been soldered. The coat prevents corrosion and leakage currents or shorting due to condensation. The earliest conformal coats were wax; modern conformal coats are usually dips of dilu... | A conformal coating can be applied by spraying the PCB or by doing what else to it? | {
"text": [
"dipping"
],
"answer_start": [
91
]
} |
572fe1edb2c2fd1400568555 | Printed_circuit_board | PCBs intended for extreme environments often have a conformal coating, which is applied by dipping or spraying after the components have been soldered. The coat prevents corrosion and leakage currents or shorting due to condensation. The earliest conformal coats were wax; modern conformal coats are usually dips of dilu... | The conformal coating can prevent leaking, shorts, and what other type of moisture damage? | {
"text": [
"corrosion"
],
"answer_start": [
170
]
} |
572fe1edb2c2fd1400568556 | Printed_circuit_board | PCBs intended for extreme environments often have a conformal coating, which is applied by dipping or spraying after the components have been soldered. The coat prevents corrosion and leakage currents or shorting due to condensation. The earliest conformal coats were wax; modern conformal coats are usually dips of dilu... | What material was first used for conformal coating? | {
"text": [
"wax"
],
"answer_start": [
268
]
} |
572fe1edb2c2fd1400568557 | Printed_circuit_board | PCBs intended for extreme environments often have a conformal coating, which is applied by dipping or spraying after the components have been soldered. The coat prevents corrosion and leakage currents or shorting due to condensation. The earliest conformal coats were wax; modern conformal coats are usually dips of dilu... | What action is made much more difficult for boards that have a conformal coating? | {
"text": [
"servicing"
],
"answer_start": [
555
]
} |
572fe399a23a5019007fcae1 | Printed_circuit_board | Many assembled PCBs are static sensitive, and therefore must be placed in antistatic bags during transport. When handling these boards, the user must be grounded (earthed). Improper handling techniques might transmit an accumulated static charge through the board, damaging or destroying components. Even bare boards are... | What special protection are most PCBs shipped in? | {
"text": [
"antistatic bags"
],
"answer_start": [
74
]
} |
572fe399a23a5019007fcae2 | Printed_circuit_board | Many assembled PCBs are static sensitive, and therefore must be placed in antistatic bags during transport. When handling these boards, the user must be grounded (earthed). Improper handling techniques might transmit an accumulated static charge through the board, damaging or destroying components. Even bare boards are... | What's another term for "grounded" in the context of PCBs? | {
"text": [
"earthed"
],
"answer_start": [
163
]
} |
572fe399a23a5019007fcae3 | Printed_circuit_board | Many assembled PCBs are static sensitive, and therefore must be placed in antistatic bags during transport. When handling these boards, the user must be grounded (earthed). Improper handling techniques might transmit an accumulated static charge through the board, damaging or destroying components. Even bare boards are... | What force can easily change or even completely destroy an etch on a PCB? | {
"text": [
"static charge"
],
"answer_start": [
470
]
} |
572fe399a23a5019007fcae4 | Printed_circuit_board | Many assembled PCBs are static sensitive, and therefore must be placed in antistatic bags during transport. When handling these boards, the user must be grounded (earthed). Improper handling techniques might transmit an accumulated static charge through the board, damaging or destroying components. Even bare boards are... | What class of PCBs are even more susceptible to static than standard ones? | {
"text": [
"non-traditional"
],
"answer_start": [
512
]
} |
572fe399a23a5019007fcae5 | Printed_circuit_board | Many assembled PCBs are static sensitive, and therefore must be placed in antistatic bags during transport. When handling these boards, the user must be grounded (earthed). Improper handling techniques might transmit an accumulated static charge through the board, damaging or destroying components. Even bare boards are... | Non-traditional PCBs include microwave PCBs and what other type of board? | {
"text": [
"MCMs"
],
"answer_start": [
541
]
} |
572fe51904bcaa1900d76e5f | Printed_circuit_board | The first PCBs used through-hole technology, mounting electronic components by leads inserted through holes on one side of the board and soldered onto copper traces on the other side. Boards may be single-sided, with an unplated component side, or more compact double-sided boards, with components soldered on both sides... | If a lead wasn't soldered manually, what device was used? | {
"text": [
"wave soldering machine"
],
"answer_start": [
743
]
} |
572fe51904bcaa1900d76e60 | Printed_circuit_board | The first PCBs used through-hole technology, mounting electronic components by leads inserted through holes on one side of the board and soldered onto copper traces on the other side. Boards may be single-sided, with an unplated component side, or more compact double-sided boards, with components soldered on both sides... | Which type of PCB construction technique was used first? | {
"text": [
"through-hole"
],
"answer_start": [
20
]
} |
572fe51904bcaa1900d76e61 | Printed_circuit_board | The first PCBs used through-hole technology, mounting electronic components by leads inserted through holes on one side of the board and soldered onto copper traces on the other side. Boards may be single-sided, with an unplated component side, or more compact double-sided boards, with components soldered on both sides... | In through-hole construction, what are the leads on the front attached to on the back? | {
"text": [
"copper traces"
],
"answer_start": [
151
]
} |
572fe51904bcaa1900d76e62 | Printed_circuit_board | The first PCBs used through-hole technology, mounting electronic components by leads inserted through holes on one side of the board and soldered onto copper traces on the other side. Boards may be single-sided, with an unplated component side, or more compact double-sided boards, with components soldered on both sides... | For boards with two sides, to what angle are leads bent to in order to install them horizontally? | {
"text": [
"90 degrees"
],
"answer_start": [
462
]
} |
572fe51904bcaa1900d76e63 | Printed_circuit_board | The first PCBs used through-hole technology, mounting electronic components by leads inserted through holes on one side of the board and soldered onto copper traces on the other side. Boards may be single-sided, with an unplated component side, or more compact double-sided boards, with components soldered on both sides... | What is improved by bending leads in opposite directions on the back of double-sided PCBs? | {
"text": [
"mechanical strength"
],
"answer_start": [
627
]
} |
572fe9d5a23a5019007fcb2b | Printed_circuit_board | Through-hole manufacture adds to board cost by requiring many holes to be drilled accurately, and limits the available routing area for signal traces on layers immediately below the top layer on multi-layer boards since the holes must pass through all layers to the opposite side. Once surface-mounting came into use, sm... | Which type of construction is more expensive? | {
"text": [
"Through-hole"
],
"answer_start": [
0
]
} |
572fe9d5a23a5019007fcb2c | Printed_circuit_board | Through-hole manufacture adds to board cost by requiring many holes to be drilled accurately, and limits the available routing area for signal traces on layers immediately below the top layer on multi-layer boards since the holes must pass through all layers to the opposite side. Once surface-mounting came into use, sm... | What type of boards end up with limited routing space in through-hole manufacture? | {
"text": [
"multi-layer"
],
"answer_start": [
195
]
} |
572fe9d5a23a5019007fcb2d | Printed_circuit_board | Through-hole manufacture adds to board cost by requiring many holes to be drilled accurately, and limits the available routing area for signal traces on layers immediately below the top layer on multi-layer boards since the holes must pass through all layers to the opposite side. Once surface-mounting came into use, sm... | What force might damage a PCB if large components are surface mounted? | {
"text": [
"mechanical stress"
],
"answer_start": [
522
]
} |
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