PCBA焊锡常识与检验

三.Rectangular or Square Components--End Joint
Width(3)
Acceptable: *End joint width (C) is minimum 75% of component termination width (W) or 75% land width (P), whichever is greater-- Class 3
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一.JUMPER WIRE GENERAL RULES
-The wire and the glue must be added in areas that will not inhibit the ability to use in-circuit or functional test probe contacts . ( E.g : via hole , test plots , etc .. ) 跳線和點膠必須在不影響效能和功能測試的區域 (列如:貫穿孔和測試點) -In all cases , the wires must always be parallel with boardedges .( No diagonals ) 跳線必須與板邊平行(不能有對角線)
Length(4)
Target: *Side joint length equals length of component termination. Acceptable: *Side joint length is not required.However, a properly wetted fillet is evident..
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三.Rectangular or Square Components--End Joint
Width(3)
Defect: *Less than minimum acceptable End joint width.
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三.Rectangular or Square Components--Side Joint
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三.Rectangular or Square Components --Side
overhang(1)
Defect : *Side overhang (A) is greater than 50% width of component termination width (W) or 50% land width (P),whichever is greater; --Class 1,2 *Side overhang (A) is greater than 25% width of component termination width (W) or 25% land width (P),whichever is greater; --Class 3
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三.Rectangular or Square Components --Side overhang
Target: *No side overhang.
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三.Rectangular or Square Components --Side
overhang(1)
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一.JUMPER WIRE GENERAL RULES
-No jumper wire for these signals: 跳線不能在這 些訊號上 *GTL signals(north-bridge to CPU). GTL訊號(北 橋到CPU) *Memory signals. Memory訊號 *AGP signals. AGP訊號 *CLK signals. CLK訊號
Acceptable : *Side overhang (A) is less than or equal to 50% width of component termination area (W) or 50% width of land (P),whichever is less; --Class 1,2 *Side overhang (A) is less than or equal to 25% width of component termination area (W) or 25% width of land (P),whichever is less; --Class 3
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三.Rectangular or Square Components—Maximum
Fillet Height (5)
Acceptable: *Maximum fillet height (E) may overhang land or extend onto the top of the end cap metallization,but not extend further onto the component body. --Class 1,2,3
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三.Rectangular or Square Components—Maximum
Fillet Height (5)
Target: *Maximum fillet height is the solder thickness plus component termination height.
三.Rectangular or Square Components—minimum
Fillet Height (6)
Acceptable: *A properly wetted fillet is evident --Class 1,2 *Minimum fillet height (F) is solder thickness (G) plus 25% termination height (H),or 0.5mm[0.02in],whichever is less.—Class 3. Defect: *A properly wetted fillet is not evident –Class 1,2 *Minimum fillet height (F) is less than solder thickness (G) plus 25% (H),or solder thickness (G) plus 0.5mm[0.02in],whichever is less.—Class 3.
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二.Staking adhesive
Defect: *Adhesive is present in the solder connection area that reduces solder contact to less than 50% of the component termination width.
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二.Staking adhesive
Process Indicator: * Adhesive material extending from under the component is visible in the termination area,but joint width meets minimum requirements. Defect: *Adhesive materials extending from under the component are visible in the termination area.
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一.JUMPER WIRE GENERAL RULES
Sample:
<Finish>
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二.Staking adhesive Target:
*No adhesive present on soldered surfaces of the connection area; *Adhesive is centered between the lands.
Width(3)
Acceptable: *End joint width (C) is minimum 50% of component termination width (W) 50% land width (P), whichever is less-- Class 1,2
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一.JUMPER WIRE GENERAL RULES
-Wire must be mono-filament and black color wire (#28 or #30) 跳線必須是單芯黑色跳線(#28 或者#30) -It must be 1 cm minimum from the board edge .and 0.5 mm minimum from the tape. 跳線必須至少離板邊1cm,裸線不可超過0.5mm -If the wire is 3 cm long or more, an adhesive point must be used every 3 cm 如果跳線超出3cm,每3cm要點膠
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三.Rectangular or Square Components—Maximum
Fillet Height (5)
Defect: *Solder fillet extends onto the component body --Class 1,2,3
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