IEC 60191-4-2018 pdf free.Mechanical standardization of semiconductor devices – Part 4: Coding system and classification into forms of package outlines for semiconductor device packages.
4.3.3Terminal-position prefix
The two-letter, package-outline-style code may be supplemented with a single-letter prefix thatidentifies the physical terminal positions or,if applicable,the interconnect land pattern.Examples of three-letter designators include common acronyms or abbreviations, such as DIPLcc (Qcc preferred),PGA,QFP,SIP,ZIP.
NOTE 1 A terminal is defined as an externally available point of connection.
NOTE 2 The proper terminal-position prefix is determined by the interconnect land structure.For example,thecode for a single row of terminals formed into a staggered configuration would be “Z”.
Table 2 gives a list of one-letter, terminal-position prefix codes.
4.3.4Package-body-material prefix
The three-letter descriptive designator (see 4.3.2) may be further supplemented by a singleletter prefix that identifies the predominant package-body material. This prefix shall not beused unless the terminal-position prefix described in 4.3.2 is also used.Examples of such four-letter descriptive designators include common acronyms or abbreviations, such as CDIP, PDIPPLCC (PQcC preferred),MELF,PQFP.
Table 3 gives a list of one-letter package-body-material prefix codes.
lf the package-body material is other than one of those defined in Table 3, the letter “X” shallbe used within the descriptive designator to signify a special or new material and shall later bereplaced with an lEC-approved code.
4.3.5Package-specific feature prefix
Package-specific features may be described through the use of a multiletter prefix. Thepackage-specific feature prefix shall be set off from the following portion of the descriptivedesignator by a dash (一).
Table 4 gives a list of package-specific feature prefix codes. Figure 2 shows the relationship ofcodes to profile and pitch.
4.3.6Lead-form and terminal-count suffixes General lead-form and number of terminals
The general lead form (or terminal shape) and/or the number of terminals on a package maybe described through the use of two fields, the lead-form suffix and the terminal-count suffix.These two fields shall be set off from the preceding portion of the descriptive designator by adash (一).
Users of this system may choose to use the lead-form suffix,or the terminal-count suffix,orboth. If the lead-form suffix is used in conjunction with the terminal-count suffix,it shalprecede the terminal-count suffix.
The lead-form suffix is a one-letter suffix that identifies the standard form or shape of the lead.Table 5 gives a list of one-letter, lead-form suffix codes.
lf more than one type of terminal is present,the terminals carrying the principal currentdetermine the lead-form code. If one of these terminals is a mounting stud or flange, its shape shall not govern the choice of lead-form (or terminal-shape) suffix because that has alreadybeen described by the package-outline-style code. lf the lead form is other than one of thosedefined in Table 5, the letter “X” shall be used within the descriptive designator to signify aspecial or new lead form and shall later be replaced with an lEC-approved code. Examples areiliustrated in Figure A.2. suffix
The terminal-count suffix is a numeric field used to identify the number of terminals on thedevice package. If there is more than one type of terminal, the terminal count shall include onlythose terminals that were used to determine the lead-form suffix in accordance with terminal count (including terminals not used) is less than the number of available terminalpositions, the latter may be added in parentheses, for example 20(26) and 168(289).IEC 60191-4 pdf download.