Creating new pattern, newbie question

Making your own components and patterns, organizing and using libraries.
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ChrisA7875
Posts: 2
Joined: 12 Sep 2016, 22:07

Creating new pattern, newbie question

#1 Post by ChrisA7875 » 12 Sep 2016, 22:35

I'm trying to create a new pattern for a few resistors, capacitors, and transistors. All the components I'm working with right now are through-hole. I just started using Diptrace and had some very basic questions. I'll give an example of what I am trying to do and then my questions. For instance a resistor I'm trying to create a pattern for is a Yageo FMP200FRF52-75K, the Digikey P/N is 75KYCT-ND. It measures 9 mm long and 3.9 mm in diameter body, the diameter of the pins are .55 mm. The link to the data sheet is:
http://www.yageo.com/documents/recent/Y ... P_2013.pdf

When I go into Diptrace I select pattern editor and enter into a new library to create my new pattern. I select a generic RES-7.62/4x1.5, then modify from there to meet my pattern needs. Now my questions. Most of them pertain to the Pattern Template area, should I select line or rectangle? If I select "Line" then I select the number of lines as "1", and number of pads "2", what should I set my pad spacing to? If I use 9mm, the overall length to the body of the resistor, isn't that going to be to tight to pull the pins through? Is there a offset I should generally add to set my Pad Spacing properly? Is it based on the diameter of the pins? Where do I enter the body diameter or is that not needed for the pattern? My last question is what the heck does the line spacing adjust? I don't see any changes in my pattern.

Sorry for all the questions but just trying to do this right and learn more about it. It seems like an awesome program.

Thanks
Chris

Tomg
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Posts: 1402
Joined: 20 Jun 2015, 14:39

Re: Creating new pattern, newbie question

#2 Post by Tomg » 13 Sep 2016, 07:25

ChrisA7875 wrote:"...I select a generic RES-7.62/4x1.5, then modify from there to meet my pattern needs..."
The pattern named "RES-13.55/10x4" would make a better choice.
ChrisA7875 wrote:"...should I select line or rectangle?..."
The Pattern Template sets up the pad pattern, not the body size. You don't have to worry about this if you are modifying another pattern. If you are starting from scratch, set Style: Lines, Number of Lines: 1, Number of Pads: 2, Pad Spacing: 14mm, Line Spacing: (doesn't matter since there is only one line of pads).
ChrisA7875 wrote:"...If I use 9mm, the overall length to the body of the resistor, isn't that going to be to tight to pull the pins through?..."
Yes. 9mm is the body length, not the pad spacing.
ChrisA7875 wrote:"...what should I set my pad spacing to?..."
"...Is there a offset I should generally add to set my Pad Spacing properly? Is it based on the diameter of the pins?..."
Set your pad spacing to at least 14mm to account for lead bend radius and to provide some strain relief.
ChrisA7875 wrote:"...Where do I enter the body diameter or is that not needed for the pattern?..."
There is no entry for body diameter. Indicate the body diameter with the silkscreen drawing, which will act as a guide during component placement in the PCB layout process. Since it is a 2W resistor, think about keeping a small air gap between the resistor body and the surface of the PCB during loading; but this spacing shouldn't affect the pattern design.
ChrisA7875 wrote:"...what the heck does the line spacing adjust? I don't see any changes in my pattern..."
It adjusts the spacing between lines of pads if you have more than one line specified (Number of Lines = 2 or more).

I recommend a pad hole diameter of 0.80mm: maximum specified lead diameter of 0.60mm (0.55mm +/- 0.05mm), + 0.15mm breathing room for lead insertion and solder, rounded up to the nearest 0.1mm for easier drill selection for the board house). The diameter of the pad (ring) should be twice the hole size. In this case 1.60mm; more if you want it to be more robust.
Tom

ChrisA7875
Posts: 2
Joined: 12 Sep 2016, 22:07

Re: Creating new pattern, newbie question

#3 Post by ChrisA7875 » 13 Sep 2016, 07:43

Tom,
Thanks so much, for taking the time to answer my questions. A light bulb just went off in my head when I read the answer about line spacing. It really seems like a great program so looking forward to learning to use it.

schemer
Posts: 5
Joined: 19 Oct 2019, 12:35

Re: Creating new pattern, newbie question

#4 Post by schemer » 19 Oct 2019, 19:09

I am a noob here and was wondering the same thing about making my own components starting with the axial resistors. So could you break down the following line for me so I know what the best base resistor to start with in the future?
The pattern named "RES-13.55/10x4" would make a better choice.

13.55 Is that the overall length of the pad spacing?
10 Is that the body length?
4 Is that the diameter?

Thanks,
schemer

Tomg
Expert
Posts: 1402
Joined: 20 Jun 2015, 14:39

Re: Creating new pattern, newbie question

#5 Post by Tomg » 21 Oct 2019, 08:36

Here's a guide showing how to decipher pattern names - https://diptrace.com/books/Pattern_names_help.pdf
Tom

schemer
Posts: 5
Joined: 19 Oct 2019, 12:35

Re: Creating new pattern, newbie question

#6 Post by schemer » 21 Oct 2019, 12:42

Thanks Tomg,
That will come in handy. I don't always have the datasheets for all the components I have picked up over the years but the pad spacing should really be all I need for now.
schemer

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