qfn_wizard.py

from __future__ import division
import pcbnew
import HelpfulFootprintWizardPlugin as HFPW
import PadArray as PA

import math

class ThermalViasArray(PA.PadGridArray):
    def NamingFunction(self, x, y):
        return self.firstPadNum

class QFNWizard(HFPW.HelpfulFootprintWizardPlugin):

    def GetName(self):
        return "QFN"

    def GetDescription(self):
        return "QFN Wizard"

    def GenerateParameterList(self):
        self.AddParam("Pads", "nbpads", self.uNatural, 20)
        self.AddParam("Pads", "pitch", self.uMM, 0.5)
        self.AddParam("Pads", "pad width", self.uMM, 0.25)
        self.AddParam("Pads", "pad length", self.uMM, 0.4)
        self.AddParam("Pads", "pitch", self.uMM, 0.5)
        self.AddParam("Pads", "oval", self.uBool, True)
        self.AddParam("Pads", "Width", self.uMM, 4)
        self.AddParam("Pads", "Length", self.uMM, 4)
        self.AddParam("Pads", "Fillet", self.uMM, 0.3)

        self.AddParam("TPad", "tpad", self.uBool, True)
        self.AddParam("TPad", "W", self.uMM, 2.6)
        self.AddParam("TPad", "L", self.uMM, 2.6)
        
        self.AddParam("TPaste", "tpaste", self.uBool, True)
        self.AddParam("TPaste", "box rows", self.uNatural, 4)
	self.AddParam("TPaste", "box cols", self.uNatural, 4)
        self.AddParam("TPaste", "percent", self.uNatural, 50)

        self.AddParam("TVias", "tvias", self.uBool, True)
        self.AddParam("TVias", "rows", self.uNatural, 3)
        self.AddParam("TVias", "cols", self.uNatural, 3)
        self.AddParam("TVias", "drill", self.uMM, 0.3)
        self.AddParam("TVias", "size", self.uMM, 0.6)
        self.AddParam("TVias", "pitch", self.uMM, 1)

    def CheckParameters(self):
        self.CheckParamInt("Pads", "*nbpads")
        self.CheckParamInt("Pads", "*nbpads", is_multiple_of=4)
        self.CheckParamBool("Pads", "*oval")
        self.CheckParamBool("TPad", "*tpad")
        self.CheckParamBool("TVias", "*tvias")
        self.CheckParamBool("TPaste", "*tpaste")

    def GetValue(self):
        return "QFN%d_%dx%dmm" % (self.parameters["Pads"]["*nbpads"],pcbnew.ToMM(self.parameters["Pads"]["Width"]),pcbnew.ToMM(self.parameters["Pads"]["Length"]))

    def GetReferencePrefix(self):
        return "U"

    def DrawThermalPadSolderPaste(self, x, y, rows, cols, percent):
	# Calculate the paste area given percentage
	x_total_size = x / (math.sqrt(1/(percent/100)))
	y_total_size = y / (math.sqrt(1/(percent/100)))

	x_box = x_total_size / cols
	y_box = y_total_size / cols

	x_spacer = (x - cols * x_box) / (cols - 1)
	y_spacer = (y - rows * y_box) / (rows -1)

        x_step = x_spacer + x_box
        y_step = y_spacer + y_box

        
	self.draw.SetLayer(pcbnew.F_Paste)

	# Calculate position of each box
	for i in range(0, rows -1):
	        y_pos = (y_step * rows) / 2 - i * y_step
	        for j in range(0, cols -1):
	                x_pos = (x_step * cols) / 2 - j * x_step
			self.draw.Box(x_pos, y_pos, x_box, y_box)

        self.draw.SetLayer(pcbnew.F_SilkS)

    def BuildThisFootprint(self):
        tpad = self.parameters["TPad"]
        pads = self.parameters["Pads"]
        tvias = self.parameters["TVias"]
	tpaste = self.parameters["TPaste"]

        if(tpad["*tpad"]):
            thermal_pad = PA.PadMaker(self.module).SMDPad(tpad["W"], tpad["L"], pcbnew.PAD_RECT)
            origin = pcbnew.wxPoint(0,0);
            array = PA.PadLineArray(thermal_pad, 1, 0, False)
            array.SetFirstPadInArray(pads["*nbpads"]+1)
            array.AddPadsToModule(self.draw)
            if(tvias["*tvias"]):
                via_size = tvias["size"]
                via_drill = tvias["drill"]
                via_rows = tvias["*rows"]
                via_cols = tvias["*cols"]
                via_pitch = tvias["pitch"]
                thermal_via = PA.PadMaker(self.module).THRoundPad(via_size, via_drill)
                array = ThermalViasArray(thermal_via, via_cols, via_rows, via_pitch, via_pitch)
                array.SetFirstPadInArray(pads["*nbpads"]+1)
                array.AddPadsToModule(self.draw)
		if(tpaste["*tpaste"]):
			self.DrawThermalPadSolderPaste(tpad["W"], tpad["L"], tpaste["*box rows"], tpaste["*box cols"], tpaste["*percent"])

        nb_pads_row = pads["*nbpads"] / 4;
        line_start = pads["pitch"] * (nb_pads_row - 1) / 2

        pad_len = pads["pad length"]
        fillet = pads["Fillet"]
        pad_total = pad_len + fillet
        len_2 = pads["Length"] / 2
        wid_2 = pads["Width"] / 2

        pad_center_l = (len_2 - pad_len + (pad_len+fillet)/2)
        pad_center_w = (wid_2 - pad_len + (pad_len+fillet)/2)

        pad_shape = pcbnew.PAD_OVAL if pads["*oval"] else pcbnew.PAD_RECT

        v_pad = PA.PadMaker(self.module).SMDPad(pads["pad width"], pad_total, shape=pad_shape)
        h_pad = PA.PadMaker(self.module).SMDPad(pad_total, pads["pad width"], shape=pad_shape)

        pin1pos = pcbnew.wxPoint(-pad_center_l, 0)
        array = PA.PadLineArray(v_pad, nb_pads_row, pads["pitch"], True, pin1pos)
        array.SetFirstPadInArray(1)
        array.AddPadsToModule(self.draw)

        pin1pos = pcbnew.wxPoint(0, pad_center_w)
        array = PA.PadLineArray(h_pad, nb_pads_row, pads["pitch"], False, pin1pos)
        array.SetFirstPadInArray(int(nb_pads_row + 1))
        array.AddPadsToModule(self.draw)

        pin1pos = pcbnew.wxPoint(pad_center_l, 0)
        array = PA.PadLineArray(v_pad, nb_pads_row, -pads["pitch"], True, pin1pos)
        array.SetFirstPadInArray(int(nb_pads_row*2 + 1))
        array.AddPadsToModule(self.draw)

        pin1pos = pcbnew.wxPoint(0, -pad_center_w)
        array = PA.PadLineArray(h_pad, nb_pads_row, -pads["pitch"], False, pin1pos)
        array.SetFirstPadInArray(int(nb_pads_row*3 + 1))
        array.AddPadsToModule(self.draw)

        self.draw.BoxWithDiagonalAtCorner(0, 0, pads["Length"], pads["Width"], pcbnew.FromMM(0.3))
        text_size = pcbnew.FromMM(1.2)
        self.draw.Value(0, pads["Width"] + fillet, text_size)
        self.draw.Reference(0, -pads["Width"] - fillet, text_size)

QFNWizard().register()