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")

        self.CheckParamInt("TPaste", "*box rows", min_value=2)
        self.CheckParamInt("TPaste", "*box cols", min_value=2)
        self.CheckParamInt("TPaste", "*percent")

    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, 1):
            y_pos = (y_step * rows) / 2 - i * y_step
            for j in range(0, cols - 1, 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()