Paste in Hole#

Code	BG.014
Validator	Not yet implemented
Applies to	`board_paste` / `board_barrel` prims (THT)
Requirement level	MUST when paste-in-hole applies (otherwise no paste association for THT)
Tags	`board`, `paste`, `hole`, `tht`

Summary#

For through-hole components the paste association MUST be empty unless the paste-in-hole (pin-in-paste / through-hole reflow) process applies. When it does, the deposit is a normal board_paste prim naming its contact with pcba:board:refdes + pcba:board:componentPinNumber and carrying its side, exactly like SMT paste.

This page follows PCBA to USD Input Contract 1.0.2, sections 10 and 12.

Description#

Standard through-hole parts are wave- or selective-soldered and have no solder paste, so no board_paste deposit and no association exist for their holes. Authoring an empty or fabricated paste association for an ordinary through-hole joint would mislead solder synthesis.

The exception is paste-in-hole, where paste is stencil-printed over or into the plated hole so the lead reflows with the SMT parts. In that case the board supplies a board_paste deposit for the hole and it MUST carry the normal association (BG.007) and side (BG.008). For paste in a hole the barrel’s occupancy governs whether the pair is owed.

This requirement is a conditional gate keyed on the actual assembly process, not on processClass alone. Whether a given pin takes solder at all is stated per pin by pcba:pin:solderable.

Fields#

Attribute	On	Type	Req	Notes
`pcba:board:refdes` · `pcba:board:componentPinNumber`	`board_paste`	`string`	MUST when paste-in-hole (else no deposit exists for the THT joint)	The through-hole contact the deposit serves (BG.007).
`pcba:board:solderLayer`	`board_paste`	`token`	MUST when paste-in-hole — or derivable	`top` \| `bottom` (BG.008).
`pcba:board:pasteFor`	`board_paste`	`rel`	SHOULD when the component prim exists	Direct handle; must agree with the pair.

Why is it required?#

Ordinary THT has no paste; a spurious association would inject false paste geometry and defects.
Paste-in-hole is a real reflow process that does deposit paste on the hole and must be modelled like SMT paste.

Example#

# Ordinary through-hole joint: barrel only, NO board_paste.
def Mesh "barrel_J1_1"
{
    token  pcba:mesh:role = "board_barrel"
    token  pcba:mesh:matClass = "copper"
    float  pcba:board:holeRadiusMm = 0.5
    bool   pcba:board:occupied = true
    string pcba:board:refdes = "J1"
    string pcba:board:componentPinNumber = "1"
}

# Paste-in-hole process: a board_paste deposit IS supplied and associated.
def Mesh "paste_J2_1"
{
    token  pcba:mesh:role = "board_paste"
    token  pcba:mesh:matClass = "solder"
    token  pcba:board:solderLayer = "top"
    string pcba:board:refdes = "J2"
    string pcba:board:componentPinNumber = "1"
}

How to comply#

For wave- or selective-soldered THT, author no board_paste for the joint.
For paste-in-hole parts, author a board_paste deposit with the refdes + componentPinNumber pair and its side, as for SMT paste.
Gate on the actual assembly process.

No executable rule exists for this code; it is not part of the enforced feature set.