Ask Helena & Leo

Visual Acuity Requirements for Soldering

Question: What are the requirements for Visual Acuity? Could not find a specific reference in either J-STD-001 or IPC -A-610.

PEM^® Nut Soldering Criteria

Question: We have boards with PEM^® nuts being soldered during production. Has IPC established minimum soldering criteria for SMT PEM^®s?

Solder Flow Near Through-Hole Component Body

Question: We have a through-hole integrated circuit (IC) component that has good wetting when it goes through the wave soldering machine, and the solder climbs pretty far up the lead.

Maximum Limits of Solder Bath Contamination

Question: If we are using a solder pot to tin wires and create solder joints (splices), what Maximum Limits of Solder Bath Contaminant do we adhere to (IPC J-STD-001, table 3-1)? Preconditioning or Assembly? What exactly does Preconditioning mean in this context?

Defining Standard Industry Practices for Torque of Threaded Fasteners

Question: While reviewing IPC-A-610, Section 4.1.5.1 (Torque of Threaded Fasteners), the question of “what is the standard industry practice” came up. I checked several reference documents like IPC-AJ-820 but found nothing that explained this to any length. Can you explain what the “standard industry practice” is?

J-STD-001F 4.5.1 Gold Removal Class 2 Requirement Changed

Question: Why did the IPC make the gold removal requirement for Class 2 products a requirement (D2D3) when in Rev E of J-STD-001 it was a process indicator (P2D3)?

The Use of Bifurcated vs Slotted Terminals

Question: We are trying to understand the rationale for choosing to install bifurcated terminals for power lead attachments versus slotted terminals. For years we’ve designed with slotted terminals in PWBs for leaded component (hi-rel transistors and diodes) and stranded wire straps.

Soldering PTH Components In-line with Stranded Wire

Question: Can a PTH component (resistor, fuse, or solid wire) be reliably soldered in-line with stranded wire? Similarly to a wire lap joint, but with a component between the two wires. Is there an IPC standard that covers this situation?

Scoring of Soldered Boards with Online Testing

Question: I am working through the online testing for our employees. I have a question regarding the score for the solder board for J-STD-001 and how and when that gets submitted in the system. Having worked through the first test and realizing that the test does not get submitted until the end date, that was entered in the system when it was set up, I was thinking that on that date it may ask for a solder score. It does not. Where does this get submitted?

75% Barrel Fill Requirement for Class 2 Change in J-STD-001 Revision F

Question: Why did the IPC change the barrel fill requirement for Class 2 in J-STD-001 Revision F? Revision E allowed 50% when there was a thermal plane. Now, Rev. F states 75% regardless of thermal plane. It all depends on how many leads the component has, with 14 being the magic number.

Could you shed some light on “WHY” the IPC changed the standard?

Is the J-STD-001FS Certification Available

Question: Is the J-STD-001FS Certification available for delivery yet? I know the document is available.

SMT Terminal Style Components Acceptability for Class 3 (J-STD-001 and or IPC-A-610)

Question: Do Nail Head Type surface mount terminals meet the criteria of J-STD-001 and IPC-A-610, or rather, has the IPC established any criteria for this type of component?

J-STD-001 vs NASA 8739.3

Question: Is the IPC’s J-STD-001 going to be replacing or taking a precedence over the NASA STD 8739.3?

J-STD-001F vs Space Addendum

Question: We were looking over the J-STD-001 and the Space Addendum requirements for partially visible or hidden solder connections 4.18.3. Why does the space addendum give you the option to x-ray the parts in Note D, but in the J-STD-001 book there is no option for inspection if you don’t meet the 3 criteria?

J-STD-001FS Space Addendum Module 6 Certificate

Question: I am training my first space addendum class in a few weeks and would like to know how I get the certificate for the specialists I train? They all currently have a valid certificate in the J-STD-001 plus 1 other module.

Information and Training on Reflow Profiling Setup

Question: I am looking for an institute that can teach how to set up individual reflow oven profiles for products. Do you offer anything like this?

Calibration of Microscopes

Question: Since IPC-A-610 calls out magnification ranges, do scopes have to be calibrated/validated on a periodic basis? I never recall one being out.

PCB Design For Conformal Coating

Question: Are there any specifications for designing a PCB layout in regards to the conformal coating process?

Failing to Remove Gold Plating in Final Assembly

Question: If the gold plating on the surface of via holes is not removed from the printed circuit boards, does this constitute a defect or failure of the board’s acceptance in final assembly?

Piggy Backing of MELF Components (non-glass)

Question: Is it acceptable to piggyback non-glass embodied MELF components per Class 3 of IPC-A-610?

J-STD-001 Train the Trainer Prerequisites

Question: What are the prerequisites for the J-STD-001 Train the Trainer?

J-STD-001 and the Space Addendum

Question: What J-STD-001 modules are needed in order to be able to take the Space Addendum?

No Clean Flux Application and Cleaning

Question: Quite often we have discussions about application of no clean solder and cleaning the flux off the board. We would like to put together a training course that talks about this. Do you have any information that you could direct us to?

Conformal Coating Does Not Adhere to Teflon Wire

Question: We are having and issue with the conformal coating not adhering to the Teflon wire that we use in units. Is there anything in the IPC-A-610 or the J-STD-001 that allows the conformal coat not to adhere to Teflon wire?

Problems with Component Tombstone on Flex Circuit

Question: Can you tell me if there are other reasons that components tombstone? We have looked at the pad size and the amount of paste on the pads. If this helps, the laminate is flex kapton.

Cup Terminal Soldering Requirements

Question: I have a couple of questions regard cup terminals. J-STD-001, IPC-A-610 and IPC-A-620 all require solder to be “visible” in the inspection hole (if present). Is there a more specific requirement to this?

IPC-A-610 Revision F Paragraph 7.3.5.1 Supported Holes – Solder – Vertical Fill (A)

Question: We have a couple of questions regarding the new IPC-A-610 Revision F document and vertical fill.

Soldering Wires to Pads With a Lap Joint

Question: I was wondering if you might be able to help me. We have some strain gauges on an assembly and need to solder wires to the strain gauge pads. We are concerned that we might not be able to get two wires soldered on flat against the pads as the wire is fairly thick compared to the pad. Can you solder one wire onto the pad and solder the second wire on top of the first?

Insulation Clearance for Solid Wire

Question: As it pertains to 5.4.1.1b (IPC A 610) Maximum Insulation Clearance, does this requirement also apply to solid wire that is not purchased with insulation on? In other words when the insulation is installed on the wire and then it is soldered to a terminal.

Ceramic CCA’s and Aqueous Wash and Bake Out Prior to Parylene Coating

Question: I have a question concerning ceramic CCA and their bake out after aqueous wash cycle prior to parylene coating. In theory, parylene deposition will draw off any moisture before the coating process.

IPC-5704 vs IPC-6012 Bare Board Cleanliness Comparison

Question: I am reviewing IPC-5704, and have a question. When reviewing table 4-1, the chloride limit is 0.75 ug/cm2, which converts to 4.4 ug/in2, however; IPC 6012 still has the board cleanliness limit for sodium chloride as 1.56 ug/cm2 (10.06 ug/in2).

Building to IPC-A-610 or J-STD-001

Question: I see so many places say that they build to IPC-A-610, yet I thought you build to J-STD-001, and inspect to IPC-A-610. Is this correct?

Shelf Life of Soldered Components

Question: There has been some request by our customers asking how long products can be stored before solderability becomes a concern. Assuming the following storing conditions, Humidity-10-70% Temperature 12-30C. Does the IPC cover anything on shelf life of soldered components?

Training in Wire Bonding

Question: Do you offer training in wire bonding? If not, do you know who does?

Interpretation of the J-STD-001 / IPC-A-610 Turret Terminal Soldering

Question: I am an IPC certified J-STD-001 and A-610 Trainer and have a question that I’m hoping you can help clarify for me. It is in regards to the interpretation of the acceptability of the top side solder filet requirements for a soldered in thru hole turret terminal.

J-STD-001 Space Addendum – Vision Requirements Section 1.10.1

Question: In the J-STD-001 Space Addendum, the vision requirements states it shall be required, but it does not state with what frequency. Is it required every two years?

Vapor Phase Soldering to Immersion Tin Plated Pads

Question: I have a customer who seems to be having issues making acceptable solder connections using the vapor phase process. Can you tell me if there are any specific issues related to vapor phase soldering to immersion tin plated pads on relatively thick multilayer PCBs?

Bubbles in Conformal Coating

Question: If there is a bubble in the conformal coating that covers two traces, but both traces are covered with soldermask is this rejectable? Also, how do you avoid bubbles in the coating?

Problems With PCB Micro Voiding

Question: We are having certain batches of PC boards exhibiting micro voiding at the copper-lead free intermetallic region after thermal stress. Can you give me some background on this issue, as we are trying to determine the root cause of this problem?

Type of Water to Use on Soldering Sponges

Question: Are there any benefits to using deionized water versus tap water on the solder iron sponges? What is the best type of water to use?

Solder Touching Glass Body Components Like Diodes

Question: IPC-610 has many areas that are left to ones interpretation. The area for solder touching glass body components is one of them. The IPC mentions this along with the subject of maximum fillet height and the image that sets in some peoples minds is that it’s just a defect if solder is only touching on top of the body as stated on other body styles. Please give clarity that solder should not touch any component body except for SOIC’s and SOT’s?

Soldering Stranded Wire

Question: Once a wire is pre-tinned with lead free – no clean solder, can it then be considered solid wire and then be soldered to a PCBA using water soluble flux?

IPC-A-600H PowerPoint Corrections for CIS Level Training

Question: I’m looking for the corrections that are supposed to be online for the IPC-A-600H CIS Training Program. Do you know the direct link or where I can find it?

Air Bubbles or Voids in Solder Joints

Question: We did some cross sectioning of solder joints on a PCB assembly and found some air bubbles trapped in the solder joints. Do you know if there is an IPC standard to specify the maximum allowable air bubbles or voids in a solder joint?

IPC-A-610 Acceptable Requirements for Nicks and Chip-Outs

Question: In IPC-A-610 section 9.4 on page 9-8 component damage there seems to be a lack of class three acceptable requirements for nicks or chip-outs in ceramic bodied components that are not in the termination area. Could you elaborate on the requirement please?

Training Materials, Certificates and Soldering Kits

Question: Can you tell me where I can purchase training standards, IPC certificates and soldering kits now that I am an instructor, to train our employees?

ESD and Foot Straps

Question: Very simply, do you wear one or two foot straps to protect against ESD?

Copper Elongation and Tensile Strength Requirements

Question: IPC-TM-650, 2.4.18.1 is the method for testing in-house plating for tensile strength and elongation, but where can I find the IPC requirements for results? For example, military standard MIL-PRF-31032 states copper elongation shall be 12% minimum, and tensile strength shall be 248 MPa minimum. What are the minimums per IPC?

Information on Lead-Free Soldering

Question: Are there any references or materials I can look at or download specific to Lead-Free Soldering?

Gold Wire Bond Failing Pull Test

Question: We have a situation where we have gold boards which accept gold wire bonding, but are failing a pull test. Other than making sure the boards are clean with a quick trip into the degreaser, is there any other way to refresh gold plating to help these boards pass pull testing?