Teensy 4.0 bottom pins - finding a suitable header and connector

If I'm to use the Teensy 4.0 as my voice controller MCU, I need to use the 10 additional pins on the back to get to the second SPI.

This means I either have to solder pins to the 10 pads, or use a breakout board with castellated connections like https://forum.pjrc.com/threads/57672-Another-Teensy-4-0-Breakout-Board?highlight=Teensy+4.0+rear+pins

If I am to solder pins, I need to make sure that I can find a matching mating connector. As the SMD pin header is higher, the mating connector needs to be lower. Also, the pins need to be short enough to fit the connector.

I measured the pre-soldered pins on the Teensy, the bottom plastic is 2.54mm high, the pin is 5mm.

Normally, mating connectors for the single rows are 8.5mm high, with some saying that the pins may be 6.6mm long.

I am going to try out the following:

Pins (from Farnell):

Samtec TSM-105-04-L-DV

These have a 0.15" (3.81mm) height before the pins, or 1.27mm more than the ones on the Teensy. The pins are 3.05mm, which is a bit on the short side.

Update: Samtec TSM-105-01-F-DV has a pin height of 5.84 which may be more suitable.

GCT BG050-10A-0-0450-0737-0350-L-D

These have a height of 3.5mm before the pins, but the pins are 4.5mm. That looks very promising. Unfortunately, ordering these in Norway incurs a $13 fee because they are only in stock in the US.

F = 3.5mm, D=4.5mm

Female connectors (from Farnell):

Amphenol 76342-305LF

This is a 7mm high receptacle. combined with the GCT connector it would give a total height of 10.5mm, as opposed to the 11.04mm of the side connectors, leaving a 0.5mm gap. This is probably fine. Combined with the Samtec one the gap is reduced to 0.2mm, but the short pins (3mm) may not be long enough. The max pin length is not stated but from the "normal" connector we can guess around 4.9mm.

AMP 215307-5

Similarly, a 7mm high receptacle. Max pin length is not stated for this one either, but it says that the connection point is 2.2mm into the connector which is a tad too long for the 3mm Samtec pins.

From JLCPCB:

I managed to find a couple of 7mm headers from JLCPCB as well:

Liansheng FH-00097

part C2829902, though only 8 are in stock right now:

Wcon 2171-210SG0CUNT3

part C721788 - unfortunately, the mating position is  3.57mm down which again may be too far for the pins.

I will order the Farnell ones shortly to test.

Update:  Results from Farnell

14 pin socket:

Part 1593466 / 2212-14SG-85 

May pull pins 0.8mm out and still have good contact. Tested using pins that protude about 5.66mm and has 2.54mm plastic at the bottom

When pressed together, pins and header measure 10.87mm. Header is 8.42.

10 way SMD

Pins: 3551099 / Samtec TSM-105-01-F-DV (NB: F, not L). Plastic + bent pins measure 3.86mm. The pins measure 5.68mm so the total height is 9.66mm

Header: 1098050 / Amphenol 76342-305LF. Measures 6.97mm. Pins may be pulled out at least 1mm and still have good fit. Height with pins is 10.85mm

Header: 3419216 / AMP 215307-5. Measures 6.96mm. Pins may be pulled out at least 2mm and still have good fit. Height with pins is 10.84mm. Has a very nice, tight fit

Conclusion: The combination of either of the headers with the SMD pins will work, and the height is damn near spot on when used with the 14 pin socket and standard pins!

I still have the GCT BG050-10A-0-0450-0737-0350-L-D on order and will add the results when they get here, but it seems the Samtec ones work nicely.

Update 2:

Pins: 1798977 / GCT BG050-10A-0-0450-0737-0350-L-D. Plastic + bent pins measure 3.65mm. 

Combined with header the total is 10.62. The pins are at least 1mm shorter than the Samtec ones. They still fit quite well even when pulled back 0.2mm

Pins: 3585115 / Samtec TSM-105-04-L-DV. Pins above plastic is 3mm, which is too short to be comfortable. I would not recommend this.

Final conclusion:

The clear winner is the Samtec TSM-105-01-F-DV pins with either of the two headers. Since I've bought enough of the GCT pins already, and they work fairly well, I will go with those. The price is also between half and 1/3 of the Samtec, so if you're in the US they are probably a lot cheaper. Since I had to pay extra they are more or less the same. Had I not bought them I would have gone with the Samtec.

Both SHOULD work with the LCPCB headers too.