Card generations, lanes and transfer rates on this page follow the SD Association SD Express specifications (SD 7.0, SD 7.1, SD 8.0); every KINGCONN socket value comes from the part drawings.
What SD Express changes for the socket
SD 7.0 and SD 8.0 (SD Express) cards move the high-speed lanes to a PCIe/NVMe-based interface while keeping mechanical backward compatibility with legacy SD media. For the socket that means a 2nd contact row and tighter signal-integrity discipline — the connector is no longer a passive afterthought but part of the high-speed channel.
| Card bus | Contact rows | PCIe link | Max transfer | Socket needed |
|---|---|---|---|---|
| SD UHS-I | 1 row, 9 | — | 104 MB/s | legacy socket |
| SD UHS-II | 2nd row, 8 | — | 312 MB/s | SD 4.0 dual-row socket |
| SD Express 7.0 | 2nd row | PCIe 3.0 ×1 | 985 MB/s | SD Express socket |
| SD Express 8.0 | 2nd / 3rd row | PCIe 4.0 ×1 / ×2 | 1,969 / 3,938 MB/s | SD Express socket (3 rows for ×2) |
| microSD Express (SD 7.1) | 2nd row | PCIe 3.0 ×1 | 985 MB/s | microSD Express socket |
The 2nd row is the same mechanical row UHS-II introduced, but the signals on it are different: SD Express puts a PCIe differential pair in each direction plus a reference clock there. Route it as a PCIe channel — controlled impedance, matched lengths, ground reference — not as SD bus wiring. SD 8.0 with 2 lanes adds a 3rd row, which is why a 2-lane design needs a socket published for it.
Height options
The KINGCONN SD 7.0 & SD 8.0 family publishes 8 models with mated profile options including 1.8mm, 2.94mm, 2.98mm, 3.9mm, 4.0mm and 5.0mm — from slim embedded slots to full-size reader decks. Profile is the value that usually decides the part: the card standard fixes the card, and the enclosure fixes the space above the board.
Legacy compatibility planning
Because SD Express cards fall back to legacy SD modes in a legacy socket, the socket choice decides the ceiling of your product's card performance, not its floor. If your roadmap includes SD Express media, wiring the new-generation socket now costs a layout cycle; retrofitting it later costs a respin. Cameras, industrial vision and data loggers that write at PCIe rates are the designs where the socket is on the critical path.
Materials and verification
Housings use LCP rated UL94V-0; contacts are copper alloy (C5210 / C7025 grades appear in the published materials). RoHS compliant, and each part page cites its source drawing number for verification.
KINGCONN SD Express and UHS-II sockets
7SD70-F0-0001SD 7.0 Reversed 1.8mm Recessed Card Socket
7SD70-F0-0007SD7.0 TOP H:5.0mm NON PUSH
7SD80-F0-0001SD8.0 30u" NON-PUSH H:2.94mm
7SD80-F0-0002SD8.0 Gen4X2 Push H:2.98mm
7SD40-FA-0000SD4.0 Top, Push/Push Type,H 3.00mm
7MSD7-F0-0001MICRO SD 7.1 PUSH H:2.525SD 7.0 and SD 8.0 Express sockets, an SD 4.0 (UHS-II) dual-row socket and a microSD Express socket.
Shortlist and RFQ
See the SD 7.0 & SD 8.0 series page for all 8 models, read SD card socket types for the pinout and bus generations, or email service@kingconn.com.tw with your target height and card generation and our engineering team will advise.