Intermediate heat sink (20-I) for a liquid cooling system for an electronic board , said electronic board including at least one electronic component, said system comprising a cold plate for receiving said heat sink (20-I), said cold plate being sized to at least partially cover the electronic board and comprising a cooling circuit including channels inside which circulates a so-called "cold" heat transfer fluid for supplying at least said heat sink (20-I), and a discharge circuit including channels inside which circulates a so-called "hot" heat-transfer fluid having been heated through the heat sink (20-I), the heat sink (20-I) comprising a cooling block comprising a lower portion (21-1) constituting the main heat exchange zone and an upper portion (21-3) which is intended to be connected to the cold plate , the intermediate heat sink (20-I) being characterised in that it comprises: - a so-called "cold" inlet connector intended to be fluidically connected to a cold outlet connector of an upstream heat sink (20-E) and fluidically connected to the upper portion (21-3) of said cooling block so that said cooling block is supplied with cold heat transfer fluid, - a so-called "hot" inlet connector intended to be fluidically connected to a hot outlet connector of an upstream heat sink (20-E) and fluidically connected to the upper portion (21-3) of said cooling block , - a so-called "hot" outlet connector intended to be fluidically connected to a hot inlet connector of a downstream heat sink (20-S), - a so-called "cold" outlet connector intended to be fluidically connected to a cold inlet connector of a downstream heat sink (20-S), the upper portion (21-3) of the cooling block being configured to: - divide the flow of heat transfer fluid entering through the cold inlet connector into a first flow, which is directed towards the lower portion (21-1) of the cooling block so as to collect the heat generated by the electronic board by being routed to the hot outlet connector , and a second flow which is directed directly towards the cold outlet connector , - route the flow of heated heat transfer fluid received at the hot inlet connector directly towards the hot outlet connector . - a so-called "cold" inlet connector intended to be fluidically connected to a cold outlet connector of an upstream heat sink (20-E) and fluidically connected to the upper portion (21-3) of said cooling block so that said cooling block is supplied with cold heat transfer fluid, - a so-called "hot" inlet connector intended to be fluidically connected to a hot outlet connector of an upstream heat sink (20-E) and fluidically connected to the upper portion (21-3) of said cooling block , - a so-called "hot" outlet connector intended to be fluidically connected to a hot inlet connector of a downstream heat sink (20-S), - a so-called "cold" outlet connector intended to be fluidically connected to a cold inlet connector of a downstream heat sink (20-S), - divide the flow of heat transfer fluid entering through the cold inlet connector into a first flow, which is directed towards the lower portion (21-1) of the cooling block so as to collect the heat generated by the electronic board by being routed to the hot outlet connector , and a second flow which is directed directly towards the cold outlet connector , - route the flow of heated heat transfer fluid received at the hot inlet connector directly towards the hot outlet connector . <EOS>