Childhood believe that we have played the kind of game shown in the picture below, small make up to parents to several times in childhood, just bought a game! Although now think it play very single, but it is we can not go back to the good memories of childhood!


This kind of game machine will have a circuit board inside, disassembled this kind of game machine friends may know that its circuit board has a black thing, is not very curious about this black thing what use? Small make up as a child is very curious about what it is used, the following to introduce the black thing what is used.

Hereinafter referred to as COB

To put it crudely, this black knot is just a chip, but in a special package. The black epoxy coating is used to protect the chip from damage. Underneath it is a CHIP (IC), a software package called CHIP ON BOARD (COB).

Hereinafter referred to as COB

It is different from ordinary direct insert chips, such as the NE 555 chip shown below.

NE 555 chip

It covers the chip directly with black epoxy resin, and leads lead directly to the circuit board. If the IC used by us is broken, it can be removed and replaced. If it is covered with epoxy resin, it cannot be replaced unless a new board is replaced.


Once the neighbor’s kid’s toy was broken. I brought it to see if it could be fixed. This thing can not be fixed well, and can not buy the same type of board, so it is not fixed.

Small toy manufacturers buy bare chips from semiconductor chip manufacturers, which are not packaged. The manufacturer USES a certain technique (wafer bonding) to connect the pin contacts of the chip to the circuit board with wires. Finally, the pin contacts are covered with a black resin material.

Black knobs

Since it’s cheap, it’s a good idea to make low-cost toys or cheap circuit boards. Like some children’s music toys, it also has these black bumps inside, some remote controls, calculators, cheap watches.