Quality of PCB assembly
To assess the performance of products, the criterion of compliance with the state is used. In advance, the contractor agrees with the customer on the operational quality criteria and at the end. If the consumer does not specify the parameters, the manufacturer is guided by the requirements of the standard. The document distinguishes three groups: “suitable”, permissible deviation and marriage.
The first criterion in pcb design and development is a given state: a high-quality layout is combined with flawless operation. The reference mode is the goal of all technological operations related to the assembly of printed circuit assemblies. The accompanying documents are stamped “suitable”.
The second option is products in the “permissible state” status. Quality indicator: the operation of the electronic device corresponds to the errors that the customer set for mounting and soldering printed circuit boards. For products in the “acceptable state”, the measured characteristics may be at the limits of the parameters. The block without modification is sent to the customer or transferred to the next operation.
Occasionally, during the serial launch of products, there is a tendency to increase failures. The standard recommends investigating the causes and analyzing the circumstances of the occurrence of failures :
- after mounting or soldering electronic components;
- when assembling equipment from modules;
- outside of process control.
In case of frequent repetition of failures, GOST developers recommend revising the process quality criteria, including for the “good” category.
The third category is an unacceptable state: the electronic module is outside the tolerances set by the customer. After checking, the block is sent for marriage or revision. The documentation makes a mark “invalid condition” or “not good”.
The increase in marriage is a reason for taking emergency measures related to the revision of quality criteria or the technological cycle.