Product case manufacturing - Page 1
Forum section: electronics / general

author: bootloader9800
author_rank: Contributor
timestamp: February 25, 2021, 06:39:14 pm
content: Hello All and hope all is well with you.I always had this nagging question.Let us take the TI89 Calculator for example.Who/ Which department does the actual outer product design. Look at the pic of the calculator.1) Where/how do companies go to get the grey plastic case, buttons etc. made?2) Does the PCB inside follow the outer case design OR does the outer case design follow the PCB design?Thanks for your replies.

author: Mike_GFY
author_rank: Newbie
timestamp: February 26, 2021, 02:15:53 pm
content: 1. it should be the mechanical engineers first design the case and then send to the tooling company to get the tooling finished and the go to the injection company finish the cases, it may be also involved companies do the printing.2. i think it depends, for consuming product, it seems case design is more important and PCB design try to fit it but for the functional product like some workshop equiment, case design seems follow the PCB design. The calculator i think the PCB follow the Outer case design.

author: SMTech
author_rank: Frequent Contributor
timestamp: February 26, 2021, 06:20:48 pm
content: ... one would assume the product spec set down the size of the display and the number of buttons, ergonomics turns that into a size. The portrait format is simple and conventional. After the PCB and keypad membranes etc get designed that might affect things like the thickness of the case. Something as complex as a calculator probably iterates as the various engineers involved tweak their own bits and cut cost at every opportunity, no difference there to developing some software for a 3rd party. Everything on things like a calculator is probably bespoke and tooled for that exact model, inclusion the display.There are specialist suppliers of things like keypads and membranes and displays. Go to an electronics exhibition and they will have one of the biggest sections, or the whole show..One of our clients makes HiFi, they start with the look (+rear IO) and then figure out how to cram everything into the resulting case, its sufficiently expensive that things like knobs are custom machined. Switches and buttons tho' are "standard" items because as soon as you make those bespoke you will end up with supply issues, suppliers of both are terrible. Weirdly its quite rare to find machining, anodising and printing under one roof.Our own product line of industrial controls, you start with the off the shelf enclosure its going in and build the PCB(s) to fit it, you might go the other way if your enclosure goes EOL.

author: phil from seattle
author_rank: Super Contributor
timestamp: February 26, 2021, 06:35:20 pm
content: Quote from: bootloader9800 on February 25, 2021, 06:39:14 pmI'll start with #2. For most products (especially hand held devices), the ergonomics take precedent. A huge percentage of hobbyists don't do this and then you see cries of "I can't find a good case for my project". Always start with the external aspects of your product/project and work inwards. I would go so far as to mock up how you think it should look and work before laying out a PCB. An extreme example of this is the modern smart phone. The outer look and workings of the phone are hammered out in tremendous detail by a design team. It is then handed to the engineering team to figure out how to make it work. Often engineers are part of the design team. There will be some back and forth when design expectations can't be met by the engineering team. That gives rise to things like the odd camera bumps we often see on cell phones.On question #1, for high volume, the design is given to a manufacturing team that specializes in that sort of thing. They work with injection molding companies to get all the pieces just right. For a one-off or very low volume product, the best approach is find a case that works for you and adapt your design to fit. Many case manufacturers have a data sheet for each product that describes the shape of the PCB that will fit and they will make custom panels for connectors and such.

author: Mecanix
author_rank: Frequent Contributor
timestamp: February 26, 2021, 07:09:38 pm
content: 1) The Product Design and M.Engineering teams does this work. On the manufacturing side; that calculator was manufactured using an IMM (injection molding machine) with two/multi-shots capabilities. Material used is a common and inexpensive mix of ABS & PC blend polymers and clear polycarbonate for that window (the later may be fused in a two-step injection mfg process or added separately later during assembly). You are looking at aprox. 8K~16k(US$) in mold tooling for this 2-parts enclosure (front & back, ideally using a single two-part mold).The buttons are made of liquid silicon rubber (LSR) and require specialized IM. A single two-part mold can be used for that array too. Most (not all) Injection Molding Manufacturers will accommodate for this material.Lastly the printing/transfer deco, all adds to the cost.2) Depends. e.g. a 1-din car headunit would follow a pre-defined H&W size (iso).

author: Mecanix
author_rank: Frequent Contributor
timestamp: February 26, 2021, 07:23:35 pm
content: ps. the liaison between all those involved PD/ME/EE/MFG dept is facilitated using a MCAD & ECAD Team focused software suite. If you wonder how all of those folks comm and work this out...